Foo Wei Han, Chia Wen Yi, Tang Doris Ying Ying, Koay Sherlyn Sze Ning, Lim Siew Shee, Chew Kit Wayne
School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor, Malaysia.
Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia.
J Hazard Mater. 2021 Sep 5;417:126129. doi: 10.1016/j.jhazmat.2021.126129. Epub 2021 May 16.
Waste cooking oil (WCO) is considered as one of the hazardous wastes because improper disposal of WCO can cause significant environmental problems such as blockages of drains and sewers as well as water or soil pollution. In this review, the physical and chemical properties of WCO are evaluated along with its regulations and policies in different countries to promote WCO refined biofuels. Blended WCO can be an auxiliary fuel for municipal solid waste incinerators while the heat produced is able to form superheated steam and subsequently generate electricity via combined heat and power system. Also, WCO contains high ratio of hydrogen atoms compared to carbon and oxygen atoms, making it able to be catalytically cracked, synthesizing hydrogen gas. WCO-based biodiesel has been traditionally produced by transesterification in order to substitute petroleum-based diesel which has non-degradability as well as non-renewable features. Hence, the potentials of hazardous WCO as a green alternative energy source for electricity generation, hydrogen gas as well as biofuels production (e.g. biodiesel, biogas, biojet fuel) are critically discussed due to its attractive psychochemical properties as well as its economic feasibility. Challenges of the WCO utilization as a source of energy are also reported while highlighting its future prospects.
废食用油（WCO）被视为危险废物之一，因为对废食用油处置不当会导致严重的环境问题，如排水管道和下水道堵塞以及水或土壤污染。在本综述中，对废食用油的物理和化学性质以及不同国家的相关法规政策进行了评估，以推广废食用油精炼生物燃料。混合废食用油可作为城市固体废物焚烧炉的辅助燃料，产生的热量能够形成过热蒸汽，随后通过热电联产系统发电。此外，与碳原子和氧原子相比，废食用油中的氢原子比例较高，使其能够进行催化裂解以合成氢气。传统上，基于废食用油的生物柴油是通过酯交换反应生产的，以替代具有不可降解性和不可再生特性的石油基柴油。因此，鉴于其具有吸引力的物理化学性质和经济可行性，本文对危险废食用油作为绿色替代能源用于发电、制氢以及生产生物燃料（如生物柴油、沼气、生物喷气燃料）的潜力进行了深入讨论。同时还报告了将废食用油用作能源的挑战，并突出了其未来前景。
