Enzymatic biodiesel production from microalgae biomass using propane as pressurized fluid

Microalgae are a promising feedstock for biodiesel production. Harvesting of microalgal biomass is still a bottleneck to its commercial scale application, due to small cell size, low culture densities, colloidal stability and thus economic disadvantage. The aim of this study was to evaluate the biomass separation of the small size microalgae Chlorella sp. by electrochemical flotation process with rectangle electrodes using aluminum or iron plates. The most effective conditions for this experiment involved the use of an aluminum electrode for 30 min with a current density of 1.5 mA/cm2, whereas the iron electrode has been used ineffectively with the same of conditions. The effect of current density (0.5–3 mA/cm2), concentration of microalgae biomass (0.29–1.5 g/L), and electrolyte (0–2 g/L) for aluminum electrode were analyzed. The highest recovery efficiency of 90 % was obtained for Chlorella sp. at 1.5 mA/cm2 in 30 min and concentration of microalgae biomass of 0.74 - 1.5 g/L with power consumption of 1.36 kWh/kg. The electrochemical flotation process with aluminum electrodes could be a possible harvesting step at commercial scale for microalgal biomass production.

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Microalgae Cultivation in Photobioreactors Aiming at Biodiesel Production

10.5772/intechopen.93547 ◽

2020 ◽

Author(s):

Mateus S. Amaral ◽

Carla C.A. Loures ◽

Fabiano L. Naves ◽

Gisella L. Samanamud ◽

Messias B. Silva ◽

...

Keyword(s):

Fossil Fuels ◽

Biomass Productivity ◽

Raw Material ◽

Biodiesel Production ◽

Alternative Source ◽

Biodiesel Synthesis ◽

Microalgae Biomass ◽

Increase Productivity ◽

Bad Weather ◽

Micro Organisms

The search for a renewable source as an alternative to fossil fuels has driven the research on new sources of biomass for biofuels. An alternative source of biomass that has come to prominence is microalgae, photosynthetic micro-organisms capable of capturing atmospheric CO2 and accumulating high levels of lipids in their biomass, making them attractive as a raw material for biodiesel synthesis. Thus, various studies have been conducted in developing different types of photobioreactors for the cultivation of microalgae. Photobioreactors can be divided into two groups: open and closed. Open photobioreactors are more susceptible to contamination and bad weather, reducing biomass productivity. Closed photobioreactors allow greater control against contamination and bad weather and lead to higher rates of biomass production; they are widely used in research to improve new species and processes. Therefore, many configurations of closed photobioreactors have been developed over the years to increase productivity of microalgae biomass.

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Polishing of municipal secondary effluent using native microalgae consortia

Water Science & Technology ◽

10.2166/wst.2017.046 ◽

2017 ◽

Vol 75 (7) ◽

pp. 1693-1701 ◽

Cited By ~ 7

Author(s):

Julio César Beltrán-Rocha ◽

Icela Dagmar Barceló-Quintal ◽

Magdalena García-Martínez ◽

Luis Osornio-Berthet ◽

Nidia Saavedra-Villarreal ◽

...

Keyword(s):

Municipal Wastewater ◽

Subsequent Treatment ◽

Biodiesel Production ◽

High Rate ◽

Secondary Effluent ◽

Total N ◽

Operational Conditions ◽

Microalgae Biomass ◽

Secondary Effluents ◽

P Removal

This work evaluates the use of native microalgae consortia for a dual role: polishing treatment of municipal wastewater effluents and microalgae biomass feedstock potential for biodiesel or biofertilizer production. An initial screening was undertaken to test N and P removal from secondary effluents and biomass production by 12 consortia. A subsequent treatment was performed by selected consortia (01 and 12) under three operational conditions: stirring (S), S + 12 h of daily aeration (S + A) and S + A enriched with CO2 (S + AC). All treatments resulted in compliance with environmental regulations (e.g. Directive 91/271/EEC) and high removal efficiency of nutrients: 64–79% and 80–94% of total N and PO43−-P respectively. During the experiments it was shown that pH alkalinization due to microalgae growth benefits the chemical removal of ammonia and phosphorus. Moreover, advantages of pH increase could be accomplished by intermittent CO2 addition which in this research (treatment S + AC) promoted higher yield and lipid concentration. The resulting dry biomass analysis showed a low lipid content (0.5–4.3%) not ideal for biodiesel production. Moreover, the high rate of ash (29.3–53.0%) suggests that biomass could be readily recycled as a biofertilizer due to mineral supply and organic constituents formed by C, N and P (e.g. carbohydrate, protein, and lipids).

