nitel Technologies, an Illinois-based designer and builder of pilot and mini-plants, announced that it has received a patent for a new technology to make fatty acids from a feedstock “soup” of cultivated algae and water.
“The major stumbling block in the algae space has to do with the fact that all the players want to start with immobilized algal oil,” said Serge Randhava, CEO of Unitel. “That’s easy to do in a laboratory environment, but real life is a very different situation. You have to deal with massive volumes of water, followed by complicated dewatering, drying and oil extraction operations. In some instances, the amount of energy consumed for this purpose can actually exceed the energy value of the algal oil,” he adds.
Unitel’s approach offers a radical departure from the standard practice. Instead of focusing on oil, the Unitel patent is based on the concept of directly converting the algae “soup” into fatty acids, an easier starting point for decarboxylation and conversion into paraffinic hydrocarbons (alkanes), followed by mild hydro-cracking and hydro-isomerization to make biojet fuel comprised of C10-C15 branched paraffins.
In the Unitel process, the primary feedstock — a slurry or “soup” of water and cultivated algae (1% to 20%) by weight is continuously treated in a choice of hydrolysis reactors to yield 1) a fatty acid product, 2) a “sweet” water stream containing glycerol and other solubles, and 3) deoiled algal biomass. A small fraction of the fatty acid product is fed back into the reactor as catalyst.