Harisankar S, Prashanth P Francis, Nallasivam Jeganathan, Vinu R
Department of Chemical Engineering and National Center for Combustion Research and Development, Indian Institute of Technology Madras, Chennai, 600036 India.
Biomass Convers Biorefin. 2022 May 23:1-15. doi: 10.1007/s13399-022-02793-7.
Refuse-derived fuels (RDF) are rich in resources that make them an attractive feedstock for the production of energy and biofuels. Hydrothermal liquefaction (HTL) is a promising thermochemical conversion technology to handle wet feedstocks and convert them to valuable bio-crude, bio-char and aqueous products. This study highlights the advantages of using glycerol as the co-solvent along with water in different proportions to produce bio-crude from RDF via HTL. The ratio of water:glycerol (vol.%:vol.%) was varied for each experiment (100:0, 90:10, 80:20, 70:30, 60:40, 50:50), and the product yields and their quality were studied. The results demonstrate that increasing the proportion of glycerol until 50 vol.% in the solvent enhances the bio-crude yield (36.2 wt.%) and its higher heating value (HHV) (30.9 MJ kg). Deoxygenation achieved in the bio-crude was 42%. The production of bio-char was minimum (9.5 wt.%) at 50 vol.% glycerol with HHV of 31.9 MJ kg. The selectivity to phenolic compounds in the bio-crude increased, while that of cyclic oxygenates decreased when the glycerol content was more than 20 vol.%. The gas-phase analysis revealed that the major deoxygenation pathway was decarboxylation. The yield of aqueous products drastically increased with the addition of glycerol. The minimum amount of glycerol in the co-solvent that favours an energetically feasible process with low carbon footprint is 30 vol.%. Using 50 vol.% glycerol resulted in the highest energy recovery in the bio-crude and bio-char (80%), the lowest energy consumption ratio (0.43) and lowest environmental factor (0.1). The mass-based process mass intensity factor, calculated based on only bio-crude and bio-char as the valuable products, decreased with an increase in addition of glycerol, while it was close to unity when the aqueous phase is also considered as a valuable product.
垃圾衍生燃料（RDF）富含资源，这使其成为生产能源和生物燃料的有吸引力的原料。水热液化（HTL）是一种很有前景的热化学转化技术，可用于处理湿原料并将其转化为有价值的生物原油、生物炭和水性产物。本研究强调了在不同比例下将甘油与水作为共溶剂用于通过HTL从RDF生产生物原油的优势。每个实验中，水与甘油的比例（体积%:体积%）各不相同（100:0、90:10、80:20、70:30、60:40、50:50），并对产物产率及其质量进行了研究。结果表明，在溶剂中甘油比例增加至50体积%时，生物原油产率（36.2重量%）及其高热值（HHV）（30.9兆焦/千克）会提高。生物原油中的脱氧率达到42%。在甘油含量为50体积%时，生物炭产量最低（9.5重量%），HHV为31.9兆焦/千克。当甘油含量超过20体积%时，生物原油中酚类化合物的选择性增加，而环状含氧化合物的选择性降低。气相分析表明，主要的脱氧途径是脱羧反应。随着甘油的添加，水性产物的产率急剧增加。共溶剂中有利于实现低能耗、低碳足迹的能量可行过程的甘油最小含量为30体积%。使用50体积%的甘油可使生物原油和生物炭中的能量回收率最高（80%），能量消耗比最低（0.43），环境因子最低（0.1）。仅基于生物原油和生物炭作为有价值产物计算的基于质量的过程质量强度因子随甘油添加量的增加而降低，而当水相也被视为有价值产物时，该因子接近1。
