Recent developments in the production of liquid fuels via catalytic conversion of microalgae: experiments and simulations

Abstract

Due to continuing high demand, depletion of non-renewable resources and increasing concerns about climate change, the use of fossil fuel-derived transportation fuels faces relentless challenges both from a world markets and an environmental perspective. The production of renewable transportation fuel from microalgae continues to attract much attention because of its potential for fast growth rates, high oil content, ability to grow in unconventional scenarios, and inherent carbon neutrality. Moreover, the use of microalgae would minimize ''food versus fuel'' concerns associated with several biomass strategies, as microalgae do not compete with food crops in the food chain. This paper reviews the progress of recent research on the production of transportation fuels via homogeneous and heterogeneous catalytic conversions of microalgae. This review also describes the development of tools that may allow for a more fundamental understanding of catalyst selection and conversion processes using computational modelling. The catalytic conversion reaction pathways that have been investigated are fully discussed based on both experimental and theoretical approaches. Finally, this work makes several projections for the potential of various thermocatalytic pathways to produce alternative transportation fuels from algae, and identifies key areas where the authors feel that computational modelling should be directed to elucidate key information to optimize the process.

Catalytic effect of ultrananocrystalline Fe3O4on algal bio-crude productionviaHTL process

“…Table 1 shows the yield, higher heating values (HHV), and energy recovery (ER) of the bio-crude and bio-char after HTL processing of UFMA employing different UNCFO loadings and the reaction conditions proposed by Singh et al 4 on the same biomass. These conditions are in the maximal bio-crude yield range reported by Shi et al 24 , Yang et al 25 and many other studies [26][27][28][29][30][31][32] . It was found that the baseline (i.e., no catalyst) bio-crude yield is 23.3 ± 0.4% for the dry biomass in ash-free basis, which is higher than the value reported (11%) by Singh and coworkers 4 , even when adjusted to our applied formula (18.78%).…”

Characterization of newly isolated oleaginous microalga Monoraphidium sp. for lipid production under different conditions

“…The membranes of algal cells also contain polar lipids, such as glycolipids, phospholipids and sterols [27]. All these types of lipids can yield biodiesel through transesterification, and gasoline or jet fuel through pyrolysis, thermal-cracking and HTL process [28]. But to achieve that it is necessary to select the strain with high lipid content and lipid productivity, which are the two commonly used indicators for assessing the performance of lipid production by lipid-rich microalgae.…”

Botryococcus braunii for biodiesel production

“…Trans/esterification is the most studied biodiesel production phase of the last decade. Comprehensive pathways of microalgae biomass trans/esterification have already been investigated [73,81,83,[96][97][98]. Methanol and ethanol are frequently used, especially the former one, for producing biodiesel and glycerol.…”