Apparatus and method for utilizing off-gases from a power-to-X system
A power-to-X system for the utilization of off-gases, includes an electrolyzer for generating hydrogen H2 and oxygen O2, a unit, connected to the electrolyzer, for processing the hydrogen H2, for removing any remaining water H2O and oxygen O2 from the generated stream of hydrogen H2, a compressor, connected to the unit for processing the hydrogen H2, for compressing the hydrogen H2, and a chemical reactor, connected to the compressor, for producing a synthesis gas consisting of hydrogen H2 and carbon dioxide CO2 that can be added. An oxy-fuel combustion system to which non-condensable off-gases from the chemical reactor and oxygen O2 from the electrolyzer can be supplied, and carbon dioxide CO2 generated during the combustion of the off-gases in the oxy-fuel combustion system can be returned to the stream of hydrogen H2 downstream of the electrolyzer via a return line.
1. A power-to-X plant for utilizing off-gases, comprising:
an electrolyzer for production of hydrogen H 2 and oxygen O 2 ,
a plant for processing of the hydrogen, connected to the electrolyzer, for separation of remaining oxygen O 2 and water H 2 O from a stream of hydrogen H 2 produced,
at least one compressor for compression of the hydrogen H 2 or of a mixture of hydrogen H 2 and carbon dioxide CO 2 ,
a chemical reactor for production of alcohols or hydrocarbons, and
an oxyfuel combustion plant, to which noncondensable off-gases from the chemical reactor and oxygen O 2 from the electrolyzer are supplied, and carbon dioxide CO 2 which is formed in the oxyfuel combustion plant as a result of the combustion of the off-gases is recycled via a return line into the stream of hydrogen H 2 downstream of the electrolyzer.
2. The power-to-X plant as claimed in claim 1 ,
wherein the oxyfuel combustion plant comprises a heat exchanger by which the heat generated during the combustion is dissipated and is integrated into other parts of the power-to-X plant.
3. The power-to-X plant as claimed in claim 1 ,
wherein biomass and/or processed waste is, alternatively or additionally, supplied to the oxyfuel combustion plant and/or the oxyfuel combustion plant comprises a heater by which it is electrically heated using electricity from renewable sources.
4. The power-to-X plant as claimed in claim 1 , further comprising:
a removal flow line through which synthesis gas from the chemical reactor is supplied to the oxyfuel combustion plant.
5. The power-to-X plant as claimed in claim 1 ,
wherein a lambda probe is arranged in the return line of the oxyfuel combustion plant, so that, by measurement and regulation of a quantity of oxygen O 2 introduced, complete combustion of the off-gases to form CO 2 is ensured.
6. The power-to-X plant as claimed in claim 1 ,
wherein the compressor for compression of hydrogen H 2 and carbon dioxide CO 2 is a piston compressor designed for operating pressures above 10 bar, and the plant for processing of the hydrogen is a DeOxoDryer.
7. The power-to-X plant as claimed in claim 1 , further comprising:
a return line for carbon dioxide CO 2 through which the carbon dioxide CO 2 from the oxyfuel combustion plant is supplied into the stream for hydrogen H 2 upstream of the compressor.
8. The power-to-X plant as claimed in claim 1 , further comprising:
a contaminant remover which is connected to the oxyfuel combustion plant and in which contaminants produced in the oxyfuel process, are removed, and the purified carbon dioxide CO 2 is supplied via a return line to the stream of hydrogen H 2 upstream of the compressor.
9. A method for utilizing off-gases in a power-to-X plant, comprising:
producing hydrogen H 2 and oxygen O 2 by an electrolyzer,
separating remaining water H 2 O and oxygen O 2 from the hydrogen H 2 in a plant for processing of the hydrogen,
compressing the hydrogen H 2 in a compressor,
producing synthesis gas in a chemical reactor from the hydrogen H 2 together with carbon dioxide CO 2 , and
supplying noncondensable off-gases, contained in the synthesis gas, from the chemical reactor together with oxygen O 2 from the electrolyzer are supplied to an oxyfuel combustion plant, and carbon dioxide CO 2 which is formed as a result of the combustion of the off-gases is recycled into the stream of hydrogen H 2 downstream of the electrolyzer.
10. The method as claimed in claim 9 ,
wherein the oxyfuel combustion plant comprises a heat exchanger by which the heat generated during the combustion is dissipated and is integrated into other parts of the power-to-X plant.
11. The method as claimed in claim 9 ,
wherein biomass and/or processed waste for incineration is, alternatively or additionally, combusted in the oxyfuel combustion plant and/or wherein the oxyfuel combustion plant comprises a heater by which it is electrically heated using electricity from renewable sources.
12. The method as claimed in claim 9 ,
wherein synthesis gas from the chemical reactor is supplied to the oxyfuel combustion plant via a removal flow line.
13. The method according to claim 9 ,
wherein the oxygen concentration in the oxyfuel combustion plant is measured by a lambda probe in a return line, and complete combustion of the mixed gases to form CO 2 is ensured by regulation of the quantity of oxygen O 2 introduced.
14. The method as claimed in claim 9 ,
wherein the compressor is a piston compressor which is operated at a pressure of above 10 bar and wherein the plant for processing of the hydrogen is a DeOxoDryer.
15. The method as claimed in claim 9 ,
wherein the carbon dioxide CO 2 from the oxyfuel combustion plant is supplied through a return line for carbon dioxide CO 2 into the line for hydrogen H 2 upstream of the compressor.
16. The method as claimed in claim 9 ,
wherein contaminants produced in the oxyfuel process, are removed in a contaminant remover, and the purified carbon dioxide CO 2 is supplied into the stream of hydrogen H 2 via a return line upstream of the compressor.
17. The power-to-X plant as claimed in claim 2 ,
wherein the heat generated during the combustion is dissipated and is integrated into crude methanol processing and/or into auxiliary steam generation for start-up of the chemical reactor.
18. The power-to-X plant as claimed in claim 8 ,
wherein the oxygen O2 is removed cryogenically.
19. The method as claimed in claim 10 ,
wherein the heat generated during the combustion is dissipated and is integrated into crude methanol processing and/or into auxiliary steam generation for start-up of the chemical reactor.
20. The method as claimed in claim 16 ,
wherein the oxygen O2 is removed cryogenically.