Bioethanol production from agricultural residues as lignocellulosic biomass feedstock's waste valorization approach: A comprehensive review.

Bioenergy is becoming very popular, drawing attention as a renewable energy source that may assist in managing growing energy costs, besides possibly affording revenue to underprivileged farmers and rural populations worldwide. Bioethanol made from agricultural residual-biomass provides irreplaceable environmental, socioeconomic, and strategic benefits and can be considered as a safe and cleaner liquid fuel alternative to traditional fossil fuels. There is a significant advancement made at the bench scale towards fuel ethanol production from agricultural lignocellulosic materials (ALCM). These process technologies include pretreatment of ALCM biomass employment of cellulolytic enzymes for depolymerizing carbohydrate polymers into fermentable sugars to effectively achieve it by applying healthy fermentative microbes for bioethanol generation. Amongst all the available process methods, weak acid hydrolysis followed by enzymatic hydrolysis process technique. Recovering higher proficient celluloses is more attractive in terms of economic benefits and long-term environmental effects. Besides, the state of ALCM biomass based bioethanol production methods is discussed in detail, which could make it easier for the scientific and industrial communities to utilize agricultural leftovers properly.

Waste Ox bone based heterogeneous catalyst synthesis, characterization, utilization and reaction kinetics of biodiesel generation from Jatropha curcas oil.

The present investigation has been carried out to utilize waste animal (Ox) bone for the progress of an innovative, low-budget, pollution free, and extremely resourceful heterogeneous catalyst synthesis for Jatropha curcas oil (JCO) conversion into biodiesel. The heterogeneous catalyst synthesized was characterized by its basic strength and subjected to spectroscopic (Fourier TransformInfrared and X-Ray Diffraction) and thermogravimetric analyses. Also, the physical properties of produced biodiesel were studied. The calcined Ox bone catalyst characterization distinctly showed that there was a tremendous catalytic activity for biodiesel synthesis. The kinetic study was accomplished employing a tri-necked RB flask furnished with a condenser and agitator. At the agitation speed of 500 rpm, 5% catalyst loading rate (w/w) of oil and 12:1 methanol-oil ratio (molar), biodiesel yields were tracked based on reaction time (1-4 h) and temperature (313-338 K). The temperature at 338 K was found to be optimal to obtain maximum (96.82%) biodiesel yield. Pseudo-first order kinetics was followed in the reaction. The energy required for the activation (Ea) was 38.55 kJ mol-1 with a frequency factor (ko) of 7.03 × 106 h-1. The reusability studies demonstrated that the calcined animal bone catalyst was much stable up to three cycles with >90% FAME yield, which was reduced significantly (P < 0.05) to 61% in the fourth cycle. The outcome of this investigation brought to light the possibilities of utilizing calcined Ox bone catalyst and JCO as low-cost and frequently obtainable discarded waste materials that can be used as feedstock for the commercial-scale generation of biodiesel to fulfill the prospective community demands.