Diseño de un proceso para la producción de bioetanol a partir de cáscara de papa

Abstract

The design of the process for the production of bioethanol was carried out with the purpose of producing this biofuel, which in Peru is used as a gasoline additive, in order to improve the quality of the fuel because it increases oxygen levels and reduces greenhouse gas emissions. The designed process has the capacity to produce 5086.36 m3 /year (32 MBLS) of bioethanol with high purity (99.7% v/v), which could supply 2.9% of the imported volume in Peru. In addition, it was considered to use potato peel as raw material due to its high content of fermentable sugars. Based on the bibliographic references, it was decided to work with enzymatic hydrolysis due to its high yield of sugars, and fermentation using the yeast Saccharomyces cerevisiae since it is a microorganism capable of efficiently fermenting hexoses, producing ethanol. For the extractive distillation, the solvent tetraethylene glycol was used because it allows a good separation in the distillation, it isn’t toxic and doesn’t pollute the environment, in addition, it had a solvent recovery stage. In this work, the design of the dryer, reactors, distillation columns, pumps, heat exchangers, among others, was carried out. For the design of the reactors, the kinetics that occur in each of them were analyzed and their dimensions were determined, obtaining a capacity of 34 m3 for the hydrolysis step and a reactor with a capacity of 187 m3 for the fermentation step. Also, the design of three distillation columns was carried out, determining the number of real stages, the height and the diameter. Likewise, the design of the equipment was carried out, such as the dryer, nine heat exchangers and a boiler whose energy source is natural gas with a consumption of 2600.42 Sm3 per day. In order to determine the operating conditions of the three distillation columns, the ProMax 4.0 simulator was used. Through simulation, the thermal power in the reboiler and condenser was determined, the number of theoretical stages necessary to obtain the desired concentration in the distillate and bottom stream, determining that 17, 26 and 11 stages are needed for the first, second and third distillation column, respectively. Likewise, the concentration of ethanol, water and tetraethylene glycol in the distillate flow and bottom was analyzed as the position of the feed stage varied, determining the optimal position for each of the distillation columns. Finally, the economic evaluation was carried out at a horizon of 20 years considering the price with which it is sold in the United States ($ 0.7/L), determining through the cash flow that the project is profitable from the fifth year, with an internal rate of return (IRR) of 25% and a net present value (NPV) of $ 4,880,405.94. With the sensitivity analysis, it was found that OPEX is more sensitive compared to the sale price of bioethanol and CAPEX since it was shown that when OPEX increases by 30%, an IRR of 12% is obtained.

Date of Award	2021
Original language	Spanish (Peru)
Supervisor	Patricia Araujo Pantoja (Asesor)