가스화기에서 WGS 반응을 통한 합성가스의 수소 전환

Abstract

A gasification process with pre-combustion <TEX>$CO_2$</TEX> capture process, which converts coal into environment-friendly synthetic gas, might be promising option for sustainable energy conversion. In the coal gasification for power generation, coal is converted into <TEX>$H_2$</TEX>, CO and <TEX>$CO_2$</TEX>. To reduce the cost of <TEX>$CO_2$</TEX> capture and to maximize hydrogen production, the removal of CO and the additional production of hydrogen might be needed. In this study, a 2l/min water gas shift system for a coal gasifier has been studied. To control the concentration of major components such as <TEX>$H_2$</TEX>, CO, and <TEX>$CO_2$</TEX>, MFCs were used in experimental apparatus. The gas concentration in these experiments was equal with syngas concentration from dry coal gasifiers (<TEX>$H_2$</TEX>: 25-35, CO: 60-65, <TEX>$CO_2$</TEX>: 5-15 vol%). The operation conditions of the WGS system were <TEX>$200-400^{\circ}C$</TEX>, 1-10bar. Steam/Carbon ratios were between 2.0 and 5.0. The commercial catalysts were used in the high temperature shift reactor and the low temperature shift reactor. As steam/carbon ratio increased, the conversion (1-<TEX>$CO_{out}/CO_{in}$</TEX>) increased from 93% to 97% at the condition of CO: 65, <TEX>$H_2$</TEX>: 30, <TEX>$CO_2$</TEX>: 5%. However the conversion decreased with increasing of gas flow and temperature. The gas concentration from LTS was <TEX>$H_2$</TEX>: 54.7-60.0, <TEX>$CO_2$</TEX>: 38.8-44.9, CO: 0.3-1%.