Economics of biodiesel production: Review

Biodiesel production is commonly carried out through the process of transesterification reaction. The reaction is expedited with a suitable catalyst either homogeneous or heterogeneous. The selection of an appropriate catalyst depends on the amount of free fatty acids in the oil. Recently, homogeneous catalysts are widely chosen for biodiesel production in large scale operation. However, they are toxic, highly flammable and corrosive in nature. Furthermore, the use of homogeneous catalyst produced soaps as by-product and large amount of wastewater that required additional processing technologies and cost for proper disposal. On the contrary, heterogeneous catalysts are capable to overcome the problems faced by the former ones. However, they were mostly derived from non-renewable resources, highly expensive with low stability. Recently, heterogeneous catalysts derived from biological waste have gotten more attention. This type of catalysts offers several advantages, including renewable resources, non-toxic, reusable, high catalytic activity, stability in both acidic and basic conditions and high water tolerance properties, which depend on the amount and strengths of active acid or basic sites. Basic catalyst can be subdivided based on the type of metal oxides and their derivatives. Similarly, acidic catalyst can be subdivided depending upon their active acidic sites. In this article, efforts have been taken to review the bio-based heterogeneous catalyst utilized for sustainable biodiesel production and their suitability for industrial application. Catalyst generated from bio-waste and other biocatalysts, which are heterogeneous in nature and extensively reported in literature are also reviewed. The utilization of these biomass derived catalysts provides a greener synthesis route for biodiesel production.

A review of biomass-derived heterogeneous catalyst for a sustainable biodiesel production

Biodiesel, which could be derived from plant oils and animal fats, is considered as a promising substitute for petroleum diesel fuel because of its advantages, such as renewability, biodegradability, less environmental toxicity, and superior combustion efficiency. The feedstock used for biodiesel production primarily include edible oils, non-edible oils, waste oils, and animal fats. Consistent scientific investigations are performed to locate innovative oil resources and minimize the utilization of expensive food-grade oils for biodiesel production. The extensive research information is available on the determination of physico-chemical properties of different plant oils. This review will present a general information related to the existing varieties of oil feedstocks, their lipid content, and fatty acid composition. This article further discusses different methods employed to enable the usage of plant oils as biofuel, such as its direct use, blending, thermal cracking, microemulsion, and alcoholysis process. Among the possible methodologies for biodiesel production, alcoholysis process, in the presence or absence of a catalytic material, have been frequently employed. The benefits and limitations of using homogeneous, heterogeneous, enzyme catalysts, and supercritical method for the alcoholysis process are comprehensively discussed. In the current article, efforts have been made to review the recent inventions in homogeneous and heterogeneous catalytic materials utilized for biodiesel production. The present study shall provide a tool for the selection of an optimal catalyst for a large-scale biodiesel production.

A review on recent advancement in catalytic materials for biodiesel production.

Valorization of biomass to hydroxymethylfurfural, levulinic acid, and fatty acid methyl ester by heterogeneous catalysts

Egg shell waste as heterogeneous nanocatalyst for biodiesel production: Optimized by response surface methodology.

Characterization of calcium oxide catalysts from natural sources and their application in the transesterification of sunflower oil

Characterization and application of dolomite as catalytic precursor for canola and sunflower oils for biodiesel production

Chitosan, an abundant biopolymer extracted from crustacean shells, can be used as a structuring agent by the insertion of calcium oxide and used as a catalyst in transesterification reactions. These calcium-incorporated chitosan spheres were calcined in order to obtain a porous calcium catalyst without organic material. The materials were characterized using X-ray diffraction, thermogravimetric analysis, Fourier transform infrared and X-ray photoelectron spectroscopies, temperature-programmed desorption of CO2, scanning electron microscopy and specific surface area analysis. Afterwards the calcined calcium/chitosan spheres were used in the transesterification reaction of sunflower oil with methanol. The conversion of sunflower oil to methyl esters (YFAME), under optimized reaction conditions, which were determined by factorial experimental design (XMR, 1:9; XCAT, 3 wt%; time, 4 h; temperature, 60 °C; magnetic stirring, 1000 rpm), was 56.12 ± 0.32 wt%. These results show that chitosan can be used as a precursor for the formation of calcium/chitosan spheres, yielding a porous calcium oxide (with higher surface area) that can be used as an alkaline catalyst for biodiesel production. © 2014 Society of Chemical Industry

Natália de Sousa Campelo

Papers

Characterization of calcium oxide catalysts from natural sources and their application in the transesterification of sunflower oil

Characterization and application of dolomite as catalytic precursor for canola and sunflower oils for biodiesel production

Calcium/chitosan spheres as catalyst for biodiesel production