Doczekalska Beata, Bartkowiak Monika, Waliszewska Bogusława, Orszulak Grażyna, Cerazy-Waliszewska Joanna, Pniewski Tomasz
Institute of Chemical Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 38/42, 60-637 Poznań, Poland.
Institute of Plant Genetics of the Polish Academic of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland.
Materials (Basel). 2020 Apr 2;13(7):1654. doi: 10.3390/ma13071654.
Lignocellulosic biomass, including that of energy crops, can be an alternative source to produce activated carbons (ACs). Miscanthus and switchgrass straw were used to produce ACs in a two-step process. Crushed plant material was carbonized at 600 °C and then obtained carbon was activated using NaOH or KOH at 750 °C. The content of surface oxygen groups was determined using Boehm's method. The porosity of ACs was assayed using the nitrogen adsorption/desorption technique, while their thermal resistance using the thermogravimetric method. The ACs derived from miscanthus and switchgrass were characterized by surfaces rich in chemical groups and a highly developed porous structure. The highest specific surface areas, over 1600 m/g, were obtained after carbon treatment with NaOH. High values of iodine number, 1200-1240 mg/g, indicate an extensive system of micropores and their good adsorption properties. The type of activator affected the contents of oxygen functional groups and some porosity parameters as well as thermal stability ranges of the ACs. Among obtained carbons, the highest quality was found for these derived from followed by switchgrass, after activation with NaOH. Hence, while these crop species are not as effective biomass sources as other energy grasses, they can become valuable feedstocks for ACs.
木质纤维素生物质，包括能源作物的生物质，可作为生产活性炭（AC）的替代来源。芒草和柳枝稷秸秆通过两步法用于生产活性炭。将粉碎的植物材料在600℃碳化，然后将所得碳在750℃用氢氧化钠或氢氧化钾活化。使用 Boehm 法测定表面氧基团的含量。用氮气吸附/脱附技术测定活性炭的孔隙率，用热重法测定其热阻。源自芒草和柳枝稷的活性炭的特点是表面富含化学基团且具有高度发达的多孔结构。用氢氧化钠进行碳处理后，获得了最高比表面积，超过1600 m²/g。碘值高，为1200 - 1240 mg/g，表明存在广泛的微孔体系及其良好的吸附性能。活化剂的类型影响了活性炭的氧官能团含量、一些孔隙率参数以及热稳定性范围。在所得碳中，经氢氧化钠活化后，源自芒草的活性炭质量最高，其次是柳枝稷。因此，虽然这些作物物种作为生物质来源不如其他能源草有效，但它们可以成为生产活性炭的有价值原料。
