WO2023130566A1

WO2023130566A1 - Method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of pet polyester waste plastic

Info

Publication number: WO2023130566A1
Application number: PCT/CN2022/080073
Authority: WO
Inventors: 王树荣; 苏红才; 朱玲君; 李天�; 高翔; 严建华; 岑可法
Original assignee: 浙江大学
Priority date: 2022-01-07
Filing date: 2022-03-10
Publication date: 2023-07-13
Also published as: CN114436806A; CN114436806B

Abstract

Provided is a method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of PET polyester waste plastic. The method comprises: directly mixing PET polyester waste plastic with a catalyst according to a certain proportion, adding the mixture to a low-concentration NaOH solution, taking multiple effects of NaOH and directional catalytic characteristics of the catalyst as links, under a specific low-temperature hydrothermal condition, coupling a PET hydrothermal depolymerization reaction to an in-situ reforming reaction of a PET depolymerization product, so that efficient one-step complete conversion of PET in a reaction system is realized, directly obtaining high-purity hydrogen having a purity approximate to 99% and a crude disodium terephthalate solution by a one-step method, and then performing simple refining and crystallization on the crude disodium terephthalate solution to obtain a high-purity disodium terephthalate crystal. High-valued recycling of the PET polyester waste plastic is achieved, the process is simple and ingenious, the energy consumption is low, the industrial application value is extremely high, and secondary pollution to the environment is avoided.

Description

一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法One-step low-temperature transformation of PET polyester waste plastics to prepare disodium terephthalate and high-purity hydrogen

技术领域technical field

本发明涉及废塑料热化学转化的技术领域，特别是一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法。The invention relates to the technical field of thermochemical conversion of waste plastics, in particular to a method for preparing disodium terephthalate and high-purity hydrogen by converting PET polyester waste plastics at low temperature in one step.

背景技术Background technique

近几十年来，塑料由于其低生产成本以及良好的耐用性和耐腐蚀性，在工业生产和日常生活中发挥了重要作用。然而，废弃塑料的高效安全处置亟需得到重视，目前大多废塑料被作为固体废弃物进行集中处理，主要采用填埋或焚烧进行处理，而未被集中处理的废塑料则进入到生态环境中。由于废塑料的难自然降解性，对土壤和水体环境造成长久性危害。一部分废塑料进入海洋中破碎成微塑料，对海洋环境和海洋生物的生长生存造成严重影响。因此，将废塑料进行定向资源化和高值化利用是我国的重大需求，对改善生态环境、优化我国的能源结构，以及双碳目标的实现都具有极为重要的意义。In recent decades, plastics have played an important role in industrial production and daily life due to their low production cost as well as good durability and corrosion resistance. However, the efficient and safe disposal of waste plastics needs to be paid attention to urgently. At present, most waste plastics are treated as solid waste, mainly by landfill or incineration, while waste plastics that have not been centrally treated enter the ecological environment. Due to the refractory natural degradability of waste plastics, it will cause permanent harm to the soil and water environment. A part of waste plastics enters the ocean and breaks into microplastics, which has a serious impact on the marine environment and the growth and survival of marine organisms. Therefore, the directional recycling and high-value utilization of waste plastics is a major demand of our country, and it is of great significance to improving the ecological environment, optimizing our country's energy structure, and realizing the dual carbon goals.

由于化学稳定性强、力学强度高以及加工性能好等优点，聚对苯二甲酸乙二醇酯（PET）成为热塑性聚酯塑料中应用最广的一种，在产品包装、饮料灌装、布料纺织等领域应用较为广泛。在城市有机固废和工业有机固废中，PET废塑料是主要成分之一。由于PET塑料骨架中存在重复的芳香族对苯二甲酸酯单元，导致PET废塑料极难在自然环境中被降解，因此亟需开发新工艺对PET塑料进行定向解聚并转化制备清洁能源和高值化学品，将能够减少环境污染也能够提高废塑料利用率。Due to the advantages of strong chemical stability, high mechanical strength and good processing performance, polyethylene terephthalate (PET) has become the most widely used thermoplastic polyester plastic, in product packaging, beverage filling, cloth It is widely used in textile and other fields. In urban organic solid waste and industrial organic solid waste, PET waste plastic is one of the main components. Due to the repeated aromatic terephthalate units in the PET plastic skeleton, PET waste plastics are extremely difficult to degrade in the natural environment. Therefore, it is urgent to develop new processes for directional depolymerization of PET plastics and transform them into clean energy and High-value chemicals will reduce environmental pollution and increase the utilization rate of waste plastics.

目前，对于PET废塑料现有的热化学解聚工艺主要包括醇解法、水解法、氨解法等，主要存在的问题是PET解聚产物中乙二醇的流失，得到的目标产物也不纯，而且过程中使用的高浓度碱溶液会造成大量废液的产生。PET作为一种高含氢的有机化合物，具有转化为氢气的潜力。高温热解气化可以通过热裂解-重整工艺将废塑料转化为富氢合成气。然而废塑料热解气化的气相产物中二氧化碳和烷烃等副产物含量较高，且热解气化过程中产生的焦油较难处置。另外，由于PET是一种结构特点较为明确的物质，因此如何利用PET的结构特点，采用一种简单巧妙的方式将其定向转化为高值燃料及高值化学品是提高PET废塑料综合利用价值和快速减量的必经之路。At present, the existing thermochemical depolymerization processes for PET waste plastics mainly include alcoholysis, hydrolysis, ammonolysis, etc. The main problem is the loss of ethylene glycol in PET depolymerization products, and the obtained target products are not pure. Moreover, the high-concentration alkaline solution used in the process will cause a large amount of waste liquid to be produced. As a highly hydrogen-containing organic compound, PET has the potential to be converted into hydrogen gas. High-temperature pyrolysis gasification can convert waste plastics into hydrogen-rich synthesis gas through a pyrolysis-reforming process. However, the gas phase products of waste plastic pyrolysis and gasification contain high content of by-products such as carbon dioxide and alkanes, and the tar produced during the pyrolysis and gasification process is difficult to dispose of. In addition, since PET is a substance with relatively clear structural characteristics, how to use the structural characteristics of PET to convert it into high-value fuels and high-value chemicals in a simple and ingenious way is the key to improving the comprehensive utilization value of PET waste plastics. And the only way to reduce weight quickly.

技术问题technical problem

本发明的目的就是解决现有技术中的问题，提出了一种一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，可以在低温水热环境下将PET聚酯塑料高效转化为对苯二甲酸二钠和高纯氢气，工艺流程简单，经济效益高，实现了PET聚酯废塑料的清洁高值化利用，降低了废塑料处置过程对环境带来的潜在负面影响。The purpose of the present invention is to solve the problems in the prior art. It proposes a method for preparing disodium terephthalate and high-purity hydrogen by converting PET polyester waste plastics at low temperature in a one-step method. PET can be polymerized under low-temperature hydrothermal environment. The efficient conversion of ester plastics into disodium terephthalate and high-purity hydrogen has a simple process and high economic benefits, realizing the clean and high-value utilization of PET polyester waste plastics, and reducing the potential of waste plastics disposal process on the environment Negative impact.

