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Ebshish A.,National University of Malaysia | Yaakob Z.,National University of Malaysia | Narayanan B.,Sree Neelakanta Government Sanskrit College | Bshish A.,National University of Malaysia | Wan Daud W.R.,National University of Malaysia
Energy Procedia | Year: 2012

Momentous amount of glycerol is produced as a by-product during bio-diesel production by the transesterification of vegetable oils, which are available at low cost in large supply from renewable raw materials. As hydrogen is a clean energy carrier, conversion of glycerol to hydrogen is one among the most attractive ways to make use of glycerol. In this study, the catalytic production of hydrogen by steam reforming of glycerol has been experimentally performed in a fixed-bed reactor. The performance of this process was evaluated over 10wt% Ni supported alumina xerogel catalysts. Ni is impregnated over alumina xerogel which was pretreated at different temperatures of 700°C, 800°C, 900°C and 1000°C. For a comparative purpose, the steam reforming experiments were conducted under same operating conditions, i.e., reaction temperature of 600°C, atmospheric pressure and 1:6 glycerol to water molar ratio where we are getting 100% glycerol conversion in all the runs. The results showed that the hydrogen production increased with the increase in the treatment temperature of the support. The highest amount of hydrogen produced was attained over 10wt% Ni doped alumina xerogel pretreated at 1000°C. The catalytic enhancement over the best catalyst system is due to the thermal stability of the support which is treated at highest temperature. Sol gel method of preparation is implemented in the support development and different catalyst systems used in the reforming process were characterized using X-ray powder diffraction, BET surface area and SEM analysis. © 2012 Published by Elsevier Ltd.

Remakanthan A.,Sree Neelakanta Government Sanskrit College | Menon T.G.,Rajiv Gandhi Center for Biotechnology | Soniya E.V.,Rajiv Gandhi Center for Biotechnology
In Vitro Cellular and Developmental Biology - Plant | Year: 2014

An improved, rapid, reproducible, and simple protocol has been developed for somatic embryogenesis in banana cv. 'Grand Naine' using explants derived from actively growing multiple shoot cultures. Many restrictive factors remain in banana embryogenesis such as long duration, unpredictability, and a high degree of genotype dependence. In the present study, we used split shoot tips from 4-wk-old cultures as explants. Somatic embryos were induced in 15 d directly in Murashige and Skoog (MS) medium supplemented with different combinations of 0-8.28 μM picloram and 0.22-4.44 μM 6-benzylaminopurine (BA) without callus formation. Maximum embryo induction (100%) occurred when 4.14 μM picloram and 0.22 μM BA were used. Conversion of somatic embryos into plantlets occurred sporadically (2-3%) in MS medium containing α-naphthalene acetic acid (NAA; 0.53-2.68 μM) together with BA (2.22-44.39 μM), or thidiazuron (4.54 μM) plus glutamine (200 mg/L). This protocol is far superior to those already reported for fast and high frequency induction of somatic embryo. In liquid agitated culture, individual embryos separated easily and produced a large number of secondary embryos within 10 d which, upon transfer to filter paper overlaid on MS liquid medium supplemented with 4.44 μM BA, resulted in conversion (3%) into plantlets. © 2013 The Society for In Vitro Biology.

Yaakob Z.,National University of Malaysia | Sukarman I.S.B.,National University of Malaysia | Narayanan B.,Sree Neelakanta Government Sanskrit College | Abdullah S.R.S.,National University of Malaysia | Ismail M.,National University of Malaysia
Bioresource Technology | Year: 2012

Transesterification reaction of Jatropha curcas oil with methanol was carried out in the presence of ash generated from Palm empty fruit bunch (EFB) in a heterogeneous catalyzed process. The ash was doped with KOH by impregnation to achieve a potassium level of 20. wt.%. Under optimum conditions for the EFB-catalyzed (65 °C, oil/methanol ratio of 15, 90. min, 20. wt.% EFB ash catalyst) and the KOH-EFB-catalyzed reactions (65 °C, oil/methanol ratio of 15, 45. min, 15. wt.% of KOH doped EFB ash), biodiesel (>98%) with specifications higher than those stipulated by European biodiesel quality standard EN 14214 was obtained. © 2011 Elsevier Ltd.

Binitha N.N.,Sree Neelakanta Government Sanskrit College | Binitha N.N.,National University of Malaysia | Yaakob Z.,National University of Malaysia | Resmi R.,Sree Neelakanta Government Sanskrit College
Central European Journal of Chemistry | Year: 2010

Synthesis of various zirconium doped titania based photocatalysts were carried out by adapting different synthetic strategies. Doping is done on commercially available anatase titania, sol-gel titania and template mediated sol gel titania. A comparative study of the various prepared photocataysts was done using physico-chemical characterization techniques such as X-ray diffraction (XRD), surface area- pore volume measurements, UV-VIS Diffuse reflectance spectra (DRS), elemental analysis (XRF) and transmission electron microscopic (TEM) studies. The effect of zirconium and preparation methods on the photocatalytic degradation of methylorange is studied extensively. Both the surface properties and photo activity of zirconium doped titania were found to have a great dependence on the preparation methods. Among the different photocatalytic systems, the catalyst prepared by doping in the presence of urea template was found to produce a maximum photodegradation of 97.5%. © Versita Warsaw and Springer-Verlag Berlin Heidelberg.

Bshish A.,National University of Malaysia | Yaakob Z.,National University of Malaysia | Narayanan B.,National University of Malaysia | Narayanan B.,Sree Neelakanta Government Sanskrit College | And 2 more authors.
Chemical Papers | Year: 2011

Production of hydrogen by steam-reforming of ethanol has been performed using different catalytic systems. The present review focuses on various catalyst systems used for this purpose. The activity of catalysts depends on several factors such as the nature of the active metal catalyst and the catalyst support, the precursor used, the method adopted for catalyst preparation, and the presence of promoters as well as reaction conditions like the water-to-ethanol molar ratio, temperature, and space velocity. Among the active metals used to date for hydrogen production from ethanol, promoted-Ni is found to be a suitable choice in terms of the activity of the resulting catalyst. Cu is the most commonly used promoter with nickel-based catalysts to overcome the inactivity of nickel in the water-gas shift reaction. γ-Al 2O3 support has been preferred by many researchers because of its ability to withstand reaction conditions. However, γ-Al 2O3, being acidic, possesses the disadvantage of favouring ethanol dehydration to ethylene which is considered to be a source of carbon deposit found on the catalyst. To overcome this difficulty and to obtain the long-term catalyst stability, basic oxide supports such as CeO2, MgO, La2O3, etc. are mixed with alumina which neutralises the acidic sites. Most of the catalysts which can provide higher ethanol conversion and hydrogen selectivity were prepared by a combination of impregnation method and sol-gel method. High temperature and high water-to-ethanol molar ratio are two important factors in increasing the ethanol conversion and hydrogen selectivity, whereas an increase in pressure can adversely affect hydrogen production. © 2011 Institute of Chemistry, Slovak Academy of Sciences.

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