A Comprehensive Approach to Utilize an Agricultural Pea peel (Pisum sativum) Waste as a Potential Source for Bio-ethanol Production

In the present study, a Central Composite Design (CCD) from Response Surface Methodology (RSM) was adopted to produce bio-ethanol using pre-treated pea peel (Pisum sativum). With an aim to achieve optimal yield the concentration of acid load; 1.0, 1.5 and 2.0%, treatment time; 15, 30 and 45 min, and temperature in the range of 100, 110 and 120 degrees C was selected. Solid P. sativum loading of 10% (w/v) was selected during pre-treatment. After dilute sulfuric acid pre-treatment maximum increase in glucose content (35.97%) of pea peel was achieved at their optimized conditions (1.80%, 30min. and 120 degrees C). Maximal yield of glucose (after 72 h) from pea peel after dilute sulfuric acid pretreatment and enzymatic saccharification (50 degrees C, pH 4.8 and 120 rpm) by using an enzyme loading of 0.11 g celluclast 1.5 g/L cellulase and 0.05 g cellubiase/g was 17.72 g/L. Fermentation, the last and important step of bio-ethanol production was carried out using fermentative fungal S. bayanus and F. oxysporum. The bio-ethanol yield from pre-treated enzyme saccharified pea peel solid fraction (50 g) by S. bayanus at pH 4.8, and 25 degrees C in 72h was 0.37 g/g of available glucose and 0.16 g/g of dry pea peel whereas in case of F. oxysporum under the same conditions except at pH 6, the ethanol yield was 0.29 g/g of available glucose and 0.13 g/g of dry matter. From these results we come to know that pea peel can also prove a better candidate for bio-ethanol production on large scale.