技术解决方案technical solution

为实现上述目的，本发明提出了一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，将PET聚酯废塑料与重整催化剂按一定比例混合加入到低浓度NaOH溶液中，以NaOH在反应体系中的多重作用以及重整催化剂的定向催化特性为纽带，在低温水热条件下，将PET水热解聚反应和PET解聚产物的原位重整反应进行耦合，使PET在一个反应体系中实现一步完全转化，一步法直接得到纯度接近99%的高纯氢气和粗制的对苯二甲酸二钠溶液。In order to achieve the above object, the present invention proposes a one-step method of low-temperature conversion of PET polyester waste plastics to prepare disodium terephthalate and high-purity hydrogen. PET polyester waste plastics and reforming catalysts are mixed in a certain proportion and added to low concentration In NaOH solution, based on the multiple functions of NaOH in the reaction system and the directional catalytic characteristics of the reforming catalyst, under low temperature hydrothermal conditions, the hydrothermal depolymerization reaction of PET and the in situ reforming reaction of PET depolymerization products were carried out. Coupling, so that PET can be completely converted in one step in one reaction system, and high-purity hydrogen with a purity close to 99% and crude disodium terephthalate solution can be directly obtained in one step.

在本发明提出的PET聚酯废塑料一步法转化的反应体系中，NaOH创造的碱性环境促进了PET聚酯废塑料的水热解聚，使其首先被转化为对苯二甲酸二钠和乙二醇。而得到的乙二醇在重整催化剂的催化下在同一反应体系中进行原位液相重整。其中，重整催化剂对乙二醇的C-C键断裂和水煤气反应具有催化作用，可以使乙二醇转化为氢气、二氧化碳、一氧化碳以及少量烷烃。更重要的是生成的二氧化碳被反应体系中存在的NaOH去除，并以CO ₃ ^2-的形式储存在Na ₂CO ₃中。而二氧化碳的去除又促进了水煤气反应去消耗一氧化碳，同时也通过抑制了甲烷化反应大大降低了甲烷的产率。因此，PET一步转化过程得到只含有微量烷烃且不含CO _x，纯度接近99%的高纯氢气。而得到的液体产物经过简单精制和蒸发结晶过程可得到高纯度的对苯二甲酸二钠晶体以及不含任何有害杂质的水。高纯度的对苯二甲酸二钠晶体由于其高钠离子容量、良好的循环性能和高可逆容量，有望作为一种优良的电极材料被广泛应用。 In the one-step conversion reaction system of PET polyester waste plastics proposed by the present invention, the alkaline environment created by NaOH promotes the hydrothermal depolymerization of PET polyester waste plastics, so that it is first converted into disodium terephthalate and ethylene glycol. The obtained ethylene glycol undergoes in-situ liquid-phase reforming in the same reaction system under the catalysis of the reforming catalyst. Among them, the reforming catalyst has a catalytic effect on the CC bond breaking and water gas reaction of ethylene glycol, and can convert ethylene glycol into hydrogen, carbon dioxide, carbon monoxide and a small amount of alkanes. More importantly, the generated carbon dioxide is removed by NaOH present in the reaction system and stored in Na ₂ CO ₃ in the form of CO ₃ ^2- . The removal of carbon dioxide promotes the water gas reaction to consume carbon monoxide, and at the same time greatly reduces the yield of methane by inhibiting the methanation reaction. Therefore, the one-step conversion process of PET can obtain high-purity hydrogen containing only trace alkanes and no CO _x , with a purity close to 99%. And the obtained liquid product can obtain high-purity disodium terephthalate crystals and water without any harmful impurities through simple refining and evaporative crystallization process. High-purity disodium terephthalate crystals are expected to be widely used as excellent electrode materials due to their high sodium ion capacity, good cycle performance, and high reversible capacity.

作为优选，所述低浓度NaOH溶液中NaOH的量为完全中和PET水解产物中的对苯二甲酸的量以及完全去除乙二醇原位液相重整中产物中CO ₂的量之和，以确保加入的NaOH试剂可完全去除PET聚酯废塑料的一步转化产生的对苯二甲酸和二氧化碳。 As preferably, the amount of NaOH in the low-concentration NaOH solution is the amount of completely neutralizing the terephthalic acid in the PET hydrolyzate and completely removing the CO in the product in the in-situ liquid phase reforming of ethylene glycol _{The sum} of the amount, To ensure that the added NaOH reagent can completely remove terephthalic acid and carbon dioxide produced by the one-step conversion of PET polyester waste plastics.

作为优选，所述低浓度NaOH溶液的NaOH浓度值为1.2-4.8%，相对于要求较高NaOH浓度（20-30%）的传统PET碱性水解过程，本发明大大降低了对运行设备的腐蚀，同时也避免了含大量碱物质的废水排放。As a preference, the NaOH concentration value of the low-concentration NaOH solution is 1.2-4.8%. Compared with the traditional PET alkaline hydrolysis process that requires a higher NaOH concentration (20-30%), the present invention greatly reduces the corrosion of operating equipment , At the same time, it also avoids the discharge of wastewater containing a large amount of alkali substances.

作为优选，所述低温水热条件的温度为180-260℃，以同时实现PET在低浓度NaOH溶液中的完全解聚以及PET解聚产物中乙二醇的原位液相重整过程。由于本发明中NaOH的浓度值为1.2-4.8%，在低于180℃的条件下不能实现PET的完全解聚，并且由于一步法工艺过程中PET解聚产物乙二醇原位液相重整所需温度在180℃以上，因此，为了实现本发明的一步法转化PET制备高纯氢气和对苯二甲酸二钠盐的过程，运行温度控制在180-260℃之间。 Preferably, the temperature of the low-temperature hydrothermal condition is 180-260° C., so as to simultaneously realize the complete depolymerization of PET in a low-concentration NaOH solution and the in-situ liquid phase reforming process of ethylene glycol in PET depolymerization products. Since the concentration of NaOH in the present invention is 1.2-4.8%, the complete depolymerization of PET cannot be achieved at a temperature lower than 180°C, and the in-situ liquid phase reformation of PET depolymerization product ethylene glycol in the one-step process The required temperature is above 180°C. Therefore, in order to realize the one-step conversion of PET to prepare high-purity hydrogen and disodium terephthalate, the operating temperature is controlled between 180-260°C.

作为优选，所述低浓度NaOH溶液与PET聚酯废塑料质量比范围为：50:1-100:1。Preferably, the mass ratio range of the low-concentration NaOH solution to PET polyester waste plastics is 50:1-100:1.

