Abiotic factors improving fatty acid profiling of freshwater indigenous microalgae isolated from Kumaun region of Uttarakhand, India

Microalgae have grabbed huge attention as a potential feedstock for biofuel production in response to the rise in energy consumption and the energy crisis. In the present study, indigenous microalgal strains were isolated from four freshwater lakes in the Kumaun region, Uttarakhand, India. Based on growth and lipid profiles, the four best-performing isolates were selected for further experiments. Initial identification of isolates was done by morphological observations, which were further validated by molecular identification using ITS sequencing. The screened cultures were subjected to abiotic stress conditions (varying concentrations of nitrogen and different temperatures) to monitor the biomass, lipid accumulation, and biochemical compositions (chlorophyll and carotenoids). The quantification of fatty acids was checked via gas chromatographic analysis. The strains were identified as KU_MA3 Chlamydopodium starrii, KU_MA4 Tetradesmus nygaardii, KU_MA5 Desmodesmus intermedius, and KU_MA6 Tetradesmus nygaardii. KU_MA3 Chlamydopodium starrii showed the best results in terms of growth and lipid production at 21 °C and 0.37 g/L NaNO2 concentration. The percentage of fatty acid methyl esters (FAMEs) attained >80% and met the standard for biodiesel properties. The strain has the potential to attain higher biomass and accumulate higher lipid content, and after some more studies, it can be used for upscaling processes and large-scale biodiesel production.

Investigations on evaluation of marine macroalgae Dictyota bartayresiana oil for industrial scale production of biodiesel through technoeconomic analysis

The investigation on utilizing macroalgae for industrial scale biodiesel production is an imperative action needed for commercialization. In the present research work, the biooil from marine macroalgae Dictyota bartayresiana was used for biodiesel production using calcium oxide nanocatalyst synthesized using waste collected from building demolition site. The optimization results obtained were the calcination temperature 573 °C, concentration of catalyst 5.62%, methanol to oil molar ratio 14.36:1, temperature 55.7 °C and time 67.57 min for the transesterification with the biodiesel yield of 89.6%. The techno-economic aspects of biodiesel production were investigated for 20 MT/batch. The return on investment and internal rate of return from the biodiesel production plant was found to be 25.39% and 31.13% respectively. The plant payback period was about 3.94 years with a positive NPV value of about 14,053,000 $/yr. Thus, Dictyota bartayresiana biomass can be efficiently used for the sustainable production of biodiesel.

Biodiesel Production from Waste Animal Fat by Transesterification Using H2SO4 and KOH Catalysts: A Study of Physiochemical Properties

Biodiesel is marketed as a long-term renewable fuel that may partially replace fossil fuels in transportation while also helping to reduce global warming. The current study is focused on using waste animal fat as a feedstock for biodiesel production. Sulfuric acid (H2SO4) and potassium hydroxide (KOH) are used as catalysts, with methanol as an alcohol. Temperature at 60°C, reaction time 2 hrs for acid catalyst, and 55°C, reaction time 90 min for base catalyst with a methanol to oil ratio of 5 : 1 are the experimental and optimized process conditions. With the H2SO4 catalyst, the biodiesel yield was 65.7%, while with the KOH catalyst, it was 48.8%. The ASTM standards are used to compare and study the physicochemical characteristics. This study offers an environmentally friendly solution to a global problem of atmospheric pollution, and at the same time, it shows a commercial alternative to reduce the ecological impact caused by waste animal fat.