Method for combined hydrogen production by absorbing carbon dioxide and recovering sulfur through industrial by-product gypsum

Abstract

The invention discloses a method for combined hydrogen production by absorbing carbon dioxide and recovering sulfur through industrial by-product gypsum, and belongs to the field of waste residue resource utilization, the method comprises the following steps: calcining crushed industrial by-product gypsum in the absence of oxygen and in the presence of a reducing agent at 500-800 DEG C, and obtaining a solid product containing calcium sulfide after the reaction is finished; at normal temperature, a solid product containing calcium sulfide is added into water, CO2 gas is introduced, gas generated by reaction is introduced into an anode chamber of a sealed electrochemical device, an iron salt solution is placed in the anode chamber, a cathode chamber is water, the anode chamber and the cathode chamber are separated by an ion exchange membrane, hydrogen generated by reaction is collected in the cathode chamber in the reaction process, and hydrogen is collected in the anode chamber. After the reaction is finished, elemental sulfur is obtained from the anode chamber; according to the invention, resource utilization of the industrial byproduct gypsum, carbon capture and preparation of new energy hydrogen are realized at the same time.

Description

Technical Field

[0001] The invention relates to a method for industrial by-product gypsum to absorb carbon dioxide, recover sulfur and jointly produce hydrogen, belonging to the field of waste residue resource utilization. Background Art

[0002] Industrial by-product gypsum, also known as chemical gypsum, refers to by-products or waste residues generated by chemical reactions in industrial production with calcium sulfate as the main component. Under strict environmental protection requirements, how to effectively treat a large amount of accumulated industrial by-product gypsum has become an urgent issue. The current "stacking" treatment method seriously restricts the development of enterprises, not only occupying a large amount of land, polluting groundwater, but also requiring enterprises to pay expensive stacking fees. Therefore, whether from the perspective of the survival and development of enterprises, environmental protection, or from the perspective of resource development and comprehensive utilization of industrial by-product gypsum, the fundamental way to solve the application problem of industrial by-product gypsum lies in how to utilize the characteristics of industrial by-product gypsum itself and adopt practical process methods to process industrial by-product gypsum into various gypsum building materials. The resource utilization of this industrial waste has not only obvious economic benefits but also social benefits.

[0003] It is of special significance to use industrial by-product gypsum as a renewable resource. With the development of the gypsum industry and cement industry, the mining volume of gypsum producing countries has increased year by year. Natural gypsum resources are limited. If the mining speed continues to increase, there will be a gypsum resource crisis in the near future. Therefore, the development and utilization of industrial by-product gypsum can alleviate the contradiction between supply and demand of natural gypsum. From the perspective of environmental protection and sustainable development, using industrial by-product gypsum as a renewable resource has good social benefits. Nowadays, countries around the world have reached a consensus on the major issue of protecting the earth's environment, and sustainable development as a new development strategy has attracted the attention of governments of various countries. It can be expected that with the improvement of social requirements for pollution control and environmental remediation, the utilization of industrial by-product gypsum will be greatly accelerated, so as to achieve the purpose of turning harm into benefit and turning waste into treasure. The use of industrial by-product gypsum also has obvious economic benefits. Although my country has the largest gypsum reserves, gypsum mines are unevenly distributed, mostly in the central, southern, southwestern and northwestern regions. A considerable part of the region lacks natural gypsum resources. If industrial production purchases gypsum from a long distance, it will not only aggravate the contradiction of transportation, but also increase production costs. On the other hand, in places where natural gypsum resources are scarce, the amount of industrial by-product gypsum discharged is very large. If local industrial by-product gypsum is actively used, production costs can be reduced. Summary of the invention

[0004] In view of the problem of recycling industrial by-product gypsum resources in the prior art, the present invention provides a method for industrial by-product gypsum to absorb carbon dioxide, recover sulfur and jointly produce hydrogen. The present invention obtains a solid product rich in calcium sulfide by calcining industrial by-product gypsum at high temperature without oxygen in the presence of a reducing agent, and uses the solid product to capture carbon dioxide. The gas generated by the reaction is then passed through an electrochemical reaction device to achieve sulfur resource recovery in industrial by-product gypsum and generate new energy hydrogen.

