How Waste Cooking Oil Became an Underground Resource for Cities Recycled heavy oil made from waste cooking oil (Showa Shell Sekiyu K.K., 1990s)

How Waste Cooking Oil Became an Underground Resource for Cities Recycled heavy oil made from waste cooking oil (Showa Shell Sekiyu K.K., 1990s)
In Japan in the 1990s, the expansion of the restaurant industry and the spread of deep-frying at home generated a large amount of waste cooking oil, much of which was incinerated or improperly disposed of. The amount of waste oil from restaurants reached several hundred thousand tons per year, causing social problems such as soaring disposal costs, tight final disposal sites, clogged sewers, and illegal dumping. At this time, interest in global warming was growing rapidly, and there was a need for resource-recycling energy sources that would reduce dependence on fossil fuels.
Under these circumstances, Showa Shell Sekiyu K.K. promoted an initiative to refine waste cooking oil and recycle it as recycled heavy oil. The recovered waste oil contains many impurities such as food residues and water, so it undergoes a process of heating, dehydration, filtration, and chemical treatment to improve its combustibility and viscosity and make it a fuel that can be used in factory boilers and other equipment. This technology links waste treatment and energy supply, and the CO2 emitted during combustion is considered carbon neutral due to the characteristics of biologically-derived oils and fats, thus contributing to both waste reduction and global warming countermeasures.
In addition, a resource circulation model was formed in the region through the creation of a network for collecting waste cooking oil in cooperation with local governments and restaurants. These technologies and demonstrations later became the foundation for the spread of biodiesel fuel (BDF) throughout Japan and led to the reevaluation of waste oil from urban life as a new resource.