Paper mulberry fruit juice: a novel biomass resource for bioethanol production

By way of broadening the use of diverse sustainable bioethanol feedstocks, the potentials of Paper mulberry fruit juice (PMFJ), as a non-food, sugar-based substrate, were evaluated for fuel ethanol production. The suitability of PMFJ was proven, as maximum ethanol concentration (56.4 g/L) and yield (0.39 g/g) were achieved within half a day of the start of fermentation, corresponding to very high ethanol productivity of 4.7 g/L/hr. The established potentials were further optimally maximized through the response surface methodology (RSM). At the optimal temperature of 30 °C, yeast concentration of 0.55 g/L, and pH of 5, ethanol concentration, productivity, and yield obtained were 73.69 g/L, 4.61 g/L/hr, and 0.48 g/g, respectively. Under these ideal conditions, diverse metal salts were afterward screened for their effects on PMFJ fermentation. Based on a two-level fractional factorial design, nutrient addition had no positive impact on ethanol production. Thus, under the optimal process conditions, and without any external nutrient supplementation, bioethanol from PMFJ compared favorably with typical sugar-based energy crops, highlighting its resourcefulness as a high-value biomass resource for fuel ethanol production. Graphical Abstract

Análise empírica da volatilidade do etanol: aplicação de modelos ARCH nos preços à vista e futuros no período 2011-2015

Esta pesquisa teve a finalidade de analisar a dinâmica e a transmissão da volatilidade dos preços à vista e futuros do etanol pelos modelos ARCH, GARCH, EGARCH e TARCH. A amostra utilizada nesta pesquisa é composta pelas cotações diárias do etanol hidratado spot negociado na base de Paulínia (SP), disponibilizadas pelo CEPEA/ESALQ e das cotações futuro na CBOT (Chicago Board of Trade) Denatured Fuel Ethanol Futures), no período de 03/10/2011 a 27/11/2015, em um total de 2.032 observações. Dentre os modelos analisados, destaca-se que os modelos EGARCH (2,2) para o spot e EGARCH (1,2) para o futuro são os que possuem o melhor ajustamento da série, considerado os Critérios de Informação de Akaike (AIC) e de Schwarz (SC), demonstrando um efeito assimetria principalmente na série de retornos futuros do etanol, e mostrando que os impactos resultantes dos choques positivos e negativos foram diferenciados na volatilidade, dentro do período analisado.

Conversion of corn fiber into fuel ethanol

Corn fiber due to its chemical composition (up to 20% starch, 50 - 60% non-starch polysaccharides) and availability has potential to serve as a substrate for manufacture of various products, including fuel ethanol. This paper deals with assessment of fiber-to-ethanol conversion. The water/dry fiber ratio in suspensions was 10/1. Enzyme liquefaction and saccharification of residual starch in corn fiber was carried out in two steps with thermostable α-amylase (20 min, 120°C) and mixture of pullulanase and glucomalyse (24 hours, 60°C). Procedures resulted in release of 57.7±1.6 mg of glucose per gram of dry fiber basis. It responds to the dextrose equivalent expression to 96.7±2.2%. By fermentation of the starch hydrolysates by yeasts Saccharomyces cerevisiae CCY-11-3 (5% v/v inoculum, 28°C, 72 hours) 0.48 g of ethanol per gram of glucose in hydrolysates was obtained. The solids after starch hydrolysis were separated by filtration and processed by acid pretreatment (0.1 g of conc. HCl/g of biomass/5 ml of water, 120°C, 20 min) with subsequent enzyme hydrolysis (24 hours, 60°C) by the multienzyme preparations containing cellulases and hemicellulases. Overall yield of reducing sugars after these two steps was 740.7±3.9 mg/gram of dry corn fiber basis. Fermentation of lignocellulosic hydrolysates by yeasts Pichia stipitis CCY-39-50-1 and Candida shehatea CCY-29-68-4 (in both cases 5% v/v inoculum, 28°C, 72 hours) resulted in 0.38 and 0.12 g of ethanol per gram of reducing sugars. The results indicate that applied pretreatment methods and used microorganisms are able to produce ethanol from corn fiber.

Paper Mulberry Fruit Juice: a Novel Biomass Resource For Bioethanol Production

By way of broadening the use of diverse sustainable bioethanol feedstocks, the potentials of Paper mulberry fruit juice (PMFJ), as a non-food, sugar-based substrate, was for the first time evaluated for fuel ethanol production. Without any external nutrient supplementation, the suitability of PMFJ was proven, as maximum ethanol concentration (56.4 g/L), and yield (0.39 g/g), were achieved within half a day of the start of fermentation, corresponding to a very high ethanol productivity of 4.7 g/L/hr. Using Response Surface Methodology, established potentials were further maximized through statistical optimization of process conditions of temperature (20 – 40 ⁰C), yeast concentration (0.5 – 2 g/L), and pH (4 – 6). At the optimal temperature of 30 ⁰C, inoculum size of 0.55 g/L, and pH of 5, ethanol concentration, productivity, and yield obtained were 73.69 g/L, 4.61 g/L/hr, and 0.48 g/g, respectively. Under this ideal process conditions, bioethanol from PMFJ compares favorably with typical sugar-based energy crops, highlighting its resourcefulness as a high value biomass resource for fuel ethanol production.

Feasibility Study on Bioethanol Production by One Phase Transition Separation Based on Advanced Solid-State Fermentation

To fulfill the consumption demand of low-cost fuel ethanol, an advanced process for feedstock fermentation and bioethanol extraction was required. This study proposed a process of combined continuous solid-state distillation and vapor permeation to extract ethanol from fermented sweet sorghum bagasse on the basis of advanced solid-state fermentation technology. Ethanol undergoes only one phase transition separation in the whole process, which drastically reduces energy consumption compared to the repeating phase transitions that occur in conventional bioethanol production. The mass balance and energy consumption of combining processes were simulated overall. A techno-economic evaluation was conducted on the flowsheet. Costs and profit of fuel ethanol produced by one phase transition separation bioethanol-producing technology were comprehensively calculated. The results of the present study show that the proposed process is an energy efficient and cost-effective alternative to conventional bioethanol production.