The photo is sourced from enerkem.com
Agricultural crops still remain the most popular feedstock for bioethanol production. “In our region, the gasoline include about 10% ethanol produced from corn wheat and rice as they have been stored more than 5 years,” points out Li Feng, Professor at China University of Science and Technology and a Global Energy Association expert. Waste, he said, is used rather for fertiliser production than energy. “Household waste is of a low calorific value, and it produces toxic substances while burning. In China, I think it is less than 1% that is used for energy purposes,” the professor said. An exception is used sunflower oil collected in the catering segment.
To prove household waste suitability for bioethanol production, the Enerkem proposed a multi-stage process of recycling. Initially, the waste is sorted so that to exclude recyclable waste, as well as inert materials – crushed stone, sand and expanded clay, which are used in construction. The sorted waste is thoroughly shredded and then subjected to high-temperature treatment to get raw syngas with the key components – carbon monoxide and hydrogen – that are the building blocks in a number of important chemical processes. Raw syngas is purified and conditioned at the next stage, and finally converted into liquid methanol or fuel ethanol.
The Enerkem has tested its technology at the plant in Edmonton, Canada, commissioned in 2017, for production of biomethanol and cellulosic ethanol derived from plant fiber. The facility receives 100,000 tons of municipal solid waste annually as feedstock, through an agreement with the City of Edmonton. Both Canadian and the U.S. regulators have approved Ethanol from this production site. The U.S. Environmental Protection Agency issued a permit in 2017 as part of the Renewable Fuel Standard Program, which has been in effect in the U.S. since 2006. The program sets a minimum threshold for cellulosic and biomass-based biofuels each year: from 4 billion gallons in 2006 to 36 billion gallons in 2022 (with the U.S. gasoline demand of 138 billion gallons, according to the Energy Information Administration forecast for 2022).
The Enerkem’s development seems to be used at three new facilities in the coming years: in Quebec, Canada, where the first stage of the new plant is to be commissioned in 2023, in Rotterdam and the city of Tarragona, northeastern Spain. The Rotterdam project is implemented with the participation of Shell, and in Tarragona – with the Repsol, Spain, planning to increase the capacity of biofuel production from 0.7 million tons last year to 1.3 million tons in 2025 and 2 million tons in 2030. Large companies are interested in the new technology because it makes possible elimination of indirect environmental damage associated with conventional ethanol production requiring large agricultural areas for growing feedstock.