Achieving plastics with net-zero emissions

Combining “circular” technologies including recycling, biomass processing, and carbon dioxide  capture could offer a way to produce plastics with net-zero greenhouse gas (GHG) emissions, according to a new study. The production of plastics – one of the most ubiquitous human-made materials – currently accounts for 6% of global oil consumption and is expected to rise to nearly 20% within the next 30 years. Thus, to meet global climate targets, achieving net-zero GHG in the plastics economy is critically important. Proposed strategies to mitigate GHG in the lifecycle of plastics include decarbonization of the plastics supply chain and the implementation of circular technologies that reuse fossil carbon feedstock, such as chemical and mechanical recycling, biomass utilization, and carbon capture and utilization (CCU). However, while a great deal of research has focused on finding more sustainable building blocks for next-generation plastics, mitigating the lifecycle greenhouse gas emissions of current-generation plastics using circular technologies is often perceived as being energy-intensive and costly. Here, Raoul Meys and colleagues present a bottom-up model for plastics production and waste treatment based on more than 400 technology datasets representing the lifecycle of more than 90% of global plastics. Using this model, Meys et al. project five different pathways for lifecycle GHG emissions of plastics in the year 2050. The findings show that by combining recycling, biomass utilization, and CCU, net-zero GHG emission plastics could be achieved with lower energy demands and lower operational costs than those associated with current fossil-fuel based production technologies combined with carbon capture and storage. According to the authors, realizing the full cost-saving potential of $288 billion requires a low-cost supply of renewable biomass and CO₂, a high-cost supply of oil, and policies that incentivize large-scale recycling and lower investment barriers for technologies that use renewable carbon feedstock.