Research Project Information

Research Project Summary Information


Research Foundation of SUNY


Agricultural residues such as sweet sorghum and corn stover could be used to produce biofuels and other bioproducts in New York. A forecast ~ 1 billion tons of agri-biomass is potentially available in the U.S. for large-scale biorefinery projects. Pretreatment is needed to prepare the sugar streams in this biomass for production of bioproducts. Pretreatment processes tend to produce compounds that inhibit fermentation, and other products that foul membranes used in downstream processes. Flocculation can be used to significantly reduce membrane fouling and remove inhibitory compounds from a pretreatment extract called hydrolyzate. Many other removal methods for inhibitors are cost prohibitive. Recent laboratory and and pilot scale demonstration of a SUNY ESF flocculation technology with hydrolyzates from hard wood chips was successful at the 1000 L scale but has not been tried with agricultural residues. Sweetwater Energy uses patent-pending technology to produce low-cost sugars from biomass, including wood and agricultural residues. Their lignin byproduct is low in acid and non-sulfonated, making it useful in applications like animal feed or solid fuel. Their technology is small scale, so biomass transport costs are reduced. They produce separate and concentrated C5 and C6 sugar streams that are easily fermentable. Their demonstration scale system is under construction near Rochester, and they hope to commission their first full-scale facility in 2012.

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Project Description

The goal is to use an innovative polymer-induced flocculation and separation technology on hydrolyzates from sweet sorghum and corn stover to improve hydrolyzate quality and reduce membrane fouling. Specific objectives include: 1) prepare hydrolyzates of sweet sorghum and corn stover at Sweetwater Energy; 2) perform testing on the hydrolyzates and analyze benchmark hydrolyzates and treated hydrolyzates for turbidity, total solids, colloidal solids, particle size, charge, lignin, sugars, carbohydrate composition, lignin composition and fermentabiilty; 3) determine optimal conditions for mass removal and carbohydrate concentration; 4) perform flocculation with four different flocculants at three dosage levels and optimize two hydrolyzate concentrations, three shear speeds, and various pH and temperature; 5) prepare a summary of the optimal dosage levels of the most suitable polymer for separation and purification of sweet sorghum and corn stover extracts at different conditions, minimizing the inhibitory compounds and maximizing the quality of the carbohydrates; 6) scale-up the process and repeat the testing at the pilot scale and then commercial scale; and, 7) perform an economic analysis to compare flocculant effectiveness and cost.


Using agricultural residues as feedstocks for biofuels and other bioproducts will reduce dependence on crude oil, increase the use of cellulosic biomass feedstocks, and create rural jobs. The flocculation technology developed at SUNY ESF removed up to 95% of the suspended solids in hydrolysates from wood, and membrane cycles were extended by ten times. Even a small (less than 10%) improvement in the productivity of hydrolyzate would yield a large economic benefit. SUNY ESF has filed for intellectual property rights for the technology. The lignin byproduct is non-sulfonated, making it more useful in applications such as biocomposites.

Project Results


Research Foundation of SUNY
P.O. Box 9 Attn: John Loonan
Albany, NY 12207

Principle Investigator

Bandaru Ramarao

Universities Involved

SUNY College of Environmental Science an


Project Type:

Indigenous/Renewable Energy Resources

Technologies Types:

NYSERDA Contact Information

Judy Jarnefeld


R&D - Environment & Energy Res

Contract Details

Start Date: 4/3/2012 1
Project Status: Active
Contract Number: 25919

Last Updated: 10/3/2014