Assessment of a dry and a wet route for the production of biofuels from microalgae: energy balance analysis.

In this study, the energy balance of two microalgae-to-biofuel concepts, one via a so called "dry route" (oil extraction from dried algae) and one via a "wet route" (oil extraction in the water phase), are assessed. Both routes are intended to convert the chemical energy contained in the microalgae into high-value biofuels with minimal fossil energy consumption. The analysis shows that the drying process in the dry route and the oil extraction process in the wet route consume a significant amount of energy. By coupling waste heat from a nearby power plant to the process, the energy balance can be improved and a potential fossil energy ratio (FER) up to 2.38 and 1.82 can be reached for the dry and wet route, respectively. The results indicate that based on current available technologies, the dry route has higher FER and the wet route has more potential in producing high valuable biofuels.

[1]  Charles A. Mullen,et al.  Bio-oil and bio-char production from corn cobs and stover by fast pyrolysis , 2010 .

[2]  T. Minowa,et al.  A novel microalgal system for energy production with nitrogen cycling , 1999 .

[3]  R. Geider,et al.  Redfield revisited: variability of C:N:P in marine microalgae and its biochemical basis , 2002 .

[4]  D. S. Dahiya,et al.  Deamination of amino acids by Bacillus pasteurii , 1984 .

[5]  Mark A. White,et al.  Environmental life cycle comparison of algae to other bioenergy feedstocks. , 2010, Environmental science & technology.

[6]  Nicholas Sazdanoff,et al.  Modeling and Simulation of the Algae to Biodiesel Fuel Cycle , 2006 .

[7]  R. Wijffels,et al.  An Outlook on Microalgal Biofuels , 2010, Science.

[8]  Illman,et al.  Increase in Chlorella strains calorific values when grown in low nitrogen medium. , 2000, Enzyme and microbial technology.

[9]  Lucas Reijnders,et al.  Microalgal and Terrestrial Transport Biofuels to Displace Fossil Fuels , 2009 .

[10]  W. J. Dyer,et al.  A rapid method of total lipid extraction and purification. , 1959, Canadian journal of biochemistry and physiology.

[11]  John Sheehan,et al.  An Overview of Biodiesel and Petroleum Diesel Life Cycles , 2000 .

[12]  Arnaud Hélias,et al.  Life-cycle assessment of biodiesel production from microalgae. , 2009, Environmental science & technology.

[13]  H. Oh,et al.  Comparison of several methods for effective lipid extraction from microalgae. , 2010, Bioresource technology.

[14]  Sanford Gordon,et al.  Computer program for calculation of complex chemical equilibrium compositions , 1972 .

[15]  C. Howe,et al.  Life-Cycle Assessment of Potential Algal Biodiesel Production in the United Kingdom: A Comparison of Raceways and Air-Lift Tubular Bioreactors , 2010 .

[16]  G. W. Van Gemert,et al.  The Delta dryer: Theoretical and technological development of an energy-efficient dryer for sludge , 2009 .

[17]  D. Batten,et al.  Life cycle assessment of biodiesel production from microalgae in ponds. , 2011, Bioresource technology.

[18]  Teresa M. Mata,et al.  Microalgae for biodiesel production and other applications: A review , 2010 .

[19]  J. Benemann,et al.  Look Back at the U.S. Department of Energy's Aquatic Species Program: Biodiesel from Algae; Close-Out Report , 1998 .

[20]  Shabbir H. Gheewala,et al.  Full chain energy analysis of biodiesel production from palm oil in Thailand , 2009 .

[21]  Samuel A. Lewis,et al.  Bio-oil upgrading over platinum catalysts using in situ generated hydrogen , 2009 .

[22]  Sergey Paltsev,et al.  Biomass Energy and Competition for Land , 2008, GTAP Working Paper.

[23]  Michael Q. Wang,et al.  The Energy Balance of Corn Ethanol: An Update , 2002 .

[24]  S. Amin.  Review on biofuel oil and gas production processes from microalgae , 2009 .

[25]  Q. Hu,et al.  Life-cycle analysis on biodiesel production from microalgae: water footprint and nutrients balance. , 2011, Bioresource technology.

[26]  Christoph Syldatk,et al.  Mechanical disruption of Arthrobacter sp. DSM 3747 in stirred ball mills for the release of hydantoin-cleaving enzymes , 1992 .

[27]  K. L Kadam,et al.  Environmental implications of power generation via coal-microalgae cofiring , 2002 .

[28]  Derk Willem Frederik Brilman,et al.  Catalytic and Non-catalytic Supercritical Water Gasification of Microalgae and Glycerol , 2010 .

[29]  Martin Hassebrauck,et al.  Two examples of thermal drying of sewage sludge , 1996 .

[30]  Kunio Yoshikawa,et al.  Study on the hydrothermal drying technology of sewage sludge , 2010 .

[31]  L. Lardon,et al.  Life-cycle assessment of microalgae culture coupled to biogas production. , 2011, Bioresource technology.

[32]  René H Wijffels,et al.  Potential of sponges and microalgae for marine biotechnology. , 2008, Trends in biotechnology.

[33]  Sujit Banerjee,et al.  Pilot study of impulse drying industrial sludge , 1998 .

[34]  F. Mercader,et al.  Pyrolysis oil upgrading for co-processing in standard refinery units , 2010 .

[35]  Yusuf Chisti,et al.  Response to Reijnders: Do biofuels from microalgae beat biofuels from terrestrial plants? , 2008 .