Algal Biofuels: Ponds and Promises

Presentation on past and current algal biofuels researc

Potential for Biofuels from Algae

Presentation on the potential for biofuels from algae presented at the 2007 Algae Biomass Summit in San Francisco, CA

An alternative biorefinery approach to address microalgal seasonality:Blending with spent coffee grounds

An effective method for the production of fuels and chemicals from microalgae is to ferment the carbohydrate fraction, extract the lipids and convert the resulting solids through hydrothermal liquefaction (HTL). In this process, known as Combined Algal Processing (CAP), multiple fuel precursors are produced effectively. However, one of the key challenges associated with a microalgae-based biorefinery is the reduced productivity of algae in the colder seasons. In this investigation, the potential for spent coffee grounds (SCG), a potentially valuable waste stream, to be blended with biomass from the microalgae Scenedesmus acutus (HCSD) to make up for the productivity shortfalls in periods of lower microalgae productivity to maximize the capacity for downstream equipment throughout the year was evaluated. Two different blend ratios were compared to only microalgae biomass or SCG, one representing winter season (40% microalgae and 60% SCG-blend 1) and another representing autumn and early spring (60% microalgae and 40% SCG-blend 2). Pretreatment of the blends showed higher monosaccharide release yields compared to microalgae alone, with an increase in mannose and galactose specifically. In the fermentation of the pretreated slurries, all the monosaccharides were consumed, resulting in ethanol titers of up to 23 g L-1 for the SCG blend, compared to 14 g L-1 ethanol for the algae alone. The lipid extraction from the blends resulted in yields of 95.5-99.7% (which translates to 173.8-193.5 kg per tonne of dry biomass processed in this biorefinery scenario) compared to 92.2% in HCSD (216.2 kg per tonne of dry biomass) and 68.1% in SCG (90.8 kg per tonne of dry biomass) alone. The residual solids left after fermentation and lipid extraction were converted via hydrothermal liquefaction (HTL) to produce bio-crude. The bio-crude yield was higher for microalgae (24.6%) than for the two blend cases (blend 1-17.5% and blend 2-19.7%). Theoretical energy calculations showed that the addition of SCG gave similar yields of fuel (gallon of gasoline equivalents) from the blends when compared to microalgae alone (94.7-96.5% depending on the blend of SCG). This work demonstrates that SCG can be easily incorporated with microalgae into a combined processing methodology and can therefore be used effectively during periods of lower availability of microalgae maintaining maximum operating levels of the conversion process equipment year-round. Moreover, co-processing algae with SCG not only leads to increased ethanol titers in the fermentation but also improves the lipid extraction yields. This journal is </p

Renewable Diesel from Algal Lipids: An Integrated Baseline for Cost, Emissions, and Resource Potential from a Harmonized Model

The U.S. Department of Energy's Biomass Program has begun an initiative to obtain consistent quantitative metrics for algal biofuel production to establish an 'integrated baseline' by harmonizing and combining the Program's national resource assessment (RA), techno-economic analysis (TEA), and life-cycle analysis (LCA) models. The baseline attempts to represent a plausible near-term production scenario with freshwater microalgae growth, extraction of lipids, and conversion via hydroprocessing to produce a renewable diesel (RD) blendstock. Differences in the prior TEA and LCA models were reconciled (harmonized) and the RA model was used to prioritize and select the most favorable consortium of sites that supports production of 5 billion gallons per year of RD. Aligning the TEA and LCA models produced slightly higher costs and emissions compared to the pre-harmonized results. However, after then applying the productivities predicted by the RA model (13 g/m2/d on annual average vs. 25 g/m2/d in the original models), the integrated baseline resulted in markedly higher costs and emissions. The relationship between performance (cost and emissions) and either productivity or lipid fraction was found to be non-linear, and important implications on the TEA and LCA results were observed after introducing seasonal variability from the RA model. Increasing productivity and lipid fraction alone was insufficient to achieve cost and emission targets; however, combined with lower energy, less expensive alternative technology scenarios, emissions and costs were substantially reduced

