CCUS is a rapidly emerging industry that will play a key role in corporate decarbonization strategies. According to global growth consulting firm Sullivan, the CCUS market is expected to grow significantly at a compound annual growth rate (CAGR) of 49.7% from 2022 to 2030. By 2030, revenues are projected to reach $42.48 billion, and by 2034, revenues may peak at $45.21 billion.
The high-value utilization of CO2 after capture is a crucial step in enhancing the value of CO2. Polymers are high-value products, and the process of converting CO2 into high-molecular-weight polymers through catalysts or other means adds value to the CO2 supply chain, creating an environmentally friendly and sustainable development path.
The diagram below summarizes the most promising CO2-to-polymer pathways:
I. Overview of Key Pathways
1. Catalytic Conversion
• CO2 is catalytically reacted with extracts to produce intermediate products, eventually generating polymers such as polyesters, polyureas, and non-isocyanate polyurethanes (NIPU).
• CO2 reacts with epoxides (such as ethylene oxide, propylene oxide, etc.) under the action of catalysts to undergo polymerization, resulting in aliphatic polycarbonates or polyalkylene carbonates (PAC).
• CO2 reacts with epoxides or alcohols to catalytically synthesize polyols, which, when reacted with isocyanates, can form polyurethanes.
• CO2 and H2 are catalytically converted into syngas, which is further transformed into polyolefins through Fischer-Tropsch synthesis. Polyolefins are widely used polymers, including polyethylene (PE) and polypropylene.
2. Hydrogenation Pathway
• CO2 reacts with hydrogen (H2) through a series of hydrogenation steps to produce methanol, which can then be converted into olefins (such as ethylene and propylene) using Methanol-to-Olefins (MTO) technology. These olefins can further polymerize into polyolefins.
• CO2 reacts with hydrogen (H2) via electrochemical reactions to produce ethylene glycol (MEG), ethylene, hydrogen cyanide, and other products, which can then be used to synthesize polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyethylene furanoate (PEF), polyethylene (PE), and others. This pathway is efficient and environmentally friendly, making it one of the key directions for future CO2 conversion to polymers.
3. Fermentation Pathway
• CO2 and green hydrogen can undergo fermentation to produce intermediates such as lactic acid, succinic acid, adipic acid, ethanol, butanol, isobutanol, and others. These can then be further synthesized into bio-based biodegradable materials like polyhydroxyalkanoate esters (PHA), polylactic acid (PLA), and polybutylene succinate (PBS), which have broad application prospects.
The pathways summarized above demonstrate the various possibilities for converting CO2 into polymers. These pathways are not only theoretically feasible but have also made significant progress in experimental research and industrial applications. However, in the actual industrialization process, factors such as technological maturity, economic viability, market demand, and environmental impact must be considered comprehensively. In the future, with continuous technological advancements and cost reductions, these pathways are expected to become important routes for realizing the resource utilization of CO2.
II. Technological Maturity of Key Pathways
• Some pathways, such as the production of polyesters, polyureas, and non-isocyanate polyurethanes (NIPU), already have relatively mature technologies. However, the conversion rates directly from CO2 may still be limited.
• The production technology for polycarbonate-based polymers (such as polypropylene carbonate (PPC) and polyethylene carbonate (PEC)) is rapidly developing but still requires further research and optimization to improve yields and reduce costs.
• Technologies like electrochemical reactions and Fischer-Tropsch synthesis have potential but are still in the laboratory or small-scale industrial testing stages and need more research, development investment, and validation.
• Currently, CO2-based polyol production technologies have achieved some industrial application results. For example, some companies have successfully developed a full set of CO2-based polyol products with proprietary intellectual property, including catalysts, reaction processes, reaction equipment, and downstream applications. These products are widely used in polyurethane, synthetic leather, and foaming industries. In the future, with continuous technological advancements and innovations, the CO2-based polyol production pathway is expected to see broader applications and greater development.
III. Raw Material Costs:
CO2 has the advantage of being a low-cost raw material, as it is a widely emitted greenhouse gas that can be captured and utilized. However, the costs of other auxiliary raw materials (such as hydrogen, catalysts, solvents, biomass, etc.) may vary depending on their sources, prices, and market supply conditions.
For polymers that require fermentation production (such as polylactic acid (PLA) and polyhydroxyalkanoate esters (PHA)), the raw material costs (such as sugars, biomass, etc.) and the efficiency of the fermentation process will also impact their economic viability.
IV. Market Demand:
The size and growth rate of market demand will directly impact the economic feasibility of these technologies:
• With the increasing awareness of environmental protection and the rising demand for sustainable development, the demand for bio-based and biodegradable polymers is growing, which helps drive the development of CO2-to-polymer technologies.
• As the potential of low-carbon fuels becomes more apparent and the global pursuit of sustainability continues, the market demand for green methanol is steadily increasing. Green methanol has a wide range of applications, including automotive fuel, fuel cells, marine fuel, organic additives, and more. As CO2 conversion and green hydrogen technologies continue to advance and costs decrease, the application of green methanol in these fields will become more widespread, and market demand will continue to grow.
V. Environmental Impact:
CO2-to-polymer technologies help reduce greenhouse gas emissions, decrease plastic pollution, promote resource recycling, and minimize waste generation. However, some pathways may produce other pollutants or have potential environmental impacts.
A comprehensive environmental impact assessment is necessary, and appropriate measures must be taken to mitigate any negative effects.
Although CO2-to-polymer technologies have many environmental advantages, they still face some technical challenges. For example, improving the CO2 conversion rate and optimizing polymer material performance to meet various application needs. However, with the continuous efforts of research institutions and companies, these technical challenges are gradually being addressed. In the future, with ongoing technological advancements and expanded applications, CO2-to-polymer technologies are expected to play a more significant role in environmental protection and resource recycling.
Conclusion
In summary, the proposed routes for CO2 conversion to polymers present various challenges and opportunities in terms of technological feasibility and economic viability. To achieve the commercialization of these technologies, further efforts are needed to strengthen research and development, optimize process conditions, reduce production costs, improve energy efficiency, and carefully consider market demand and environmental impacts. At the same time, external factors such as government policies, financial support, and market demand will also play a crucial role in the development of these technologies.
