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The present work aimed at the standardization of transesterification process parameters for the production of methyl ester of filtered neem oil and fuel characterization for engine performance. The effect of process parameters such as molar ratio, preheating temperature, catalyst concentration and reaction time was studied to standardize the transesterification process for estimating the highest recovery of ester with lowest possible viscosity. Based on the observations of the ester recovery and kinematic viscosity, it was found that filtered neem oil at 6:1 M ratio (methanol to oil) preheated at 55 °C temperature and maintaining 60 °C reaction temperature for 60 min in the presence of 2 percent KOH and then allowed to settle for 24 h in order to get lowest kinematic viscosity (2.7 cSt) with ester recovery (83.36%). Different fuel properties of the neem methyl ester and neem oil were also measured. Results show that the methyl ester of neem obtained under the optimum condition is an excellent substitute for fossil fuels.

Abstract The combined effect of anions of ionic liquids (IL) and anti-solvents on pre-treatment and dissolution mechanisms of biomass are not well studied. To reveal the above effect, three different ionic liquids composed with fixed cation ([EMIM]+) but varied anions were studied for Miscanthus dissolution. Results showed that [EMIM]+[Ac]– was very good in altering the cellulose structure and crystallinity followed by enzymatic digestibility with a sugar yield of 0.98 (g/g of cellulose). The IL [EMIM]+[HSO4]– was very efficient to remove lignin and partially solubilize hemicellulose, however, the sugar yield was low (0.43 g/g of cellulose) compared with [EMIM]+[MeSO3]– and even the untreated Miscanthus. The regenerated biomass with water-acetone mixture (1:1 v/v) as anti-solvent resulted in higher glucose yield. The hydrogen bond basicity (β value) correlated well with cellulose crystallinity, lignin removal, and glucose yield.

Abstract For meeting the increasing demand of energy, biohydrogen production is to be considered in higher yield. Biohydrogen can be produced both by dark and photofermentative process. In this study, the photofermentative pathway is followed by using dl malic acid (IUPAC name: 2-hydroxybutanedioic acid, molecular weight: 134.08744 g mol −1 , molecular formula: C 4 H 6 O 5 ) as carbon source. Pure strain of purple non-sulfur (PNS) bacteria: Rhodobacter sphaeroides strain O.U.001 was studied to produce biohydrogen using the photobioreactor. The photobioreactor was constructed aiming the uniform light distribution. The objective of this study was to investigate the performance of 1 L annular photobioreactor operating in indoor conditions. The highest rate of hydrogen production was obtained at 92 h. In the designed photobioreactor, using Rhodobacter sphaeroides strain O.U.001 (initial dl malic acid concentration of 2.01 g L −1 ) at an initial pH of 6.8 ± 0.2, temperature 32 ± 2 °C, inoculum volume 10% (v/v), inoculum age of 48 h, 250 rpm (rotation per minute) stirring and light intensity of 15 ± 1.1 W m −2 , the average H 2 production rate was about 6.5 ± 0.1 mL H 2 h −1 L −1 media and yield 4.5 ± 0.05 mol of H 2 mol −1 of dl malic acid. Luedeking–Piret model was applied for the data fitting to determine the relationship between the cell growth and photofermentative hydrogen production. The photofermentative hydrogen production by this PNS bacterium was found to be microbial mixed growth associated function.

Abstract Bamboo forms an important component in the traditional landscape of North East India. For biomass estimation of village bamboos of Barak Valley, North East India, allometric relationships were developed by harvest method describing leaf, branch and culm biomass with DBH as an independent variable using a log linear model. The culm density of the stand was 8950 culms ha−1 during 2005 of which 67% of growing stock was represented by Bambusa cacharensis, 17.88% by Bambusa vulgaris and 15.12% by Bambusa balcooa. Above ground stand biomass was 121.51 t ha−1 of which 86% was contributed by culm component followed by branch (10%) and leaf (4%). With respect to species, B. cacharensis made up to 46% of total stand biomass followed by B. vulgaris (28%) and B. balcooa (26%). Carbon storage in the above ground biomass was 61.05 t ha−1. Allocation of C was more in culm components (53.05 t ha−1) than in branch (5.81 t ha−1) and leaf (2.19 t ha−1). Carbon storage in the litter floor mass was 2.40 t ha−1, of which leaf litter made up the highest amount (1.37 t ha−1) followed by sheath (0.86 t ha−1) and branch (0.17 t ha−1). Carbon stock in the soil up to 30 cm depth was 57.3 t ha−1. Gross C stock in the plantation was estimated to be 120.75 t ha−1. Carbon storage estimated in the bamboo stand of present study offers insights into the opportunity of village bamboos in the rural landscape for carbon storage through carbon sequestration. Management and utilization of village bamboos as a potential source of carbon sink by smallholder farmers are discussed in the context of their livelihood security and the Millennium Development Goals of the United Nations.

