Maria C. Fernandes

Enzymatic saccharification and bioethanol production from Cynara cardunculus pretreated by steam explosion.

The correct choice of the specific lignocellulosic biomass pretreatment allows obtaining high biomass conversions for biorefinery implementations and cellulosic bioethanol production from renewable resources. Cynara cardunculus (cardoon) pretreated by steam explosion (SE) was involved in second-generation bioethanol production using separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) processes. Steam explosion pretreatment led to partial solubilisation of hemicelluloses and increased the accessibility of residual polysaccharides towards enzymatic hydrolysis revealing 64% of sugars yield against 11% from untreated plant material. Alkaline extraction after SE pretreatment of cardoon (CSEOH) promoted partial removal of degraded lignin, tannins, extractives and hemicelluloses thus allowing to double glucose concentration upon saccharification step. Bioethanol fermentation in SSF mode was faster than SHF process providing the best results: ethanol concentration 18.7 g L(-1), fermentation efficiency of 66.6% and a yield of 26.6g ethanol/100 g CSEOH or 10.1 g ethanol/100 g untreated cardoon.

Recovering bioethanol from olive bagasse fermentation by nanofiltration

Abstract The aim of this manuscript was the study of the recovery of bioethanol produced by the fermentation of the lignocellulosic biomass (olive bagasse) by nanofiltration. In terms of downstream processing, the nanofiltration permeate stream was expected to be comprised mostly of water and ethanol, and as such, ethanol may be further recovered by conventional distillation. Different nanofiltration membranes (NF90 and NF270) were tested for their efficiency in the separation of bioethanol. Model aqueous solutions of ethanol and sugars, and real liquors were processed by nanofiltration focusing on flux and rejection performance. The results shown that the more complex medium of a real liquor interacts with the membrane and lower the rejection to target solutes. Generally, both membranes tested were suitable for separating and recovering ethanol from a fermentation medium. The diafiltration mathematical model developed in this work shown to be capable of describing experimental results, which may be consi...

Bioethanol production from extracted olive pomace: dilute acid hydrolysis

Abstract Residues from olive oil industry such as Extracted Olive Pomace (EOP) are potential substrates for bioethanol production. In this work, enzymatic hydrolysis of EOP pretreated by dilute acid hydrolysis (DAH) was assessed, and the enzymatic hydrolysis and bioconversion were carried out both by separate hydrolysis and fermentation (SHF) and pre-saccharification followed by simultaneous saccharification and fermentation (PSSF). DAH led to a significant removal hemicellulose, but the subsequent enzymatic treatments showed that the resulting residue was still partially recalcitrant to cellulase hydrolysis. Size reduction and further treatment of EOP-DAH with an alkaline solution were also tested. Alkaline post-treatment allowed a decrease in lignin content, but had little effect on enzymatic saccharification comparing to size reduction. Hence fermentation study was performed with ground EOP-DAH. The PSSF process showed a relatively higher bioethanol fermentation yield (0.46 gg-1) when compared to the SHF process.

Influence Of Commercial And Organic Waste Amendments On Metalaxyl Soil Sorption

The influence of two commercial humic amendments of agricultural origin (LF and SF) and the amendment with a solid waste from the olive oil processing industry (A) on metalaxyl soil sorption was assessed. Three soils of different physiochemical properties were treated with 10 YO w/w organic amendment and sorption studies performed by batch equilibration procedure. In order to examine the influence of sorption on leaching, metalaxyl was applied to the top of 30 x 5 cm methacrylate handpicked soil columns and leached under saturated/unsaturated flow conditions. For the three soils, addition of SF and A products increased sorption of metalaxyl, but in the case of LF, sorption remained unaffected or slightly decreased, which has been attributed to competition of dissolved organic matter for soil sorption sites. Laboratory leaching studies with B7, B7+LF and B7+SF confirmed sorption behaviour and indicated earlier breakthrough in soils amended with LF than in unamended soil, whereas in the case of SF leaching was reduced.