Lipid conversion of Scenedesmus rubescens biomass into biodiesel using biochar catalysts from malt spent rootlets

Abstract

BACKGROUNDMicroalgae are considered a third–generation raw material for biofuel production. This work compared the conversion of the extracted oil from the freshwater microalgae Scenedesmus rubescens via transesterification for the production of biodiesel. Considering the cost of biodiesel production, heterogeneous catalysts present a significant advantage because of their stability and reusability. Biochar and modified biochar with H2SO4 were used as catalysts.RESULTSBiochar (BC) was pyrolyzed at 850 °C, under limited oxygen conditions, and was activated by sulphuric acid (H–BC). The catalyst: oil mass ratios tested were from 0 to 0.7:1 for BC, and from 0 to 1:1 for H–BC. The biochar sample exhibited a strong buffer capacity in the pH range between 7 and 5.5, while the acid treated biochar was strongly acidic and could neutralize a significant amount of bases. The produced methyl esters are almost the same in all cases examined. BC samples gave better transesterification results, as far as it concerns the conversion, compared to H–BC.CONCLUSIONThe enhanced activity of the BC with mass used may be correlated with the basic minerals presented on the biochar surface. Raw biochar gave better conversion results (47%) during transesterification compared to the modified biochar with H2SO4 (24%) with better catalyst to molar ratio, 0.7:1 and 0.1:1, respectively. © 2020 Society of Chemical Industry

Circular economy in the brewing chain

“…The biochar sorbent properties for several water contaminants (e.g., chlorine, chloroform, chromium, mercury, methylene blue, phenanthrene, trimethoprim, and uranium) were reported by Grilla et al (2020) and Neylon et al (2020). Untreated MBR biochar was also used as a catalyst in the transesterification step of biodiesel production (Tsavatopoulou et al, 2020).…”

“…As the fifth priority choice being reported in Table 6, MBRs are converted into biochar, its use for soil amendment (Chan et al, 2007), as a sorbent for several water contaminants (Grilla et al, 2020;Neylon et al, 2020), or as a catalyst in the transesterification step of biodiesel production (Tsavatopoulou et al, 2020).…”

Steam activation tuned porous structure and surface wetting behaviors of mesoporous biochars for corrosive oily wastewater treatments

“…Biochars are chemically stable and have a high resistance to acidic and alkali solutions, so they are promising substrates for developing low‐cost and corrosive‐resistant separation materials 9 . In general, biochars are conveniently prepared by the pyrolysis of biomass at high temperatures 10 and they feature unique structural properties, such as well‐developed porous structure, high specific surface area, and abundant active functional groups, thus providing accessible active sites for achieving desired separation purposes 11 . A variety of biochars have been developed by employing different biomasses as the raw materials that are utilized for the adsorptive removal of targeted pollutants from wastewater 12‐15 .…”

Long-Term Toxicity of ZnO Nanoparticles on Scenedesmus rubescens Cultivated in Semi-Batch Mode

“…The effects of NPs on microalgae are considered an important environmental concern since they are primary producers, and undoubtedly are at the bottom of the food chain [15], as well as being the main organisms in natural wastewater treatment systems. Furthermore, algae are considered one of the most promising products for the production of biofuels, which is why many studies have focused on this area [16,17]. Scenedesmus rubescens is a common microalgal species which is often found in municipal wastewater and is studied for its high lipid content [16][17][18].…”

“…Furthermore, algae are considered one of the most promising products for the production of biofuels, which is why many studies have focused on this area [16,17]. Scenedesmus rubescens is a common microalgal species which is often found in municipal wastewater and is studied for its high lipid content [16][17][18]. Scenedesmus sp.…”