Energy innovation potential of oleaginous microalgae

Abstract

Algae have contributed greatly to the creation of the Earth's environment and the development of human civilization. Currently, microalgae are considered to be among the most promising sources for biofuel. Most microalgae accumulate triacylglycerols; however, fatty acid methyl esters produced from triacylglycerols by transesterification have critical end-use issues. Hydrocarbons produced by Botryococcus and Aurantiochytrium are the most suitable algal oils for replacing existing transportation fuels and are highly compatible with existing petroleum infrastructure. Over the years, many technologies have been investigated for achieving sustainable biofuel production using oleaginous microalgae; however, existing techniques of algal fuel production are suitable mainly for small-scale procedures or for the recovery or removal of high-value products. This situation strongly influences life cycle assessment studies for algal fuel production, and published life cycle assessments show different and discrepant results-reliable data on inputs and outputs from industrial-scale experiments are needed for solving these problems. The estimated cost of algal fuel production is still high compared with that of fossil crude oils. The integration of water treatment and algal biomass production, in a coupled hybrid production system comprising of phototrophic and heterotrophic algae, has tremendous potential for improving the economy of future algal fuels.

Algal Biorefineries

“…177 Terpenes are polymers of isoprene C 5 H 8 . 179,180 Two metabolic pathways are capable of producing the isoprenoid building blocks, isopentenyl pyrophosphate and dimethylallyl diphosphate: the mevalonate (MVA) pathway and the methylerythritol phosphate (MEP) pathway, also known as the 1-deoxy-d-xylulose-5-phosphate pathway and the nonmevalonate pathway. The name "terpene" is derived from the word "turpentine."…”

Catalytic Deoxygenation of Hexadecyl Palmitate as a Model Compound of Euglena Oil in H2 and N2 Atmospheres

“…Moreover, the ratio of n-C 15 H 32 in the total C 15 hydrocarbons was much higher than the ratio of n-C 16 H 34 in the total C 16 hydrocarbons ( Figure 8B). Thus, Reaction (7) was the main decarboxylation reaction (as compared to Reaction (8) Figure 10 shows the dependence of C15H31COOC16H33 conversion and C10-C16 hydrocarbon yield on reaction temperature for the catalytic deoxygenation of C15H31COOC16H33 in N2 atmosphere, for 2 h, over the 1 wt.% Pd/Mg(Al)O catalyst. C15H31COOC16H33 conversion increased with an increasing reaction temperature from 275 to 375 °C, and achieved a conversion of over 99% for the reaction at 375 °C for 2 h. The yield of C10-C16 hydrocarbons increased with an increasing reaction temperature from 275 to 325 °C.…”

“…Moreover, the ratio of n-C15H32 in the total C15 hydrocarbons was much higher than the ratio of n-C16H34 in the total C16 hydrocarbons ( Figure 8B). Thus, Reaction (7) was the main decarboxylation reaction (as compared to Reaction (8)) in the catalytic deoxygenation of C15H31COOC16H33 in N2 atmosphere.…”

“…Algae oils have recently become a promising alternative feedstock for vegetable oils because the oil yields from algae are significantly higher than those from any other crop [8][9][10][11]. Euglena is a promising algae biomass because it is easily cultivated on a large scale.…”

“…Euglena is a promising algae biomass because it is easily cultivated on a large scale. Most algae produce oils composed of triglycerides and fatty acids [8]. However, Euglena produces an oil wax that contains a mixture of saturated esters with long carbon chains (C m H 2m+1 COOC n H 2n+1 , m = 11-15, n = 12-16) [12,13].…”