Fly ash-derived MCM-41 as a low-cost silica support for polyethyleneimine in post-combustion CO2 capture
Fly ash-derived MCM-41 as a low-cost silica support for polyethyleneimine in post-combustion CO2 capture
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DOI：
10.1016/j.jcou.2017.09.015
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发表时间：
2017-12-01
影响因子：
7.7
通讯作者：
Snape, C. E.
中科院分区：
文献类型：
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作者：
Panek, R.;Wdowin, M.;Snape, C. E.
以水热法生产沸石的副产物粉煤灰（PFA）为原料合成了介孔硅酸盐分子筛MCM-41。稻壳灰也用于比较，但与氢氧化钠的熔融用于制备硅酸盐滤液，沿着与使用PFA作为MCM-41合成的前体的早期报道类似的路线。MCM-41样品在化学和矿物学上类似于市售样品，但具有由中孔（0.92- 1.13cf. 0.88 cm（3）g（-1））。在用于CO2捕获的聚乙烯亚胺（PEI）浸渍之后，灰衍生的MCM-41样品显示出比商业样品更高的吸收，其中最大可实现的PEI负载量为60重量%在颗粒附聚发生之前的PEI（干基），与11重量%相比约为13，后者与文献中的早期报告相当。PFA样品表现出最快的动力学，达到90%的平衡吸收，具有最大的中孔体积1.13 cm（3）g（-1）。考虑到PFA衍生的MCM-41使用废硅酸盐溶液进行水热制备并且不需要预先制备，即使使用灰分，在需要通过碱处理制备硅酸盐溶液的情况下，生产成本估计也相当低，如本文使用的RHA衍生的MCM-41。
The mesoporous silicate molecular sieve, MCM-41, has been synthesized from pulverized coal fly ash (PFA), where the silicate filtrate used is a by-product from hydrothermal zeolite production. Rice husk ash was also used for comparison but fusion with sodium hydroxide was used to prepare the silicate filtrate, along similar lines to earlier reports of using PFA as a precursor for MCM-41 synthesis. The MCM-41 samples are chemically and mineralogically similar to a commercially available sample, but with higher pore volumes dominated by mesopores (0.92-1.13 cf. 0.88 cm(3) g(-1)). After polyethyleneimine (PEI) impregnation for CO2 capture, the ash derived MCM-41 samples displayed higher uptakes than the commercial sample with the maximum achievable PEI loading of 60 Wt.% PEI (dry basis) before particle agglomeration occurs, approximately 13 compared to 11 Wt.%, respectively, the latter being comparable to earlier reports in the literature. The PFA sample that displays the fastest kinetics to achieve 90% of the equilibrium uptake had the largest mesopore volume of 1.13 cm(3) g(-1). Given the PFA-derived MCM-41 uses a waste silicate solution for hydrothermal preparation and no prior preparation is needed, production costs are estimated to be considerable lower where silicate solutions need to be prepared by base treatment, even if ash is used, as for the RHA derived MCM-41 used here.