<b>Citric waste saccharification under different chemical treatments

Abstract

ABSTRACT. Second generation ethanol from lignocellulose materials has been used in applications for food processing wastes. Since Brazil has a leading position in orange juice exports, the influence of acid and alkali pretreatments on liquor saccharification, solubilization of solid fraction and mass yield was evaluated. Time and C acid or C alkaline at different concentrations of solids (low to moderate, 1 to 9%) and high catalyst concentrations were analyzed. A hydrothermal pretreatment was conducted under the same conditions of acid and alkaline treatments to investigate the relative selectivity increase in using the catalysts. The chemical analyses of wastes indicated a 70% total carbohydrate level denoting a promising raw material for bioethanol production. Pretreatment caused acid saccharifications between 25 and 65% in total reducing sugars (TRS) and mass yields (MY) between 30 and 40%. In alkaline pretreatment, these rates ranged between 2 and 22.5% and between 30 and 80, respectively. In hydrothermal pretreatment, solubilized TRS varied between 3 and 37%, whereas MY remained between 45 and 60%, respectively. C biomass strongly influenced the three variables; in the same way, time affected MY.Keywords: pretreatment, biomass, experimental design, orange.Sacarificação de resíduo cítrico sob diferentes tratamentos químicos RESUMO. Etanol de segunda geração a partir de materiais lignocelulósicos tem sido abordado como uma das aplicações de resíduos de processamento de alimentos. Sendo o Brasil líder na exportação de suco de laranja, avaliou-se a influência de pré-tratamentos ácidos e alcalinos na sacarificação do licor, na solubilização da fração sólida e no rendimento mássico. Para isso, estudou-se tempo e C ácido ou C álcali em diferentes concentrações de sólidos (baixo a moderado, 1-9%) e altas concentrações de catalisador. Um pré-tratamento hidrotérmico foi realizado, tendo as mesmas condições dos tratamentos ácido e alcalino, a fim de investigar o aumento da seletividade em relação ao uso desses catalisadores. Análises químicas de resíduos indicaram um nível total de carboidratos de 70%, denotando uma matéria-prima promissora para a produção de bioetanol. O pré-tratamento conduziu a sacarificações ácidas de 25 a 65% em açúcares redutores totais (ART) e rendimentos mássicos (RM) entre 30 e 40%. Para o pré-tratamento alcalino, esses valores foram de 2 a 22,5%, e de 30 a 80%, respectivamente. No pré-tratamento hidrotérmico, o ART solubilizado variou entre 3 e 37%, enquanto que o RM manteve-se entre 45 e 60%. A C biomassa influenciou fortemente as três variáveis, bem como o tempo utilizado com o RM.Palavras-chave: pré-tratamento, biomassa, planejamento experimental, laranja.

Bioethanol production from coconut husk fiber

“…Pretreatment of biomass for conversion to 2G ethanol (second generation ethanol) has shown to be challenging because it must eliminate lignin, reduce crystallinity of cellulose, and dissolve hemicellulose, turning the biomass into a feedstock more susceptible to biological and chemical hydrolysis (SARKAR et al, 2012). Thus, in order to be considered effective, pretreatment methods have to yield large amounts of fermentable sugars, avoiding waste of biomass, degradation of carbohydrates, and formation of inhibitors of hydrolysis and fermentation, being economically viable (SILVA et al, 2015). Currently, pretreatment methods of biomass are classified into biological, physical, chemical or physicochemical methods.…”

Peer Review #2 of "Cellobiohydrolase B of Aspergillus niger over-expressed in Pichia pastoris stimulates hydrolysis of oil palm empty fruit bunches (v0.1)"

“…Saccharification of OPEFB was performed in 1 mL reaction mixtures containing 25 mM pH 5 sodium acetate buffer and 1% (w/v) pre-treated OPEFB at 50 °C with shaking at 1,000 rpm for 5 h (Thermomixer Comfort, Eppendorf AG, Hamburg, Germany). Production of reducing sugars were measured using the DNS reagent (Miller, 1959) and total reducing sugars (TRS) calculated using the following equation (Farias Silva et al, 2015):…”

Saccharification of Orange Bagasse Pre-treated with Calcium Hydroxide using an enzymatic blendDiluted Hydrochloric Acid

“…The potential use of these materials is based on their large availability and low cost [3,6]. The biomass productions costs in Brazil are considered the lowest in the world, with great possibilities of promising results [7]. Orange is vastly consumed all around the world, for its flavor as well as its medicinal and nutritional properties.…”