作为优选，所述PET聚酯废塑料与重整催化剂质量比范围为：10:1-20:1。 Preferably, the range of the mass ratio of the PET polyester waste plastic to the reforming catalyst is 10:1-20:1.

作为优选，PET聚酯废塑料在一个反应体系中一步完全转化的产物还包括液相产物和固体催化剂，所述液相产物和固体催化剂用于再循环利用，包括以下步骤：将PET聚酯废塑料和一定量的NaOH试剂再次加入到含有固体催化剂的液相产物中，再次用于制备对苯二甲酸二钠和氢气，每次循环后得到的液相产物中的对苯二甲酸二钠和Na ₂CO ₃对新一轮的PET聚酯废塑料一步转化反应没有明显影响。 As a preference, the one-step complete conversion of PET polyester waste plastics in a reaction system also includes liquid phase products and solid catalysts, and the liquid phase products and solid catalysts are used for recycling, including the following steps: The plastic and a certain amount of NaOH reagent are added to the liquid phase product containing the solid catalyst again, which is used again to prepare disodium terephthalate and hydrogen, and the disodium terephthalate and hydrogen in the liquid phase product obtained after each cycle Na ₂ CO ₃ has no obvious effect on the new round of one-step conversion reaction of PET polyester waste plastics.

作为优选，PET聚酯废塑料一步完全转化后还包括对苯二甲酸二钠的精制处理，具体包括以下步骤：将循环后得到的固体催化剂、粗制的对苯二甲酸二钠水溶液的混合物进行过滤，分离出粗制的对苯二甲酸二钠水溶液，然后将适量的对苯二甲酸加入到粗制的对苯二甲酸二钠水溶液中，去除残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液。 As preferably, PET polyester waste plastics also includes the refining treatment of disodium terephthalate after one-step complete conversion, specifically comprises the following steps: the mixture of the solid catalyst obtained after recycling and the crude disodium terephthalate aqueous solution is carried out Filter to separate the crude disodium terephthalate _aqueous solution, then add appropriate amount of terephthalic acid into the crude disodium terephthalate aqueous solution to remove residual _Na2CO3 and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution.

作为优选，精制的对苯二甲酸二钠水溶液通过蒸发结晶得到纯净的对苯二甲酸二钠晶体。Preferably, the purified disodium terephthalate aqueous solution is crystallized by evaporation to obtain pure disodium terephthalate crystals.

作为优选，所述重整催化剂为活性金属含量为0.1-10wt.%的贵金属催化剂，优选活性金属含量为5wt.%的贵金属催化剂。Preferably, the reforming catalyst is a noble metal catalyst with an active metal content of 0.1-10 wt.%, preferably a noble metal catalyst with an active metal content of 5 wt.%.

作为优选，所述的贵金属催化剂为Ru、Pt、Pd、Rh负载的生物炭基催化剂，优选Ru负载的生物炭基催化剂。Preferably, the noble metal catalyst is a biochar-based catalyst supported by Ru, Pt, Pd, Rh, preferably a Ru-supported biochar-based catalyst.

作为优选，所述PET聚酯废塑料包括塑料饮料瓶、一次性餐饮用具、涤纶布料等PET制品废弃物。Preferably, the PET polyester waste plastics include PET product wastes such as plastic beverage bottles, disposable catering utensils, and polyester cloth.

有益效果Beneficial effect

一、本发明开发了一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，最终可以得到对苯二甲酸二钠和纯度接近99%的氢气，实现了PET聚酯废塑料一步法快速处理，并得到了高值产物。1. The present invention has developed a one-step method of low-temperature transformation of PET polyester waste plastics to prepare disodium terephthalate and high-purity hydrogen. Finally, disodium terephthalate and hydrogen with a purity close to 99% can be obtained, realizing PET poly One-step rapid treatment of ester waste plastics, and high-value products were obtained.

二、本发明的反应条件温和，该工艺中使用了浓度为1.2-4.8%的NaOH溶液，与传统的高浓度（20-30%）的NaOH解聚PET工艺相比，本发明提供的工艺不会对运行设备造成严重腐蚀。另外，本发明在基于使用低浓度NaOH溶液的基础上，采用了NaOH计算理论值，即NaOH的量为完全中和PET水解产物中的对苯二甲酸的理论量以及完全去除乙二醇原位液相重整中产物中CO ₂的理论量之和，因此一步转化反应末端不会产生含大量强碱的废水。并且经过对苯二甲酸二钠盐纯化过程后，得到的液体不含有任何有害杂质。 Two, the reaction condition of the present invention is gentle, has used the NaOH solution that concentration is 1.2-4.8% in this technique, compares with the NaOH depolymerization PET technique of traditional high concentration (20-30%), technique provided by the present invention does not Can cause severe corrosion to operating equipment. In addition, the present invention uses the theoretical value of NaOH calculation based on the use of low-concentration NaOH solution, that is, the amount of NaOH is the theoretical amount for completely neutralizing the terephthalic acid in the PET hydrolyzate and completely removing the in-situ ethylene glycol. The sum of the theoretical amount of _CO2 in the product in the liquid phase reforming, so the end of the one-step conversion reaction will not produce waste water containing a large amount of strong alkali. And after going through the disodium terephthalate purification process, the obtained liquid does not contain any harmful impurities.

三、本发明与传统的“PET碱性水热解聚+强酸置换对苯二甲酸”工艺相比，真正实现了PET解聚产物的一步法全利用，避免了PET解聚产物中乙二醇的流失和工业末端含大量Na ₂SO ₄/NaCl废水的排放，并且本发明得到的对苯二甲酸二钠盐具有比对苯二甲酸更高的市场价值。 3. Compared with the traditional "PET alkaline hydrothermal depolymerization + strong acid replacement of terephthalic acid" process, the present invention truly realizes the one-step full utilization of PET depolymerization products, avoiding the ethylene glycol in PET depolymerization products The loss of industrial end and the discharge of a large amount of Na ₂ SO ₄ /NaCl wastewater, and the disodium terephthalic acid obtained in the present invention has a higher market value than terephthalic acid.

四、本发明制备的氢气具有接近99%的高纯度，得到的粗制的对苯二甲酸二钠溶液只需经过简单的精制和蒸发结晶后，可在工艺末端得到的高纯度苯二甲酸二钠盐。并且通过核磁共振波谱、傅立叶变换红外光谱以及X射线衍射检测，证明了其具有极高的纯度，几乎不含任何杂质，可用于电化学工艺中的电极材料制备。Four, the hydrogen prepared by the present invention has a high purity close to 99%, and the obtained crude disodium terephthalate solution only needs to undergo simple refining and evaporation crystallization, and the high-purity diphthalic acid diphthalate that can be obtained at the end of the process sodium salt. And through nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction detection, it has been proved that it has extremely high purity and hardly contains any impurities, and can be used for the preparation of electrode materials in electrochemical processes.

