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This study focuses on the extraction of nanocrystalline cellulose (NCC) from the dried stalk of Corchorus olitorius, commonly known as jute, using a combination of a microwave-assisted alkaline peroxide pulping process (AHP) and ultrasonication. Dried jute stalk powder was pretreated using sodium hydroxide under microwave irradiation for the removal of lignin. The partially delignified sample was bleached using 30% hydrogen peroxide solution. The resulting crude cellulose was hydrolyzed using ultrasonication in the presence of ionic liquid and sulfuric acid. The effect of hydrolyzing medium on the physicochemical characteristics of the extracted nanocellulose was investigated. The nanocrystalline cellulose (NCC) obtained after combined treatments was rod-like, with diameters of 10 to 15 nm and lengths of 92 to 105 nm. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD) showed that some breakages of intramolecular hydrogen bonds and glycosidic bonds occurred during the hydrolysis reaction of pretreated biomass. Ultrasonication in the presence of an acid hydrolyzing medium most effectively accelerated these breakages in the long chain cellulose biopolymer, leading to the formation of nanocrystalline cellulose (NCC) with higher crystallinity. [ABSTRACT FROM AUTHOR]

The viability of most fermentation processes is very much dependent on the cheap fermentation medium used. Palm kernel cake (PKC) is an abundant biomass generated from the palm oil processing industry that can be used as the carbon source for the growth and production of acetone-butanolethanol fermentation (ABE) by Clostridia. In this study, ABE production from the fermentation of PKC using Clostridium acetobutylicum YM1 in a batch culture was conducted. The PKC was subjected to treatment with acids (sulphuric and hydrochloric acids), alkali (sodium hydroxide and alkaline peroxide), enzymatic hydrolysis, and hydrothermal treatment (in autoclave). The sulphuric acid-treated PKC (2% SAPKC) method produced the highest concentration of reducing sugars (30 g/L) compared with the other methods applied. The results showed that increasing the concentration of H2SO4 up to 3% decreased the amounts of generated reducing sugars to 20.4 g/L, which is about 32% less. The fermentation of 1%, 2%, and 3% SAPKC resulted in the production of ABE of 1.07, 5.72, and 3.48 g/L, respectively. This study showed that the pretreatment of PKC improved the content of fermentable sugars and subsequently enhanced the production of ABE by C. acetobutylicum YM1. This study also revealed that PKC can be regarded as a potentially low cost substrate for ABE fermentation. [ABSTRACT FROM AUTHOR]

King Grass is a fast growing, high yield, hybrid grass that grows in a variety of soil conditions and does not compete with food crops. King Grass is perennial and can be harvested several times per year. Therefore it has a high potential for ethanol production in tropical countries. The pretreatments alkaline delignification (66.6–133 °C, 30–180 min, solid to liquid ratio 1:13.3–1:20 wt and NaOH concentration 0.7–2% wt), diluted acid hydrolysis (2% wt sulfuric acid, solid to liquid ratio of 1.0 g biomass/mL solution, stirring at 90 °C for 90 min), steam explosion (at 180 °C for 5 min, i.e., severity 3.05), alkaline peroxide (2% vol. H 2 O 2 , liquid to solid ratio of 20:1 wt, pH 11.5, stirring at 35 °C for 3 h) and aqueous ammonia soaking (15% wt ammonia solution, 8 mL of ammonia solution per gram of material, at 60 °C for 6 h) were studied. The alkaline pretreatment with NaOH led to the highest concentration of reducing sugars, i.e., 58.6 g/L, and to the highest ethanol concentration, i.e., 17.9 g/L. A more detailed study of the effect of the alkaline pretreatment conditions (temperature, solid to liquid ratio, NaOH concentration and residence time) on the production of ethanol from King Grass was carried out. Under pretreatment conditions of 120 °C for 1 h with 2% wt NaOH and a solid to liquid ratio of 1:20 the highest ethanol yield reported so far was obtained, i.e., 27.7 g/L (165.9 mg ethanol/g dry biomass, 92% of theoretical yield). Furthermore, this pretreatment allowed the removal of most of lignin present in King Grass, i.e., 94%, and allowed a high recovery of the cellulosic fraction in the solid (93–99%). Under typical growing conditions of King Grass in Colombia this maximum ethanol yield corresponds to 12,616 L/ha/year which is higher than that obtained from sugar cane bagasse (4602 L/ha/year). [ABSTRACT FROM AUTHOR]