device with a nuclear heated heliumkreislauf for production of methane or synthesis gas from coal

摘要

Prodn. of methane and/or synthesis gas (CO/H2 mixts.) from carbonaceous materials, esp. coa , uses additional heat supplied by helium circulating through a nuclear reactor. Part of the carbon is reacted with hydrogen in a gasifier to produce CH4, and another part reacted with steam in a gasifier to produce synthetis gas. At least part of the methane is reacted with steam in a methane reformer, to give hydrogen. A process steam superheater is inserted in the helium circulation between the steam gasifier and the reformer, the superheated steam being used in the streasm gasifier. Pref. a steam generator is also placed in the helium stream after the reformer, the steam being used to drive a turbine and then directly in the reformer, and after superheating, in the steam gasifier. Superheating allows more steam to be used for gasification, which requires temps. of 790 degrees C. for coal and 630-660 degrees C. for brown coal, thus increasing output of gas from a given heat output from the reactor. Additional cost of the superheater is small, since the amt. of process steam used is relatively low. Pressure of steam can be reduced, e.g. from 180 to 40 bar, by the turbine before superheating.