ETHANOL PRODUCTION FROM COCOYAM (Хanthosoma sagittifolium): APPLICATION OF THERMODYNAMIC-TOPOLOGICAL ANALYSIS

Cocoyam (Xanthosoma sagittifolium (L.) Schott) is a tropical plant of the family of Araceas. Nigeria, China and Ghana are the countries that currently own most of the world production of this plant. In Colombia, there are not extensive crops of this plant, but it is used for animal feeding mainly. The plant has an aerial part with a high content of protein (leaves) and a tuber with an average starch content about 25% w/w. Compared to others starchy raw materials, this is a high value. Due to this fact this first-generation starchy material could be considered as a possible feedstock for the production of ethanol. Process design must ensure that the most advanced concepts are applied at the design and processing stage for every raw material to ensure efficient and more sustainable processes. For this reason, thermodynamic-topological analysis was used for the design of the stage of the produced ethanol purification. This work presents the process of ethanol production using cocoyam tuber. The software Aspen Plus v8.6 (Aspen Technology, Inc., USA) was used for the techno-economic assessment, and the Waste Reduction Algorithm (WAR) of the Environmental Protection Agency of the EE.UU. (EPA) was used to measure the environmental performance. The obtained production cost was 1,6 USD per kilogram, and the environmental impact was very low. This is an excellent incentive to promote the application of this feedstock to obtain a feasible alternative for the production of ethanol. Additionally, the use of thermodynamic-topological analysis in the design stage of the purification stage of the process proved to be very useful and easily applied.

RESEARCH OF VARIOUS ISO-MANIFOLDS IN FOUR COMPONENT SYSTEMS CONTAINING BIAZEOTROPIC BINARY CONSTITUENTS

In the present work, an analysis of the mutual arrangement of a number of iso-manifolds in the concentration tetrahedron formed by the components of the separated mixture and an additional substance, an extractive agent, was carried out to estimate the possibility of separating three-component mixtures containing biazeotropic constituents by extractive rectification. The objects of research were four-component systems formed by ternary constituents (butyl propionate (BP) - propionic acid (PA) - butyl butyrate (BB), butyl propionate - propionic acid - butyric acid (BA), butyl butyrate - butyric acid -butyl propionate, butyl butyrate - butyric acid -propionic acid) of the commercially important BP-PA-BB-BA system, and the extractive agent sulfolane. Using the results of the computational experiment based on mathematical model NRTL-HOC we obtained complete data on the vapor-liquid equilibrium in binary, three- and four-component systems. The structures of liquid-vapor phase diagrams were obtained, and thermodynamic-topological analysis of all four-component systems was carried out. The mutual arrangement in the concentration tetrahedron of manifolds of relative volatility (equal to 1) of the components, reflecting the evolution of pseudo-azeotropes in sections with a constant concentration of the extractive agent; pseudo-ideal manifolds along which the activity coefficients of the components of the base (separated) mixture are equal to each other; isothermo-isobaric manifolds generated by Bancroft points in binary azeotropic constituents were determined. We established that it is possible to separate the studied three-component mixtures by extractive rectification using sulfolane.

SEPARATION OF A MULTICOMPONENT SYSTEM FORMED IN THE PRODUCTION OF EPICHLOROHYDRIN

Epichlorohydrin is an important product of the basic organic synthesis. One promising direction of epichlorohydrin manufacturing is the liquid-phase epoxidation of allyl chloride with an aqueous solution of hydrogen peroxide in an organic solvent, methanol, in the presence of a heterogeneous catalyst, a titanium-containing zeolite. The multicomponent system of epichlorohydrin production according to this method contains allyl chloride, methanol, water, epichlorohydrin, 3-chloro-1,2-propanediol, 3-chloro-1-methoxypropanol-2 and hydrogen peroxide. In this work the thermodynamic topological analysis of the phase diagram of this multicomponent system of epichlorohydrin production was performed. On the basis of this study a principal technological scheme of separation of the studied system containing five distillation columns and a Florentine vessel was proposed.