Abstract:
The main objective of this study was to prepare a series of biochars and activated biocarbons via conventional pyrolysis as well as chemical or physical activation of solid residue after solvent extraction of wild growing plant (popular weed)-mugwort. The influence of the variant of the thermochemical treatment of the precursor on such parameters as elemental composition, textural parameters, acidic-basic character of the surface as well as adsorption abilities of the prepared carbonaceous materials was checked. Moreover, the suitability of the biochars prepared as renewable fuels was also investigated. It has been shown that the products obtained from the mugwort stems differ in many respects from the analogous materials obtained from mugwort leaves. The products were micro/mesoporous materials with surface area reaching 974.4 m2/g and total pore volume-1.190 cm3/g. Surface characterization showed that chemical activation with H3PO4 results in the acidic character of the adsorbents surface, whereas products of pyrolysis and especially physical activation show strongly alkaline surface properties. All the adsorbents were used for methylene blue and iodine adsorption from the aquatic environment. To understand the nature of the sorption process, the Langmuir, Freundlich and Temkin isotherm models were employed. The Langmuir model best described the experimental results, and the maximum sorption capacity calculated for this model reached 164.14 mg of methylene blue per gram of adsorbent. In case of iodine removal, the maximum capacity reached 948.00 mg/g. The research carried out for the biochars prepared via conventional pyrolysis showed that the value of their heat of combustion varies in the range from 21.74 to 30.27 MJ/kg, so they can be applied as the renewable fuels.
摘要:
本研究的主要目的是通过常规热解制备一系列生物炭和活化的生物碳,以及在对野生生长植物(流行杂草)-艾草进行溶剂萃取后对固体残留物进行化学或物理活化。前体的热化学处理的变化对元素组成等参数的影响,纹理参数,检查了表面的酸性-碱性特性以及所制备的碳质材料的吸附能力。此外,还研究了作为可再生燃料制备的生物炭的适用性。已经表明,从艾叶获得的产品在许多方面与从艾叶获得的类似材料不同。产物是微/介孔材料,其表面积达到974.4m2/g,总孔体积为1.190cm3/g。表面表征表明,H3PO4的化学活化导致吸附剂表面的酸性特征,而热解产物,尤其是物理活化产物表现出强碱性的表面性质。所有吸附剂均用于从水生环境中吸附亚甲基蓝和碘。要了解吸附过程的性质,Langmuir,采用Freundlich和Temkin等温线模型。Langmuir模型最好地描述了实验结果,该模型计算的最大吸附容量达到每克吸附剂164.14毫克亚甲基蓝。在碘去除的情况下,最大容量达到948.00mg/g。对通过常规热解制备的生物炭进行的研究表明,它们的燃烧热值在21.74至30.27MJ/kg的范围内变化,所以它们可以用作可再生燃料。