METHOD FOR PRODUCING SYNTHESIS GAS

Abstract

A method for producing synthesis gas may involve introducing a hydrocarbon-containing coke-oven gas and a carbon dioxide-containing converter gas into a first reaction zone where hydrogen present in the hydrocarbon-containing coke-oven gas reacts at least partly with carbon dioxide to form water, which reacts thermally with hydrocarbon to form synthesis gas containing carbon monoxide and hydrogen. The method may further involve introducing an oxygen-containing gas in a second reaction zone, and using the oxygen-containing gas and some hydrogen from the first reaction zone to produce thermal energy. Still further, the method may involve supplying the thermal energy produced in the second reaction zone to the first reaction zone.

Claims

1-10. (canceled)

11. A method for producing synthesis gas, the method comprising: introducing a hydrocarbon-containing coke-oven gas and a carbon dioxide-containing converter gas into a first reaction zone where hydrogen in the hydrocarbon-containing coke-oven gas reacts at least partly with carbon dioxide to form water, which reacts thermally with hydrocarbon to form synthesis gas containing carbon monoxide and hydrogen; introducing an oxygen-containing gas in a second reaction zone; producing thermal energy from the oxygen-containing gas and some of the hydrogen from the first reaction zone; and supplying the thermal energy produced in the second reaction zone to the first reaction zone.

12. The method of claim 11 comprising executing a fixed bed comprising a granular solid as a moving bed that is moved from the second reaction zone to the first reaction zone.

13. The method of claim 12 comprising recycling the granular solid.

14. The method of claim 12 comprising: running a gas emerging from the second reaction zone counter-current to the moving bed and thus cooling the gas emerging from the second reaction zone with the moving bed in direct heat exchange; and running the hydrocarbon-containing coke oven gas and the carbon dioxide-containing converter gas counter-current to the moving bed into the first reaction zone and thus heating the hydrocarbon-containing coke oven gas and the carbon dioxide-containing converter gas with the moving bed in direct heat exchange.

15. The method of claim 12 comprising separating carbon deposited on the granular solid downstream of the first reaction zone or a first heat-exchange zone and removing the carbon from the moving bed.

16. The method of claim 12 comprising using corundum (Al.sub.2O.sub.3), quartz glass (SiO.sub.2), mullite (Al.sub.2O.sub.3.SiO.sub.2), cordierite ((Mg,Fe).sub.2(Al.sub.2Si)[Al.sub.2Si.sub.4O.sub.18]), steatite (SiO.sub.2.MgO. Al.sub.2O.sub.3), coal, coke, or hydrocarbon produced in the method by thermal hydrocarbon decomposition as the granular solid.

17. The method of claim 11 comprising supplying water or steam to the first reaction zone.

18. The method of claim 11 wherein the hydrocarbon-containing coke-oven gas is a methane-rich gas.

19. The method of claim 18 wherein the carbon dioxide-containing converter gas is a converter gas produced from operation of a steelworks.

20. The method of claim 11 wherein the carbon dioxide-containing converter gas is a converter gas produced from operation of a steelworks.

21. The method of claim 11 wherein a ratio of a gas quantity of the hydrocarbon-containing coke-oven gas to the carbon dioxide-containing converter gas is set between 0.5 and 3 to set a hydrogen to carbon monoxide ratio in the synthesis gas at an output of a reactor between 0.8 and 2.5.

22. The method of claim 11 comprising adding hydrocarbons to the first reaction zone to set a hydrogen to carbon monoxide ratio in the synthesis gas at an output of a reactor between 0.8 and 2.5.

23. The method of claim 11 comprising adding methane to the first reaction zone to set a hydrogen to carbon monoxide ratio in the synthesis gas at an output of a reactor between 0.8 and 2.5.

24. The method of claim 11 comprising adding natural gas to the first reaction zone to set a hydrogen to carbon monoxide ratio in the synthesis gas at an output of a reactor between 0.8 and 2.5.

25. The method of claim 11 comprising adding carbon dioxide to the first reaction zone to set a hydrogen to carbon monoxide ratio in the synthesis gas at an output of a reactor between 0.8 and 2.5.

26. The method of claim 11 wherein the thermal energy in the second reaction zone is produced at least partially by electric current.