[0005] The method for combining industrial by-product gypsum with carbon dioxide absorption, sulfur recovery and hydrogen production of the present invention comprises the following specific steps: (1) The crushed industrial by-product gypsum is calcined at 500-1000°C for 1-3 hours in the absence of oxygen and in the presence of a reducing agent (coal, sulfur, hydrogen, hydrogen sulfide, carbon monoxide), and a solid product containing calcium sulfide is obtained after the reaction is completed; (2) At room temperature, a solid product containing calcium sulfide is added to water and CO2 gas is introduced. The gas generated by the reaction is introduced into the anode chamber of a sealed electrochemical device. An iron salt solution is placed in the anode chamber, and water is placed in the cathode chamber. The anode chamber and the cathode chamber are separated by an ion exchange membrane. During the reaction, the hydrogen generated by the reaction is collected in the cathode chamber, and sulfur is obtained in the anode chamber after the reaction is completed.

[0006] The ion exchange membrane is a cation exchange membrane.

[0007] The beneficial effects of the present invention are as follows: The present invention realizes the recovery of sulfur resources in industrial by-product gypsum, and the obtained elemental sulfur can be used not only in industrial production, but also in the fields of medicine, agriculture, etc. The present invention realizes the preparation of green new energy hydrogen; (2) The present invention simultaneously achieves carbon capture, industrial by-product gypsum sulfur resource recovery, and new energy hydrogen generation, thereby improving resource utilization efficiency; BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is the XRD spectrum of industrial by-product gypsum after calcination with reducing agent lignite. DETAILED DESCRIPTION

[0009] The present invention is further described in detail below in conjunction with specific implementation modes, but the protection scope of the present invention is not limited to the described contents.

[0010] Example 1: Method for recovering sulfur from industrial by-product gypsum by absorbing carbon dioxide and producing hydrogen (1) Using 10 g lignite as a reducing agent, 5 g of industrial by-product gypsum was calcined at 500 °C for 3 h in the absence of oxygen. After cooling after the reaction, a solid product containing calcium sulfide was obtained. The XRD spectrum of the calcined industrial by-product gypsum is as follows: Figure 1As shown in the figure, it can be seen that the main component of the calcined slag is calcium sulfide; (2) 0.5 g of a solid product containing calcium sulfide was added to 10 mL of water and CO2 gas was passed through it. The gas after the reaction was passed into a sealed electrochemical device, wherein the electrochemical device comprises a sealed shell, the shell is divided into an anode chamber and a cathode chamber by a cation exchange membrane, a graphite anode and a 0.05 mol / L FeCl3 solution (250 mL) are placed in the anode chamber, an air inlet is opened on the anode chamber, a platinum electrode and water are placed in the cathode chamber, an air outlet is opened on the cathode chamber, and the cathode and anode are respectively connected to a power source; Under the condition of power on (15V), the gas generated after calcium sulfide captures CO2 is passed into the anode chamber, and the reaction is carried out until no gas is generated at the anode. During the reaction, an air bag is used to collect the gas after the reaction at the outlet of the cathode chamber. The gas is detected by gas chromatography, and the result shows that all the gas obtained by the reaction except the carrier gas nitrogen is H2. The liquid in the anode chamber is collected and centrifuged, and the solid is placed in an oven at 100°C for drying. The solid sample obtained is weighed and detected by atomic absorption spectroscopy, and the result shows that the purity of S is 99.99% and the weight is 0.0746g.

[0011] Example 2: Method for recovering sulfur from industrial by-product gypsum by absorbing carbon dioxide and producing hydrogen (1) Using CO as a reducing agent, 5 g of industrial by-product gypsum was calcined at 600 °C in the absence of oxygen for 2.5 h. During the reaction, N2 containing 10% CO by volume was introduced at a flow rate of 100 mL / min. After the reaction was completed, the solid product containing calcium sulfide was obtained by cooling. (2) 0.5 g of solid product containing calcium sulfide was added to 15 mL of water and CO2 gas was passed through. The gas after the reaction was passed into a sealed electrochemical device. The structure of the electrochemical device was the same as that of Example 1, except that a 0.10 mol / LFeCl3 solution (250 mL) was placed in the anode chamber. Under the condition of power on (15V), the gas generated after calcium sulfide captures CO2 is passed into the anode chamber, and the reaction is carried out until no gas is generated at the anode. During the reaction, an air bag is used to collect the gas after the reaction at the outlet of the cathode chamber. The gas is detected by gas chromatography, and the result shows that except for nitrogen, all the gas obtained by the reaction is H2. The liquid in the anode chamber is collected and centrifuged, and the solid is placed in an oven at 100°C for drying. The obtained solid sample is weighed and detected by atomic absorption spectroscopy, and the result shows that the purity of S is 99.99% and the weight is 0.1144g.

