From ethanol refineries to steel mills, major industrial processors are partnering with emerging advanced biofuels producers to monetize their emissions in a process loosely referred to as carbon capture and utilization (CCU). With carbon regulations once again gaining traction, this could prove to be the paradigm of industrial synergy. Industrial players generate revenue from a liability, otherwise regarded as waste; biofuels producers gain access to carbon-rich flue gases, which their proprietary industrial microbes or algae consume, resulting in the production of bio-based fuels and chemicals.
Companies targeting waste streams as a strategic feedstock for advanced chemical and biofuels production avoid one of the primary hurdles to commercial scale for conversion processes: the lack of access to inexpensive feedstock. In the case of flue gas, advanced biofuels producers avoid a costly frontend feedstock conversion that can derail project feasibility.
Growing on CO2
There are many advanced biofuels ventures targeting carbon-rich gaseous feedstock sources through colocation partnerships with industrial facilities. In the United States, BioProcess Algae, which designs, builds, and operates commercial-scale bioreactors that convert light and CO2 into high-value microbial feedstock, has deployed a demonstration plant at a first-generation ethanol plant in Iowa.
Algae are the ideal partner for industrial carbon emitters, digesting CO2 as they grow. The more CO2 the algae consume, the faster they grow.
During this process, the algae return clean oxygen to the environment while also producing high-value oils and proteins. These oils and proteins can be used in the production of transportation fuels, animal feed, chemicals, and food products. As an added bonus, once the lipids and other co-products have been extracted from the algae, the residues can be used as a fuel for power generation, either co-fired in combustion facilities or converted to biogas in an anaerobic digester.
Among many advanced biofuels production pathways, algae’s unique advantage is high per-acre productivity. Microalgae can potentially produce 2 to 20 times more oil per acre than other plants, making algae platforms a compelling solution to offsetting petroleum imports without converting large swaths of farmland to grow dedicated energy crops.
Unfortunately for the emerging U.S. algae industry and other companies targeting flue gas in the United States, though, the Environmental Protection Agency (EPA) excluded CCU as an approved strategy for emissions mitigation in its proposed Clean Power Rule.
Most algae companies today have long-term aspirations to partner with utilities for access to CO2 produced at power plants. With nearly 5,000 potential industrial sources of CO2 across the United States – most of these power generation facilities – the addressable market for these emerging technologies is significant. At its demonstration facility in Hawaii, Cellana currently relies on flue gas from diesel generators to feed its algae. A CO2 source from power plants could potentially make the operation more economically feasible in the future, according to the company.
While algae companies argue that their technologies are ready for prime time after years of researching and building small-scale test projects, challenges remain. Industrial algae production is effectively an agricultural play that requires advances in cultivation and harvesting to lower production costs to a level that can compete with commodity products.