Howaniec Natalia
Department of Energy Saving and Air Protection, Central Mining Institute, Pl. Gwarkow 1, 40-166 Katowice, Poland.
Materials (Basel). 2019 Sep 5;12(18):2872. doi: 10.3390/ma12182872.
The valorization of waste and by-products from various industrial activities is a must in our world of depleting natural resources and increasing volume of environmentally negative waste materials. The economic utilization of solid biowaste involves predominantly its use as a carbon-neutral energy resource or a precursor of porous carbon materials, with a potential application range including sorption processes, energy storage, and electric engineering. With the considerable number of lignocellulosic residues tested and applied as the most suitable porous material precursors, such as woods, shells, stones, peels, husks, and stalks of various crop plants, there is still space and need for further developments in the valorization of high amounts of other types of biowaste. Here, the olive pomace was considered because of both the vast volume and the environmentally undesired (when stored) phytotoxic effect of its components. While the literature on chemical (acidic and alkali treatment) and physical activation (temperature, carbon dioxide, and/or steam) of various biowaste precursors is considerable, the effects of pressure in the carbonization step are reported rarely, although the results observed are promising. The same applies to reports on the application of olive pomace for porous materials production, which indicate that olive pomace currently seems to be underestimated as a carbon materials precursor. In the study presented, the combined effects of pressure (0.1-3 MPa), temperature (800 °C), and carbon dioxide atmosphere in the carbonization of olive pomace were assessed on the basis of qualitative and quantitative data on micro- and mesoporosity of the carbon materials produced. The results showed the positive effect of increasing the process pressure on the development of a porous structure, and particularly, on the development of supermicropores and ultramicropores under the carbonization conditions applied. Carbon material with the most developed porous structure and the highest share of micropores was obtained under the maximum pressure tested.
在自然资源日益枯竭、环境负面废料量不断增加的当今世界，对各种工业活动产生的废物和副产品进行增值利用势在必行。固体生物废料的经济利用主要包括将其用作碳中性能源或多孔碳材料的前驱体，其潜在应用范围包括吸附过程、能量存储和电气工程。虽然已经测试并应用了大量木质纤维素残渣作为最合适的多孔材料前驱体，如各种农作物的木材、外壳、石头、果皮、果壳和秸秆，但对于大量其他类型生物废料的增值利用仍有进一步发展的空间和需求。在此，考虑到橄榄果渣的产量巨大及其成分在储存时对环境产生的不良（植物毒性）影响，故而对其进行研究。虽然关于各种生物废料前驱体的化学（酸处理和碱处理）和物理活化（温度、二氧化碳和/或蒸汽）的文献颇多，但碳化步骤中压力的影响鲜有报道，尽管观察到的结果很有前景。关于将橄榄果渣用于生产多孔材料的报道也是如此，这些报道表明，橄榄果渣目前似乎被低估为一种碳材料前驱体。在本研究中，基于所制备碳材料的微孔和介孔的定性和定量数据，评估了压力（0.1 - 3 MPa）、温度（800℃）和二氧化碳气氛在橄榄果渣碳化过程中的综合影响。结果表明，在所应用的碳化条件下，提高工艺压力对多孔结构的形成具有积极影响，特别是对超微孔和极微孔的形成有促进作用。在测试的最大压力下，获得了具有最发达多孔结构和最高微孔比例的碳材料。
