Henry C. Kelly
Petrochemicals without fossil fuels:
A practical way to make petrochemicals and fuels without using fossil fuels would surely be a breakthrough equivalent to fusion energy in combating climate change. Plants and microorganisms have been doing this for billions of years — though not terribly efficiently. But we’ve never found a practical way to improve on their processes. This may change. Advances in electrochemistry, biochemistry, artificial intelligence, and other research areas are generating exciting new opportunities. Laboratories are demonstrating technologies that use electricity or sunlight to make complex chemicals. They don’t require requiring prohibitive amounts of rare or dangerous materials or facilities. Some, like plants, even remove climate-damaging carbon dioxide from the air.
These opportunities have not received nearly the attention and public support that they deserve. Government funding to pursue them is a tiny fraction of that being devoted to fusion and other conventional energy technologies. This needs to change. An initiative to make petrochemicals safely and affordably without fossil fuels deserves significant investment and much higher priority in federal policy.
This report was made possible by a grant to the George Mason University Foundation by Breakthrough Energy.
Please cite this report as: Henry C. Kelly, New Technology Options to Decarbonize Petrochemical Production, George Mason University Center for Energy Science and Policy, 2023.
Manufacturing of plastics and other petrochemicals is on track to become the leading end use of fossil fuels in the next three decades and thus a central challenge for reducing greenhouse gas (GHG) emissions. Plastics are cheap, waterproof, durable, lightweight, and easy to shape. Indeed, they are in demand in part because they substitute for more GHG-intensive materials to improve the energy efficiency of cars and other products. At issue is whether society can continue to enjoy the unquestionable benefits of plastics without paying an unacceptable environmental price.
Substitutes are likely to erode fossil fuel use in transportation and electric power, the largest markets today, while global demand for petrochemicals is likely to continue to grow because few substitutes are available. Reducing emissions in petrochemical production is complicated by the fact that, unlike other manufacturing processes, it uses fossil fuels both for energy and as a feedstock. Emissions from this sector are very poorly understood, but clearly significant. They arise from extraction and transportation of fossil fuels, chemical production and use, and end-of-life decay. Petrochemicals made using alternative energy and feedstocks that draw their carbon from the atmosphere would make this issue moot. Even their end-of-life decay would simply return the carbon to the atmosphere. (However, this new production strategy would not address other impacts of plastic waste on health and the environment that are becoming all too clear).
Strategies for making petrochemicals without fossil fuels fall into three categories: (1) using grasses or other crops as a process fuel and feedstock, (2) using recycled plastics for these requirements, and (3) producing them directly from carbon dioxide and water. This paper reviews these options in detail. It concludes that only the direct production method can promise zero or negative lifecycle emissions at the volumes required by the global economy.
Grasses, wood, and other plant-based, non-food feedstocks can make a significant contribution to future production of petrochemicals. Key strategies include separation and fermentation using engineered microorganisms as well as breaking down biomass with heat and then upgrading the resulting compounds using industrial chemistry. But the biomass resource is limited, and there is high demand for it from other sectors, including fuel production and electricity generation. While commercial interest has been growing, costs remain a major challenge, along with net environmental impacts.
Chemical recycling relies on techniques similar to those used for bio-based production. This approach faces the monumental challenges of collecting recyclable material in sufficient quantities and finding ways to cope with the mixed inputs it contains. Some advanced chemical recycling processes may eliminate most of the emissions that are released by conventional methods today. Commercial investments suggest that at least some pathways may become profitable in the future.
Petrochemicals can be produced in a number of ways directly from water (which yields hydrogen when electrolyzed) and carbon dioxide (usually supplied in a concentrated stream but potentially drawn from the air). Sophisticated catalysts can drive the creation of methanol and other chemicals. Integrated devices can be built that use electricity to carry out the major steps of chemical production in a single device. Similar devices may be powered directly by sunlight to carry out “artificial photosynthesis” leading to chemical production. Engineered microbes may substitute for these devices, converting carbon dioxide and water into complex chemicals. Hybrid systems attempt to make the most efficient use of electrochemical and biological systems. Most of these technologies remain in laboratories, but major advances are being made and some are being tested at commercial scale.
Innovative approaches to petrochemical production face major market challenges, particularly in the United States. There are huge uncertainties about how, or if, these technologies will be integrated into the existing petrochemical industry – an industry that may go through major changes as climate policy threatens its core markets in gasoline and other fuels. The absence of a clear way to account for lifecycle emissions makes it difficult to give petrochemical innovations the credit they deserve.
U.S. innovators face an additional challenge: natural gas prices in Europe and Asia are significantly higher. As a result, government and commercial interest in these new technologies is higher overseas. The European Commission, for instance, has established an ambitious goal: “by 2030, at least 20% of the carbon used in products should come from sustainable non-fossil sources.”
A practical system for slashing greenhouse emissions by making petrochemicals from electricity or sunlight would be an achievement equivalent to any on the horizon. U.S. policy should reflect this extraordinary new opportunity by creating a major new research and development initiative that draws on expertise from a wide range of disciplines and institutions. Incentives for procurement of key products should be based on a clear and complete accounting of their net environmental impact. But all of this depends on a much broader public understanding of the extraordinary opportunities that research has provided us. The speed of progress has clearly outstripped the ability of policymakers to respond.