WO2021112778A1

WO2021112778A1 - A method for obtaining hydrogen gas from chitin containing materials

Info

Publication number: WO2021112778A1
Application number: PCT/TR2019/051026
Authority: WO
Inventors: Ahmet Cemal SAYDAM
Original assignee: Chitlig Enerji Uretim Ve Pazarlama A.S
Priority date: 2019-12-04
Filing date: 2019-12-04
Publication date: 2021-06-10

Abstract

The present invention relates to a method obtaining hydrogen gas from chitin containing materials characterized by the steps of; introducing oxalic acid to chitin containing material for reacting with the chitin containing material, either as an aqueous solution or in solid phase, adding water to the mixture of oxalic acid and chitin containing material if the oxalic acid is introduced in solid phase, reacting the chitin containing material with the oxalic acid under pressure, obtaining hydrogen gas as a result of this reaction.

Description

A METHOD FOR OBTAINING HYDROGEN GAS FROM CHITIN CONTAINING MATERIALS

Technical Field

The present invention relates to a method for obtaining hydrogen gas from chitin containing materials, and especially from shale rocks.

Background of the Invention

Hydrogen is a highly combustible gas. When combusted, the only products are heat and water, making it a zero-emission fuel. For this reason, hydrogen is highly valuable as a fuel.

The majority of hydrogen is produced from fossil fuels. Even though hydrogen is a clean fuel, the dependence of its production on the fossil fuels renders it non renewable.

The production methods of hydrogen in the state of the art include reacting steam with methane, at high temperature (700-1000 °C) and pressure (14-40 bar), in the presence of a nickel catalyst. This method is called steam reforming. Another method for producing hydrogen is partial oxidation of methane. Partial oxidation of methane, as well, requires high temperatures (>800 °C).

Another method for producing hydrogen is electrolysis. This method involves applying electric current to an electrolyte. Since electrical energy needs to be utilized, this method is an inefficient method of obtaining hydrogen for producing energy. Additionally, traditional hydrogen production methods produce, as a by-product, Sulphur compounds. These Sulphur compounds are undesirable by-products.

Therefore, a method for producing hydrogen which does not require high temperatures to be utilized, and which does not produce undesirable by-products is needed.

The United States patent document numbered US7198107 in the background of the invention relates to a method for obtaining hydrogen gas. In the said document, water is injected inside the shale rocks, and in this way, the gases that have been trapped inside the gas can be gathered.

None of the documents in the state of the art disclose a method for obtaining hydrogen as in the present application.

Summary of the Invention

The object of the invention is to provide a method for producing hydrogen which does not require high temperatures to be utilized.

Another object of the invention is to provide a method for producing hydrogen which does not yield sulphurous by-products.

Brief Description of the Drawings

The following figures provided for the method for obtaining hydrogen gases in order to fulfill the objects of the present invention:

Figure 1. The graph showing the pressure change over time in pressurized container. Detailed Description of the Invention

The inventive method for obtaining hydrogen gas from chitin containing materials comprises the steps of;

- introducing oxalic acid to chitin containing material for reacting with the chitin containing material, either as an aqueous solution or in solid phase,

- adding water to the mixture of oxalic acid and chitin containing material if the oxalic acid is introduced in solid phase,

- reacting the chitin containing material with the oxalic acid under pressure,

- obtaining hydrogen gas as a result of this reaction.

In the inventive method, any one or more chitin containing material such as shale rock, sub-bituminous coal, half-bituminous coal, bituminous shale, kerogenous shale, bituminous schist rock, marl, tar sand, oil sand, chitin, lignin, Sahara dust, and desert dust rock might be reacted with oxalic acid thereby producing hydrogen. Oxalic acid might be prepared as aqueous solution, or it might be mixed with the chitin containing material and water could be added to this mixture.

The chitin containing material might be milled in order to increase the surface area contacting oxalic acid solution.

Since the oil reservoirs have shale layers, the proposed method could be utilized in oil reservoirs as well. For this, the oxalic acid is introduced into the reservoir and it reacts with the shale rocks present in the reservoir. As indicated above, oxalic acid might be prepared as an aqueous solution, or it might be introduced into the well, and after that water could be introduced. The oil reservoirs are already pressurized, as a result, the oil reservoirs meet the condition of reacting the chitin containing material (i.e. shale rocks) with oxalic acid solution. The hydrogen, together with other gasses produced by the reaction of oxalic acid and shale, increase the pressure inside the reservoir, thereby forcing the oil through the piping reaching the reservoir. This is especially useful because the traditional method for extracting the oil from the reservoir requires a gas to be forced from outside to inside of the reservoir, or burning some of the oil inside the reservoir, in order to increase the pressure inside the reservoir. Pumping a gas inside a reservoir requires energy, and burning the material inside the reservoir causes some of the precious material to be lost. By the virtue of the present invention, the pressure inside the reservoir could be increased without needing to pump gas inside the reservoir, or burning the material inside the reservoir, while producing hydrogen gas.

