Optimization of direct conversion of wet algae to biodiesel under supercritical methanol conditions

Prafulla D. Patil, Veera Gnaneswar Gude, Aravind Mannarswamy, Shuguang Deng, Peter Cooke, Stuart Munson-McGee, Isaac Rhodes, Pete Lammers, Nagamany Nirmalakhandan

Research output: Contribution to journalArticle

246 Scopus citations


This study demonstrated a one-step process for direct liquefaction and conversion of wet algal biomass containing about 90% of water to biodiesel under supercritical methanol conditions. This one-step process enables simultaneous extraction and transesterification of wet algal biomass. The process conditions are milder than those required for pyrolysis and prevent the formation of by-products. In the proposed process, fatty acid methyl esters (FAMEs) can be produced from polar phospholipids, free fatty acids, and triglycerides. A response surface methodology (RSM) was used to analyze the influence of the three process variables, namely, the wet algae to methanol (wt./vol.) ratio, the reaction temperature, and the reaction time, on the FAMEs conversion. Algal biodiesel samples were analyzed by ATR-FTIR and GC-MS. Based on the experimental analysis and RSM study, optimal conditions for this process are reported as: wet algae to methanol (wt./vol.) ratio of around 1:9, reaction temperature and time of about 255°C, and 25. min respectively. This single-step process can potentially be an energy efficient and economical route for algal biodiesel production.

Original languageEnglish (US)
Pages (from-to)118-122
Number of pages5
JournalBioresource Technology
Issue number1
StatePublished - Jan 1 2011
Externally publishedYes



  • Biodiesel
  • Response surface methodology
  • Supercritical methanol
  • Wet algae

ASJC Scopus subject areas

  • Bioengineering
  • Environmental Engineering
  • Renewable Energy, Sustainability and the Environment
  • Waste Management and Disposal

Cite this

Patil, P. D., Gude, V. G., Mannarswamy, A., Deng, S., Cooke, P., Munson-McGee, S., Rhodes, I., Lammers, P., & Nirmalakhandan, N. (2011). Optimization of direct conversion of wet algae to biodiesel under supercritical methanol conditions. Bioresource Technology, 102(1), 118-122. https://doi.org/10.1016/j.biortech.2010.06.031