The Impact of Feedstock Availability on Defossilizing the Production of Chemical Building Blocks

Abstract

Alternative carbon sources (ACSs) such as CO2, biomass, and plastic waste can be used to defossilize chemical building blocks (CBBs) such as methanol, olefins, and aromatics. While the existing literature estimates the quantities of ACSs to replace fossil fuel in specific processes, hubs, or areas, this work adds to the current state of the art by evaluating the impact of ACS feedstock availability on the portfolio of technologies that can be deployed to defossilize an existing petrochemical cluster. A superstructure-based multiobjective optimization model of the Port of Rotterdam was run with eight novel ACS-based processes to evaluate the impact of defossilizing CBB production. The paper explicitly evaluates the performance of the cluster using the following performance indicators: amount of feedstock use, byproduct production, CAPEX, electricity demand, water demand, and change in the minimum selling price of the products. Three cases are analyzed: the fossil-based cluster and two cases, one with unlimited and one with limited feedstock availability. The results show that if feedstocks are considered unlimited, plastic waste-based pyrolysis, methanol-to-olefin, and methanol-to-aromatics routes appear to be the most promising technologies. However, when feedstock constraints are included in the model, a combination of ACS and fossil-based technologies is required to meet product demand, and the level of defossilization significantly decreases. This research underscores the critical need to balance technological choices and realistic assessments of ACS feedstock availability to ensure a sustainable and economically viable transition of the chemical industry.