Chapter 11 - Waste feedstocks for sustainable chemicals and fuels

Abstract

Abstract The energy transition toward more sustainable production systems is currently one of the most urgent goals of the worldwide community. Carbon footprint reduction within main industry sectors may be achieved by implementing carbon capture and utilization technology as well as by substituting conventional fossil feedstock with more sustainable ones. In this scenario, the circular economy model promoting the reuse of material instead of the disposal would allow for a better use of resources and energy. Wastes having a high heating value, in particular municipal solid waste, refuse-derived fuel, and plastic waste, may be considered a precious source of carbon to be used in substitution of conventional fossil sources. Through a gasification technology working under a high-temperature and pure oxygen environment, waste may be converted into a syngas rich in H2 and CO and thus suitable to work as intermediate of a new green chemistry model. Sustainable production of chemicals such as biomethanol, bioethanol, biomethane, as well as biopolymers may be achieved from waste sources once properly converted into syngas. The waste-to-chemical approach is a valid alternative to the waste-to-energy route, allowing for a reuse of carbon into a useful end product instead of downgrading to diluted CO2 discharged as flue gas. The synergy between two different industries, waste management and the chemical industry, may account for a strategic solution in line with the principles of a circular economy and is sustainable from technical and economical points of view, as shown by two case studies here analyzed.