五、此工艺简单巧妙，操作容易，PET转化率接近100%，环境友好，并可以实现液相产物和催化剂的多次循环利用，具有极高的工业应用价值。5. The process is simple and ingenious, easy to operate, and the conversion rate of PET is close to 100%. It is environmentally friendly, and can realize multiple recycling of liquid phase products and catalysts, and has extremely high industrial application value.

本发明的特征及优点将通过实施例结合附图进行详细说明。The features and advantages of the present invention will be described in detail with reference to the accompanying drawings.

附图说明Description of drawings

图1为本发明一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法的工艺流程图；Fig. 1 is the process flow diagram of the method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of PET polyester waste plastics of the present invention;

图2为液相产物循环测试结果图；Fig. 2 is a figure of liquid phase product cycle test result;

图3为催化剂循环对比测试结果图；Fig. 3 is a graph of catalyst cycle comparison test results;

图4 为以不同PET塑料制品废弃物为原料生产的对苯二甲酸二钠傅立叶变换红外吸收光谱对比图。Figure 4 is a comparison chart of Fourier transform infrared absorption spectra of disodium terephthalate produced with different PET plastic wastes as raw materials.

图5 为以不同PET塑料制品废弃物为原料生产的对苯二甲酸二钠核磁共振波谱对比图。Figure 5 is a comparison chart of NMR spectra of disodium terephthalate produced with different PET plastic wastes as raw materials.

本发明的最佳实施方式BEST MODE FOR CARRYING OUT THE INVENTION

传统的PET水热解聚的目的是在温度低于180℃条件下生成对苯二甲酸二钠，然后利用强酸制弱酸的原理通过加入硫酸/盐酸产出对苯二甲酸。由于在较低水热温度条件下实现PET的完全解聚需要较高的NaOH浓度（20-30%），所以易对设备产生严重腐蚀，且对苯二甲酸提纯过程会产生大量含盐（Na ₂SO ₄/NaCl）废水。另外，乙二醇作为PET水解的另外一种主要产物在此过程中会与废水混合，导致其难以回收，从而造成乙二醇的流失以及较低的PET的转化利用率。针对上述问题，本发明一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，参阅图1的工艺流程图，该方法具体包括以下步骤： The purpose of traditional PET hydrothermal depolymerization is to generate disodium terephthalate at a temperature lower than 180°C, and then use the principle of strong acid to make weak acid to produce terephthalic acid by adding sulfuric acid/hydrochloric acid. Since the complete depolymerization of PET requires a high NaOH concentration (20-30%) at a relatively low hydrothermal temperature, it is easy to cause serious corrosion to the equipment, and the purification process of terephthalic acid will produce a large amount of salt (NaOH ₂ SO ₄ /NaCl) wastewater. In addition, ethylene glycol, as another main product of PET hydrolysis, will be mixed with wastewater during the process, making it difficult to recover, resulting in the loss of ethylene glycol and lower conversion utilization of PET. In view of the above problems, the present invention provides a method for preparing disodium terephthalate and high-purity hydrogen by converting PET polyester waste plastics at low temperature in one step, referring to the process flow diagram of Fig. 1, the method specifically includes the following steps:

S1.按10:1-20:1的PET聚酯废塑料与重整催化剂质量比，将回收的PET聚酯废塑料和重整催化剂混合，按50:1-100:1的低浓度NaOH溶液与PET聚酯废塑料质量比，将PET聚酯废塑料和重整催化剂的混合物加入到低浓度的NaOH溶液中，在反应温度180-260℃、反应压力为0.5-3MPa的条件下，以NaOH的多重作用以及催化剂的定向催化特性为纽带，在特定的低温水热条件下，将PET水热解聚反应和PET解聚产物的原位重整反应进行耦合，一步法直接得到纯度接近99%的高纯氢气、粗制的对苯二甲酸二钠溶液，以及固体催化剂。S1. According to the mass ratio of PET polyester waste plastic to reforming catalyst of 10:1-20:1, mix the recycled PET polyester waste plastic and reforming catalyst, and use a low-concentration NaOH solution of 50:1-100:1 Compared with the mass ratio of PET polyester waste plastics, the mixture of PET polyester waste plastics and reforming catalysts is added to a low-concentration NaOH solution. The multiple functions of the catalyst and the directional catalytic characteristics of the catalyst are the link. Under specific low-temperature hydrothermal conditions, the PET hydrothermal depolymerization reaction and the in-situ reforming reaction of the PET depolymerization product are coupled, and the purity is close to 99% by one-step method. High-purity hydrogen, crude disodium terephthalate solution, and solid catalyst.

其中，所述低浓度NaOH溶液的NaOH浓度值为1.2-4.8%，NaOH的量为完全中和PET水解产物中的对苯二甲酸的理论量以及完全去除乙二醇原位液相重整中产物中CO ₂的理论量之和，以确保加入的NaOH试剂可完全去除PET聚酯废塑料的一步转化产生的对苯二甲酸和二氧化碳。所述重整催化剂为采用浸渍法制备的活性金属含量为5wt.%的Ru，Pt，Pd，Rh负载的生物炭基催化剂。所述PET聚酯废塑料为塑料饮料瓶、一次性餐饮用具、涤纶布料等PET制品废弃物。 Wherein, the NaOH concentration value of the low-concentration NaOH solution is 1.2-4.8%, and the amount of NaOH is to completely neutralize the theoretical amount of terephthalic acid in the PET hydrolyzate and completely remove the The sum of the theoretical amount of _CO in the product to ensure that the added NaOH reagent can completely remove the terephthalic acid and carbon dioxide produced by the one-step conversion of PET polyester waste plastics. The reforming catalyst is a Ru, Pt, Pd, Rh loaded biochar-based catalyst prepared by an impregnation method with an active metal content of 5 wt.%. The PET polyester waste plastics are PET product wastes such as plastic beverage bottles, disposable catering utensils, and polyester cloth.

S2.对液相产物和固体催化剂进行再循环利用：将PET聚酯废塑料和一定量的NaOH试剂再次加入到含有固体催化剂的液相产物中，在反应温度180-260℃、反应压力为0.5-3MPa下进行一步反应，再次用于制备对苯二甲酸二钠和高纯氢气。每次循环后得到的液相产物中的对苯二甲酸二钠和Na ₂CO ₃对新一轮的PET聚酯废塑料一步转化反应没有明显影响。 S2. Recycle the liquid phase product and solid catalyst: Add PET polyester waste plastics and a certain amount of NaOH reagent to the liquid phase product containing solid catalyst again, at a reaction temperature of 180-260 °C and a reaction pressure of 0.5 -3MPa for one-step reaction, again for the preparation of disodium terephthalate and high-purity hydrogen. The disodium terephthalate and Na ₂ CO ₃ in the liquid phase products obtained after each cycle had no obvious effect on the new round of one-step conversion reaction of PET polyester waste plastics.

