2022 Horizons Symposium
Baltimore, Maryland, USA • April 21 – 22, 2022
Cold Water for Plants in the Desert: Heat Rejection for Water-starved Locations
T. J. Paskach, PhD
Chief Technology Officer
Frontline BioEnergy LLC
Dr. T.J. Paskach is Chief Technology Officer for Frontline BioEnergy, a developer of renewable energy technology and projects based in Nevada, Iowa. He is also the President of San Joaquin Renewables, a startup company developing a commercial biomass-to-natural gas plant in California. Dr. Paskach is a Professor of Practice, teaching process and plant design to graduating seniors in the chemical engineering department at Iowa State University (ISU), where he earned both his B.S. and Ph.D. in Chemical Engineering. Dr. Paskach lives in Ames, Iowa with his wife Jeanne and his youngest son, Ryan, a senior at Ames High School. His daughter, Dagney, is a Master's Student in Education at ISU. His two sons are also at ISU. Nathan is a Junior in Computer Engineering, and Eric is a sophomore in Industrial Design.
Zero effluent and zero water makeup is possible, and even economically attractive, when it is made a priority during process design. The 3.3 million MMBtu per year San Joaquin Renewables biomass-to-natural gas plant designed by Frontline BioEnergy has achieved this goal. Traditional evaporative cooling towers may require 0.06 gpm per ton of cooling load (300 gallons per MMBtu) for evaporation and blowdown makeup. For the San Joaquin Renewables biomass to natural gas plant requiring 50MMBtu per hour, that would have amounted to an unattractive consumption of 360,000 gallons of water per day, or 30% more than the entire residential consumption of the city of McFarland, California (3,300 homes) where the plant will be located. Instead of this, all of the cooling load is provided through a combination of efficient electric chillers and absorption chillers utilizing waste heat from internal combustion engine exhaust. The result is a plant that neither requires makeup water nor produces wastewater. The plant design makes extensive use of chilled water for process cooling needs, condensers, and product cooling. Additionally, a detailed study revealed significant efficiency gains possible through cooling of compressor inlets and interstage cooling.