Using trash as a fuel source is not a new concept, especially to those of us in the waste management industry. There are incinerators, digesters, biomass reactors of every sort, and even some facilities that can convert plastic back into petroleum. But many of these technologies are limited by what types of waste they can convert into renewable energy or products. Some can only process organics, while others can only handle recyclable materials. Others require extensive regulation and ventilation systems in order to ensure no toxic substances are emitted by the energy conversion process.
But there is another type of waste-to-energy that is seldom heard of outside of the clean tech industry: gasification. You may recall that we discussed gasification systems in a previous post highlighting the Air Force’s use of a plasma gasification system at the Hurlburt Air Force Base in Florida. That system in particular was designed to be self-sufficient, providing only as much energy output as needed to power the facility’s operations. But now there is a new gasification system being built in Edmonton, Canada that will take the concept of disintegrating waste to the next level.
Montreal-based Enerkem is building a commercial-scale gasification system that can process 15 different categories of waste into renewable electricity, biofuels, and petrol-based products. Enerkem’s new plant utilizes non-recyclable waste, such as shoes and furniture, as a feedstock for its gasification reactor. This reactor uses high heat and pressure to break down the feedstock into its constituent molecules, resulting in a primary gas blend of hydrogen and carbon monoxide. These gases are then mixed with steam to produce a synthetic gas that is converted to methanol, a base chemical that can be synthesized into fuel additives or other petroleum products.
The entire process is very similar to the way other plants work, but Enerkem’s system is unique in that it uses significantly lower temperatures and pressures to achieve the gasification process. This results in lower capital and operating costs, making their technology appealing to many cities that are trying to reduce their waste streams, while also looking for renewable energy sources.
The Alberta plant is expected to produce 10 million gallons of ethanol per year which will be sold as a fuel additive for vehicles. In total, the facility will be able to divert 100,000 metric tons of municipal solid waste a year, boosting Edmonton’s landfill diversion rate from 60% to 90%. Currently, Enerkem plans to build a similar facility in Mississippi, though the plant remains in the development stage.
Source: The Guardian