CO₂ as a Feedstock: Comparison of CCU Pathways

Publication Overview

The aim of this study is to present a holistic assessment of the viability (both technically and from a market perspective) of carbon capture and utilisation (CCU) routes and to identify areas of strength and weakness within individual routes, compare different CCU pathways, and identify common drivers, barriers, and enablers. The results of this study will be of interest to the technical community, as well as industry and manufacturers. The study assessed commodities across four different CCU categories (building materials, chemicals, polymers and fuels) regarding their mitigation potential, market uptake potential, technical scalability and other impacts.

Publication Summary

• Almost all CCU routes showed potential for lower life cycle emissions per tonne of product compared to their counterfactual. The potential scale for deployment was much greater for fuels and building materials than for chemicals and polymers, which typically had existing markets orders of magnitude smaller.
• For fuels, annual abatement levels greater than 1 GtCO₂-eq could be achieved for direct replacement ‘drop-in’ fuels. For building materials, annual abatement levels greater than 100 MtCO₂-eq could be achieved. CCU building materials also have potential to offer negative emissions when CO₂ is sourced from direct air capture (DAC). With the exception of methanol, the total mitigation potential of polymers and chemicals was limited to below 20 MtCO₂-eq per year.
• Most CCU routes within the chemicals and fuels categories were found to be considerably more expensive than conventional fossil-based production routes, due to high energy requirements for green hydrogen feedstock, low yields and high catalyst costs. CCU building materials and polymers can offer cost reductions.
• There are a range of potential co-benefits (e.g. re-use of waste residues, raw materials reduction, safer production process, improved product properties, energy storage) for CCU routes but there can also be trade-offs (e.g. high energy demand, additional land-use, increased water consumption).
• Deployment of CCU routes may be more favourable in regions with: (i) low-cost or extensive availability of renewable energy; (ii) high cost or lack of available fossil resources; or (iii) significant low-carbon ambition coupled with political or regulatory mechanisms. The current distribution of CCU R&D projects is concentrated mostly in the EU and the US.
• CO₂ utilisation opportunities are diverse, and each route has its own specific drivers, barriers, and enablers. There are, however, some common themes that span across, e.g.: regulations such as mandates or standards, financial provisions, policies that level the field by recognising sustainability benefits, sustainable product development, regional energy availability, costs.
• Recommendations:
       o Report sufficient data to allow for life cycle and techno-economic assessments (LCA and TEA).
       o Highlight priority areas for CCU development and identify end-uses where CCU is expected to be a necessary component of future decarbonisation pathways.
       o Engage with the public and policy makers to improve understanding of the benefits and limitations of CCU routes.
       o Increase awareness of upstream emissions in supply chains and identify opportunities to switch to more sustainable production routes.
       o Introducing support mechanisms that allow CCU to receive recognition for sustainability benefits.
       o Incorporate CCU products appropriately into existing support schemes, regulations, and product standards.
       o Provide funding for research programmes, demonstration projects etc.
       o Develop and clarify frameworks for the carbon accounting of CCU routes.