Making Petrochemicals from CO2
Can CO2 Emissions Become A Useful Feedstock?
A fascinating article in Chemical & Engineering News describes current German research and development work focused on developing new industrial processes for making organic chemicals from CO2. These public/private partnerships capitalize on the country’s long expertise in industrial chemistry and its highly successful chemical sector. They are also extremely timely, not just because of growing concern about steadily increasing levels of CO2 in the atmosphere, but because Germany’s “Energiewende”, which includes the rapid phase-out of nuclear power, is actually raising the country’s emissions as it relies increasingly on coal for baseload electricity generation.
In my last post I explained why it is unlikely that fossil fuels could be phased out rapidly enough to threaten the current valuations of oil and gas firms. But if carbon-based fuels will be with us for some time, that leaves open the large question of what to do about the CO2 emitted when they are burned, particularly from stationary installations like factories and power plants. The long-mooted approach of carbon capture and sequestration (CCS) still faces significant obstacles in terms of cost and social acceptance. That makes CO2 utilization efforts such as those underway in Germany especially intriguing.
The Advantages of Turning Lemons into Lemonade
It’s impossible to predict today whether any of the CO2 utilization processes that German companies and universities are pursuing will ever become commercial. However, they share some key advantages over “classic” CCS and efforts to produce fuels and other chemicals from CO2 captured directly from the atmosphere:
- Producing chemicals, rather than fuels, finesses a fundamental obstacle to recycling CO2. Thermodynamics dictate that reversing the results of combustion requires more energy than the fuels released when burned. As long as most energy globally comes from fossil fuels, it will be hard to come out ahead from an energy, emissions or cost perspective when turning CO2 back into fuels. However, if the output is valuable chemicals, that energy deficit might not be such a hindrance.
- The target chemicals for these projects, including polyols, polypropylene carbonate, and acrylates, are widely used and have a global market. While most don’t quite fall into the category of premium specialty chemicals, they are unlikely to become as commoditized as motor fuels. So while cost is an important consideration, there’s probably a bit more leeway for a new process to compete and become successful.
- The scale of production for these chemicals is much smaller than for motor fuels, by orders of magnitude. That means that a company investing in producing them from CO2 can hope to capture meaningful revenue and market share with a manageable scale-up from the laboratory. Yet they’re not so small that a single new plant on a scale large enough to demonstrate CO2 utilization would swamp the global market and destroy the margins that made the investment attractive in the first place.
- These projects appear to be focused mainly on using the CO2 effluent from other industrial processes or power generation, ranging from 4-14% for power plants and up to 90% for some industrial processes, rather than having to collect it from the atmosphere, where it is present at just 0.04%. Starting with a CO2 concentration 100-1000 times higher than in air entails much less surface area for absorption, and likely lower energy consumption and overall capture cost.
- Germany is committed to significant CO2 reduction, but the German public seems uncomfortable with the prospect of burying CO2 underground. Lacking large numbers of mature oil fields that could be revived by CO2 injection, a commercial-scale CO2 utilization industry would solve Germany’s problem of what to do with at least some of the CO2 it will eventually want to capture from their coal- and gas-fired power plants and other sources.
Conclusions – One Slice, But Not The Whole Pie
As promising as these efforts look, they are unlikely to reduce global CO2 emissions by enough to meet current goals. While chemical markets are big enough to take up some captured-and-converted CO2, they are much smaller than the global fossil fuel consumption responsible for most man-made CO2 emissions. If carbon capture really took off, the volumes of concentrated CO2 involved would require multiple, large-scale dispositions including enhanced oil recovery, fuel production–perhaps driven by advanced nuclear power–underground burial, and possibly chemical sequestration as carbonate rock.
In the meantime, turning some CO2 that would otherwise end up in the atmosphere into organic chemicals that will end up in more durable products seems worth pursuing. If these processes can become commercial, they will help move us in the right direction, and more cost-effectively than some other approaches receiving large ongoing government subsidies, rather than the seed money involved in these cases. I’ll be very interested to see how these efforts turn out.