Design and control of an alternative distillation sequence for bioethanol purification

Abstract

BACKGROUND Bioethanol is a green fuel considered to be a sustainable alternative to petro‐derived gasoline. The transport sector contributes significantly to carbon dioxide emission and consequently has a negative impact on the air quality and is responsible for the increase of the greenhouse effect. The availability of environment‐friendly and economical fuels is a worldwide priority. The separation process is a significant technology in the production of fuel grade ethanol in terms of both operating and capital costs. In the present work an alternative distillation sequence for bioethanol separation is presented. The steady state performance and the dynamic beavior are analyzed compared with the classical configuration reported in the literature. RESULTS Ethanol–water azeotropic separation represents a challenge for bioethanol purification. Usually a three column sequence is used to obtain fuel grade bioethanol by extractive distillation. In order to reduce bioethanol purification cost a two column separation sequence is proposed. This configuration shows a 10% saving in capital costs together with higher ethanol recovery and better control properties compared with the classical three column sequence. CONCLUSIONS Based on the steady state and dynamic results obtained, the two‐column configuration represents a valid alternative to the classical configuration for the separation of bioethanol. © 2014 Society of Chemical Industry

Optimization of the composition of mixed entrainer for economic extractive distillation process in view of the separation of tetrahydrofuran/ethanol/water ternary azeotrope

“…Special distillation processes such as azeotropic distillation, pressure‐swing distillation, and extractive distillation are widely used for separating azeotropes. Extractive distillation (ED) can change the relative volatility between the light and heavy components by adding a third component called entrainer and has been widely and deeply studied for separating binary azeotropic mixtures.…”

ETHANOL PRODUCTION FROM FERMENTATION OF ARUM MANIS MANGO SEEDS (MANGIFERA INDICA L.) USING Saccharomyces Crevisiaea

“…The purification of ethanol is achieved in two stages, 1) the purification by distillation to obtain 95.6% concentration of ethanol and dehydration of ethanol to obtain absolute ethanol. Ethanol purification cannot be conducted with a single stage (simple distillation) as ethanol and water form an azeotrope mixture (Errico et al, 2014;Kusuma & Dwiatmoko, 2009). The basic principle of this distillation apparatus is a separation based on the difference of the boiling or melting point of each constituent of a homogeneous mixture.…”

Sustainability and process control: A survey and perspective

“…Control of the fermentation reactor for bioethanol production has been pursued within the framework of optimal control [166] and MPC [167][168][169][170]. Similarly, control of the separation system has been targeted using PI control [171,172] and optimal control [173]. In the context of bio-diesel production, most of the control studies have focused on the control of the transesterification reactor which is the heart of the bio-diesel production process.…”