Direct production of high hydrogen syngas by steam gasification of Shengli lignite/chars: Significant catalytic effect of calcium and its possible active intermediate complexes
Direct production of high hydrogen syngas by steam gasification of Shengli lignite/chars: Significant catalytic effect of calcium and its possible active intermediate complexes
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胜利褐煤/炭蒸汽气化直接生产高氢合成气：钙及其可能的活性中间配合物的显着催化作用
DOI：
10.1016/j.fuel.2017.05.010
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发表时间：
2017-09-01
期刊：
影响因子：
7.4
通讯作者：
Liu, Quansheng
中科院分区：
文献类型：
--
作者：
Li, Na;Li, Yang;Liu, Quansheng
研究了钙对胜利焦水蒸气气化反应的催化作用。以添加氧化钙的脱矿胜利褐煤为原料，在氩气保护下热解制备了添加氧化钙的半焦。采用SEM-EDX、XRD、拉曼、FTIR和XPS等手段对半焦进行了表征，并在固定床反应器上对其进行了水蒸气气化性能评价。钙对半焦水蒸气气化反应有显著的促进作用，其活化能降低。结果表明，当煤焦中H2含量大于5wt%时，H2的生成量明显增加，从而提高了合成气的H2/CO比。SEM-EDS和XRD结果表明，Ca在煤焦颗粒中高度分散，CaO和CaS存在于煤焦样品中，但盐酸处理导致这些Ca化合物的大量损失。酸处理后的煤焦水蒸气气化速率仍远高于未加钙的煤焦，说明加钙煤焦水蒸气气化性能的上级原因不是煤焦中的CaO物种，而是热解过程中形成的一种特殊的褐煤钙中间体复合物“R-1-O-Ca-O-R-2”（R代表芳香族或脂肪族组分）。因此，钙与煤焦之间的“R-1-O-Ca-O-R-2”结构是促进胜利煤焦水蒸气气化反应的决定性因素，并能产生更多的高氢合成气。(C)2017爱思唯尔有限公司版权所有。
The catalytic effect of calcium on the steam gasification of Shengli chars was studied in this work. The calcium-added chars were prepared by pyrolysis under argon atmosphere from calcium oxide added demineralized Shengli lignite. The chars were characterized in detail by SEM-EDX, XRD, Raman, FTIR and XPS and were tested on a fixed-bed reactor to evaluate its performances steam gasification. Calcium was found to have significantly promotional effect on the steam gasification of char samples with reduces of activation energy. It was observed the presences of 5 wt% or above in the char significantly enhanced H-2 productions, which resulted in high H-2/CO ratio of syngas. The SEM-EDS and XRD results suggested calcium was highly dispersed within the char particles, CaO and CaS presented in the char samples, but the hydrochloric acid treatment of the char caused significant loss of these calcium compounds. The steam gasification rate of the acid-treated samples was still much higher than that of the no-calcium-added char, which elucidates that superior steam gasification performance of the Ca-added chars was not the simple CaO species in the char, instead, a special calcium lignite intermediate complex "R-1-O-Ca-O-R-2" (R representing aromatic or aliphatic constituents), formed within char during the pyrolysis. Thus the crosslink-like intermediate complexes "R-1-O-Ca-O-R-2" structure between calcium and chars was postulated to be the decisive factor to promote the steam gasification of Shengli chars with more production of high hydrogen syngas. (C) 2017 Elsevier Ltd. All rights reserved.