Sustainable Algal Biofuels Consortium (SABC)

Project: Research project

Description

Assuming a moderate algal biomass productivity of 25 g/m2/day with a 30% oil (triacylglycerol) content (on dry cell weight (DCW) basis), a biofuels industry that uses approximately 5 million acres for cultivating its algal biomass in outdoor open raceway ponds and/or closed photobioreactors would be capable of producing about 13 billion gallons of oil. This intermediate oil product can be converted into a variety of transportation fuels such as biodiesel (transesterification) and green diesel and jet fuel (hydrotreating). This level of biomass production would also result in the co-generation of about 116 million tons of lipid-extracted biomass residue per year. Although much thought has been given to the development of high value co-products from algal biomass, few of the proposed co-products match this volume of biomass to be generated. This issue of scale indicates that conversion of algal biomass for the production of additional non-lipid based advanced biofuels is a requirement for profitable biofuels production and offers a realistic solution for cost effective biomass utilization especially in light of the recent progress towards attainment of technoeconomic targets for economic production of advanced biofuels. Therefore, we will investigate the potential for converting as much of the non-lipid fraction of the algal biomass into alternative liquid biofuels, which could be either sold on the open market or used on-site in the various biorefinery operations. All of the primary macromolecular components of algal biomass fats (oils), carbohydrates, and proteins can be converted into different fuels and co-products, through existing biochemical, enzymatic or microbial conversion means. In this regard, algal biomass conversion is not dramatically different conceptually from the conversion of lignocellulosic feedstocks to biofuels and co-products. However, given that the chemical and structural make-up of algal biomass is different from lignocellulosic biomass, it is likely that modified processes and perhaps even new enzymes may need to be employed. Nevertheless, this proposal will take advantage of and build upon the experience and knowledge developed in the lignocellulosic biofuels community. Although most proposed processes for conversion of algal biomass into lipid-based biofuels and co-products are based on extraction and subsequent conversion of residual biomass to co-products, the SABC proposes that an additional focus on biochemical conversion of algal biomass to generate both lipid based biofuels and fermentation-based biofuels can completely change the algal biomass processing paradigm. While the major focus of this work is designed to provide a better understanding of the potential of algal residues to be converted into low-cost sugars using existing biochemical conversion technologies, we also plan to exploit existing biochemical processing technologies to reorder the conventional process by evaluating the opportunity for using whole algal cells as a feedstock for biochemical processing before the lipid recovery step. We will integrate the potential for carrying out chemical pretreatment and enzymatic hydrolysis steps followed by lipid recovery. Building upon the research developed in the lignocellulose community we will focus first on the complete characterization of algal biomass residuals with respect to chemical composition and structures. We will identify a number of pretreatment conditions and June 21, 2010 2 test existing enzyme cocktails to develop a baseline, and based on our characterization activities we will explore the development and testing of new pretreatment steps and enzyme formulations. While we will focus on algal residuals, we will also test biochemical conversions on whole cell algae and test whether conversion of whole cell algae will facilitate lipid extraction while at the same time producing fermentable sugars in order to produce a new par
StatusFinished
Effective start/end date9/1/102/28/13

Funding

  • DOE: Golden Field Office: $2,850,000.00

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biofuels
biomass
coproducts
algae
lipids
oils
pretreatment
feedstocks
biomass production
enzymes
testing
cells
bioenergy industry
sugars
biorefining
air transportation
raceways
lignocellulose
transesterification
production economics