88 J. Jpn. Inst. Energy, Vol. 101, No. 5, 2022 Efect of Reaction Temperature on Biocrude Yield from Hydrothermal Liquefaction of Rice Husk Mohammad Kaneshka P AKZAD ※1※2 , Tofael AHAMED ※3 , and Ryozo NOGUCHI ※4† (Received February 10, 2021) The annual production of rice husk worldwide is 134 Tg (134 million tons). However, rice husk is one of the least used biomasses. Rice husk can be converted to the bio-crude in a batch reactor through hydrothermal liquefaction; the efect of reaction temperature on the yield of the bio-crude was investigated herein. We ran the experiment at three diferent temperatures (350, 300, and 250 °C) with a holding time of 60 min. The highest bio- crude yield of 0.693 kg/kg-dry was obtained at 250 °C. However, the bio-crude obtained at 300 °C had HHV of 17.98 MJ/kg. Furthermore, we attempted to extract crude oil from bio-crude using chloroform/methanol solvent at a ratio of 2:1. The highest crude oil yield of 0.222 kg/kg-dry was obtained from the bio-crude produced at 300 °C. Additionally, the production of hydro-char from bio-crude after crude oil extraction was evaluated. The results show that the highest hydro-char yield (0.611 kg/kg-dry) was produced at 250 °C. Key Words HTL, Biocrude, Rice husk, Crude oil, Hydro char ※1 Graduate School of Life and Environmental Sciences, University of Tsukuba 1-1-1, Tennodai, Tsukuba-shu, Ibaraki 305-8572, Japan ※2 Ministry of Agriculture, Irrigation, and Livestock, Directorate of Agricultural Mechanization, Afghanistan ※3 Faculty of Life and Environmental Sciences, University of Tsukuba 1-1-1, Tennodai, Tsukuba-shu, Ibaraki 305-8572, Japan ※4 Faculty of Life and Environmental Sciences, University of Tsukuba (Present affiliation: Laboratory of Agricultural Systems Engineering, Division of Environmental Science and Technology, Graduate School of Agriculture, Kyoto University) †Corresponding author: noguchi.ryozo.8j@kyoto-u.ac.jp Journal of the Japan Institute of Energy , 101 , 88-94（2022） Technical Paper 1.　Introduction The dominant global energy supply has been fossil fuel since the industrial revolution. The primary energy sources are thus coal, oil, and gas. However, the direct energy supply by coal, oil, and natural gas has increased by 65 %, 22 %, and 50 % since 2000, respectively, while the use of renewable energy has increased by 48 % over the same period. Bioenergy is the largest energy source among all renewable energy sources, accounting for 70 % of all renewable energy utilization in 2017 1) . Moving toward renewable energy resources is a viable option for reducing greenhouse gas emissions. Biomass is the only source of organic carbon and an environmentally friendly equivalent to fossil fuels. Energy crops, wood wastes, aquatic plants, crops, their waste products, and municipal and animal wastes are referred to as biomass sources 2) . One of the most abundant non-edible organic resources is lignocellulosic biomass, which is a promising renewable energy source to meet future demands 3) . The conversion of biomass to biofuel integrates with many processes and technologies, and it requires the efcient utilization of all biomass components to make it economically feasible 4) . Based on the International Renewable Energy Agency (IRENA) global renewable energy roadmap, renewable energy accounts for 36 % of the world energy mix by 2030 if all potential renewable energy technologies are implemented. This amount is double the renewable energy share of 2010 5) . Rice is a staple food that forms the main diet of a large population worldwide, especially in Asian countries, making rice the most consumed cereal crop. The processing of paddy rice generates husk, an agricultural waste, that is difficult to dispose of in an environmentally friendly manner 6) . The production of rice is approximately 758.6 Tg (758.6 million tons) each year globally. Rice husk forms 20 % of the rice paddy, which means 152 Tg (152 million tons) The content of this paper was presented at the 8th Asian Conference on Biomass Science