Feedstock For Biobutanol Production Research Articles

Exploring the potential of multiple lignocellulosic biomass as a feedstock for biobutanol production

To improve the cost-effectiveness of biobutanol production, lignocellulosic biomass is used as a cheap and sustainable feedstock. It provides fermentable sugars for microbial fermentation but lacks nitrogen resources and other nutrients. This study investigated the effects of combining multiple types of lignocellulosic biomass with nitrogen-rich wheat bran on ABE fermentation. Depending on the composition and fermentation effects, the optimal mixing ratio of wheat bran added with sugarcane bagasse, corncob and pine was 1:1, 1:4 and 2:3, respectively. The addition of corn steep powder as a nutritional source significantly enhanced sugar consumption and solvent concentration. Integration of pervaporation with ABE fermentation facilitated timely removal of butanol and alleviated product inhibition, resulting in a final total solvents concentration of 14.51 g/L, comparable to fermentation with TYA synthetic medium. This study demonstrates the feasibility of using combined lignocellulosic biomass to reduce feedstock costs and enhance the application of biobutanol production.

Enhancing starch accumulation/production in Chlorococcum humicola through sulphur limitation and 2,4- D treatment for butanol production

Depleting fuel resources is a global concern worldwide due to the unstable and cost of fuel resources. Increased transportation has gradually depleted the fossil-based fuel resources leading to find a cost-effective, readily available, and renewable source. Considering these issues, various private and government organizations have focussed on producing bio-based fuels from natural sources. In this scenario, algae are a potential emerging source of feedstock or biomass for biobutanol production, which can effectively replace fossil fuels and their environmental drawbacks. The present study focussed on evaluating the potential of freshwater microalga Chlorococcum humicola isolated from temple pond as feedstock for biobutanol production using Clostridium acetobutylicum. The results indicated that C. humicola produced 846.33 μgmg−1of starch under full strength Chu10 medium. While under sulphur and phosphorus limitation, the accumulation of starch was 947.33 μg mg−1 and 766.67 μgmg−1, respectively. Also, C. humicola was exposed to different concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D). At 10μgml−1 of 2,4-D, the highest starch concentration of 989μgmg−1was achieved in C. humicola. Finally, starch in C. humicola were hydrolysed and ABE fermentation was performed using C. acetobutylicum under anaerobic condition in a 5 L automated fermenter. After 72 h of fermentation, the fermented broth is analyed in Gas Chromatography showing the fermented product containing Acetone: Butanol: Ethanol. The present study is the first report on the production of biobutanol from C. humicola isolated from Temple pond. This study emphasizes the importance of local isolates of microalgae as a third-generation substrate to produce butanol to replace fossil-based fuels.

Biobutanol production from coffee silverskin

BackgroundCoffee silverskin, a by-product from coffee roasting industries, was evaluated as a feedstock for biobutanol production by acetone–butanol–ethanol fermentation. This lignocellulosic biomass contained approximately 30% total carbohydrates and 30% lignin. Coffee silverskin was subjected to autohydrolysis at 170 °C during 20 min, with a biomass-to-solvent ratio of 20%, and a subsequent enzymatic hydrolysis with commercial enzymes in order to release simple sugars. The fermentability of the hydrolysate was assessed with four solventogenic strains from the genus Clostridium. In addition, fermentation conditions were optimised via response surface methodology to improve butanol concentration in the final broth.ResultsThe coffee silverskin hydrolysate contained 34.39 ± 2.61 g/L total sugars, which represents a sugar recovery of 34 ± 3%. It was verified that this hydrolysate was fermentable without the need of any detoxification method and that C. beijerinckii CECT 508 was the most efficient strain for butanol production, attaining final values of 4.14 ± 0.21 g/L acetone, 7.02 ± 0.27 g/L butanol and 0.25 ± 0.01 g/L ethanol, consuming 76.5 ± 0.8% sugars and reaching a butanol yield of 0.269 ± 0.008 gB/gS under optimal conditions.ConclusionsCoffee silverskin could be an adequate feedstock for butanol production in biorefineries. When working with complex matrices like lignocellulosic biomass, it is essential to select an adequate bacterial strain and to optimize its fermentation conditions (such as pH, temperature or CaCO3 concentration).

