Author(s)

A. K. Mathew, K. Chaney, M. Crook & A. C. Humphries

Abstract

Oilseed rape (OSR) straw can serve as a low-cost feedstock for bioethanol production. Glucose and other fermentable sugars were extracted from OSR straw using sulfuric acid pre-treatment and enzymatic hydrolysis. Batch fermentation of enzymatic hydrolysate with Saccharomyces cerevisiae immobilised in Lentikat® was found to be superior to free cells in terms of bioethanol yield. The maximum bioethanol concentration from free and immobilised cells was 6.73 and 9.45 g.l-1, respectively, with corresponding yields of 0.41and 0.49 g bioethanol. g glucose-1. Keywords: bioethanol, dilute acid pre-treatment, immobilisation, oilseed rape straw. 1 Introduction In 2007, consumption of liquid fuels in the transportation sector was 46 million barrels per day and is expected to increase by 67 million barrels per day by 2035 EIA [1]. In 2007, the use of liquid fuels was responsible for 38% of global greenhouse gas (GHG) emissions, providing a significant contribution to climate change EIA [1]. The replacement of gasoline (petrol) with bioethanol is encouraged globally as a mechanism to reduce exposure to volatility in the oil market, and minimise the extent to which road transport contributes to global warming. Bioethanol can be produced from two different types of feedstocks: first-generation feedstocks (maize, wheat and sugarcane) and second-generation feedstocks (lignocellulosic materials such as straws, forest residue or any agriculture waste) (Balat [2]). Commercial production of bioethanol from firstgeneration feedstocks is limited by land availability, and concerns regarding the

Keywords

bioethanol, dilute acid pre-treatment, immobilisation, oilseed rape straw.