煤水蒸气气化过程中钾催化剂与矿物质的相互作用

Interaction of potassium with mineral matter in coal during steam gasification

在固定床反应器中研究了碳酸钾对煤的水蒸气催化气化,考察了钾与10种煤中矿物质的相互作用,采用XRD和XRF分析经过水浸取后的气化残渣。结果表明,在煤水蒸气气化过程中,碳酸钾催化剂与煤中矿物质相互作用形成难溶于水的化合物。当煤的灰分中钙含量较少时,钾催化剂与矿物质反应的量和气化灰渣中铝含量成线性关系,即K:Al=1:1。当煤的灰分中含钙量较多时,钙能够以钙铝黄长石(Ca2Al2SiO7)的形式固定大量的铝,一定程度上抑制钾催化剂和矿物质的反应。钾和矿物质反应的量影响钾催化剂的催化作用。

The catalysis of potassium carbonate on the steam gasification of coals was investigated in a fixed-bed reactor. The interaction of potassium with mineral matter in ten coals was examined. The gasification residue after leaching with water was analysed by X-ray diffraction （XRD） and X-ray fluorescence （XRF）. The results show that potassium aluminum silicate is the major crystallite derived from the interaction of potassium with mineral matter. As the ash is in low calcium content, the molar ratio of non-recoverable potassium to aluminum is one. However, as the ash is in high calcium content, the calcium can fix a large number of aluminum in the form of gehlenite （Ca2Al2SiO7）, which would inhibit the deactivation of potassium.