Hydrolysis of Miscanthus for bioethanol production using dilute acid presoaking combined with wet explosion pre-treatment and enzymatic treatment

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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A Comparative Study of Bioprocess Performance for Improvement of Bioethanol Production from Macroalgae

Chemical and Biochemical Engineering Quarterly ◽

10.15255/cabeq.2018.1499 ◽

2019 ◽

Vol 33 (1) ◽

pp. 133-140 ◽

Cited By ~ 3

Author(s):

Benan İnan ◽

Didem Özçimen

Keyword(s):

Potassium Hydroxide ◽

Algal Biomass ◽

Treatment Time ◽

Treatment Temperature ◽

Biodiesel Production ◽

Marmara Sea ◽

Bioethanol Production ◽

Dilute Acid ◽

Pre Treatment ◽

Bioethanol Yield

In the last decade, studies that have focused on biodiesel production from algal biomass have been replaced with bioethanol production from algae, because bioethanol production from algae seems more promising when assessed on economic terms. Most coastal areas are covered with macroalgae, which are considered as a waste, and thus become a great problem for the municipality. Instead of their disposal, they can be alternatively utilized for bioethanol production. In this study, macroalgae located in the coastal regions of the Marmara Sea were collected and utilized for bioethanol production, and effects of the concentration of pre-treatment chemicals, pre-treatment temperature, and pre-treatment time on bioethanol yield were investigated. The highest bioethanol yields for dilute acid and alkaline pre-treatments were obtained under the conditions of 2 N sulfuric acid and 0.15 N potassium hydroxide solutions at the pre-treatment temperature of 100 °C and pre-treatment time of 60 minutes.

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Study of Pretreatment and Enzymatic Hydrolysis on Microcrystalline Cellulose and HVS A4 Paper in Pressurized CO2 Media

Modern Applied Science ◽

10.5539/mas.v9n7p16 ◽

2015 ◽

Vol 9 (7) ◽

pp. 16 ◽

Cited By ~ 1

Author(s):

Ian Eka Pramudita ◽

Marcella Lauditta Noviana ◽

Henky Muljana

Keyword(s):

High Performance Liquid Chromatography ◽

Enzymatic Hydrolysis ◽

Microcrystalline Cellulose ◽

Levulinic Acid ◽

High Performance ◽

Model Compound ◽

Bioethanol Production ◽

Fixed Temperature ◽

Pre Treatment ◽

Hydrolysis Of

The aim of this work is to investigate the potential used of pressurized CO2 in the pre-treatment and the enzymatic hydrolysis of waste HVS A4 paperto produce a monomeric sugars (C5 and C6 sugars) which is a precursor for bioethanol production. Prior to the utilization of waste HVS A4 paper, the microcrystalline cellulose and HVS A4 paper were first used in the experiments as model compound in order to gain better insights of the process. The experiment consists of two main parts which are the preliminary experimentsto determine the best pretreatment conditionsbetween two selected pressure values (80 and 100 bar) at a fixed temperature (T = 75 oC) and the enzymatic hydrolysis experiments. In the latter, the microcrystalline and HVS A4 paper were hydrolyzed at different pressures (100 bar, 125 bar, and 150 bar) and at different cellulase intakes (1% (v/v), 3% (v/v), and 5% (v/v)) with a fixed temperature (50°C). The hydrolyzed products were analyzed with a High Performance Liquid Chromatography (HPLC) to quantify the monomeric sugars and to determine the presence of the side products (furfural, HMF and levulinic acid). Within the experimental range, a maximum glucose concentration of 7602.35 ppm and 4560.79 ppm are obtained for microcrystalline and HVS A4 paper, respectively. In addition, there are no furfural, HMF and levulinic acid detected in the products This study shows a potential used of pressurized CO2 in the pretreatment and enzymatic hydrolysis of the model compound and gives a better insight for further application.

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