Hydrothermal Liquefaction Conversion of Dairy Flocculant to Biofuel
Faculty Mentor Information
Dr. Owen McDougal, Boise State University
Presentation Date
7-15-2026
Abstract
Dairy wastewater generated from clean in-place sanitation is treated to aggregate particulate matter into flocs for removal and disposal. Transporting 32,000 gallons of high-moisture content floc from a single processing facility each day is costly. The focus of our work is to upcycle this byproduct into energy, clean water, and soil additives. The floc is composed of more than 90% water with the remaining 10% being organic and inorganic matter, making hydrothermal liquefaction (HTL) an ideal conversion technology. HTL utilizes high pressure and temperature conditions to convert wet biomass into energy-dense biocrude, water, and biochar. The aim of this project is to characterize the properties of the biocrude and assess its potential as a biofuel. The energy content of the flocculant and biocrude was determined using bomb calorimetry. HTL conversion of floc led to a 45% increase in energy content. Gas chromatography-mass spectrometry (GC-MS) was used to identify fatty acid methyl esters (FAME) in the flocculant and biocrude as octadecenoic acid, palmitic acid, and methyl isotridecanoate. The near doubling of energy content from floc to HTL converted biocrude is a favorable outcome and justifies further investigation to quantify the FAMEs and conduct elemental composition on the biochar.
Hydrothermal Liquefaction Conversion of Dairy Flocculant to Biofuel
Dairy wastewater generated from clean in-place sanitation is treated to aggregate particulate matter into flocs for removal and disposal. Transporting 32,000 gallons of high-moisture content floc from a single processing facility each day is costly. The focus of our work is to upcycle this byproduct into energy, clean water, and soil additives. The floc is composed of more than 90% water with the remaining 10% being organic and inorganic matter, making hydrothermal liquefaction (HTL) an ideal conversion technology. HTL utilizes high pressure and temperature conditions to convert wet biomass into energy-dense biocrude, water, and biochar. The aim of this project is to characterize the properties of the biocrude and assess its potential as a biofuel. The energy content of the flocculant and biocrude was determined using bomb calorimetry. HTL conversion of floc led to a 45% increase in energy content. Gas chromatography-mass spectrometry (GC-MS) was used to identify fatty acid methyl esters (FAME) in the flocculant and biocrude as octadecenoic acid, palmitic acid, and methyl isotridecanoate. The near doubling of energy content from floc to HTL converted biocrude is a favorable outcome and justifies further investigation to quantify the FAMEs and conduct elemental composition on the biochar.