Biodiesel production from Ulva lactuca: Insights into kinetic and thermodynamic evaluation of lipid transesterification

Utilization of marine ulva lactuca seaweed and freshwater azolla filiculoides macroalgae feedstocks toward biodiesel production: Kinetics, thermodynamics, and optimization studies

In this study, the biodiesel produced from Ulva lactuca, a marine green seaweed by solid oxide catalyst derived from low-cost waste eggshells is evaluated. Waste eggshells were calcined at 500 °C, 600 °C and 700 °C to increase catalytic activity which was characterized by X-ray diffraction pattern. The peaks of CaO were obtained by calcinations carried out at 700 °C for varied time periods. Comparison of images of scanning electron microscope of calcined eggshells with natural eggshells showed the formation of porous structure with an average pore diameter of 39.17 nm. Biodiesel was prepared by transesterification of algal oil by uncalcined eggshells, calcined eggshells and commercial calcium oxide with methanol. The yield of biodiesel was higher for calcined eggshells (78 %) than uncalcined eggshells (53 %). The produced biodiesel was sampled and analyzed for Gas chromatography – mass spectrometry, which confirmed the presence of predominant alkyl esters like hexadecenoic acid methyl ester, docosanoic methyl ester, palmitic acid methyl ester and oleic acid methyl ester. The heterogeneous catalyst can be reused upto seven times without any prescribed loss of catalyst activity. The Introduction of this eco-friendly catalyst in the transesterification reaction of biodiesel from Ulva lactuca will be cost-reduction for the production of an alternative green fuel.

This study assesses the bioenergy potential of two types of aquatic biomass found in the Republic of Congo: the green macroalgae Ulva lactuca (UL) and Ledermanniella schlechteri (LS). Their combustion behaviour was assessed using elemental and biochemical analysis, TGA, bomb calorimetry and metal analysis. Their anaerobic digestion behaviour was determined using biochemical methane potential (BMP) tests. The average HHV for LS is 14.1 MJ kg−1, whereas UL is lower (10.5 MJ kg−1). Both biomasses have high ash contents and would be problematic during thermal conversion due to unfavourable ash behaviour. Biochemical analysis indicated high levels of carbohydrate and protein and low levels of lipids and lignin. Although the lipid profile is desirable for biodiesel production, the levels are too low for feasible extraction. High levels of carbohydrates and protein make both biomasses suitable for anaerobic digestion. BMP tests showed that LS and UL have an average of 262 and 161 mL CH4 gVS−1, respectively. The biodegradability (BI) of LS and UL had an average value of 76.5% and 43.5%, respectively. The analysis indicated that these aquatic biomasses are unsuitable for thermal conversion and lipid extraction; however, conversion through anaerobic digestion is promising.

Biodiesel production from different algal oil using immobilized pure lipase and tailor made rPichia pastoris with Cal A and Cal B genes

Comparative assessment for biodiesel production from low-cost feedstocks of third oil generation

Microalgal biomass as a biorefinery platform for biobutanol and biodiesel production

Synergism of clay with zinc oxide as nanocatalyst for production of biodiesel from marine Ulva lactuca

Biodiesel is a type of renewable energy source. Researchers have considered it as a substitute for fossil fuel. Combustion of biodiesel generates fewer pollutants such as CO2, CO, particulate matter, except NOx. Fatty acid methyl esters (FAMEs) are the key components of biodiesel which can be synthesized through transesterification of lipid in the presence of alcohol, base, acid, enzyme or solid catalyst. Traditional biodiesel from rapeseed, palm, sunflower, jatropha and soya bean has been strongly criticized as they require long extension of lands for cultivation. In that context, food waste is better choice for biodiesel production. The reports of FAO of the United Nations say that approximately 1.3 billion tons of food waste is disposed through worldwide. Exponential growth of population will cause a continuous increase of food waste generation in developing countries in Asia. Usually, food waste is disposed in landfills. This is causing world’s mounting food waste disposal problem. This practice of disposing food waste disposal in landfills has harmful effect in human life such as bad odour, air pollution and leaching. Carbon dioxide, methane and other toxic gaseous substances are emitted from landfills. Therefore, food waste can be utilized as non-edible resources for biodiesel production which is a better option for not to use lands limited for food crop. The cost of traditional biodiesel production is relatively high based on high cost of feedstock as well as biodiesel production technologies. This article reviews the aspects of biodiesel production from food waste as well as potential of biodiesel production from food waste.

