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Biodiesel represents a promising solution for sustainable energy needs, offering an eco-friendly alternative to conventional fossil fuels. In this research, we investigate the use of a catalyst derived from mussel shells to facilitate biodiesel production from Jatropha curcas oil. Our findings from X-ray Fluorescence (XRF) analysis emphasize the importance of carefully selecting calcination temperatures for mussel shell-based catalysts, with 1100 °C identified as optimal for maximizing CaO content. We identify a reaction time of 6 h as potentially optimal, with a reaction temperature of approximately 110 °C yielding the desired methyl ester composition. Notably, a methanol-to-oil ratio of 18:1 is the most favorable condition, and the optimal methyl ester composition is achieved at a calcined catalyst temperature of 900 °C. We also assess the stability of the catalyst, demonstrating its potential for reuse up to five times. Additionally, a thorough analysis of J. curcas Methyl Ester (JCME) biodiesel properties confirmed compliance with industry standards, with variations attributed to the unique characteristics of JCME. Comparing homogeneous (NaOH) and heterogeneous (CaO) catalysts highlights the potential of environmentally sourced heterogeneous catalysts to replace their homogeneous counterparts while maintaining efficiency. Our study presents a novel approach to sustainable biodiesel production, outlining optimal conditions and catalyst stability and highlighting additional benefits compared with NaOH catalysts. Therefore, utilizing mussel shell waste for catalyst synthesis can efficiently eliminate waste and produce cost-effective catalysts. [ABSTRACT FROM AUTHOR]

Catalytic co-pyrolysis behavior of food waste digestate (FD) and corn husk (CH) with CaO catalysts derived from calcining calcium hydroxide (CH–CaO) and calcium acetate monohydrate (CA-CaO) for upgrading bio-oil was studied. For co-pyrolysis process, the char yield decreased while the bio-oil and non-condensable gas yields increased with the CH/FD mass ratio increased. Compared to co-pyrolysis without catalysts, the relative contents of acids and esters in bio-oil decreased while the phenols increased in the case of catalytic co-pyrolysis. The relative contents of nitrogen-containing compounds (NCCs) increased with the presence of CaO catalysts. When the CH/FD mass ratio was 1/4, the relative content of nitrogen-containing components in bio-oil was 41.42% for co-pyrolysis without CaO catalysts, but increased to 45.10% and 52.03% with CH–CaO and CA-CaO catalysts, respectively. CaO catalysts also reduced the content of CO 2 and increased the contents of H 2 , CO and CH 4 in non-condensable gas. Compared to CH–CaO, CA-CaO exhibited better catalytic performance for upgrading bio-oil for the more developed porous structure and more basic sites. Furthermore, a reaction pathway and mechanism of main NCCs formation during co-pyrolysis of FD and CH with CaO catalysts was proposed. [Display omitted] • Co-pyrolysis of food waste digestate and corn husk with CaO catalysts was studied. • Addition of corn husk improved the pyrolysis behavior of food waste digestate. • CaO catalysts effectively reduced the oxygen-containing components in bio-oil. • Nitrogen-containing compounds in bio-oil was enriched with CaO catalysts. • A reaction pathway of nitrogen-containing compounds formation was proposed. [ABSTRACT FROM AUTHOR]

In this research work, the comparative analysis of the production of high yield and environmental friendly biodiesel obtained from the transesterification of waste soybean oil, using technical grade CaO catalyst and CaO catalyst derived from chicken eggshells, was investigated. The results of the transesterification process, SEM (using ME 600T polarising optical microscope) and XRF (using Thermo Scientific ARL OP-TIM'X 166) analysis revealed a similar catalytic performance trend when the two forms of the CaO catalysts were used separately. For technical grade CaO catalyst (using response optimizer), the optimal conditions established for the production of biodiesel were methanol/oil mole ratio of 7.1, catalyst concentration of 5.9 wt/wt% oil and reaction time of 2.1 hours, with 92.6% biodiesel yield. Using CaO catalyst derived from chicken eggshells, the optimal conditions were 7.0 methanol/oil mole ratio, 6.0 wt/wt% catalyst concentration and reaction time of 2.2 hours, with 91.4% biodiesel yield. Impact assessment of the biodiesel production was carried out using ReCiPe Endpoint (E) V1.12/World ReCiPe E/E method (SimaPro 8.0 software) and AAnalyst 200 Perkin Elmer (AAS). The results of the impact assessment showed that technical grade CaO catalyst has more negative impact on human health and a lesser impact on ecosystems. In contrast, CaO catalyst derived from chicken eggshells waste has a fairly lesser negative impact on human health and a fairly more pronounced negative effects on ecosystems. [ABSTRACT FROM AUTHOR]

The low cost and efficient CaO catalysts have been successfully prepared from chicken manure by a simple calcination, in this present work. Chicken manure contains significant content of calcium compounds that can easily be converted into the active calcium oxide catalyst after calcination at 850 °C under air. The Hammett indicator test showed that the obtained CaO catalyst has the basic strength in a range of 15 < H_ < 18.4, revealing that the basicity of the obtained catalyst is mainly ascribed to the strong basic properties of metal–O groups. The obtained CaO catalyst exhibited high catalytic activity for biodiesel production from transesterification of waste cooking oil and methanol. Up to 90% FAME yield was obtained at optimum reaction condition (i.e. 7.5 wt% of catalyst, 15:1 of methanol:oil molar ratio and 65 °C). The experimental kinetic data fitted well with the pseudo-first order model and the activation energy was found to be 78.8 kJ mol −1 . Moreover, fuel properties of the produced biodiesel were determined according to the European standard and found to be within the specifications. The uses of chicken manure as a catalyst source and waste cooking oil as a raw material for biodiesel production not only offers the environmentally friendly and cost-effective way to recycle those wastes, but also help to lower the biodiesel production cost to make biodiesel competitive with petroleum-based diesel. [ABSTRACT FROM AUTHOR]

Abstract: A series of CaO solids have been prepared by means of thermal treatment of the following precursors: carbonate, acetate, oxalate, nitrate, and two hydroxides obtained previously by precipitation of calcium acetate and nitrate in basic medium. These solids show distinct reaction rates in the catalytic transesterification of triglycerides with methanol to obtain biodiesel. An exhaustive characterization study using X-ray diffraction, N2 adsorption–desorption isotherms, infrared spectroscopy of pyrrole adsorbed, and temperature-programmed desorption of CO2 allowed us to determine the influence of the physicochemical properties (crystallite size, surface area and porosity) and surface basicity (amount and distribution of basic sites with different strength) on the overall catalytic activity. We have found that CaO obtained by decomposition of calcium carbonate, which shows the highest amount and surface density of very strong base sites, catalyzes triglycerides transesterification with higher rates. [ABSTRACT FROM AUTHOR]