Composite desulfurizer for purifying petroleum and natural gas
Technical Field
The invention relates to the technical field of petroleum and natural gas purification, in particular to a composite desulfurizer for petroleum and natural gas purification, and particularly relates to a composite desulfurizer which is high in purification depth, large in absorption capacity, low in regeneration energy consumption and environment-friendly.
Background
The petroleum and natural gas is a product in the petroleum processing process and is an important raw material of petrochemical industry and civil fuel, but hydrogen sulfide, simple substance sulfur, mercaptan, thioether and the like are generated in the petroleum refining process, so that the impurities such as inorganic sulfur, organic sulfur, carbon dioxide and the like contained in the liquefied petroleum gas bring great harm to the subsequent processing and utilization of the liquefied petroleum gas and the environment. And the impurities have intolerable odor even at extremely low concentration, so that the natural gas must be removed to a certain extent before being transported by a pipeline, for example, GB17820-1999 stipulates that H in domestic secondary natural gas2S content is less than or equal to 20mg/Nm3The total sulfur content is less than or equal to 200mg/Nm3,CO2The content is less than or equal to 3 percent (mol).
The gas desulfurization method is basically divided into dry desulfurization and wet desulfurizationFor wet desulphurization, serial solvents have been developed at home and abroad to form a complete process technology, and the requirements of various complex mixed gas conditions and different purification degrees are met. At present, alcohol amine series solvents (such as MEA (membrane electrode assembly) and MDEA (methyl-ammonium-ethyl-ammonium-acetate) and triazine desulfurizer are common, wherein alcohol amine desulfurization is a typical absorption-regeneration reaction process, and the principle is that weak alkaline alcohol amine aqueous solution is used as an absorbent, and H in feed gas is absorbed in an absorption tower2S、CO2And other sulfur-containing impurities, desorbing the rich solution absorbing the impurities in a normal-pressure regeneration tower after the temperature of the rich solution is raised, regenerating the solution, cooling the regenerated barren solution, sending the cooled barren solution to an absorption tower for recycling, and sending the acid gas at the top of the regeneration tower to a sulfur recovery device for recovering sulfur after condensation and liquid separation. The method has the defects that the alcohol amine compound has high vapor pressure, is easy to be taken away by purified gas, has large evaporation loss, is easy to foam alcohol amine solution, causes difficult operation and has low desulfurization precision. The triazine desulfurizer has the characteristics of rapid absorption, high sulfur capacity, low price and the like, but triazine derivatives are easy to generate more sulfur scales which are insoluble in water and organic solvents, have high melting points and are difficult to remove. Therefore, the composite desulfurizer is urgently needed to replace the conventional alcohol amine desulfurizer and triazine desulfurizer, can quickly remove inorganic sulfur and organic sulfur, has high purification depth and low energy consumption, keeps the activity of the desulfurizer for a long time, has high regeneration efficiency, and meets the requirement of repeated cyclic utilization in industry.
Disclosure of Invention
The invention aims to provide a composite desulfurizer for purifying petroleum and natural gas, which can remove inorganic sulfur in gas and organic sulfur in gas effectively through the synergistic effect of all components, can realize direct desulfurization by one step, has high desulfurization reaction speed, greatly reduces reversible reaction, has high purification depth, low energy consumption, is green and environment-friendly, keeps the activity of the desulfurizer for a long time, has high regeneration efficiency, meets the requirement of industrial repeated cyclic utilization, and improves economic benefit.
In order to achieve the purpose, the invention adopts the following technical scheme:
the composite desulfurizer for purifying petroleum and natural gas is characterized by comprising the following components in percentage by weight,
an absorbent: 20-30 wt% of tert-butyl amino ethoxy ethanol TBEE, 20-30 wt% of 1,3, 5-tri (2-hydroxyethyl) -hexahydro-s-triazine and 10-20 wt% of oxazolidine compounds;
a synergist: 3-5 wt% of N-methyl pyrrolidone, 3-5 wt% of polyethylene glycol dimethyl ether and 3-5 wt% of N-methyl morpholine;
auxiliary agent: 1-2 wt% of penetrating agent, 0.5-1 wt% of defoaming agent and 0.5-1 wt% of antioxidant;
the balance of deionized water;
the compound desulfurizer has the removal rate of over 95 percent on sulfur in petroleum and natural gas and on CO2The removal rate can reach more than 90 percent, so that H in the purified gas2S content of not more than 2mg/Nm3Total sulfur content of not more than 30mg/Nm3The index of a natural gas can be achieved, the regeneration efficiency of the compound desulfurizer is over 95.83 percent, and the desulfurization efficiency after regeneration is not reduced basically.
The composite desulfurizer of the invention is preferably tert-butylamine ethoxy ethanol TBEE 25 wt%, 1,3, 5-tri (2-hydroxyethyl) -hexahydro-s-triazine 20 wt% and oxazolidine compound 15 wt%.
