Duckweed Redux: Are Duckweed’s Ducks Finally in a Row for Protein, Fuels and More?

by Jim Lane (Biofuels Digest) In California, Greenbelt Resources Corporation and Duckweed DAYS commenced their inaugural Duckweed Project to commercialize the duckweed model developed by the Andrew J. Young Foundation. Tests conducted during a pilot program indicated that protein extracted from duckweed was one of the most nutritious vegetable organic protein with essential amino acids, and the bio-refining process was efficient, sustainable and economically viable.

Greenbelt will expand and refine the preliminary system that was proven successful during AYF’s pilot program, in which they invested $1.2 million. The findings were reported to the USDA in 2017 in a feasibility study.

When complete, Greenbelt’s $5.0 million ECOsystem project, a critical component of the estimated $14.0 million total project cost, will produce up to 500,000 gallons of bioethanol per year, along with a protein concentrate that will be sold to organic feed mills and food ingredient manufacturers. The biorefinery is expected to be operational 15 months after breaking ground.

In May 2013, we reported on a Princeton study on duckweed’s fuel potential. The researchers described four scenarios for duckweed refineries. Those technologies include conversion of biomass to a gas; conversion of the gas to methanol, or wood alcohol; and conversion of methanol to gasoline and other fuels. The results show that small-scale duckweed refineries could produce cost-competitive fuel when the price of oil reaches $100 per barrel. Oil would have to cost only about $72 per barrel for larger duckweed refiners to be cost-competitive.

The difference these days? The shift to focus on protein concentrates as a primary revenue stream.

A USDA-funded feasibility study conducted by Agregy Renewables on behalf of The AJY Foundation outlines a commercialization plan focused on financing and developing as many as 20 more duckweed bio-refineries over an eight-to-ten-year timeframe, initially in the southeast and western U.S. and then across the globe. If fully deployed, the commercialization plan represents more than $100 million in potential project revenues for Greenbelt over the next eight to ten years.

The modules are sold as complete system or separately, are capable of delivery via standard container transport, and complete systems are deliverable in as little as seven months, with system footprints ranging from 3,500 sq ft to 12,000 sq ft and capacity options: from 50,000 GPY to 3,000,000 GPY.

In 2012, Greenbelt sold its first system to the University of Florida for $593,000, and sold a second unit to a group of farmers doing business as Standard Ethanol Pty Ltd. for $1.8 million in 2013 (we reported that the system was ultimately commissioned in March 2017, here ) The company also operates a unit based in Paso Robles, California and provides contract manufacturing services and feedstock processing services.

In addition to demonstrating the viability of duckweed, Greenbelt recently completed successful tests on winery waste and brewery trub and found them to be suitable feedstocks for Greenbelt’s ECOsystem model.

On the yeast protein concentrate side, Greenbelt noted that local animal feed providers are looking to purchasing the project’s yeast and other protein concentrates for sale at $0.40 to $0.60 per pound as compared to $0.03 per pound for other more traditional feed uses. READ MORE