Abstract Bioethanol production from dry cashew apple pulp and coffee pulp was investigated. The pulp was digested with 2% sulfuric acid and subjected to high pressure (15 psi) cooking at 120 °C for 10 min followed by further 1 and a half hour pressure cooking at 90 °C to solubilize the pulp. Solubilized pulp was filtered and the debris on the filter paper was washed with minimum quantity of distilled water and then oven dried to find the weight of the insoluble lignin mass. Total sugar content in squeezed and dried cashew apple pulp (CAP), dry coffee pulp (DCP) and wet coffee pulp (WCP) was found to be 2.12, 1.62 and 0.62 g/100 ml of hydrolyzate. Reducing sugar content in squeezed CAP, DCP and WCP was found to be 0.14, 0.71and 0.23g/100 ml of hydrolyzate. Filtrate was neutralized with thick suspension of calcium hydroxide slurry until the pH reaches to 6.0. Neutralized slurry was kept at lab temperature overnight and the supernatant was decanted through filter paper. To 150 ml of filtrate yeast ( Saccharomyces creviciae ) was added at a concentration of 5.0 g/l concentration and subjected to fermentation for 48 h at 30 °C in a shaker incubator at 120 rpm. Ethanol content in the fermented broth was estimated by titrimetric and gas chromatographic method. Ethanol yield in the fermented broth was found to be 0.5, 0.46 and 0.46 g/g of sugar in squeezed CAP, DCP and WCP. Theoretical ethanol yield ( Y max %) of squeezed CAP, DCP and WCP was found to be 46, 9.35 and 40% respectively.

Abstract Water samples collected from the Northern region of India were used for isolation of anoxygenic photosynthetic (purple non-sulfur) bacterial isolate. The isolate was grown in modified Sistrom’s media at pH 7.0 and characterized as new strain of Rhodobacter sphaeroides NMBL-01 by 16S rDNA sequencing analysis and used for current study. Effect of pH on growth kinetics of the bacteria showed maximum growth rate at pH 8.0 using malic acid as carbon source. The effect of C/N ratio (molar ratio of carbon to nitrogen) at 1.5, 5, 10, 13, 15, 20, 25, 30, 40, 50 and 80 using malate as carbon and glutamate/ammonium sulfate as nitrogen source on hydrogen production was investigated. The maximum hydrogen potential and hydrogen production rate were 2000 ± 45 cm3 m−3 and 11.8 cm3 m−3 h−1, respectively, at C/N 13 using glutamate (1.7 mmol m−3) as nitrogen source and malate (3 g m−3) as carbon source with 66.5% malate conversion efficiency at initial medium pH 8.0. Further optimization of hydrogen production was performed keeping nitrogen source, glutamate (1.7 mmol m−3) constant with variable concentration of different carbon sources (succinate, butyrate, malate and acetate). The bacteria produced maximum hydrogen using malic acid at a concentration of 4 g m−3 as source of carbon, i.e. 2755 ± 32 cm3 m−3 with 68.3% conversion efficiency followed by succinate (1980 ± 25 cm3 m−3 with 58% conversion), butyrate (1400 ± 12 cm3 m−3 with 14.1% conversion) and acetate (650 ± 12 cm3 m−3 with 23.2% conversion).

Jatropha curcas L. (physic nut) has drawn attention in recent years as a source of seed oil that can provide an economically viable substitute for diesel. Very little work on provenance trials and genetic resources of J. curcas L. has been reported so far. Though J. curcas grows widely in India and several collections of the plant are also maintained, pedigree and provenance records are not always available. This article reports our studies on the diversity amongst the accessions of J. curcas L., both amongst already held collections as well as from a few locations in the wild. Two single-primer amplification reaction (SPAR) methods were used for this purpose. The accessions from the North East were most distant from all other accessions in UPGMA analysis. The NBRI, Bhubaneshwar and Lalkuan accessions were more related to each other. The UPGMA tree clearly shows well-separated accession groups: NBRI, Bhubaneshwar, North East, Lalkuan and Outgroup. The study suggests that this relatively recently introduced plant species shows adequate genetic diversity in India and that the SPAR methods are useful for a rapid assessment of the same. The methods provide important tools for analyzing the diversity within the available collections to shortlist the parental lines for adaptability trials and further improvement of Jatropha plants.

Abstract Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy demand of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (Note: 35 Rs approximates to $US 1.)

Abstract The hydrothermal pretreatment route is gaining research interest as a potentially green method for deconstructing lignocellusic biomass. Based on the relevant literature, the conversion of biomass into platform chemicals or energy carriers through hydrothermal processes has been found to be advantageous by reason of enhanced process performance, while being environmentally friendly and technologically innovative. In this review, an assessment has been made of recent research findings and reservations in regard to the synthesis of subcritical and supercritical hydrolysates and the production of platform chemicals namely ethanol, butanol, furfural, hydroxymethylfurfural, lactic acid, levulinic acid and its derivatives, succinic acid, sorbitol, and xylitol. This review also proposes a number of future research-oriented directions to harness the findings of primary research-oriented efforts for developing technically and economically feasible large-scale systems.