Integrated Assessment of the Leading Paths to Mitigate CO<sub>2</sub> Emissions from the Organic Chemical and Plastics Industry
Wade E. Fritzeen, Patrick O’Rourke, Jay Fuhrman, Lisa M. Colosi, Sha Yu, William Shobe, Scott C. Doney, Haewon McJeon, Andrés F. Clarens
Abstract
The chemical industry is a major and growing source of CO 2 emissions. Here, we extend the principal U.S.-based integrated assessment model, GCAM, to include a representation of steam cracking, the dominant process in the organic chemical industry today, and a suite of emerging decarbonization strategies, including catalytic cracking, lower-carbon process heat, and feedstock switching. We find that emerging catalytic production technologies only have a small impact on midcentury emissions mitigation. In contrast, process heat generation could achieve strong mitigation, reducing associated CO 2 emissions by ∼76% by 2050. Process heat generation is diversified to include carbon capture and storage (CCS), hydrogen, and electrification. A sensitivity analysis reveals that our results for future net CO 2 emissions are most sensitive to the amount of CCS deployed globally. The system as defined cannot reach net-zero emissions if the share of incineration increases as projected without coupling incineration with CCS. Less organic chemicals are produced in a net-zero CO 2 future than those in a no-policy scenario. Mitigation of feedstock emissions relies heavily on biogenic carbon used as an alternative feedstock and waste treatment of plastics. The only scenario that delivers net-negative CO 2 emissions from the organic chemical sector (by 2070) combines greater use of biogenic feedstocks with a continued reliance on landfilling of waste plastic, versus recycling or incineration, which has trade-offs.