Evaluation of Maximum Percentage Glucose Conversion for Dilute Acid Hydrolysis of Kenaf Biomass Using Statistical Analysis

Kenaf (Hibiscus cannabinus.L) is a crop- that produces about 70% of biomass larger than any of forest plantations. There is no specific way of using kenaf biomass in industry instead for animal feed and burning in various forms (waste in general). As a result, several researches had been conducted to utilize it in the production of biodegradable polymer as well as bioethanol. This is due to its complex cellulose content that is useful to be converted into glucose before further process. The conversion step from cellulose content of kenaf biomass into glucose is known as pre-treatment process. In this paper, dilute acid hydrolysis was chosen as the pre-treatment process. With the aim to evaluate the maximum percentage of glucose conversion for this kind of pre-treatment process from kenaf biomass, statistical analysis which is analysis of variance (ANOVA) design via central composite design using response surface method (RSM) was selected. Thus, the lower the mass which is at 2 g, and at higher temperature which is 180 oC in longer time which is in 60 min results about 25.33% glucose conversion with the comparison of the predicted value obtained from the experimental design.

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Bioethanol production from lignocellulosic sugarcane leaves and tops

Journal of Energy in Southern Africa ◽

10.17159/2413-3051/2017/v28i3a2354 ◽

2017 ◽

Vol 28 (3) ◽

pp. 1 ◽

Cited By ~ 6

Author(s):

Charlie Marembu Dodo ◽

Samphson Mamphweli ◽

Omobola Okoh

Keyword(s):

Acid Hydrolysis ◽

Sodium Hydroxide ◽

Cost Effective ◽

Enzyme Hydrolysis ◽

Fermentable Sugars ◽

Bioethanol Production ◽

Dilute Acid ◽

Dilute Acid Hydrolysis ◽

Pre Treatment ◽

Biological Methods

Bioethanol production is one of the most promising possible substitutes for fossil-based fuels, but there is a need to make available cost-effective methods of production if it is to be successful. Various methods for the production of bioethanol using different feedstocks have been explored. Bioethanol synthesis from sugarcane, their tops and leaves have generally been regarded as waste and discarded. This investigation examined the use of lignocellulosic sugarcane leaves and tops as biomass and evaluated their hydrolysate content. The leaves and tops were hydrolysed using concentrated and dilute sulphuric acid and compared with a combination of oxidative alkali-peroxide pre-treatment with enzyme hydrolysis using the enzyme cellulysin® cellulase. Subsequent fermentation of the hydrolysates into bioethanol was done using the yeast saccharomyces cerevisae. The problem of acid hydrolysis to produce inhibitors was eliminated by overliming using calcium hydroxide and this treatment was subsequently compared with sodium hydroxide neutralisation. It was found that oxidative alkali pre-treatment with enzyme hydrolysis gave the highest yield of fermentable sugars of 38% (g/g) for 7% (v/v) peroxide pretreated biomass than 36% (g/g) for 5% (v/v) with the least inhibitors. Concentrated and dilute acid hydrolysis each gave yields of 25% (g/g) and 22% (g/g) respectively, although the acid required a neutralisation step, resulting in dilution. Alkaline neutralisation of acid hydrolysates using sodium hydroxide resulted in less dilution and loss of fermentable sugars, compared with overliming. Higher yields of bioethanol of 13.7 g/l were obtained from enzyme hydrolysates than the 6.9 g/l ethanol from dilute acid hydrolysates. There was more bioethanol yield of 13.7 g/l after 72 hours of fermentation with the yeast than the 7.0 g/l bioethanol after 24 hours.This research showed that it is possible to use sugarcane waste material to supplement biofuel requirements and that combining the chemical and biological methods of pretreatments can give higher yields at a faster rate.

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