Chapter 14 - Bioenergy: Fungal lipase-mediated biodiesel process technology

Using wet microalgae for direct biodiesel production via microwave irradiation

There are several technological and economic challenges that need to be addressed to make biodiesel production profitable. Among the technological obstacles in enzyme-catalysed transesterification process for biodiesel production, the selection of feedstock and robust biocatalyst are the critical factors for developing a cost-effective bioprocess. Feedstocks, mainly second and third generations, have been used recently to economise biodiesel production. Nanotechnology has revolutionised the enzyme immobilisation technology by providing versatile nanomaterials. Biocompatible nanomaterial is emerging as a novel immobilisation support for lipase enzyme to advance biodiesel production. Nanomaterials possess excellent properties such as higher surface area-to-volume ratios, lower mass transfer resistance, and quick separation from the reaction mixture using magnetic field. Utilising the cheap renewable feedstock such as waste oil and microalgae oil, nanomaterial-immobilised enzyme can be reused thus economising the process of enzymatic transesterification for biodiesel production. The chapter provides an insight of recent progresses in improving immobilised lipase technology, focusing on innovation in feedstock and nanomaterial processing such as synthesis, functionalisation, and characterisation with regard to biodiesel production. This chapter concludes that synergies between nanotechnology and industrial biotechnology will become an integral part of sustainable biodiesel production.

New route for the synthesis of silica-supported calcium oxide catalyst in biodiesel production

The activated carbons (ACs) from shells of horse chestnut, chestnut, acorn, pistachio, apricot kernel, and wood shavings were evaluated to recover used oil (UO). The effects of the amount of AC, adsorption time, and temperature on the purification of the UO were investigated using the apricot kernel shells due to the high apricot production of Turkey. The kinetic evaluation was also done. The percentage improvements (PIs) in total polar materials (TPM), free fatty acids (FFA), p-anisidine value (p-AV), conjugated diene content (CD), and color of UO were found as 100, 56, 92, 51, and 90% for the apricot kernel AC in the column treatment. The most effective other ACs in decreasing FFA, p-AV, CD, and color were the horse chestnut (59%), chestnut (74%), chestnut (43%), and pistachio (72%), respectively. Consequently, these ACs can be used for the purification of UO. Practical applications Industrial wastes cause environmental pollution if they are ejected into river, sea, and soil. Therefore, they should be purified or treated for different purposes. In this study, the industrial wastes from the food and forest industries were used for the production of activated carbon to purify the used oil. The results showed that these activated carbons could be utilized for the regeneration of used oils. The most economical treatment is to blend the activated carbon with used frying oil for a certain time and remove it through centrifugation and filtration. The purified oil has the potential to be used in the biodiesel production.

Considering the need to give the correct destination to co-products generated in the production of biodiesel, as well as nutritionally characterize alternative sources of protein for cattle, the objective of this study was to evaluate ruminal parameters and nutritional value of diets containing 0, 2, 4 and 8 % replacement of cottonseed meal by radish cake utilizing a semi-automated in vitro gas production technique. The evaluation of rumen degradation kinetics, digestibility of DM, OM and NDF, as well as pH, volatile fatty acids and ammoniacal nitrogen determination were performed by incubating 0.3 g of sample in buffered medium. It was observed a cubic effect of the replacement level on the volume of gas corresponding to complete digestion of the substrate, with values of 1.69, 1.70, 1.53, 1.61 mL/mg DM, respectively, for levels 0, 2, 4 and 8 % of substitution. There was a quadratic effect of the level of cottonseed meal replacement by radish cake on the in vitro digestibility of DM, OM and NDF, with maximum points in 2.75, 2.70 and 2.63 % of radish cake, respectively. The cottonseed meal replacement by radish cake influenced total concentration of VFA, concentration of ammoniacal nitrogen and the molar ratio of acetic and propionic acid. The acetate: propionate ratio and pH were not influenced by the substitution of cottonseed meal by radish cake, with average values of 3.36 and 6.93, respectively. It is concluded that the replacement of 2.63 % of the cottonseed meal by radish cake provided better digestibility of DM, OM and NDF of the diets, suggesting that the radish cake can be used in rations of beef cattle, partially replacing the cottonseed meal.

Chapter 33 - Solar intervention in bioenergy