Climate change mitigation potential of carbon capture and utilization in the chemical industry

Abstract

Chemical production is set to become the single largest driver of global oil consumption by 2030. To reduce oil consumption and resulting greenhouse gas (GHG) emissions, carbon dioxide can be captured from stacks or air and utilized as alternative carbon source for chemicals. Here, we show that carbon capture and utilization (CCU) has the technical potential to decouple chemical production from fossil resources, reducing annual GHG emissions by up to 3.5 Gt CO₂-eq in 2030. Exploiting this potential, however, requires more than 18.1 PWh of low-carbon electricity, corresponding to 55% of the projected global electricity production in 2030. Most large-scale CCU technologies are found to be less efficient in reducing GHG emissions per unit low-carbon electricity when benchmarked to power-to-X efficiencies reported for other large-scale applications including electro-mobility (e-mobility) and heat pumps. Once and where these other demands are satisfied, CCU in the chemical industry could efficiently contribute to climate change mitigation.

Keywords: carbon capture and utilization; chemicals; circular economy; climate change; renewable energy.

Fig. 1.

Changes in the life cycle of established chemicals through the implementation of CCU technologies.

Fig. 2.

Mass flows within the chemical industry in (A) the conventional scenario and (B) the high-TRL scenario for CCU implementation. In both scenarios, the projected final demand for 20 large-volume chemicals in 2030 is produced. Note, mass flows are scaled differently in the conventional and the high-TRL scenario. The mass flows of the final demand (on the Right) are identical.

Fig. 3.

Cradle-to-grave and cradle-to-gate GHG emissions of the chemical industry producing the final demand for 20 large-volume chemicals in 2030 as function of the carbon footprint of electricity. Cradle-to-grave emissions include all emissions throughout the life cycles of the 20 large-volume chemicals, while cradle-to-gate emissions cover only the production stage and the supply of all raw materials and energy needed for production. The vertical dashed lines illustrate the climate impact of grid electricity in selected countries or of electricity from selected renewable energy technologies.

Fig. 4.

Cradle-to-grave and cradle-to-gate GHG emissions for the chemical industry in the low-TRL scenario producing the final demand for 20 large-volume chemicals in 2030 as function of the amount of additional electricity available and its carbon footprint in grams of CO₂ equivalent/kilowatt hour. Cradle-to-grave emissions include all emissions throughout the life cycles of the 20 large-volume chemicals, while cradle-to-gate emissions cover only the production stage and the supply of all raw materials and energy needed for production. The black solid line represents the GHG emissions in the conventional scenario. The light gray lines illustrate potential GHG emission reductions by using the additional electricity for e-mobility to substitute gasoline or diesel cars, or for heat generation in a heat pump or an e-boiler to substitute heat from natural gas boilers.