National Technical University of Athens, School of Chemical Engineering, Unit of Environmental Science & Technology, 9 Iroon Polytechniou Str., Zographou Campus, GR-15780 Athens, Greece.
National Technical University of Athens, School of Chemical Engineering, Unit of Environmental Science & Technology, 9 Iroon Polytechniou Str., Zographou Campus, GR-15780 Athens, Greece.
Chemosphere. 2022 Jun;296:133970. doi: 10.1016/j.chemosphere.2022.133970. Epub 2022 Feb 14.
Biofuels are a research field of great interest given the environmental benefits they offer over conventional fossil fuels. Nowadays, it is urgent to find ways of utilizing waste in the direction of biofuels production. The aim of this paper was the utilization of green waste (branches, leaves and ligno-cellulosic residues from tree prunings, hedge cuttings and grass clippings) towards biofuels production and specifically towards bioethanol and biogas. The experimental plan that was followed included biogas production through anaerobic digestion and bioethanol production through alcoholic fermentation after the necessary chemical pretreatment (acid or alkaline hydrolysis) prior to enzymatic hydrolysis and fermentation. Based on the results obtained, three valorisation scenarios of green waste were designed and compared in terms of product mass intensity, product yield and energy content of biofuels produced. The optimal results for bioethanol production were 5.22 g/L ethanol, 70.61% saccharification yield and 33.67% ethanol yield with acid pretreatment using HSO 3% w/v, 475 μL/g cellulose CellicCtec2 and 10% solids loading. Regarding biogas, the highest biogas production observed was 267.1 mL biogas/g dry substrate resulting from anaerobic digestion of the alkaline stillage. Thus, the production of biofuels from green waste is technically feasible, although it provides moderate efficiencies. However, for a sustainable valorisation of green waste, other techno-economic factors such as the cost of enzymes, chemicals, energy, etc. must be taken into account.
鉴于生物燃料相对于传统化石燃料具有环境优势，因此它是一个极具研究价值的领域。如今，寻找利用废物生产生物燃料的方法迫在眉睫。本文旨在利用绿色废物（树枝、树叶和树木修剪、树篱修剪和草屑的木质纤维素残余物）生产生物燃料，特别是生物乙醇和沼气。所遵循的实验计划包括通过厌氧消化生产沼气，以及通过必要的化学预处理（酸或碱水解）进行酶解和发酵之前，通过酒精发酵生产生物乙醇。根据获得的结果，设计了三种绿色废物的增值方案，并根据产品质量强度、产品产率和生物燃料的能量含量对其进行了比较。使用 3% w/v 的 HSO 3 、475 μL/g 纤维素的 CellicCtec2 和 10%的固体负荷进行酸预处理时，生物乙醇生产的最佳结果为 5.22 g/L 乙醇、70.61%的糖化产率和 33.67%的乙醇产率。至于沼气，从碱性酒糟的厌氧消化中观察到的最高沼气产量为 267.1 mL 沼气/g 干基质。因此，从绿色废物生产生物燃料在技术上是可行的，尽管其效率适中。然而，为了实现绿色废物的可持续增值，还必须考虑其他技术经济因素，如酶、化学品、能源等的成本。
