Progress on Conventional and Advanced Techniques of In Situ Transesterification of Microalgae Lipids for Biodiesel Production

Abstract

Global warming and the depletion of fossil fuels have spurred many efforts in the quest for finding renewable, alternative sources of fuels, such as biodiesel. Due to its auxiliary functions in areas such as carbon dioxide sequestration and wastewater treatment, the potential of microalgae as a feedstock for biodiesel production has attracted a lot of attention from researchers all over the world. Major improvements have been made from the upstream to the downstream aspects related to microalgae processing. One of the main concerns is the high cost associated with the production of biodiesel from microalgae, which includes drying of the biomass and the subsequent lipid extraction. These two processes can be circumvented by applying direct or in situ transesterification of the wet microalgae biomass, hence substantially reducing the cost. In situ transesterification is considered as a significant improvement to commercially produce biodiesel from microalgae. This review covers the methods used to extract lipids from microalgae and various in situ transesterification methods, focusing on recent developments related to the process. Nevertheless, more studies need to be conducted to further enhance the discussed in situ transesterification methods before implementing them on a commercial scale.

Evaluation of Physicochemical Properties Composite Biodiesel from Waste Cooking Oil and Schleichera oleosa Oil

“…However, the high heating value of all biodiesel was slightly lower than that of WCO biodiesel [38]. As a result, the high heating value of biodiesel is usually lower than that of conventional diesel, leading to a slight reduction in engine power and torque of 7% and 8%, respectively [27]. The current results of biodiesel which has a high heating value (HHV) correspond with previous studies.…”

“…The second generation includes biodiesel from waste cooking oil [7,26]. Nowadays, various studies worldwide are investigating biodiesel production from microalgae, which is considered the third generation [27,28].…”

Sustainable Point of View: Life Cycle Analysis for Green Extraction Technologies

“…Another challenge faced by LCA is that a majority of studies are based on theoretical analyses, which may not necessarily align with practical applications [75]. This issue is particularly evident in the field of microalgae-to-bioenergy technologies, where data from large-scale plants are currently either unavailable or insufficient [76,77]. As a result, researchers often rely on mathematical models, such as simulations and optimization procedures, to conduct scale-up studies [77].…”

“…This issue is particularly evident in the field of microalgae-to-bioenergy technologies, where data from large-scale plants are currently either unavailable or insufficient [76,77]. As a result, researchers often rely on mathematical models, such as simulations and optimization procedures, to conduct scale-up studies [77]. In such cases, the researchers have to rely on data obtained from laboratory-scale studies, which can introduce inaccuracies in the presented data.…”

Transesterification method of microalgae biomass to produce fatty acid methyl esters

“…However, a detailed comparison between d‐trans and ext‐trans using microalgae has not been elucidated. Besides the latest work of Makareviciene & Skorupskaite 19 and Ideris et al ., 20 who reviewed ext‐trans and d‐trans for biodiesel production from microalgae, not much work has been reported regarding this comparison method. Therefore, the study reported here examined the production of FAMEs from Chlorella vulgaris using d‐trans and ext‐trans.…”