• Energy Research

Abstract Development of solid mixed oxide catalyst from waste biomass is a scarcely studied area. Thus, present protocol aims to prepare an environmentally friendly, efficient, renewable and recyclable heterogeneous base catalyst from Carica papaya stem. The chemical and structural properties of the catalyst were examined by Fourier-transform infrared spectroscopy (FTIR), X-ray diffractograms (XRD), Scanning electron microscopy (SEM), Energy Dispersive X-ray spectrometry (EDX), Transmission Electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis. The CO2-TPD and Hammett indicator test was conducted to determine the basicity of the prepared catalyst. The study revealed the presence of alkali and alkaline earth metals that provide the basic sites to facilitate transesterification reaction for biodiesel production and formation of benzylidenemalononitrile (BMN). The conversion of the waste cooking oil (WO) and Scenedesmus obliquus (SO) lipid to biodiesel was confirmed by the NMR and Gas chromatography Mass Spectroscopy (GC-MS) technique. Biodiesel conversions of 95.23% and 93.33% were achieved using 2 wt % catalyst loading under optimized reaction conditions for WO and SO respectively. Reusing the catalyst showed a slight drop in activity after 6 repeated uses. The reported catalyst has shown its potential as an alternative and cheaper green solid catalyst for biodiesel production and Knoevenagel reaction.

Waste biomass derived heterogeneous catalyst is an excellent alternative to chemically synthesized catalysts. In this work, calcined Tectona grandis leaves were proposed as an eco-friendly, renewable and low cost heterogeneous base catalyst. The prepared catalyst was examined by FTIR, XRD, XPS, SEM, EDX, TEM, TGA, BET and Hammett indicator test. The catalyst has an appealing nature towards various chemical transformations due to its basic surface sites provided by alkali and alkaline earth metals. The efficiency of the catalyst was successfully investigated by its application in biodiesel production. The products were confirmed by 1H and 13C NMR. 100% FAME conversion was attained using a catalyst loading of 2.5 wt% under optimized reaction parameters. The catalyst was further explored for Knoevenagel condensation reaction, in which it showed its effectiveness and recyclability towards the formation of benzylidenemalononitrile derivatives of aryl aldehydes. Thus, it is a potential 'green catalyst' derived from waste biomass without any addition of chemicals that can replace the industrial base catalysts used for biodiesel production and Knoevenagel reaction and makes the protocol environmentally benign.

Abstract Biodiesel production process encourages use of heterogeneous catalyst over homogeneous catalysts. The major problems associated with the use of homogeneous catalysts are its non-renewable nature, separation and washing which can be overcome by the use of heterogeneous catalysts. Therefore, in this work use of Musa balbisiana Colla peels, a waste biomass material has been used for preparing eco-friendly and highly effective heterogeneous base catalyst for sustainable biodiesel production. The peels of Musa balbisiana Colla have been characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffractograms (XRD), Energy Dispersive Analysis of X-ray (EDAX), Brunauer–Emmett–Teller (BET), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) analysis. The conversion of the waste cooking oil into biodiesel was confirmed by proton nuclear magnetic resonance (1H NMR), Carbon-13 nuclear magnetic resonance (13C NMR) and Gas Chromatography-Mass Spectroscopy (GC–MS) techniques. The peels of Musa balbisiana Colla furnished 100% conversion of waste cooking oil into biodiesel. Low cost, renewable heterogeneous catalyst from banana (Musa balbisiana Colla) peels can be developed for fatty acid methyl esters (FAME) production providing a new route for sustainability of fuels.

Homogeneous catalytic system for biodiesel synthesis is no longer justifiable by industries in the near future; mainly due to ecological issues related to the conventional homogeneous catalytic system like problems associated with separation of the catalyst from the product, reusability, and its release into the environment after washing the catalyst from the product. The present study is focused on the viability of environmentally benign heterogeneous catalyst synthesis from water hyacinth (WH) a renewable aquatic plant considered hazard for other useful aquatic crops. The synthesized catalyst was characterized by fourier transform infrared spectroscopy (FTIR), powder X-ray diffractograms (XRD), energy dispersive analysis of X-ray (EDAX), brunauer-emmett-teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and hammett indicator analysis. The catalyst demonstrated a superior catalytic performance achieving fatty acid methyl esters (FAME) conversion of 97.1 % in 3 h. The catalyst could be reused efficiently with FAME conversion of more than 80 % after the third cycles. The present work reveals the possibility of developing heterogeneous catalyst from an aquatic weed for FAME synthesis, reducing the total production cost of biodiesel synthesis.

Abstract Microalgae have been accepted as a potential feedstock for biofuel production due to their high oil content and rapid biomass production. In this study, deoiled Scenedesmus obliquus (SO) was used for evaluating whether deoiled algal biomass residue is potential as an alternative energy resource for bio-ethanol production with different heterogeneous catalysts. The SO biomass was examined for its physiochemical properties and also evaluated using FTIR, XRD, and TGA techniques. The successful hydrolysis of SO was performed employing different eco-friendly bio-based heterogeneous catalysts and hydrolysate thus obtained was then subjected to fermentation using Saccharomyces cerevisiaeand was analyzed through HPLC and GC which resulted in the production of bio-ethanol with the highest yield of 68.32 % at 8.24 g/L concentration.