Algae biomass can be converted to advanced biofuels that offer promising alternatives to petroleum-based diesel and jet fuels. Additionally, algae can be used to make a range of other valuable bioproducts, such as industrial chemicals, bio-based polymers, and proteins. However, barriers related to algae cultivation, harvesting, and conversion to fuels and products need to be overcome to achieve the Department’s target of $3 per gge for advanced algal biofuels by 2030. To accomplish this goal, the Department is investing in applied research and development technologies that achieve higher biomass yields and overall values for the algae.

Funding from the new FOA, entitled “Targeted Algal Biofuels and Bioproducts (TABB)”, will support projects in two topic areas:

• Topic Area 1 awards (anticipated at 1–3 selections) will range from $5–10 million and focus on the development of algae cultures that, in addition to biofuels, produce valuable bioproducts that increase the overall value of the biomass.

• Topic Area 2 awards (anticipated at 3–7 selections) will range from $0.5–1 million and will focus on the development of crop protection or carbon dioxide utilization technologies to boost biomass productivity in ways that lead to higher yields of algae.

Under Topic Area 1, multi-disciplinary consortia will pursue technology improvements that will lead to higher overall values for the algae. This will be achieved by developing and improving yields of high-impact bioproducts (e.g. specialty or commodity chemicals or polymers or proteins) and biofuels. Consortia are required for this topic because of the broad range of expertise and facilities needed to develop technologies from algae cultivars to finished biofuels and bioproducts. A critical component of this topic area is that bioproducts are expected to increase the overall value of the algal biomass and still allow for biofuel production.

DOE emphasized that a critical component of this topic area is that bioproducts are expected to increase the overall value of the algal biomass and still allow for biofuel production. Examples of research routes that could help meet this objective include but are not limited to:

• Co-production of specific molecules with downstream applications as petro-chemical replacements.

• Redirection of carbon flux to a metabolic pathway that results in synthesis of a valuable chemical.

• Improving a strain to make a valuable protein.

Under Topic Area 2, single investigator or small teams will pursue technology improvements that will result in increased biomass productivity leading to higher overall feedstock yields. This will be achieved by projects that focus on advancements in either: 1) crop protection; or 2) CO₂ utilization. Achieving higher feedstock yields continues to be one of the most significant barriers to algal biofuels.

Biological contamination presents one of the greatest challenges in cultivating robust, reliable algal cultures that meet target performance (growth rate, target product generation, culture density, etc.) specifications. Novel, safe, and effective strategies need to be developed to control culture contamination events that result in diminished target feedstock yield(s). Additionally, integrated pest management systems need to be developed to control pathogens and herbivores. Examples of research that would contribute to crop protection include but are not limited to:

• Rapid detection systems to enable preventative treatments to ponds.

• Biological systems and/or engineering to increase resilience of culture.

• Novel chemical treatment protocols that are scalable, environmentally acceptable, and economically feasible.

Algae utilize a diversity of carbon concentrating mechanisms to maintain adequate carbon stores for photosynthesis. Obtaining adequate carbon is affected by the transfer of dissolved inorganic carbon into the cultivation system, levels of biologically available carbon, and sequestration of carbon by algae.

Reservoirs could include atmospheric CO₂, supplied CO₂, and biologically available carbon in the cultivation system. Enhancing transfer efficiency could enhance productivity through ensuring adequate intracellular carbon stores, as well as lower operating costs through more efficient utilization of carbon sources. Target improvements may be measured through enhanced photosynthetic efficiency, increased carbon efficiency, and improved rates of transfer, either into carbon reservoir, or uptake by algae from the reservoir.

Improvements must result in improved productivity that could lead to higher feedstock yields. Examples of research that could help meet this objective include, but are not limited to:

• Mechanical engineering solutions for mixing and gas exchange.

• Alternative/Advanced CO₂ or C supply-system development.

• Improved carbon uptake through strain engineering.

Successful projects under this FOA will need to integrate techno-economic modeling and life-cycle assessment into experimental plans. This will be captured to some extent in the required technical and financial data. After award selection, DOE will use these data will be used to establish a baseline and targets.