Industrial potato peel as a feedstock for biobutanol production

Potato peel from a snack factory was assessed as possible feedstock for biobutanol production. This lignocellulosic biomass was subjected to various physicochemical pretreatments (autohydrolysis and hydrolysis with dilute acids, alkalis, organic solvents or surfactants) under different conditions of time, temperature and reagent concentrations, in order to favour the release of sugars and reduce the generation of fermentation inhibitors. Thereafter, the pretreated potato peel was treated enzymatically to complete the hydrolysis. Autohydrolysis at 140 °C and 56 min was the most effective pretreatment, releasing 37.9 ± 2.99 g/L sugars from an aqueous mixture containing 10% (w/w) potato peel (sugar recovery efficiency 55 ± 13%). The fermentability of the hydrolysates was checked with six strains of Clostridium beijerinckii, C. acetobutylicum, C. saccharobutylicum and C. saccaroperbutylacetonicum. C. saccharobutylicum DSM 13864 produced 2.1 g/L acetone, 7.6 g/L butanol and 0.6 g/L ethanol in 96 h (0.186 gB/gS), whereas C. saccharoperbutylacetonicum DSM 2152 generated 1.8 g/L acetone, 8.1 g/L butanol and 1.0 g/L ethanol in 120 h (0.203 gB/gS). Detoxification steps of the hydrolysate before fermentation were not necessary. Potato peel may be an interesting feedstock for biorefineries focused on butanol production.

Pre-treatment and enzymatic hydrolysis of lettuce residues as feedstock for bio-butanol production

The residue of the fresh-cut vegetable packaging process is a major environmental concern for food industries. Actually 50% of the processed vegetables must be disposed of. But the lettuce fraction sorted and deemed unsuitable to be bagged may be used as feedstock for butanol production because it is rich in sugars. In this work acetone butanol ethanol (ABE) was produced from enzymatic-hydrolysed Lactuca sativa leaves. The lettuce leaves were first pre-treated with NaOH and then hydrolysed. The NaOH concentration was increased up to 200 kg m−3, Cellic CTec 2 (Novozymes) was used for the hydrolysis. The sugars contained in the biomass hydrolysate were fermented in batch cultures of Clostridium acetobutylicum DSMZ 792. The fermentation process was characterized in terms of sugar conversion and ABE production. The hydrolysate of the NaOH-pre-treated lettuce contained glucose and xylose (about 50/50). Under optimal conditions the sugar concentration after the enzymatic hydrolysis was 19.5 g L−1, the ABE concentration was 1.44 g L−1 and the butanol concentration was 1.1 g L−1. Some tests were also carried out with synthetic mixtures of glucose and xylose to investigate the effects of the alkaline pre-treatment on the fermentation process.

POTENTIAL OF OIL PALM FROND LIQUID EXTRACT AND FIBER AS FEEDSTOCK FOR BIO-BUTANOL PRODUCTION

Oil palm frond is the most abundant yet untapped biomass in Malaysia. The objectives of the present work are to study the influence of the age of oil palms on productive sugar yield from oil palm frond extracts and to highlight the potential OPF liquid extract and fibers as feedstock for biobutanol production. Oil palm tree age between 5-10, 10-15 and 15-25 years were sampled for the study. The analysis was conducted using DNS method. The findings indicated that OPF petiole with the age limit of 15- 25years gives higher glucose concentration of 40.50g/L as compared with 17.85g/L of 5-10 years. Furthermore, the percentage carbon content of 41.04% and 37.45% obtained from the elemental analysis conducted using various micro elemental analyzers, indicated the suitability of OPF as a promising feedstock for biobutanol production.

Characterization and kinetics of bio-butanol production with Clostridium acetobutylicum ATCC824 using mixed sugar medium simulating microalgae-based carbohydrates

Our recent work showed that Chlorella vulgaris JSC-6 can accumulate over 50% carbohydrates per dry weight, which mainly contain glucose and xylose as the monosaccharides. In this study, synthetic mixed sugars simulating the hydrolyzed biomass of C. vulgaris JSC-6 (primarily containing glucose and xylose at a ratio of 5:1–6.5:1) was used as the carbon source for bio-butanol production with Clostridium acetobutylicum ATCC824. The growth and product formation kinetics based on glucose, xylose, and mixtures of the two sugars were determined using Monod-type and Michaelis–Menten models, respectively. C. acetobutylicum ATCC824 can grow faster and produce butanol more efficiently on glucose, while the performance was markedly poorer when using xylose. The butanol production kinetics were quite similar when using glucose alone or using mixed sugars (glucose to xylose ratio=5:1 or 6.5:1), resulting in a maximum butanol production rate of 0.89–0.93g/h/L. This work demonstrated the feasibility of using the microalgae-based carbohydrates as the feedstock for biobutanol production with C. acetobutylicum ATCC824.