[0012] Example 3: Method for recovering sulfur from industrial by-product gypsum by absorbing carbon dioxide and producing hydrogen (1) Using H2 as a reducing agent, 5 g of industrial by-product gypsum was calcined at 1000°C for 1 h in the absence of oxygen. During the reaction, N2 containing 15% H2 by volume was introduced at a flow rate of 100 mL / min. After the reaction was completed, the solid product containing calcium sulfide was obtained by cooling; (2) Take 0.5 g of solid product containing calcium sulfide and add it to 10 mL of water and pass CO2 gas through it. 0.5 g of solid calcined slag, the main component of which is calcium sulfide, is added to 10 ml of aqueous solution and CO2 gas is passed through. The gas after the reaction is passed into a sealed electrochemical device. The structure of the electrochemical device is the same as that of Example 1, except that a 0.2 0 mol / L FeCl3 solution (250 mL) is placed in the anode chamber; Under the condition of power on (15V), the gas generated after calcium sulfide captures CO2 is passed into the anode chamber, and the reaction is carried out until no gas is generated at the anode. During the reaction, the gas after the reaction is collected with an air bag at the gas outlet of the cathode chamber. The gas is detected by gas chromatography, and the result shows that except for nitrogen, all the gas obtained by the reaction is H2. The liquid in the anode chamber is collected and centrifuged, and the solid is placed in an oven at 90°C for drying. The obtained solid sample is weighed and detected by atomic absorption spectroscopy, and the result shows that the purity of S is 99.99% and the weight is 0.1286g.

[0013] Example 4: Method for recovering sulfur from industrial by-product gypsum by absorbing carbon dioxide and producing hydrogen (1) Using H2 as a reducing agent, 5 g of industrial by-product gypsum was calcined at 1000°C for 1 h in the absence of oxygen. During the reaction, N2 containing 15% H2 by volume was introduced at a flow rate of 100 mL / min. After the reaction was completed, the solid product containing calcium sulfide was obtained by cooling. (2) 0.5 g of solid product containing calcium sulfide was added to 10 mL of aqueous solution and CO2 gas was passed through. The gas after the reaction was passed into a sealed electrochemical device. The structure of the electrochemical device was the same as that of Example 1, except that a 0.30 mol / LFe(NO3)3 solution (250 mL) was placed in the anode chamber; Under the condition of power on (15V), the gas generated after calcium sulfide captures CO2 is passed into the anode chamber, and the reaction is carried out until no gas is generated at the anode. During the reaction, the gas after the reaction is collected with an air bag at the gas outlet of the cathode chamber. The result of gas chromatography detection shows that all the gas obtained by the reaction except nitrogen is H2. The liquid in the anode chamber is collected and centrifuged, and the solid is placed in an oven at 60°C for drying. The obtained solid sample is weighed and tested by atomic absorption spectroscopy, and the result shows that the purity of S is 99.99% and the weight is 0.1218g.

[0014] Example 5: Method for recovering sulfur from industrial by-product gypsum by absorbing carbon dioxide and producing hydrogen (1) Using H2S as a reducing agent, 5g of industrial by-product gypsum was calcined at 500°C for 3h in the absence of oxygen, and N2 containing 15% H2S by volume was introduced at a flow rate of 100mL / min. After the reaction was completed, the mixture was cooled to obtain a solid product containing calcium sulfide; (2) 0.5 g of solid product containing calcium sulfide was added to 10 mL of aqueous solution and CO2 gas was passed through. The gas after the reaction was passed into a sealed electrochemical device. The structure of the electrochemical device was the same as that of Example 1, except that a 0.10 mol / LFe3(SO4)2 solution (250 mL) was placed in the anode chamber. Under the condition of power on (15V), the gas generated after calcium sulfide captures CO2 is passed into the anode chamber, and the reaction is carried out until no gas is generated at the anode. During the reaction, the gas after the reaction is collected with an air bag at the gas outlet of the cathode chamber. The gas is detected by gas chromatography, and the result shows that except for nitrogen, all the gas obtained by the reaction is H2. The liquid in the anode chamber is collected and centrifuged, and the solid is placed in an oven at 100°C for drying. The obtained solid sample is weighed and detected by atomic absorption spectroscopy, and the result shows that the purity of S is 99.99% and the weight is 0.0849g.