27. The method of claim 11 comprising using corundum (Al.sub.2O.sub.3), quartz glass (SiO.sub.2), mullite (Al.sub.2O.sub.3.SiO.sub.2), cordierite ((Mg,Fe).sub.2(Al.sub.2Si)[Al.sub.2Si.sub.4O.sub.18]), steatite (SiO.sub.2.MgO. Al.sub.2O.sub.3), coal, coke, or hydrocarbon produced in the method by thermal hydrocarbon decomposition as a granular solid.

Description

[0029] The invention is to be illustrated in more detail below using an exemplary embodiment shown schematically in FIG. 1.

[0030] FIG. 1 shows a preferred design of the method of the invention, in which a reactor is used, through the reaction chamber of which a moving bed of a granular solid is passed, which moving bed comprises a first and a second reaction zone as well as a first and second heat-exchange zone.

[0031] Granular solid at ambient temperature is supplied to the reaction chamber R of reactor K via pipeline 1. The granular solid is, for example carbon produced in the method by thermal hydrocarbon decomposition. The granular solid is passed downwards in a moving bed W due to the effect of gravity. A hydrocarbon-containing gas 2, together with a carbon dioxide-containing gas 4, is passed from the bottom to the reaction chamber R and run upwards in counter-current through the moving bed W. The hydrocarbon-containing gas 2 and the carbon dioxide-containing gas 4, which have ambient temperature on entering the reaction chamber R, are heated on their path upwards in direct heat exchange, in a first heat-exchange zone WT1, by the moving bed W until they reach the decomposition temperature of the hydrocarbon in the first reaction zone Z1. In a particular embodiment, the gases may also be combined in the run-up to the reactor and be introduced together in a supply pipe.

[0032] A reaction of the carbon dioxide with the hydrogen to form carbon monoxide and water via a thermal reverse water-gas shift reaction is effected in the first reaction zone Z1 on entry of the gases. The water from this reaction, together with the hydrocarbon, in the preferred case methane, is reacted in an endothermic thermal decomposition reaction to form hydrogen and carbon dioxide. The carbon dioxide may then in turn be reacted with hydrogen to form carbon monoxide. Both reactions, the reverse water-gas shift reaction and thermal steam reforming, proceed both one after another and in parallel. Together with unreacted or only partly reacted hydrocarbon, the hot hydrogen formed flows into the second reaction zone Z2 arranged above the first. An oxygen-containing gas 3 is supplied in the second reaction zone Z2. The hydrogen, together with the oxygen, is at least partly combusted and thus provides the heat of reaction required for the production of synthesis gas. Alternatively or additionally, the heat of reaction may also be introduced into the second reaction zone Z2 via electric current. The water being produced during hydrogen combustion is transferred at least partly into the first reaction zone and may be reacted there. Incompletely reacted products of the first reaction zone Z1 may be reacted further in the second reaction zone Z2. The synthesis gas 5, which is cooled in counter-current to the moving bed W in a second heat-exchange zone WT2, is removed from the second reaction zone Z2. The synthesis gas 5 has a temperature between 50 and 500 C. at the upper end of reactor K, the output of the reactor.

[0033] At the lower end of reactor K, granular solid is removed via a discharge 6 or a discharge pipe 6 at a temperature lying close to the ambient temperature, or at least between 50 and 300 C., and supplied to a regeneration device A, in which the latter is regenerated, for example by removing the attached carbon or by comminution, sifting and grading, to be returned to the reaction chamber R again as recycled solid 7.

[0034] In a further preferred design of the invention, the hydrocarbon-containing gas 2 enters the moving bed at the lower end of the reactor so that first of all partial pyrolytic decomposition of the hydrocarbon, in particular of the methane, takes place to form carbon and hydrogen. The carbon is attached to the fixed bed, hence the quantity of circulating granular fixed bed may be kept constant. The carbon dioxide-containing gas 4 is supplied to the reactor only shortly before entry into the first reaction zone Z1, separated from the addition point of the hydrocarbon-containing gas 2.

LIST OF REFERENCE DESIGNATIONS

[0035] A Regeneration device [0036] K Reactor [0037] R Reaction chamber [0038] W Moving bed [0039] WT1 First heat-exchange zone [0040] WT2 Second heat-exchange zone [0041] Z1 First reaction zone [0042] Z2 Second reaction zone [0043] 1 Supply of granular solid [0044] 2 Hydrocarbon-containing gas [0045] 3 Oxygen-containing gas [0046] 4 Carbon dioxide-containing gas [0047] 5 Synthesis gas [0048] 6 Discharge, especially discharge pipe, for granular solid [0049] 7 Recycled granular solid