S3.对苯二甲酸二钠的精制处理：将循环后得到的固体催化剂、粗制的对苯二甲酸二钠水溶液的混合物过滤，分离出粗制的对苯二甲酸二钠水溶液，然后将适量的对苯二甲酸加入到过滤后粗制的对苯二甲酸二钠水溶液中，去除溶液中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液。精制的对苯二甲酸二钠水溶液通过蒸发结晶得到高纯度对苯二甲酸二钠晶体。 S3. Refining treatment of disodium terephthalate: the mixture of the solid catalyst obtained after circulation and the crude disodium terephthalate aqueous solution is filtered to separate the crude disodium terephthalate aqueous solution, and then an appropriate amount of The terephthalic acid is added to the crude disodium terephthalate aqueous solution after filtration, and the remaining _Na2CO3 and a small amount of _NaOH in the solution are removed to obtain a refined disodium terephthalate aqueous solution. The refined disodium terephthalate aqueous solution is crystallized by evaporation to obtain high-purity disodium terephthalate crystals.

参阅实施例1至实施例5，反应温度对一步法转化PET聚酯废塑料的影响具体如下：Referring to Example 1 to Example 5, the impact of reaction temperature on the one-step conversion of PET polyester waste plastics is as follows:

本发明的实施方式Embodiments of the present invention

实施例Example 11 ：:

重整催化剂制备方法：使用浸渍法制备催化剂，按照5wt.%理论Ru负载量，将一定量的生物炭和前驱体氯化钌加入到无水乙醇中，在室温下均匀搅拌浸渍12小时后，在80℃下继续搅拌至无水乙醇蒸干，将得到的样品(Ru/C)在105℃烘箱中干燥；在500℃下，10%H ₂-90%Ar中还原5个小时。 Preparation method of reforming catalyst: use impregnation method to prepare catalyst, according to 5wt.% theoretical Ru loading, add a certain amount of biochar and precursor ruthenium chloride to absolute ethanol, stir and impregnate evenly at room temperature for 12 hours, Stirring was continued at 80°C until absolute ethanol was evaporated to dryness, and the obtained sample (Ru/C) was dried in an oven at 105°C; it was reduced in 10%H ₂ -90%Ar at 500°C for 5 hours.

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在180℃，无初压，反应压力0.5MPa条件下运行120分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为8.47 mol/kg _PET,氢气浓度为99.27%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 120 minutes at 180°C, no initial pressure, and reaction pressure 0.5MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 8.47 mol/kg _PET , and the hydrogen concentration was 99.27%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 22 ：:

重整催化剂制备方法同实施例1。The preparation method of the reforming catalyst is the same as in Example 1.

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在200℃，无初压，反应压力1MPa条件下运行120分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为18.31mol/kg _PET ,氢气浓度为98.77%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 120 minutes at 200°C, no initial pressure, and reaction pressure 1MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 18.31mol/kg _PET , and the hydrogen concentration was 98.77%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 33 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在220℃，无初压，反应压力1.5MPa条件下运行120分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为22.45 mol/kg _PET ,氢气浓度为97.99%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 120 minutes at 220°C, no initial pressure, and reaction pressure 1.5MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 22.45 mol/kg _PET , and the hydrogen concentration was 97.99%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 44 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行120分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.7 mol/kg _PET ,氢气浓度为98.31%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 120 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was carried out, and the gas produced was collected by an air bag and analyzed by gas chromatography. The hydrogen yield was 23.7 mol/kg _PET and the hydrogen concentration was 98.31%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 55 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在260℃，无初压，反应压力2.5MPa条件下运行120分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为24.38mol/kg _PET ,氢气浓度为98.42%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 120 minutes at 260°C, no initial pressure, and reaction pressure 2.5MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 24.38mol/kg _PET , and the hydrogen concentration was 98.42%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例1-5的实验结果如表1所示：The experimental result of embodiment 1-5 is as shown in table 1:

表1Table 1

参阅实施例6至实施例10，反应时间对一步法转化PET聚酯废塑料的影响具体如下：Referring to Example 6 to Example 10, the impact of reaction time on the one-step conversion of PET polyester waste plastics is as follows:

实施例Example 66 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行20分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为20.97mol/kg _PET ,氢气浓度为98.61%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 20 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 20.97mol/kg _PET , and the hydrogen concentration was 98.61%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 77 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行40分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为22.62mol/kg _PET ,氢气浓度为98.54%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 40 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was carried out, and the generated gas was collected with an air bag and analyzed by gas chromatography. The yield of hydrogen was 22.62mol/kg _PET , and the hydrogen concentration was 98.54%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 88 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行60分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为22.72 mol/kg _PET ,氢气浓度为98.47%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 60 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected with an air bag and analyzed by gas chromatography. The hydrogen yield was 22.72 mol/kg _PET and the hydrogen concentration was 98.47%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 99 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行80分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为22.60mol/kg _PET ,氢气浓度为98.44%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 80 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 22.60 mol/kg _PET , and the hydrogen concentration was 98.44%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 1010 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.71mol/kg _PET ,氢气浓度为98.31%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 23.71mol/kg _PET , and the hydrogen concentration was 98.31%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例6-10的实验结果如表2所示：The experimental result of embodiment 6-10 is as shown in table 2:

表2Table 2

参阅实施例11至实施例14，一步法转化PET工艺在常见PET聚酯废塑料的应用实例，具体如下：Referring to Example 11 to Example 14, the application examples of the one-step conversion PET process in common PET polyester waste plastics are as follows:

实施例Example 1111 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7g透明饮料瓶碎片（可乐瓶、矿泉水瓶等），70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为21.68mol/kg _PET,氢气浓度为98.26%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature transformation of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g of transparent beverage bottle fragments (coke bottles, mineral water bottles, etc.), 70ml deionized Water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 21.68mol/kg _PET , and the hydrogen concentration was 98.26%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 1212 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7g有色饮料瓶碎片（雪碧瓶等），70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.96mol/kg _PET ,氢气浓度为98.11%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g of colored beverage bottle fragments (Sprite bottles, etc.), 70ml of deionized water, 0.07 g Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 23.96mol/kg _PET , and the hydrogen concentration was 98.11%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 1313 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7g一次性PET材质塑料餐饮具碎片，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.16mol/kg _PET ,氢气浓度为98.22%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g disposable PET plastic tableware fragments, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the gas produced was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 23.16mol/kg _PET , and the hydrogen concentration was 98.22%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 1414 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7g涤纶布料碎片，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为21.52mol/kg _PET ,氢气浓度为96.16%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g of polyester cloth fragments, 70ml of deionized water, 0.07g of Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 21.52mol/kg _PET , and the hydrogen concentration was 96.16%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

图4和图5分别为以不同PET塑料制品废弃物为原料生产的对苯二甲酸二钠傅立叶变换红外吸收光谱和核磁共振波谱对比图。通过跟商用的对苯二甲酸二钠比较，表明了本发明产生的对苯二甲酸二钠较高的纯度。Figure 4 and Figure 5 are respectively the comparison charts of the Fourier transform infrared absorption spectrum and nuclear magnetic resonance spectrum of disodium terephthalate produced with different PET plastic product wastes as raw materials. By comparing with commercial disodium terephthalate, it shows that the disodium terephthalate produced by the present invention has higher purity.

