Techno-economic analysis of drop-in biofuels produced from microalgae remnants finds price would range between $5.64 and $6.81/gallon US
Researchers from Iowa State University report on a techno-economic analysis of drop-in hydrocarbon biofuels produced by the catalytic pyrolysis of microalgae remnant—the part of algae left over after lipids extraction—in a paper in the journal Fuel. The study, which compares partial mechanical drying and thermal drying scenarios with subsequent energy flow analyses, found that microalgae remnant biofuel could vary in price between $1.49 and $1.80 per liter ($5.64 and $6.81 per gallon US).
One of the most challenging barriers to this pathway for utilization of microalgae remnant is the high moisture content of harvested microalgae; the feedstock must be dewatered.
The goal of this study is to compare the economics of two catalytic pyrolysis pathways for the production of drop-in biofuels, each pathway employing its own distinct method of feedstock dewatering: thermal drying or partial mechanical dewatering. The study presents chemical process models, capital expense and operating cost estimates, and sensitivity analyses of both scenarios.
Results indicate that thermal drying prior to catalytic pyrolysis (TDCP) incurs capital costs similar to those incurred in partial mechanical dewatering prior to catalytic pyrolysis (MDCP) ($346 million vs. $409 million). TDCP and MDCP yield minimum fuel-selling prices (MFSPs) of $1.80/l and $1.49/l, respectively. Energy analysis shows that TDCP achieves 16.8% energy efficiency and MDCP achieves 26.7% efficiency.—Thilakaratne et al.
Rajeeva Thilakaratne, Mark M. Wright, Robert C. Brown (2014) “A techno-economic analysis of microalgae remnant catalytic pyrolysis and upgrading to fuels,” Fuel, Volume 128, Pages 104-112, doi: 10.1016/j.fuel.2014.02.077