Process and apparatus for the utilization of the enthalpy of a syngas by additional and post-gasification of renewable fuels
A process for the generation of a syngas in an entrained-flow gasification process includes a solid, carbon-containing fuel which is introduced via burners into a reactor which also supplies the oxygen for gasification. The fuel is introduced on a burner level where the burners are arranged concentrically around the reaction chamber or in the head area. The syngas obtained is discharged from the reaction chamber via a discharge nozzle, so that the syngas is passed into a collecting chamber for cooling by addition of low-temperature gaseous, vaporous or liquid cooling agents. A quench chamber is provided between the reactor and the collecting chamber. Additional burner levels are in the quench chamber via which a fuel material of renewable fuels or biofuels is introduced into the syngas, so that the heat enthalpy of the syngas can be utilized for the endothermic gasification reaction of the biological raw material. An apparatus for this generation of synthesis gas includes several burner levels, the renewable fuel being supplied to the gasification chamber with or without water vapor or oxygen and the enthalpy of the hot syngas being utilized for the gasification of the renewable fuel.
1. A process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels, comprising:
introducing finely ground, carbon-containing fuel in a mixture with oxygen or an oxygen-enriched gas from the outside concentrically in a horizontal direction or from the top downwards into a first refractory reaction chamber so that the fuel reacts to synthesis gas in an entrained-flow gasification in the first reaction chamber, wherein the finely ground, carbon-containing fuel is introduced into the first reaction chamber on a first burner level which extends, in direction of the synthesis gas flow, across a front section of the overall height of the first reaction chamber;
obtaining the synthesis gas at a pressure of 0.1 to 8 MPa and discharging it from the first reaction chamber in an upward or downward direction;
after having been discharged, passing the synthesis gas thus obtained into a second reaction chamber which is designed as a collecting chamber and in which the supplied synthesis gas is mixed for cooling purposes with a gaseous, vaporous or liquid substance of lower temperature, wherein the residence time of the synthesis gas after the introduction of the fuel in the entrained flow and before the entry into the downstream collecting chamber for cooling in the entrained flow ranges between 1 and 10 seconds; and
on a second or further burner level or a second or further burner gun level which also extends across a section of the overall height of the reaction path and is arranged, in the direction of the synthesis gas flow, downstream of the first burner level, a renewable fuel is introduced concentrically into the first reaction chamber, producing another entrained-flow gasification by which the temperature of the exiting synthesis gas is reduced and the enthalpy difference is utilized for the additional gasification of renewable raw materials.
2. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 1 , wherein the renewable fuel is introduced into the first reaction chamber in a mixture with a water vapour-containing or oxygen-containing gas, water vapour, or an oxygen-containing gas and water vapour.
3. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 1 , wherein the residence time of the synthesis gas after the introduction of the renewable fuel and before the entry into a collecting chamber for cooling in the entrained flow downstream of the reactor ranges between 2 and 5 seconds.
4. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 1 , wherein the temperatures in the collecting chamber range between 1400 and 1600° C. at the feed point for the renewable fuel.
5. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 1 , wherein the carbon-containing fuel is introduced into the first reaction chamber by tangentially arranged feed devices of the first burner level so to provide the carbon-containing fuel with a twist which will increase the residence time of the fuel in the reactor.
6. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 1 , wherein the synthesis gas is passed via a discharge tube into a quench chamber, and a renewable fuel is introduced concentrically into the quench chamber via burners in the quench chamber so to achieve a further reaction with the synthesis gas and thus a further reduction of the temperature of the synthesis gas.
7. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 6 , wherein the renewable fuel is introduced first into the quench chamber in flow direction of the gas and then the gaseous, vaporous or liquid agent is injected.
8. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 1 , wherein the renewable fuel is introduced into the reaction chamber or the quench chamber by tangentially arranged feed devices so that the renewable fuel is given a twist which will increase the residence time of the renewable fuel in the reactor or the quench chamber.
9. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 1 , wherein chopped, shredded, finely ground energy plants, wood of any form, straw, grass, cereals, biological residues, ocean plants or cattle dung are used as renewable fuel.
10. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 1 , wherein the renewable raw materials are submitted to a pre-treatment prior to the gasification, the pre-treatment steps including drying, carbonization, grinding or a combination of these steps.
11. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 1 , wherein renewable fuels in a mixture with carbon-containing fuels are used as fuel for the burners of the second burner level or in the quench chamber.
12. The process for the utilization of the enthalpy of a synthesis gas by additional and post-gasification of renewable fuels according to claim 11 , wherein renewable raw materials in a mixture with carbon-containing fuels are used as fuel for the first and the second burner level in the reaction vessel and for the burners in the quench chamber, the mixing ratios being different.