实施例11-14的实验结果如表3所示：The experimental result of embodiment 11-14 is as shown in table 3:

表3table 3

参阅实施例10和15-16，低浓度NaOH溶液与PET聚酯废塑料质量比，以及NaOH浓度对一步法转化PET聚酯废塑料的影响具体如下：Referring to Examples 10 and 15-16, the mass ratio of low-concentration NaOH solution to PET polyester waste plastics, and the impact of NaOH concentration on the one-step conversion of PET polyester waste plastics are as follows:

实施例Example 1515 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7g PET聚酯塑料颗粒，35ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.55 mol/kg _PET ,氢气浓度为98.72%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature transformation of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 35ml deionized water, 0.07g Ru/C Catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 23.55 mol/kg _PET , and the hydrogen concentration was 98.72%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 1616 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，18ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.55mol/kg _PET ,氢气浓度为99.6%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature transformation of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 18ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 23.55mol/kg _PET , and the hydrogen concentration was 99.6%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

参阅实施例10和17，PET聚酯废塑料与重整催化剂质量比与对一步法转化PET聚酯废塑料的影响具体如下：Referring to Examples 10 and 17, the mass ratio of PET polyester waste plastics to reforming catalyst and the impact on the one-step conversion of PET polyester waste plastics are as follows:

实施例Example 1717 ：:

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7g PET聚酯塑料颗粒，70ml去离子水，0.035g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.62 mol/kg _PET ,氢气浓度为98.4%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature transformation of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic granules, 70ml deionized water, 0.035g Ru/C Catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 23.62 mol/kg _PET , and the hydrogen concentration was 98.4%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

参阅实施例10、18和19，活性金属加载量与对一步法转化PET聚酯废塑料的影响具体如下：Referring to Examples 10, 18 and 19, the active metal loading and the impact on the one-step conversion of PET polyester waste plastics are as follows:

实施例Example 1818 ：:

重整催化剂制备方法：使用浸渍法制备催化剂，按照0.1wt.%理论Ru负载量，将一定量的生物炭和前驱体氯铂酸加入到无水乙醇中，在室温下均匀搅拌浸渍12小时后，在80℃下继续搅拌至无水乙醇蒸干，将得到的样品(Pt/C)在105℃烘箱中干燥；在500℃下，10%H ₂-90%Ar中还原5个小时。 Reforming catalyst preparation method: The catalyst was prepared by impregnation method. According to the theoretical Ru loading capacity of 0.1wt.%, a certain amount of biochar and precursor chloroplatinic acid were added to absolute ethanol, and after uniform stirring and impregnation at room temperature for 12 hours , continue stirring at 80°C until absolute ethanol evaporates to dryness, and dry the obtained sample (Pt/C) in an oven at ₁₀₅ °C;

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力0.5MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为22.32 mol/kg _PET,氢气浓度为98.51%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 0.5MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 22.32 mol/kg _PET , and the hydrogen concentration was 98.51%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 1919 ：:

重整催化剂制备方法：使用浸渍法制备催化剂，按照10wt.%理论Ru负载量，将一定量的生物炭和前驱体氯铂酸加入到无水乙醇中，在室温下均匀搅拌浸渍12小时后，在80℃下继续搅拌至无水乙醇蒸干，将得到的样品(Pt/C)在105℃烘箱中干燥；在500℃下，10%H ₂-90%Ar中还原5个小时。 Preparation method of reforming catalyst: use impregnation method to prepare catalyst, according to 10wt.% theoretical Ru loading, add a certain amount of biochar and precursor chloroplatinic acid into absolute ethanol, stir and impregnate evenly at room temperature for 12 hours, Stirring was continued at 80°C until absolute ethanol was evaporated to dryness, and the obtained sample (Pt/C) was dried in an oven at 105°C; and reduced in 10%H ₂ -90%Ar at 500°C for 5 hours.

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力0.5MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.83 mol/kg _PET,氢气浓度为98.25%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 0.5MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 23.83 mol/kg _PET , and the hydrogen concentration was 98.25%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

参阅实施例10和20-22，不同活性金属与对一步法转化PET聚酯废塑料的影响具体如下：Referring to Examples 10 and 20-22, the impact of different active metals on the one-step conversion of PET polyester waste plastics is as follows:

实施例Example 2020 ：:

重整催化剂制备方法：使用浸渍法制备催化剂，按照5wt.%理论Pt负载量，将一定量的生物炭和前驱体氯铂酸加入到无水乙醇中，在室温下均匀搅拌浸渍12小时后，在80℃下继续搅拌至无水乙醇蒸干，将得到的样品(Pt/C)在105℃烘箱中干燥；在500℃下，10%H ₂-90%Ar中还原5个小时。 Preparation method of reforming catalyst: use impregnation method to prepare catalyst, according to 5wt.% theoretical Pt loading, add a certain amount of biochar and precursor chloroplatinic acid into absolute ethanol, stir and impregnate at room temperature for 12 hours, Stirring was continued at 80°C until absolute ethanol was evaporated to dryness, and the obtained sample (Pt/C) was dried in an oven at 105°C; and reduced in 10%H ₂ -90%Ar at 500°C for 5 hours.

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Pt/C催化剂和0.874g NaOH，在240℃，无初压，反应压力0.5MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.2 mol/kg _PET,氢气浓度为98.8%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature transformation of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Pt/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 0.5MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 23.2 mol/kg _PET , and the hydrogen concentration was 98.8%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 21twenty one ：:

重整催化剂制备方法：使用浸渍法制备催化剂，按照5wt.%理论Rh负载量，将一定量的生物炭和前驱体三氯化铑加入到无水乙醇中，在室温下均匀搅拌浸渍12小时后，在80℃下继续搅拌至无水乙醇蒸干，将得到的样品(Rh/C)在105℃烘箱中干燥；在500℃下，10%H ₂-90%Ar中还原5个小时。 Preparation method of reforming catalyst: use impregnation method to prepare catalyst, according to 5wt.% theoretical Rh loading capacity, add a certain amount of biochar and precursor rhodium trichloride to absolute ethanol, stir and impregnate evenly at room temperature for 12 hours , continue stirring at 80°C until absolute ethanol evaporates to dryness, and dry the obtained sample (Rh/C) in an oven at 105°C; and reduce it in 10%H ₂ -90%Ar at 500°C for 5 hours.

