Valorization of municipal solid waste in biorefineries for the creation of a circular economy: Role of emerging technologies

The increase in the generation of municipal solid waste (MSW) is a pressing challenge worldwide. Development of new management, business models, and technology paradigms to create a circular sustainable economy is among the most challenging and fascinating problems of our generation. Currently, most of the MSW around the world is processed/disposed of via landfill and incineration, although recycling and upcycling are expected to grow in the years to come. There is a growing number of countries composting the organic fraction of MSW to produce soil amendments, but these processes tend to be costly and result in products with low added value. In most places, business models for MSW management are based on a majority of revenue coming from tipping fees, with little monetary contribution coming from the selling of products (energy, soil amendments, methane). To better manage MSW, the development of a new business model, forms of management, and technological paradigms are needed. The innovation in new policies and business models for MSW management is likely to result in economic growth, and importantly, sustainability. This chapter focuses on the need for creating a circular economy around MSW recycling. We will examine some emerging technologies (anaerobic digestion, hydrothermal liquefaction, wet oxidation, pyrolysis, hydrocracking, and gasification) and discuss how these technologies could play into novel biorefineries concepts for processing of MSWs. Although this chapter is focused on the role of centralized biorefineries in the creation of a circular economy and its primary benefits, other significant and beneficial phenomena occur with circular companies (closing of the carbon loop). The chapter concludes that there are important synergistic opportunities for coprocessing MSW, forest, and agricultural wastes in biorefineries formed by these emerging technologies.