Production of synthesis gas by reverse water-gas shift reaction using carbon dioxide and pyrolysis-derived hydrogen

Abstract

This disclosure provides a chemical system and method for producing synthesis gas using pyrolysis gas, which contains pyrolysis carbon products and pyrolysis-derived hydrogen, obtained from a pyrolysis reactor that pyrolyzes hydrocarbon feedstocks. A high-temperature carbon separation mechanism separates the pyrolysis carbon products from the pyrolysis gas while maintaining the pyrolysis gas at a temperature above 800°C. A gas stream mainly containing carbon dioxide gas is supplied from a carbon dioxide source. The high-temperature pyrolysis gas, containing pyrolysis-derived hydrogen and carbon dioxide gas, is supplied to a reverse water-gas shift reactor, where the pyrolysis gas reacts with carbon dioxide to produce synthesis gas. The synthesis gas produced in the reverse water-gas shift reactor can be used in a variety of downstream systems and applications, including the reduction of metal oxides such as iron ore to obtain metal oxide reduction products. Recycling and heat exchange are used to further improve the efficiency of the system.

Claims

1. A chemical system for producing synthesis gas, (a) A pyrolysis reactor that pyrolyzes a hydrocarbon raw material into a pyrolysis gas at a pyrolysis temperature, wherein the pyrolysis gas contains pyrolysis carbon products and pyrolysis-derived hydrogen, (b) A high-temperature carbon separation mechanism, which receives the pyrolysis gas from the pyrolysis reactor and separates the pyrolysis carbon products from the pyrolysis gas while maintaining the pyrolysis gas at a temperature above 800°C, (c) A carbon dioxide source that supplies a gas stream mainly containing carbon dioxide gas, (d) A reverse water-gas shift reactor, (1) Receiving the pyrolysis gas from the high-temperature carbon separation mechanism, (2) Receiving the gas flow from the carbon dioxide source, (3) The inverse water-gas shift reactor, which reacts the pyrolysis gas with the gas flow to produce the synthesis gas, The aforementioned synthesis gas is a chemical system that mainly contains hydrogen and carbon monoxide, and further contains a mixture of carbon dioxide and water.

2. A chemical system according to claim 1, The aforementioned hydrocarbon raw materials are basically selected from the group consisting of methane and natural gas. The aforementioned pyrolysis carbon product is a chemical system containing solid carbon.

3. A chemical system according to claim 1, A chemical system in which the thermal decomposition temperature is in the range of 500°C to 1600°C.

4. A chemical system according to claim 1, A chemical system in which the pyrolysis carbon products are fluidized by the pyrolysis gas and discharged from the pyrolysis reactor.

5. A chemical system according to claim 1, A chemical system in which the reaction yield from the hydrocarbon raw material to the hydrogen derived from the pyrolysis in the pyrolysis reactor exceeds 70%.

6. A chemical system according to claim 1, The high-temperature carbon separation mechanism is a chemical system having at least one component selected from a high-temperature cyclone and a high-temperature candle filter.

7. A chemical system according to claim 1, The high-temperature carbon separation mechanism is a chemical system that separates the pyrolysis carbon products from the pyrolysis gas with a separation efficiency of more than 60% by mass, or more than 90% by mass.

8. A chemical system according to claim 1, The carbon dioxide source is a chemical system selected from biological carbon dioxide sources and waste carbon dioxide sources.

9. A chemical system according to claim 1, A chemical system in which the carbon dioxide gas is preheated to a temperature above 300°C or above 500°C before it is received by the reverse water-gas shift reactor.

10. A chemical system according to claim 1, The aforementioned reverse water-gas shift reactor is a chemical system operated at a shift temperature exceeding 800°C.

11. A chemical system according to claim 1, The aforementioned reverse water-gas shift reactor is a chemical system that uses a nickel-based catalyst.

12. A chemical system according to claim 1, A chemical system in which the pyrolysis gas supplied from the high-temperature carbon separation mechanism to the reverse water-gas shift reactor is cooled to a temperature of less than 1200°C by carbon dioxide gas within the reverse water-gas shift reactor.

13. A chemical system according to claim 1, The aforementioned synthesis gas is a chemical system containing more than 40% hydrogen by volume and more than 15% carbon monoxide by volume.

14. A chemical system according to claim 1, The pyrolysis reactor is selected from a thermal pyrolysis reactor, a microwave pyrolysis reactor, a plasma pyrolysis reactor, a liquid metal-containing pyrolysis reactor, a liquid salt-containing pyrolysis reactor, and a catalytic pyrolysis reactor, as part of a chemical system.

15. A chemical system according to claim 1, A chemical system further comprising a heat exchanger located downstream of the reverse water-gas shift reactor for transferring heat from the synthesis gas to the gas stream.

16. A chemical system according to claim 1, A chemical system further comprising a heat exchanger located downstream of the reverse water-gas shift reactor for transferring heat from the synthesis gas to the hydrocarbon feedstock.

17. A chemical system according to claim 1, A chemical system further comprising a wet scrubber system located downstream of the reverse water-gas shift reactor for removing contaminants from the synthesis gas.

18. A chemical system according to claim 1, Further comprising a removal system located downstream of the reverse water-gas shift reactor, for removing at least a portion of the mixture of carbon dioxide and water from the synthesis gas, The removal system is a chemical system in which at least one selected from a flash separation system, a pressure swing adsorption system, a thermal swing adsorption system, and a dehydration / carbon dioxide removal system.

19. A chemical system according to claim 1, A control system, (a) Changing the ratio of the hydrocarbon raw material and the carbon dioxide gas in the gas stream, (b) A chemical system further comprising a control system for changing the pyrolysis temperature in the pyrolysis reactor and the shift temperature in the reverse water-gas shift reactor, thereby controlling the relative composition of hydrogen, carbon monoxide, carbon dioxide, and water in the synthesis gas.

20. Synthesis gas obtained by a reaction using pyrolysis gas, The synthesis gas in question is (a) A step of providing a pyrolysis reactor for pyrolysis of a hydrocarbon raw material into a pyrolysis gas at a pyrolysis temperature, wherein the pyrolysis gas includes pyrolysis carbon products and pyrolysis-derived hydrogen, (b) A step of supplying the pyrolysis gas from the pyrolysis reactor to a high-temperature carbon separation mechanism, and separating the pyrolysis carbon products from the pyrolysis gas using the high-temperature carbon separation mechanism while maintaining the pyrolysis gas at a temperature of over 800°C, (c) A step of supplying a gas stream mainly containing carbon dioxide gas from a carbon dioxide source, (d) A step of providing a reverse water-gas shift reactor, wherein the reverse water-gas shift reactor is (1) Receiving the pyrolysis gas from the high-temperature carbon separation mechanism, (2) Receiving the gas flow from the carbon dioxide source, (3) Produced by a method comprising the step of reacting the pyrolysis gas with the gas flow to produce the synthesis gas, The aforementioned synthesis gas mainly contains hydrogen and carbon monoxide, and further contains a mixture of carbon dioxide and water.

Images