Realizing the Potential High Benefits of Circular Economy in the Chemical Industry: Ethylene Monomer Recovery via Polyethylene Pyrolysis

Abstract

The concept of the circular economy has gained wide interest in industry as a powerful strategy to reduce impacts while remaining economically competitive. Here we explore the benefits of this approach in the chemical industry, quantifying explicitly the economic and environmental benefits of ethylene recovery from polyethylene plastics using process modeling coupled with Life Cycle Assessment (LCA). Our results show that the recovered ethylene represents a win-win alternative, offering a highly competitive cost of 0.386 €/kg vs 0.835 €/ kg with the standard naphtha-based route. Furthermore, substantial reductions of as much as 87%, 89% and 164% could also be attained (compared to the naphtha-based ethylene) in impacts on human health, ecosystem quality and resources scarcity, respectively.Overall, this work aims to promote the adoption of circular economy strategies in the chemical sector, while highlighting the role of process modeling, LCA and systems thinking in quantifying the associated benefits to build strong cases for policymaking.

Quantifying Energy and Greenhouse Gas Emissions Embodied in Global Primary Plastic Trade Network

“…Recycled plastic resins have been shown to have lower embodied energy and emissions than virgin resins. − Increasing access to the material recovery infrastructure and advancing recycling technology is a key strategy to reduce both plastic pollution and embodied impacts associated with virgin plastics. New technologies capable of chemically recycling plastics to recover monomers in an economic and environmentally promising manner have been proposed and deemed technically feasible. − However, success in chemically recycling plastics requires high rates of recycling and subsequent recovery to take advantage of economies of scale and become cost-competitive with virgin plastic production. Improvements to collection and sorting infrastructure are necessary to provide sufficient quantities of clean input plastics to justify implementation of chemical recycling technologies.…”

Economic and Environmental Assessment of Plastic Waste Pyrolysis Products and Biofuels as Substitutes for Fossil-Based Fuels

“…These stem from intense land usage, water consumption and the use of fertilizers for harvesting energy crops. A significant amount of global warming impact comes from dinitrogen monoxide (N 2 O) emissions that have a 298 times higher greenhouse gas effect than CO 2 (Solomon et al, 2007). First-generation fuel feedstock in principle entails an additional carbon debt from cutting down forests and grasslands that act as carbon storage, which will eventually be released over a period of time.…”

Synthesis and Assessment of Waste-to-resource Routes for Circular Economy

“…Thus, waste accumulation and resources depletion concerns are set to grow in the next years due to the lack of effective and efficient resource and waste management policies in most countries worldwide. The chemical recycling of plastics offers a solution through more efficient waste management and material upcycling, leading to economic and environmental benefits ( Jeswani et al, 2021 ;Martín et al, 2020 ;Somoza-Tornos et al, 2020b ).…”

“…Operational costs are also estimated yearly and then both are added up to obtain a total production annual cost, which is converted to unitary costs dividing by the annual waste treatment capacity. The data and procedure for these estimations are taken from Somoza-Tornos et al (2021, 2020b, where the cost estimation is based on Sinnott and Towler (2020) .…”