Materials and energy recovery at six European MBT plants

Mechanical Biological Treatment (MBT; called dirty Materials Recovery Facilities in the U.S.) is a waste management method, developed mostly in Europe, which combines sorting of recyclable materials (metals, paper, plastics, glass) with composting/digestion of green/ food wastes and, in some cases production of a fuel material. In 2018-19, the authors visited six MBT facilities in Europe that use different approaches for the recovery of materials and energy from mixed MSW. These plants were studied with respect to feedstock composition, operating conditions, capital expenditure, financial viability and environmental impacts. The compost product of most facilities examined did not comply with agricultural standards and, therefore, it was classified as compost-like output (CLO) and used as daily cover in landfills. The best composting practice used source separated organic materials (yard and other green wastes) and yielded a marketable compost. MBT plants that did not include the recovery of fuel materials had lower landfill diversion rates and, also, lower capital and operating costs. It was concluded that an MBT plant must include a very efficient sorting and recyclables recovery line and charge a sufficient gate fee. Also, in addition to the recycled products, there should be a stream to recover fuel materials sent to a power plant or cement plant, thus increasing revenue, and landfill diversion, and maximizing greenhouse gas (GHG) savings.

Automated summary

Mechanical Biological Treatment (MBT) is a waste management method that combines sorting of recyclable materials with composting/digestion of green/food wastes and, in some cases, production of fuel materials. The authors visited six MBT facilities in Europe and found that the compost product of most facilities did not meet agricultural standards. MBT plants without fuel material recovery had lower landfill diversion rates and costs. Therefore, an efficient sorting and recyclables recovery line, sufficient gate fee, and fuel material recovery process are necessary for a successful MBT plant to increase revenue and reduce greenhouse gas emissions.