Production, characterization and evaluation of the energetic capability of bioethanol from Salicornia Bigelovii as a renewable energy source

Abstract

Abstract Bioethanol production from biomass must be sustainable for providing a real solution to the use of bioethanol as an alternative transportation fuel. In this work, we succeed in using Salicornia Bigelovii (halophyte plant) as a raw material for bioethanol production. The characterization studies indicate a biomass composition comparable to traditional lignocellulosic biomasses: about 46.22 ± 1.20 of cellulose, 14.93 ± 0.37 of hemicellulose and, a low lignin content (1.96 ± 0.21). The highest cellulose content (75.4%) without the presence of furfural aldehyde is obtained employing the wet oxidation pretreatment method, it is performed at 200 °C with test cycles of 10 min applying 1.0 MPa of oxygen pressure. The enzymatic hydrolysis of cellulose is improved employing a dilute-acid hydrolysis after the pretreatment cycle, reaching an overall glucose yield of 91%. Moreover, inhibition of cellulose enzymatic conversion by filtrates is not observed during this process. The simultaneous saccharification and fermentation (employing Saccharomyces cerevisiae yeast for 120 h) of the pretreated material (using wet oxidation followed by dilute-acid hydrolysis), shows a higher ethanol production yield of 98%. These results demonstrate that there is no need of additional nutrients for the fermentation of Salicornia Bigelovii hydrolysates. Additionally, the electrochemical evaluation demonstrate that bioethanol has a similar energetic capability than analytical ethanol, presenting a current density of ∼0.23 mA cm−2.