Waste to Methanol (WtM) is an innovative technology where urban waste and non-recyclable plastic are converted into methanol through a process architecture based on high temperature gasification, syngas purification and conditioning up to methanol synthesis. The WtM process allows to produce methanol with a reduction of greenhouse gas emissions of more than 35% with respect to methanol production from fossil fuels. Eni evaluated this technology as a new potential circular economy project and studied together with NextChem, process licensor, a potential application within an existing Eni Refinery industrial area for a sustainable integration / reconversion of a brown field. This article reviews the results of the basic design study, highlighting main aspects characterizing the core technology and relevant synergies with existing refinery. The plant is designed for a production capacity of 100,000 tons/year of methanol, starting from a mix of approximately 193,000 tons/year of urban solid waste (CSS) and non-recyclable plastic (PLASMIX). Main process section is the gasification unit, where feedstock is converted into a syngas rich in H2 and CO and a vitrified inert material through a converter working under pure oxygen environment. All the impurities coming from waste feedstock are deeply removed from the syngas through a proper architecture based on adsorbent and catalyst beds while a condition step accounts for a proper H2/CO ratio according to methanol synthesis requirements. Main target of basic design study has been the techno-economics evaluation of the project once defined utilities consumption, maximized the use of existing facilities in the refinery and defined the new ones to be installed.
Waste generation, and resource consumption, are increasing dramatically as the world's population grows; hence the surge of the idea of a "circular economy", where products are made, used and re-used, rather than being discarded into a landfill. However, most of the systems needed to achieve circularity are not yet in place - or even designed.