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Rh/C催化剂和0.874g NaOH，在240℃，无初压，反应压力0.5MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为22.9 mol/kg _PET,氢气浓度为98.2%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature transformation of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Rh/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 0.5MPa. After the reaction was completed, rapid cooling was performed, and the generated gas was collected by an air bag and analyzed by gas chromatography. The yield of hydrogen was 22.9 mol/kg _PET , and the hydrogen concentration was 98.2%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 22twenty two ：:

重整催化剂制备方法：使用浸渍法制备催化剂，按照5wt.%理论Pd负载量，将一定量的生物炭和前驱体硝酸钯加入到无水乙醇中，在室温下均匀搅拌浸渍12小时后，在80℃下继续搅拌至无水乙醇蒸干，将得到的样品(Pd/C)在105℃烘箱中干燥；在500℃下，10%H ₂-90%Ar中还原5个小时。 Preparation method of reforming catalyst: use impregnation method to prepare catalyst, add a certain amount of biochar and precursor palladium nitrate into absolute ethanol according to 5wt.% theoretical Pd loading, stir and impregnate evenly at room temperature for 12 hours, in Stirring was continued at 80°C until absolute ethanol was evaporated to dryness, and the obtained sample (Pd/C) was dried in an oven at 105°C; at 500°C, it was reduced in 10%H ₂ -90%Ar for 5 hours.

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Pd/C催化剂和0.874g NaOH，在240℃，无初压，反应压力0.5MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，获得氢气产率为23.3 mol/kg _PET,氢气浓度为98.5%。将液相产物和固体催化剂循环利用5次后，对液相产物和固体催化剂进行过滤；向过滤得到的水溶液中加入对苯二甲酸，直到对苯二甲酸无法溶解为止，以除去其中残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液，最后，通过蒸发结晶方法得到纯净的对苯二甲酸二钠固体。 One-step low-temperature transformation of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Pd/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 0.5MPa. After the reaction was completed, rapid cooling was carried out, and the generated gas was collected with an air bag and analyzed by gas chromatography. The yield of hydrogen was 23.3 mol/kg _PET , and the hydrogen concentration was 98.5%. After recycling the liquid phase product and solid catalyst for 5 times, filter the liquid phase product and solid catalyst; add terephthalic acid to the filtered aqueous solution until the terephthalic acid cannot be dissolved to remove the residual Na ₂ CO ₃ and a small amount of NaOH to obtain refined disodium terephthalate aqueous solution, and finally, pure disodium terephthalate solid was obtained by evaporation crystallization method.

实施例Example 23twenty three ：液相产物循环利用测试: Liquid phase product recycling test

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07gRu/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，对液相和固体催化剂进行过滤分离。然后将过滤得到的液相产物、0.7gPET聚酯塑料颗、0.07g新鲜Ru/C催化剂和0.874g NaOH再加入到高压反应釜中在相同的工况下进行运行，以此循环5次，每次都收集产生的气体并使用气相色谱仪器进行分析，得到液相产物循环利用影响规律，根据图2，可知，液相产物中的对苯二甲酸二钠、碳酸钠对氢气产率无明显影响，因此具有循环利用潜力。One-step low-temperature transformation of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction is completed, the temperature is rapidly cooled, and the gas produced is collected by an air bag and analyzed by gas chromatography, and the liquid phase and the solid catalyst are separated by filtration. Then the liquid phase product obtained by filtration, 0.7gPET polyester plastic particles, 0.07g fresh Ru/C catalyst and 0.874g NaOH are added to the autoclave and run under the same operating conditions, thus circulating 5 times, each The generated gas was collected every time and analyzed using a gas chromatograph to obtain the influence law of the liquid phase product recycling. According to Figure 2, it can be seen that disodium terephthalate and sodium carbonate in the liquid phase product have no significant impact on the hydrogen production rate , so it has recycling potential.

实施例Example 24twenty four ：: NaOHNaOH 溶液对solution pair RuRu 催化剂改性评估测试Catalyst Modification Evaluation Test

在高压反应釜中进行一步法低温转化PET聚酯废塑料来制备对苯二甲酸二钠和高纯氢气的方法：称量0.7gPET聚酯塑料颗粒，70ml去离子水，0.07g Ru/C催化剂和0.874g NaOH，在240℃，无初压，反应压力2MPa条件下运行100分钟。反应结束后进行快速冷却降温，使用气袋收集产生的气体并进行气相色谱分析，对液相和固体催化剂进行过滤分离，并将使用后的固体催化剂进行干燥。然后将0.07g干燥后的固体催化剂、0.7g PET聚酯塑料颗、70ml去离子水、和0.874g NaOH再加入到高压反应釜中在相同的工况下进行运行，以此循环5次，每次都收集产生的气体并使用气相色谱仪器进行分析，得到Ru催化剂在碱性溶液中的稳定性分析。One-step low-temperature conversion of PET polyester waste plastics in a high-pressure reactor to prepare disodium terephthalate and high-purity hydrogen: Weigh 0.7g PET polyester plastic particles, 70ml deionized water, 0.07g Ru/C catalyst and 0.874g NaOH, run for 100 minutes at 240°C, no initial pressure, and reaction pressure 2MPa. After the reaction is completed, the temperature is rapidly cooled, the gas produced is collected by an air bag and analyzed by gas chromatography, the liquid phase and the solid catalyst are separated by filtration, and the used solid catalyst is dried. Then 0.07g dried solid catalyst, 0.7g PET polyester plastic pellets, 70ml deionized water, and 0.874g NaOH are added to the autoclave and run under the same operating conditions, thus circulating 5 times, every The generated gas was collected every time and analyzed using a gas chromatograph to obtain the stability analysis of the Ru catalyst in alkaline solution.

为了形成对比，在本实施例中，称量0.226g乙二醇（0.7g PET理论解聚产量）、70ml去离子水，0.07g Ru/C催化剂在240℃，无初压，反应压力2MPa条件下运行100分钟，并按以上工艺流程进行催化剂循环利用实验。实验结果与Ru催化剂在碱性溶液中的稳定性进行对比，对比结果见图3，结果表明，NaOH溶液对Ru催化剂的改性可以显著地提高Ru催化剂的稳定性。与“NaOH+乙二醇体系”相比，在“NaOH+PET+催化剂体系”中，在NaOH溶液的影响下，平均Ru活性金属颗粒的粒径较低，说明缓解了金属团聚现象，对工业应用有较高的参考价值。For comparison, in this embodiment, weigh 0.226g ethylene glycol (0.7g Theoretical depolymerization yield of PET), 70ml deionized water, 0.07g The Ru/C catalyst was run for 100 minutes at 240°C, with no initial pressure and a reaction pressure of 2 MPa, and the catalyst recycling experiment was carried out according to the above process flow. The experimental results are compared with the stability of the Ru catalyst in alkaline solution, and the comparison results are shown in Figure 3. The results show that the modification of the Ru catalyst by NaOH solution can significantly improve the stability of the Ru catalyst. Compared with the "NaOH + ethylene glycol system", in the "NaOH + PET + catalyst system", under the influence of NaOH solution, the average particle size of Ru active metal particles is lower, indicating that the phenomenon of metal agglomeration is alleviated, which is beneficial to industrial applications. high reference value.