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Cultivation of micro-algae for Production of Biodiesel: An optimized Process

Research in Biotechnology ◽

10.19071/rib.2016.v7.3037 ◽

2016 ◽

Vol 7 ◽

Author(s):

Abebe Girma Demissie ◽

Bhaskarrao Chinthapalli ◽

Shumet Tenaw ◽

D. S. Vijaya Chitra

Keyword(s):

Algal Biomass ◽

Incubation Temperature ◽

Carbon Sources ◽

Nitrogen Sources ◽

Biodiesel Production ◽

Potential Candidate ◽

Potential Source ◽

Microalgae Biomass ◽

Basal Media

Microalgae are considered as one of the potential source of biodiesel for the future. The search to obtain the potential strains from the algal diversity capable of producing oil is critical for sustainable production of biodiesel. In the present study, microalgae biomass with oil/lipid accumulation capability and their morphological features was isolated from Lake Abaya and Chamo. The algal biomass was cultivated in vitro and media optimization for maximum biomass was done using different basal media, BG-11 medium, and Chu -10. In addition the various carbon sources, nitrogen sources, pH and temperature were considered in this study for optimization. Green algae Oedogonium, Chlorella and Cladophora species were observed to be dominant species and the maximum oil per dry algal biomass was found to be from Oedogonium sp. Thus from the present study for the cultivation of the selected algae, BG-11 medium supplemented with tryptone (0.2%) sucrose (2%) and pH- 6 with incubation temperature of 300C was found to be suitable. These results suggest that Oedogonium sp. has several desirable features that make it a potential candidate for biodiesel production.

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Insights about sustainable biodiesel production from microalgae biomass: A review

International Journal of Energy Research ◽

10.1002/er.6138 ◽

2020 ◽

Author(s):

Michael Rahul S ◽

Sundaramahalingam MA ◽

Shivamthi CS ◽

Shyam Kumar R ◽

Varalakshmi P ◽

...

Keyword(s):

Biodiesel Production ◽

Microalgae Biomass

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Direct Biodiesel Production from Wet Microalgae Biomass ofChlorella pyrenoidosathroughIn SituTransesterification

BioMed Research International ◽

10.1155/2013/930686 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 40

Author(s):

Hechun Cao ◽

Zhiling Zhang ◽

Xuwen Wu ◽

Xiaoling Miao

Keyword(s):

Water Content ◽

Dry Weight ◽

Chlorella Pyrenoidosa ◽

Biodiesel Production ◽

Optimal Conditions ◽

Microalgae Biomass ◽

Negative Effect ◽

One Step ◽

Lower Temperature ◽

Wet Microalgae

A one-step process was applied to directly converting wet oil-bearing microalgae biomass ofChlorella pyrenoidosacontaining about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production.

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Biodiesel: An Overview II

Journal of the Brazilian Chemical Society ◽

10.21577/0103-5053.20210046 ◽

2021 ◽

Author(s):

Michelle Rezende ◽

Ana Lúcia de Lima ◽

Bárbara Silva ◽

Claudio Mota ◽

Ednildo Torres ◽

...

Keyword(s):

Aromatic Hydrocarbons ◽

Carbonyl Compounds ◽

Heterogeneous Catalysts ◽

Major Ions ◽

Raw Material ◽

Biodiesel Production ◽

Pollutant Emissions ◽

Microalgae Biomass ◽

Polycyclic Aromatic ◽

Production Technologies

The crescent number of scientific articles published per year shows that research on biodiesel continues to play an important role to support the growing demand for this biofuel. The second edition of Biodiesel: An Overview presents the worldwide research in the last 15 years. Microalgae biomass is the most studied raw material alternative in this period and several studies have been carried out to develop basic heterogeneous catalysts for biodiesel production. Concerning to production technologies, supercritical conditions and intensification process have been extensively investigated. The development of new antioxidants additives has focused mainly on biomass-derived formulations and there are few studies on biocide candidates. In terms of pollutant emissions, in general, the studies showed that the addition of biodiesel generates lower concentrations of polycyclic aromatic hydrocarbons (PAH), CO and n-alkanes pollutants, but carbonyl compounds, major ions and NOx are emitted in a higher concentration compared to pure diesel.

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Challenges of Downstream Processing for the Production of Biodiesel from Microalgae

U Porto Journal of Engineering ◽

10.24840/2183-6493_003.001_0005 ◽

2018 ◽

Vol 3 (1) ◽

pp. 50-60 ◽

Cited By ~ 1

Author(s):

Vânia Novais Pôjo

Keyword(s):

Fossil Fuels ◽

Cost Effective ◽

Downstream Processing ◽

Review Article ◽

Production Costs ◽

Biodiesel Production ◽

Microalgal Biomass ◽

Promising Alternative ◽

Microalgae Biomass ◽

Research Initiatives

The continuous reliance on fossil fuels is unsustainable, due to the depletion of global reserves and the greenhouse gas emissions associated with their use. Therefore, there are vigorous research initiatives intended to develop renewable alternatives. Microalgae are a promising alternative for biodiesel production and have received increasing attention during the last few decades. However, is not yet sufficiently cost-effective to compete with petroleum-based conventional fuels. This happens essentially because of downstream processing – harvesting microalgae biomass and extraction of lipids are two of the most expensive processes from the overall process. Harvesting, drying, cell disruption, oil extraction and transesterification (into biodiesel) are highlighted processes in this review article. The techniques associated with each process present advantages and handicaps that are here discussed. Improvements that will directly affect the final production costs of microalgal biomass-based biofuels are also proposed.

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