A review of heterogeneous calcium oxide based catalyst from waste for biodiesel synthesis

Abstract

Biodiesel is one of the most promising method to replace the fossil fuels because it is more environmentally friendly. Nevertheless, biodiesel manufacturing costs are much higher compared to conventional fossil fuels. Thus, the biodiesel should be synthesizing from reusable wastes to minimize the production cost. Homogeneous catalyst is the most common catalyst employed in the commercial biodiesel field. However, there are some drawbacks in using homogeneous catalyst in the reaction such as the difficulties faced in separation process of the homogeneous catalyst from the mixture of product. The presence of promising current technology has proved that the utilization of heterogeneous catalyst can assist in overcoming the existing problem of homogeneous catalytic reaction, especially in wastewater generation. The heterogeneous catalysts are more environmentally friendly, easier to separate and its reusability property. Despite its low production cost and its beneficial use as an eco-friendly waste recycle method, waste materials may possess qualities and characteristics that differ from the conventional homogeneous catalyst prior to biodiesel production. This review paper focused in the recent discovery of the heterogeneous catalyst synthesized from natural bio-waste materials, especially CaO-based such as eggshells, seashells and bones for biodiesel production. Apart from that, gypsum, part of the construction waste is proposed as the newly found heterogeneous catalyst. Gypsum exists abundantly due to the rapid development of the economics where construction and demolition activities are happening daily. The utilization of these construction waste-based catalysts may able to provide a sustainable route for biodiesel production. This review will enhance the development and existing scientific data in the area of biodiesel production and the synthesis of CaObased catalyst especially the synthesis of CaO-based catalysts from construction material.

Modification and characterization of chicken eggshell for possible catalytic applications

“…Investigations have revealed that chicken eggshells which hitherto have been considered as dumpsite waste can be recovered, reused, and regenerated to enhance their applications. Various researchers have experimented with the utilization of chicken eggshells as an environmentally friendly catalyst for transesterification reactions with good and encouraging outcomes [10,11,12,13].…”

State of Art of Alkaline Earth Metal Oxides Catalysts Used in the Transesterification of Oils for Biodiesel Production

“…Additionally, transition metal oxides, zeolites, or activated carbon can also function as catalysts with acidic functionalities [69]. The use of solid catalysts derived from biomass such as diatomic earth, animal bones, seashells, or eggshell, has been proposed as more ecological alternatives [70]. This vast catalog of catalysts allows choosing the best system depending on the nature and quality of the oil, its availability, and the economic situation of the biorefinery or rural plant.…”

Efficient biodiesel production from oleic and palmitic acid using a novel molybdenum metal–organic framework as efficient and reusable catalyst

“…Traditional biodiesel production methods utilize homogeneous conditions in the presence of bases or an acid catalyst such as sulfuric acid and sodium hydroxide 8 .These homogeneous systems suffer from limitations such as corrosion of reactors, difficult recovery and recyclability of catalyst and environmental pollution 9 , 10 . In this context, heterogeneous catalysts provide more advantages over homogeneous catalysts, such as recyclable 10 , 11 , ease separation-purification process 12 , high glycerol purity 13 , and not corrosive 14 . To date, numerous solid acid and base catalysts with tunable structural and surface functionalities have been offered, and many of them shows high catalytic activity for biodiesel production yield.…”