[0015] Example 6: Method for recovering sulfur from industrial by-product gypsum by absorbing carbon dioxide and producing hydrogen (1) Using 5 g of lignite as a reducing agent, 5 g of industrial by-product gypsum was calcined at 600 °C for 1.5 h in the absence of oxygen. After the reaction was completed and cooled, a solid product containing calcium sulfide was obtained; (2) 0.5 g of solid product containing calcium sulfide was added to 10 mL of aqueous solution and CO2 gas was passed through. The gas after the reaction was passed into a sealed electrochemical device. The structure of the electrochemical device was the same as that of Example 2. Under the condition of power on (15V), the gas generated after calcium sulfide captures CO2 is passed into the anode chamber, and the reaction is carried out until no gas is generated at the anode. During the reaction, the gas after the reaction is collected at the gas outlet of the cathode chamber with an air bag. The result of gas chromatography detection shows that all the gas obtained by the reaction except nitrogen is H2. The liquid in the anode chamber is collected and centrifuged, and the solid is placed in an oven at 100°C for drying. The obtained solid sample is weighed and tested by atomic absorption spectroscopy, and the result shows that the purity of S is 99.99% and the weight is 0.1064g.

[0016] Example 7: Method for recovering sulfur from industrial by-product gypsum by absorbing carbon dioxide and producing hydrogen (1) Using CO as a reducing agent, 5 g of industrial by-product gypsum was calcined at 700 °C for 2 h in the absence of oxygen. During the reaction, N2 containing 10% CO by volume was introduced at a flow rate of 100 mL / min. After the reaction was completed, the solid product containing calcium sulfide was obtained by cooling. (2) 0.5 g of solid product containing calcium sulfide was added to 15 mL of aqueous solution and CO2 gas was passed through the reaction gas. The gas after the reaction was passed through an electrochemical device. The structure of the electrochemical device was the same as that of Example 1. Under the condition of power on (15V), the gas generated after calcium sulfide captures CO2 is passed into the anode chamber, and the reaction is carried out until no gas is generated at the anode. During the reaction, the gas after the reaction is collected with an air bag at the gas outlet of the cathode chamber. The gas is detected by gas chromatography, and the result shows that except for nitrogen, all the gas obtained by the reaction is H2. The liquid in the anode chamber is collected and centrifuged, and the solid is placed in an oven at 80°C for drying. The obtained solid sample is weighed and detected by atomic absorption spectroscopy, and the result shows that the purity of S is 99.99% and the weight is 0.0816g.

[0017] Example 8: Method for recovering sulfur from industrial by-product gypsum by absorbing carbon dioxide and producing hydrogen (1) Using 5 g of anthracite as a reducing agent, 5 g of industrial by-product gypsum was calcined at 800 °C for 2 h in the absence of oxygen. After cooling, a solid product containing calcium sulfide was obtained. (2) 0.5 g of solid product containing calcium sulfide was added to 15 mL of aqueous solution and CO2 gas was passed through. The gas after the reaction was passed into a sealed electrochemical device. The structure of the electrochemical device was the same as that of Example 2. Under the condition of power on (15V), the gas generated after calcium sulfide captures CO2 is passed into the anode chamber, and the reaction is carried out until no gas is generated at the anode. During the reaction, the gas after the reaction is collected with an air bag at the gas outlet of the cathode chamber. The gas is detected by gas chromatography, and the result shows that except for nitrogen, all the gas obtained by the reaction is H2. The liquid in the anode chamber is collected and centrifuged, and the solid is placed in an oven at 90°C for drying. The obtained solid sample is weighed and detected by atomic absorption spectroscopy, and the result shows that the purity of S is 99.99% and the weight is 0.1001g.

Claims

1. A method for combining industrial by-product gypsum with carbon dioxide absorption, sulfur recovery and hydrogen production, characterized in that: The specific steps are as follows: (1) The crushed industrial by-product gypsum is calcined at 500-800°C for 1-3 hours in the absence of oxygen and in the presence of a reducing agent, and a solid product containing calcium sulfide is obtained after the reaction is completed; (2) At room temperature, a solid product containing calcium sulfide is added to water and CO2 gas is introduced. The gas generated by the reaction is introduced into the anode chamber of a sealed electrochemical device. An iron salt solution is placed in the anode chamber, and water is placed in the cathode chamber. The anode chamber and the cathode chamber are separated by an ion exchange membrane. During the reaction, the hydrogen generated by the reaction is collected in the cathode chamber, and sulfur is obtained in the anode chamber after the reaction is completed.

2. The method for combining industrial by-product gypsum with carbon dioxide absorption, sulfur recovery and hydrogen production according to claim 1, characterized in that: The reducing agent is selected from coal, sulfur, hydrogen, hydrogen sulfide, and carbon monoxide.

3. The method for combining industrial by-product gypsum with carbon dioxide absorption, sulfur recovery and hydrogen production according to claim 1, characterized in that: The ion exchange membrane is a cation exchange membrane.

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