Device for generating combustible product gas from carbonaceous feedstocks

Abstract

A device is provided for generating combustible product gas from carbonaceous feedstocks through allothermal steam gasification in a pressurized gasification vessel. The pressurized allothermal steam gasification of carbonaceous fuels requires that heat be supplied to the gasification chamber at a temperature level of approximately 800-900° C. In a heat pipe reformer, as is known from EP 1 187 892 B1, combustible gas is generated from the carbonaceous feedstocks to be gasified through allothermal steam gasification in a pressurized fluidized bed gasification chamber. The heat needed for this is fed to the gasifier or reformer from a fluidized bed combustion system through a heat pipe arrangement. Due to the straight and tubular construction of heat pipes, the combustion chamber and reformer/gasification chamber are disposed one above the other in the known heat pipe reformer from EP 1 187 892 B1. The pressure vessel base is under particular stresses due to the high temperatures in the combustion chamber. In addition, the base is weakened by a plurality of heat pipe feedthroughs. The sealing of the feedthroughs also presents a problem. In conventional tubular heat pipes, the line for liquid heat transfer medium and for gaseous heat transfer medium are both disposed in the common tubular shell. The fact that the present invention uses loop heat pipes in which the liquid heat transfer medium is conveyed spatially separated from the gaseous heat transfer medium allows the number of feedthroughs to be reduced to two, namely a liquid line and a vapor line. When a plurality of such loop heat pipes is used, the separate vapor and fluid lines thereof can be combined in the

1 . A device for generating combustible product gas from carbonaceous feedstocks through allothermal steam gasification, comprising:
 a pressurized gasifier including a gasifier pressure vessel, a supply means for the carbonaceous feedstocks, a steam supply, and a product gas extracting line,   an external heat source, and   a heat transport means comprising at least one heat pipe whereby heat is transported, with the aid of a heat transfer medium undergoing a phase change, from the external heat source into the gasifier,   wherein the at least one heat pipe has a heat-releasing side disposed inside the gasifier and a heat-absorbing side disposed inside the external heat source, and   wherein the at least one heat pipe is a loop heat pipe, the heat-absorbing and the heat-releasing side of which are connected to each other via a liquid line for liquid heat transfer medium and via a steam line for vaporous heat transfer medium, and in that the liquid line and the steam line are physically separate lines.   
     
     
         2 . The device according to  claim 1 , wherein a hydrogen separating means is disposed in the liquid line of the at least one loop heat pipe. 
     
     
         3 . The device according to  claim 1 , wherein the heat transport means includes at least one loop heat pipe pumped by means of a capillary structure. 
     
     
         4 . The device according to  claim 1 , wherein the heat transport means includes at least one immersed loop heat pipe. 
     
     
         5 . The device according to  claim 1 , wherein the heat transport means includes at least one first loop heat pipe comprising a steam line for vaporous heat transfer medium and a liquid line for liquid heat transfer medium, wherein the steam line and the liquid line are disposed in a physically separate manner, the heat transport means includes at least one second heat pipe, the two heat pipes each have a heat-releasing side and a heat-absorbing side, the heat-absorbing side of the at least one first loop heat pipe is disposed inside the external heat source, and the heat-releasing side of the at least one first loop heat pipe is thermally integrated into the heat-absorbing side of the at least one second heat pipe, and the heat-releasing side of the at least one second heat pipe is disposed inside the gasifier pressure vessel. 
     
     
         6 . The device according to  claim 5 , wherein the at least one second heat pipe is a pulsed loop heat pipe which comprises a common steam/liquid line and which is disposed inside the gasifier pressure vessel. 
     
     
         7 . The device according to  claim 6 , wherein the common steam/liquid line has a meander-type shape, in that the heat-releasing side of the pulsed loop heat pipe is disposed in the upper range of the gasifier pressure vessel, and in that the heat-absorbing side is disposed in the base area of the gasifier pressure vessel. 
     
     
         8 . The device according to  claim 1 , wherein the external heat source is a fluidized bed combustion chamber. 
     
     
         9 . The device according to  claim 1 , wherein the gasifier is configured as a fluidized bed gasifier. 
     
     
         10 . The device according to either  claim 8  or  9 , wherein the gasifier pressure vessel is connected to the fluidized bed combustion chamber via a material lock for pyrolysis residues. 
     
     
         11 . The device according to  claim 9 , wherein the fluidized bed gasifier and the fluidized bed combustion chamber are disposed inside a common vessel.