Abstract-A process design study was carried out, aimed at the design of a triacetin production process from glycerol, as a way to increase the feasibility of biodiesel production. Glycerol esterification with acetic acid involves three consecutive reversible acetylation reactions and in each step, water is produced, resulting in limited conversion and low selectivity [1]. One way to increase the triacetin selectivity is to continuously remove water from the reaction medium, in order to shift the equilibrium. The proposed process is based on the reaction system described by Galan et al.[2], consisting of the esterification of glycerol using excess acetic acid as catalyst. In the first step of the present study an evaluation of the kinetic parameters was carried out, based on published experimental data [2]. The reaction conditions were then evaluated in terms of glycerol conversion and selectivity for different reaction times and temperatures. Based on the results, the process was simulated in a reactive distillation column, and different configurations were studied by using the Aspen Plus® simulator. In the separation units the NRTL-HOC equilibrium model with binary interaction parameters proposed by Hung et al.[3] was adopted. Water removal from the top stream of the column was increased by feeding hexane as an entrainer in the reactive distillation column. Hexane is recovered in a separate unit and recycled to the process. The conceptual process specifications of an optimized industrial plant configuration were estimated for minimum specific energy consumption for production of 99.9 % molar purity triacetin with complete glycerol conversion.
Bioenergy with carbon capture and storage can be an influential technological route to curb climate change to a significant extent by preventing CO2 discharge.
The rising quantities of difficult waste streams is a global concern. Prudent utilization of difficult wastes such as sewage sludge (SS), refuse derived fuel (RDF), etc. can be a small...
Neste trabalho estudou-se a extração sólido-liquido do flavonoide quercetina a partir da cebola roxa. Estudos experimentais de solvente, temperatura, massa de matéria-prima por volume de solvente e tempo de extração mostraram a melhor condição para a lixiviação: etanol 60% (v/v); 40°C; massa de matéria prima (g)/volume de solvente (mL) 1:10; 2 horas e rotação de 200 rpm; obtendo-se uma recuperação de quercetina de 209,83 mgquercetina/gmatéria-prima e 335,19 mgquercetina/gSST (Sólido Solúvel Total). Com esses valores simulou-se o processo completo de extração com auxílio do software Aspen Plus®. Partindo-se de uma base de cálculo de 1000 kg/dia de matéria-prima obteve-se uma produção de 21,7 kg/dia de quercetina, na forma de extrato alcoólico 40°BRIX. Estimou-se um reciclo do etanol de 788,2 kg/dia, sendo necessário repor 17,8 kg/dia de etanol anidro e 94,3 kg/dia de água no processo.The present work studied the solid-liquid extraction of the flavonoid quercetin from purple onion. Experimental studies of solvent, temperature, raw material mass per solvent volume and extraction time showed the best condition for leaching: ethanol 60% (v/v); 40°C; raw material mass (g)/solvent volume (ml) 1:10; 2 hours and 200 rpm shaking; with a quercetin recovery of 209.83 mgquercetin/graw material and 335.19 mgquercetin/gSST (Total Solid Soluble). With these values the complete extraction process was simulated with the aid of Aspen Plus® software. Starting from a base of calculation of 1000 kg/day of raw material it was obtained a production of 21.7 kg/day of quercetin, in the form of alcoholic extract 40 °BRIX. An ethanol recycle of 788.2 kg/day was estimated, requiring 17.8 kg/day of anhydrous ethanol and 94.3 kg/day of water in the process.
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