上述实施例是对本发明的说明，不是对本发明的限定，任何对本发明简单变换后的方案均属于本发明的保护范围。 The above-mentioned embodiment is an illustration of the present invention, not a limitation of the present invention, and any solution after a simple transformation of the present invention belongs to the protection scope of the present invention. the

Claims

一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：将PET聚酯废塑料与重整催化剂按一定比例混合加入到低浓度NaOH溶液中，在低温水热条件下，将PET水热解聚反应和PET解聚产物的原位重整反应进行耦合，使PET在一个反应体系中一步完全转化，直接得到氢气和粗制的对苯二甲酸二钠溶液。One-step low-temperature conversion of PET polyester waste plastics to prepare disodium terephthalate and high-purity hydrogen, characterized in that: PET polyester waste plastics and reforming catalysts are mixed in a certain proportion and added to low-concentration NaOH solution, Under low temperature hydrothermal conditions, the hydrothermal depolymerization reaction of PET and the in situ reforming reaction of PET depolymerization products are coupled, so that PET can be completely converted in one step in one reaction system, and hydrogen and crude terephthalic acid di sodium solution.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述低浓度NaOH溶液中NaOH的量为中和PET水解产物中的对苯二甲酸的量以及去除乙二醇原位液相重整中产物中CO ₂的量之和。 The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of PET polyester waste plastics as claimed in claim 1, wherein the amount of NaOH in the low-concentration NaOH solution is to neutralize PET hydrolyzate The sum of the amount of terephthalic acid in the product and the amount of CO ₂ removed from the product in the in-situ liquid phase reforming of ethylene glycol.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述低浓度NaOH溶液的NaOH浓度值为1.2-4.8%。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of PET polyester waste plastics according to claim 1, characterized in that: the NaOH concentration value of the low-concentration NaOH solution is 1.2-4.8%.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述低温水热条件的温度为180-260℃。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature transformation of PET polyester waste plastics according to claim 1, characterized in that: the temperature of the low-temperature hydrothermal condition is 180-260°C.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述低浓度NaOH溶液与PET聚酯废塑料质量比范围为：50:1-100:1。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature transformation of PET polyester waste plastics as claimed in claim 1, characterized in that: the mass ratio range of the low-concentration NaOH solution to PET polyester waste plastics is : 50:1-100:1.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述PET聚酯废塑料与重整催化剂质量比范围为：10:1-20:1。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of PET polyester waste plastics as claimed in claim 1, characterized in that: the mass ratio range of the PET polyester waste plastics to the reforming catalyst is: 10:1-20:1.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：PET在一个反应体系中一步完全转化的产物还包括固体催化剂，所述固体催化剂用于再循环利用，包括以下步骤：将固体催化剂、粗制的对苯二甲酸二钠水溶液的混合物过滤，分离出固体催化剂并进行干燥，然后将干燥固体催化剂、PET聚酯废塑料和去离子水按一定质量比混合，然后加入一定量的NaOH试剂，再次用于制备对苯二甲酸二钠和氢气。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of PET polyester waste plastics as claimed in claim 1, characterized in that: the product of one-step complete conversion of PET in one reaction system also includes a solid catalyst, The solid catalyst is used for recycling, comprising the following steps: filtering the mixture of the solid catalyst and the crude disodium terephthalate aqueous solution, separating the solid catalyst and drying, and then the dried solid catalyst, PET polyester waste Plastic and deionized water are mixed according to a certain mass ratio, and then a certain amount of NaOH reagent is added, which is used again to prepare disodium terephthalate and hydrogen.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：PET在一个反应体系中一步完全转化的产物还包括固体催化剂，一步完全转化后还包括对苯二甲酸二钠的精制处理，具体包括以下步骤：将固体催化剂、粗制的对苯二甲酸二钠水溶液的混合物过滤，分离出粗制的对苯二甲酸二钠水溶液，然后将适量的对苯二甲酸加入到粗制的对苯二甲酸二钠水溶液中，去除残留的Na ₂CO ₃和少量NaOH，得到精制的对苯二甲酸二钠水溶液。 The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of PET polyester waste plastics as claimed in claim 1, characterized in that: the product of one-step complete conversion of PET in one reaction system also includes a solid catalyst, After one step of complete conversion, it also includes the refining treatment of disodium terephthalate, specifically including the following steps: filtering the mixture of solid catalyst and crude disodium terephthalate aqueous solution, and separating the crude disodium terephthalate aqueous solution, and then add an appropriate amount of terephthalic acid to the crude disodium terephthalate aqueous solution to remove residual _Na2CO3 and a small amount of _NaOH to obtain a refined disodium terephthalate aqueous solution.
如权利要求8所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：精制的对苯二甲酸二钠水溶液通过蒸发结晶得到纯净的对苯二甲酸二钠晶体。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature transformation of PET polyester waste plastics as claimed in claim 8, characterized in that: the refined disodium terephthalate aqueous solution is obtained by evaporation and crystallization of pure terephthalate Disodium Phthalate Crystals.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述重整催化剂为活性金属含量为0.1-10wt.%的贵金属催化剂。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature transformation of PET polyester waste plastics as claimed in claim 1, characterized in that: the reforming catalyst is a catalyst with an active metal content of 0.1-10wt.%. noble metal catalysts.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述重整催化剂为活性金属含量为5wt.%的贵金属催化剂。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of PET polyester waste plastics as claimed in claim 1, characterized in that: the reforming catalyst is a noble metal catalyst with an active metal content of 5wt.%. .
如权利要求10或11所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述的贵金属催化剂为Ru、Pt、Pd、Rh负载的生物炭基催化剂。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature transformation of PET polyester waste plastics as claimed in claim 10 or 11, characterized in that: the precious metal catalyst is supported by Ru, Pt, Pd, Rh biochar-based catalysts.
如权利要求10或11所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述的贵金属催化剂为Ru负载的生物炭基催化剂。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature conversion of PET polyester waste plastics according to claim 10 or 11, characterized in that: the precious metal catalyst is a Ru-supported biochar-based catalyst.
如权利要求1所述的一步法低温转化PET聚酯废塑料制备对苯二甲酸二钠和高纯氢气的方法，其特征在于：所述PET聚酯废塑料包括塑料饮料瓶、一次性餐饮用具、涤纶布料。The method for preparing disodium terephthalate and high-purity hydrogen by one-step low-temperature transformation of PET polyester waste plastics as claimed in claim 1, characterized in that: said PET polyester waste plastics include plastic beverage bottles and disposable catering utensils , Polyester fabric.