Utilization of CO2 intends to close the carbon cycle in order to reduce both greenhouse gas emissions (GHG) and depletion of fossil resources. However, while intuition may suggest environmental benefits of CO2 utilization, these benefits cannot be taken for granted and an environmental assessment is required. Environmental benefits have already been identified for utilization of CO2 in polyols for polyurethane production . However, the potential to utilize CO2 for polyurethanes goes beyond direct CO2 utilization in polyols: CO2 can also be used indirectly for basic chemicals in the polyurethane supply chain.
In this work, we therefore systematically explore the environmental potential of all direct and indirect CO2 utilization options for flexible and rigid PUR foams. The analysis is based on an LCA-based PUR supply chain optimization model using linear programming to identify PUR production with minimal environmental impacts.
The presented analysis shows that it is not environmentally optimal to utilize as much CO2 as possible in the PUR supply chain. We also demonstrate that the full CO2 utilization potential for environmental impact reduction can be exploited if hydrogen production becomes more environmentally friendly. The systematic analysis framework presented thus identifies routes towards more sustainable polyurethanes.
 N. von der Assen and A. Bardow, Green Chem., 2014, 16, 3272–3280.