滇池底泥-褐煤超临界水共气化制氢实验研究

Experimental investigation on the co-gasification of Dianchi sediment and lignite for hydrogen production in supercritical water

采用间歇式超临界水反应装置,以滇池疏浚底泥和褐煤为原料,分别将褐煤、底泥单独进行超临界水气化,对比不同反应原料对气化制氢的影响。再将二者按不同混合比例(1∶9、2∶8、3∶7、4∶6、5∶5)进行共气化,对比不同混合比例对气化制氢的影响。结果表明,相对褐煤,底泥气化具有气体组分富氢、气相收率高、产气量小的特点;褐煤气化则具有碳气化率高、产气量大的特点。褐煤单独气化的气相收率低于底泥,共气化时气相收率达到834 mL/g。褐煤和底泥在超临界水共气化过程中碳气化率和产氢率存在明显协同效应。与加权平均值相比,碳气化率和H2产率分别提高了3.12%和55 mL/g。共气化存在最优比例,超过3∶7后,碳气化率逐渐下降。以最优比例进行共气化,既可达到处置底泥的目的,又可保持相对较高的H2产率(350 mL/g)和CH4产率(113 mL/g)。

Supercritical water gasification of lignite and sediment（independent and co-gasification） for hydrogen production were investigated in a batch autoclave under different conditions,including different feedstocks.The effect of different mixed ratio,i.e.1∶9,2∶8,3∶7,4∶6,5∶5,on hydrogen production were also investigated.The results indicated that the gasification of sediment is a process with a rich composition of hydrogen,high recovery of gaseous products but low gasification yields;meanwhile,the gasification of lignite is one with high carbon gasification efficiency and high gasification yields.Although the gaseous yields of lignite gasification were lower than that of sediment,it was increased to 834 mL/g under co-gasification.The obvious synergistic effect on carbon gasification efficiency and hydrogen production were observed in co-gasification process.Carbon gasification efficiency and hydrogen yield were 3.12% and 55 mL/g respectively,higher than that in terms of average value.The optimal ratio existed in co-gasification;when it is beyond 3∶7,carbon gasification efficiency declined.Therefore,co-gasification under optimal ratio not only could achieve effective sediment disposal,but also obtain high gaseous yields about 350 mL/g H2and 113 mL/g CH4.