Additionally, the inventive method could be utilized in any reservoir containing a chitin layer such as oil reservoirs, natural gas reservoirs including those which have completed their life, geologically formed gas traps. The said reservoirs act as a container for producing hydrogen. For producing hydrogen in the said containers, oxalic acid solution (or oxalic acid and water, as explained above) should be introduced to the said container.

Additionally, any underground volume (reservoir) having a pressure greater than the atmospheric pressure could be used as a container for producing hydrogen. For producing hydrogen in the said containers, chitin and oxalic acid solution (or oxalic acid and water, as explained above) should be introduced to the said container.

The inventive method could be utilized in any container, above or underground, having a pressure greater than the atmospheric pressure.

In order to prove the inventive method, we have conducted some experiments, which would be discussed in detail, below.

To mimic the under-reservoir conditions, stainless steel containers capable of handling gas pressures up to 600 bar (8700 psig) have been used. For each test, approximately 10 g of granulated shale sample and oxalic acid have been placed into the pressure container having approximately 150 ml capacity.

Pressure cap is sealed, and vacuum is applied to the pressure cap so as to suck any gaseous product from the container. After that, a noble gas, preferably argon, is introduced to the container in order to increase the pressure inside the container to a predetermined value, preferably 70 bar. Here, 70 bar is selected because it is the pressure expected inside an oil reservoir. Argon was selected in order to avoid the interference of carrier gas (gas used for providing pressure inside the container) with hydrogen peak in gas chromatography.

In the meantime, sufficient water is degassed either by applying vacuum or by stripping the water with the gas used for pressurizing. Preferably argon is used so that it does not interfere with the gas chromatography results. However, any noble gas could be used. After degassing, water is introduced to the mixture of shale rocks and oxalic acid thereby providing a medium for the oxalic acid to react with the shale rocks.

As soon as the water is introduced, a sample has been obtained from the pressurized container in order to determine the initial starting gas composition. The starting gas composition is given in Table 1. Since taking a sample decreases the pressure inside the container, the pressure is increased to the said predetermined value again by using the said noble gas.

Table 1. Composition of the starting atmosphere inside the container

After this, the pressurized container is left alone. It is observed that the pressure inside the container kept rising. Therefore, the container is left alone until the pressure reached a steady state. During the experimental phase that has started with 70 bar initial pressure, steady state is reached at 98 bar, approximately in four days. At this point, another sample is collected from the pressurized container in order to determine the resultant gas composition. The resultant gas composition is given in Table 2.

Table 2. Composition of the resultant atmosphere inside the container The results of the experiments suggest that H₂ is produced in large amounts as the outcome of the reaction of the shale rocks with oxalic acid.

In order to determine if the same results would occur in atmospheric pressure conditions, the experiment is repeated in a headspace cup under atmospheric pressure. The results of this experiment is given in Table 3.

Table 3. Composition of the resultant atmosphere inside the headspace cup. This experiment shows that the applied pressure needs to be greater than the atmospheric pressure in order to increase the yield of the hydrogen gas.

As can be seen from the results of the experiments, hydrogen is produced under reservoir conditions, where the pressure is above the atmospheric pressure, and the temperature is about 50 °C. Therefore, the inventive method does not need high temperatures. Here, high temperature is used in the meaning of the temperatures required by the conventional hydrogen production methods such as steam reforming and partial oxidation of methane, mentioned in the state of the art. Additionally, the results show that no sulphurous compounds are produced as a result of the inventive method. Therefore, the proposed method is cleaner than the conventional hydrogen production methods.

Claims

1. A method for obtaining hydrogen gas, which does not require high temperatures to be utilized and which does not yield sulphurous by-products characterized by the the steps of; introducing oxalic acid to chitin containing material for reacting with the chitin containing material, either as an aqueous solution or in solid phase, adding water to the mixture of oxalic acid and chitin containing material if the oxalic acid is introduced in solid phase, reacting the chitin containing material with the oxalic acid under pressure, obtaining hydrogen gas as a result of this reaction.

2. A method for obtaining hydrogen gas as in Claim 1 characterized in that the chitin containin material is one or multiple of materials selected from shale rock, sub-bituminous coal, half-bituminous coal, bituminous shale, kerogenous shale, bituminous schist rock, marl, tar sand, oil sand, chitin, lignin, Sahara dust, and desert dust rock.

3. A method for obtaining hydrogen gas as in Claim 1 characterized in that the chitin containing material is milled in order to increase the surface area contacting oxalic acid solution.

4. Use of the method for obtaining hydrogen gas according to any one of the preceding claims in underground volume having a pressure greater than the atmospheric pressure.

5. Use of the method for obtaining hydrogen gas according to any one of the Claims 1-3 in oil or natural gas reservoirs for increasing the pressure within.