The oxazolidine compound is one or more of N-hydroxyethyl-2, 2-bisoxazolidine, N-methyl-2, 2-bisoxazolidine and N-phenyl-2, 2-bisoxazolidine.
The penetrant is sodium sulfosuccinate or sodium isethionate.
The antioxidant is one or more of tea polyphenol, hydroquinone, naphthalene polyphenol, p-hydroxyanisole, thiodipropionic acid and diethylhydroxylamine.
The defoaming agent is polyether modified silicone oil.
Tert-butylamine ethoxy ethanol TBEE is a high-efficiency selective desulfurization solvent, has steric hindrance effect and can react with H2The relative selectivity of S is 3 times of that of MDEA, when the catalyst is used for gas purification treatment, the energy consumption is only 70 percent of that of MDEA, the energy-saving effect is obvious, no bubble is generated in the using process, no corrosion phenomenon occurs, and 1,3, 5-tri (2-hydroxyethyl) -hexahydro-S-triazineHas the advantages of rapid absorption of hydrogen sulfide, high sulfur capacity and low price. The oxazolidine compounds have high sulfur substitution speed and large sulfur capacity, preferentially absorb hydrogen sulfide, and the desulfurization product is dissolved in water without producing sulfur scale. The composite synergist N-methyl pyrrolidone, polyethylene glycol dimethyl ether and N-methyl morpholine have complementary effects and can increase the sulfur capacity. The components in the composite desulfurizer supplement each other through the synergistic effect of the components, and the obtained composite desulfurizer has the advantages of high desulfurization activity, high reaction speed, low energy consumption, high regeneration efficiency, strong adaptability and relatively wide application prospect.
The invention has the following beneficial effects:
(1) the composite desulfurizing agent provided by the invention has the advantages that after the composite desulfurizing agent reacts with inorganic sulfur, organic sulfur and the like in mixed gas, the sulfur removal rate can reach more than 95 percent, and CO is removed2The removal rate can reach more than 90 percent, and H in the purified gas2S content of not more than 2mg/Nm3Total sulfur content of not more than 30mg/Nm3Can reach the natural gas index and has the purpose of environmental protection.
(2) The composite desulfurizer of the invention has stable performance, good water solubility, nontoxic and harmless product, simple operation and wider application prospect.
(3) The composite synergist introduced by the invention is mutually complemented and cooperated with the absorbent, so that the sulfur capacity is increased, the respective desulfurization effect is enhanced, the production cost is reduced, and the application range is wide.
(4) The composite desulfurizer of the invention has high desulfurization efficiency, the regeneration efficiency is more than 95.83%, and the desulfurization efficiency after regeneration is not reduced basically, thus meeting the requirement of repeated cyclic utilization in industry and greatly improving the economic benefit.
Detailed Description
The adopted petroleum and natural gas contains 1000mg/Nm of organic sulfur3,H2S 20%(mol),CO215% (mol). The petroleum and natural gas is in reverse contact with absorption liquid in an absorption tower, purified gas after impurity removal is discharged from the top of the tower, rich liquid absorbing impurities enters a rich liquid flash evaporation tank to be flashed to obtain dissolved hydrocarbon after coming out from the bottom of the tower, and the flashed rich liquid enters a regenerated lean liquid after exchanging heat with the regenerated lean liquidThe regeneration tower desorbs and regenerates, the desorbed acid gas is discharged from the top of the regeneration tower, the regenerated barren solution is discharged from the bottom of the tower, and the barren solution returns to the absorption tower for recycling after exchanging heat with the rich solution and cooling.
Example 1: the compound desulfurizer for purifying petroleum and natural gas adopts the formula of tert-butyl amino ethoxy ethanol TBEE20 wt%, 1,3, 5-tri (2-hydroxyethyl) -hexahydro-s-triazine 30 wt%, oxazolidine compound 20 wt%; 3 wt% of N-methyl pyrrolidone, 4 wt% of polyethylene glycol dimethyl ether, 3 wt% of N-methyl morpholine, 1 wt% of sodium hydroxyethyl sulfonate, 1 wt% of polyether modified silicone oil, 0.5 wt% of hydroquinone and the balance of deionized water. The organic sulfur in the purified gas after absorption treatment is less than 20.6mg/Nm3,H2S is less than 2mg/Nm3,CO2< 0.1% (mol). The sulfur removal rate was 97.9%, the regeneration efficiency was 95.87%, and the desulfurization efficiency after regeneration was not substantially reduced.
Example 2: the compound desulfurizer for purifying petroleum and natural gas adopts the formula of 30 wt% of tert-butyl amino ethoxy ethanol TBEE, 20 wt% of 1,3, 5-tri (2-hydroxyethyl) -hexahydro-s-triazine and 10 wt% of oxazolidine compounds; 4 wt% of N-methyl pyrrolidone, 5 wt% of polyethylene glycol dimethyl ether, 3 wt% of N-methyl morpholine, 1 wt% of sodium hydroxyethyl sulfonate, 0.5 wt% of polyether modified silicone oil, 1 wt% of tea polyphenol and the balance of deionized water. The organic sulfur in the purified gas after absorption treatment is less than 28.8mg/Nm3,H2S is less than 2mg/Nm3,CO2< 0.1% (mol). The sulfur removal rate was 97.2%, the regeneration efficiency was 96.14%, and the desulfurization efficiency after regeneration was not substantially reduced.
