Repository logo
 

Faculty of Applied Sciences

Permanent URI for this communityhttp://ir-dev.dut.ac.za/handle/10321/5

Browse

Filters

20152

Settings

Has files: NoSubject: search.filters.subject.Lipase

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Biocatalytic conversion of lipids from microalgae Scenedesmus obliquus to biodiesel using Pseudomonas fluorescens lipase
    (Elsevier, 2015-01-31) Guldhe, Abhishek; Singh, Bhaskar; Rawat, Ismail; Perumal, Kugen; Bux, Faizal
    Conversion of microalgal lipids using biocatalyst is a novel and greener approach to produce biodiesel. Free and immobilized lipases from Candida sp. and Pseudomonas fluorescens along with free lipases from porcine pancreas and wheat germ were screened for biodiesel conversion of Scenedesmus obliquus lipids. Among selected lipases from various sources immobilized lipase from P. fluorescens showed superior biodiesel conversion. Optimization of reaction parameters viz. lipase amount, temperature, methanol to oil molar ratio and water content was carried out using response surface methodology. Best conversion of 66.55% was achieved at 35 °C, methanol to oil ratio of 3:1 with 10% enzyme amount and 2.5% water content based on oil weight. To tackle methanol tolerance step-wise methanol addition was applied, which improved biodiesel conversion upto 90.81%. Immobilized P. fluorescens lipase can be used for 4 batches without much loss in conversion efficiency (>95%). Biodiesel produced has the cetane number of 51.77, Calorific value of 37.67 MJ kg−1. Most of the fuel properties of biodiesel met the specifications set by ASTM and EN standards.
  • No Thumbnail Available
    Item
    Advances in synthesis of biodiesel via enzyme catalysis : Novel and sustainable approaches
    (Elsevier, 2015-01) Singh, Bhaskar; Mutanda, Taurai; Permaul, Kugen; Bux, Faizal; Guldhe, Abhishek
    Biodiesel, a renewable fuel has a great potential in fulfilling an ever-increasing transport fuel demand. The enzymatic conversion process of feedstock oil to biodiesel is greener when compared to the conventional approach of chemical conversion due to mild reaction conditions and less wastewater generation. Lipases obtained from various microbial sources have been widely applied as catalysts for the conversion of oil to biodiesel. Biodiesel and glycerol obtained by enzymatic conversion have shown a higher purity as compared to that obtained by other conversion techniques. Enzymatic conversion of oil to biodiesel is less energy intensive because of milder reaction conditions and fewer purification steps involved in processing. Lipases, due to their catalytic efficiency and specificity, have emerged as a great tool for converting a wide range of feedstock oils to biodiesel. This manuscript presents an overview of the use of enzymatic conversion for making biodiesel production sustainable and environmentally-friendly. The constraints of enzymatic conversion are the high cost of the enzyme and its inhibition by alcohol and glycerol. The possible solutions to overcome these constraints are discussed. Recent advances to develop an effective process for enzymatic conversion of feedstock oils into biodiesel are critically evaluated. Prospective and challenges in scaling up of this technology are also discussed.