Transcriptional Analysis of Lactobacillus brevis to N-Butanol and Ferulic Acid Stress Responses

The presence of anti-microbial phenolic compounds, such as the model compound ferulic acid, in biomass hydrolysates pose significant challenges to the widespread use of biomass in conjunction with whole cell biocatalysis or fermentation. Currently, these inhibitory compounds must be removed through additional downstream processing or sufficiently diluted to create environments suitable for most industrially important microbial strains. Simultaneously, product toxicity must also be overcome to allow for efficient production of next generation biofuels such as n-butanol, isopropanol, and others from these low cost feedstocks.This study explores the high ferulic acid and n-butanol tolerance in Lactobacillus brevis, a lactic acid bacterium often found in fermentation processes, by global transcriptional response analysis. The transcriptional profile of L. brevis reveals that the presence of ferulic acid triggers the expression of currently uncharacterized membrane proteins, possibly in an effort to counteract ferulic acid induced changes in membrane fluidity and ion leakage. In contrast to the ferulic acid stress response, n-butanol challenges to growing cultures primarily induce genes within the fatty acid synthesis pathway and reduced the proportion of 19:1 cyclopropane fatty acid within the L. brevis membrane. Both inhibitors also triggered generalized stress responses. Separate attempts to alter flux through the Escherichia coli fatty acid synthesis by overexpressing acetyl-CoA carboxylase subunits and deleting cyclopropane fatty acid synthase (cfa) both failed to improve n-butanol tolerance in E. coli, indicating that additional components of the stress response are required to confer n-butanol resistance.Several promising routes for understanding both ferulic acid and n-butanol tolerance have been identified from L. brevis gene expression data. These insights may be used to guide further engineering of model industrial organisms to better tolerate both classes of inhibitors to enable facile production of biofuels from lignocellulosic biomass

Schizophrenia and the Scaffolded Self

This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this recordA family of recent externalist approaches in philosophy of mind argues that our psychological capacities are synchronically and diachronically “scaffolded” by external (i.e., beyond-the-brain) resources. Despite much interest in this topic, however, it has not found its way to philosophy of psychiatry in a substantive way. I here consider how these “scaffolded” approaches to mind and self might inform debates in phenomenological psychopathology. First, I introduce the idea of “affective scaffolding”. I distinguish three forms of affective scaffolding and support this taxonomy by appealing to different sources of empirical work. Second, I put the idea of affective scaffolding to work. Using schizophrenia as a case study, I argue — along with others in phenomenological psychopathology — that schizophrenia is fundamentally a self-disturbance. However, I offer a subtle reconfiguration of these approaches. I argue that schizophrenia is not simply a disruption of ipseity or minimal self-consciousness but rather a disruption of the scaffolded self, established and regulated via its ongoing engagement with the world and others. I conclude that this way of thinking about the scaffolded self is potentially transformative both for our theoretical as well as practical understanding of the causes and character of schizophrenic experience, insofar as it suggests the need to consider new forms of intervention and treatment

Pilot Scale Integrated Biorefinery for Producing Ethanol from Hybrid Algae: Cooperative Research and Development Final Report, CRADA Number CRD-10-389

This collaboration between Algenol Biofuels Inc. and NREL will provide valuable information regarding Direct to Ethanol technology. Specifically, the cooperative R&D will analyze the use of flue gas from industrial sources in the Direct to Ethanol process, which may demonstrate the potential to significantly reduce greenhouse gas emissions while simultaneously producing a valuable product, i.e., ethanol. Additionally, Algenol Biofuels Inc. and NREL will develop both a techno-economic model with full material and energy balances and an updated life-cycle analysis to identify greenhouse gas emissions relative to gasoline, each of which will provide a better understanding of the Direct to Ethanol process and further demonstrate that it is a breakthrough technology with varied and significant benefits