Example 3: the composite desulfurizer for purifying petroleum and natural gas adopts the formula of 25 wt% of tert-butylamine ethoxy ethanol TBEE, 25 wt% of 1,3, 5-tri (2-hydroxyethyl) -hexahydro-s-triazine and 15 wt% of oxazolidine compounds; 5 wt% of N-methyl pyrrolidone, 4 wt% of polyethylene glycol dimethyl ether, 5 wt% of N-methyl morpholine, 2 wt% of sodium sulfosuccinate, 0.5 wt% of polyether modified silicone oil, 0.5 wt% of p-hydroxyanisole and the balance of deionized water. The organic sulfur in the purified gas after absorption treatment is less than 15.4mg/Nm3,H2S is less than 2mg/Nm3,CO2< 0.1% (mol). Desulfurization of sulfurThe removal rate is 98.5%, the regeneration efficiency is 95.83%, and the desulfurization efficiency after regeneration is not reduced basically.
Comparative example 1: the compound desulfurizer adopts the formula of 50 wt% of tert-butyl amino ethoxy ethanol TBEE and 20 wt% of 1,3, 5-tri (2-hydroxyethyl) -hexahydro s-triazine; 3 wt% of N-methyl pyrrolidone, 4 wt% of polyethylene glycol dimethyl ether and 3 wt% of N-methyl morpholine; 1 wt% of sodium isethionate, 1 wt% of polyether modified silicone oil, 0.5 wt% of hydroquinone and the balance of deionized water. The organic sulfur in the purified gas after absorption treatment is 332.4mg/Nm3,H2S is 145.2mg/Nm3,CO20.4% (mol). The sulfur removal rate was 66.7%.
Comparative example 2: the compound desulfurizer adopts the formula of 50 wt% of 1,3, 5-tri (2-hydroxyethyl) -hexahydro-s-triazine and 10 wt% of oxazolidine compounds; 4 wt% of N-methyl pyrrolidone, 5 wt% of polyethylene glycol dimethyl ether, 3 wt% of N-methyl morpholine, 1 wt% of sodium hydroxyethyl sulfonate, 0.5 wt% of polyether modified silicone oil, 1 wt% of tea polyphenol and the balance of deionized water. The organic sulfur in the purified gas after absorption treatment is 405.2mg/Nm3,H2S is 116.3mg/Nm3,CO20.6% (mol). The sulfur removal rate was 59.5%.
Comparative example 3: the compound desulfurizer adopts the formula of 30 wt% of tert-butyl amino ethoxy ethanol TBEE and 35 wt% of oxazolidine compounds; 5 wt% of N-methyl pyrrolidone, 4 wt% of polyethylene glycol dimethyl ether and 5 wt% of N-methyl morpholine; 2 wt% of sodium sulfosuccinate, 0.5 wt% of polyether modified silicone oil, 1 wt% of p-hydroxyanisole and the balance of deionized water. The organic sulfur in the purified gas after absorption treatment was 236.4mg/Nm3,H2S is 100.2mg/Nm3,CO20.2% (mol). The sulfur removal rate was 76.36%.
Comparative example 4: the compound desulfurizer adopts the formula of 10 wt% of tert-butyl amino ethoxy ethanol TBEE, 10 wt% of 1,3, 5-tri (2-hydroxyethyl) -hexahydro-s-triazine and 35 wt% of oxazolidine compounds; 1 wt% of N-methyl pyrrolidone, 1 wt% of polyethylene glycol dimethyl ether, 1 wt% of N-methyl morpholine, 0.5 wt% of sodium sulfosuccinate, 0.5 wt% of polyether modified silicone oil, 0.5 wt% of p-hydroxyanisole and the balance of deionized water. Purification after absorption treatmentThe organic sulfur in the gas is 415.3mg/Nm3,H2S is 113.3mg/Nm3,CO20.4% (mol). The sulfur removal rate was 56.1%.
Comparative example 5: the compound desulfurizer adopts the formula of 30 wt% of tert-butyl amino ethoxy ethanol TBEE, 20 wt% of 1,3, 5-tri (2-hydroxyethyl) -hexahydro-s-triazine, 10 wt% of oxazolidine compounds, 2 wt% of sodium sulfosuccinate, 1 wt% of polyether modified silicone oil, 1 wt% of p-hydroxyanisole and the balance of deionized water. The organic sulfur in the purified gas after absorption treatment is 100.6mg/Nm3,H2S is 53.3mg/Nm3,CO20.1% (mol). The sulfur removal rate was 89.9%.
The present invention is not limited to the above exemplary embodiments, and any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.