New Technology Turns Waste Algae into Biochemicals

Kelvin Okamoto has spent more than 30 years in the plastics and packaging industry, including more than 20 years formulating and processing bioplastics. Through his company, he has developed a process of converting microalgae into bio-based chemicals rather than disposing of it at landfills.

Founded by Okamoto in July 2014, Gen3Bio transforms waste algae into an ongoing revenue stream using enzymolysis technology licensed from The University of Toledo in Ohio. Since October 2016, the company has been headquartered at the Kurz Purdue Technical Center at Purdue University in West Lafayette, Ind., where it also is a client of the Purdue Foundry.

Seeking ways to maximize the value of microalgae as a biofeedstock, Okamoto and his team developed a process to extract basic biochemical—fats, sugars, and proteins. Waste360 recently sat down with Okamoto to discuss Gen3Bio’s process and its applications within the waste and recycling industry.

Waste360: What is the technology behind the process to convert microalgae into bio-based chemicals to reduce landfill waste?

Kelvin Okamoto: The critical technology was developed by professors Sridhar Viamajala and Sasidhar Varanasi at The University of Toledo. This technology uses a combination of inexpensive commercially available enzymes to extract the free sugars, fats and proteins from microalgae.

The enzymolysis technology is performed on 5 percent algae in warm water, which eliminates the need for dewatering required by many other processes. Additionally, the process has been demonstrated to work on several strains of microalgae to recover more than 90 percent of free sugars and proteins within the cells. The process can be run in readily available equipment and takes a total of two hours to complete.

The enzyme blend breaks open without completely digesting the cell walls of the microalgae. The enzymes then break down the carbohydrates into the individual sugar components, mostly glucose with some mannose in most cases. The insoluble broken cell walls, fats and proteins are then filtered out from the sugars. The sugars are left in the filtrate along with a small percentage of proteins. This filtrate then can go directly to fermentation to further convert the sugars. The precipitate can be further separated into proteins, fats and broken cell walls, as needed.

Waste360: What chemicals can be produced?

Kelvin Okamoto: Several different chemicals can be produced, depending upon how far down the chemical conversion pathway one wants to go. Fermentation of the sugars can lead to any fermentation byproduct, including succinic acid, lactic acid, and bioethanol. Succinic acid and lactic acid can be considered basic building blocks to produce numerous other commercially important specialty chemicals. Succinic acid and lactic acid can also be used to produce bioplastics.

The lipids can be easily converted to biodiesel and the proteins can be hydrolyzed to obtain the basic amino acids. On the other hand, the precipitate in total can be used to produce fish nutrient.

Waste360: What are the potential applications?

Kelvin Okamoto: The Gen3Bio process is best when combined with the algae process technology that other companies have developed for wastewater treatment or for flue gas remediation. The Gen3Bio process was be fed directly by the output to the algae producing processing technologies that are co-located at wastewater treatment facilities.

Waste360: How is the Gen3Bio method different from current or common methods of converting microalgae into bio-based chemicals?

Kelvin Okamoto: The Gen3Bio process has several advantages over the common algae extraction technologies, including high pressure liquefaction, high temperature liquefaction and acid, base or supercritical carbon dioxide extraction, used today.

Waste360: What other companies or organizations are you working with to develop this process?

Kelvin Okamoto: At this time, Gen3Bio is not a liberty to disclose the organizations that it is working with, however the initial target market is municipal wastewater treatment facilities. Gen3Bio is often approaching those organizations through the companies developing algae technologies for treating wastewater.

Waste360: When will the process be finalized and what are the next steps?

Kelvin Okamoto: The process has been validated in the lab and is being scaled up. A few pilot facilities should be operating in the next six months. The next step is to install pilot facilities to demonstrate and optimize the technology.