Algae Oil-Based Biorefineries

By: Dr. John Kyndt – Head Scientist of the Renewable Energy Program at Advanced Energy Independence Lab and Dr. Aecio D’Silva.

Algae have the potential to be a sustainable feedstock for the production of advanced biofuels and green chemicals. Production of advanced biofuels and bioproducts from algae, however, faces a number of challenges toward commercialization, in particular issues encountered upon scale up.

A large portion of the algal research around the world is focused on developing economically viable harvesting technologies and optimizing refining technologies for the final products…

Algae biomass composition is dependent on the algae species grown and on the environment in which the cells are cultivated. Some species have a high preference for lipids as storage material and others become rich in starch and sugars.

Depending on the hydrocarbon and sugar composition, the specific algal biomass can be further processed for biodiesel through transesterification, biogasoline or biojetfuel through hydrocracking or processed for bioethanol, either through fermentation or thermal pyrolysis (syngas formation).

Byproducts from these reactions can be fed into the current main stream chemical industry.

Importance of Integrated Algae Production Systems

Newly developed types of novel algae production systems will need to be directly integrated into an existing biorefinery or gas-fired power plants to make the overall process viable.

Biorefineries are similar to petroleum refineries in concept; however, biorefineries use renewable, sustainable biological matter (as opposed to petroleum or other fossil sources) to produce transportation fuels, chemicals, and heat and power.

An integrated system implies not only that the algae biomass is fed directly into the biorefinery but also the direct utilization of the outputs and exhausts (e.g., syngas, methane, heat, carbon dioxide, wastewater, etc.) from the biorefinery or power plant into our novel algae production systems. This will pave the way toward a robust mass production of high-end algae fuels and chemicals at manageable costs.

Our group of cientists at Advanced Energy Creations Lab is currently developing a vertically integrated production-refinery system consisting of different “platforms”. Each of these is devoted to a specific product line of fuels or high value chemicals. Here are some examples of such platforms that theoretically all can use algae biomass:

– C2 platform: Ethanol; Acetic acid production
– C3 platform: Acrylic acid; Lactic acid; Propanediols synthesis
– C4 platform: Butanol production
– C10 and up platform: Biodiesel, bio/green jetfuel, carotenoids, etc.

(The C number in each platform refers to the length of the carbon chain in each product line, for example, ethanol has a two carbon chain, butanol has a four carbon chain, etc.)

In addition, the “sugar platform” is based on biochemical conversion processes and focuses on the fermentation of sugars. The “syngas platform” is based on thermochemical conversion processes and focuses on the gasification of biomass feedstocks and by-products from the conversion processes.

The challenge is to optimize each of these processes so that they can be scaled up and performed in existing processing plants. To achieve this, we are optimizing the biomass composition and processing efficiency of the algae using state-of-the-art genetic and microbiological methods.

In the end it is always essential to conduct full life-cycle and economic analyses associated with the commercialization of the integrated bioprocesses.