Bioproducción De Ácido Lactico a Partir De Residuos De

Tecnol.   Ciencia  Ed.  (IMIQ)  vol.   23 núms.1-2,1999   2008 Tecnol. Ciencia  Ed.  (IMIQ)  vol. 14  núm.  2,  2008    79 Tecnol.   Ciencia  Ed.  (IMIQ)  23(2):  79-90,  79

Bioproducción de ácido láctico a partir de residuos de cáscara de naranja: Procesos de separación y purificación Lactic acid bioproduction from orange rind: Separation and purification processes
Ricardo HeliodoroGil-Horán*1, Rosa María Domínguez-Espinosa2, Juan Daniel Pacho-Carrillo2
1UNAM,

Facultad de Química, 2Consultores independientes Correo-e (e-mail): gilhoran@gmail.com
ABSTRACT The social awareness of the process industry environmental impact has resulted in tougher regulations and new fiscal policies that aim to encourage the chemical industry to adopt new production practices to reduce itsenvironmental impact. For this reason, the use of agricultural waste as low cost raw materials for fine chemicals production through biotransformation has attracted much interest. This option of transforming waste into raw materials appears as an attractive development path. It helps to reduce dependency on oil as raw material and also offers a way to obtain compounds that are uneconomical to produce bytraditional chemical synthesis. Mexico South East area is a main citric production zone where a large volume of solid waste in the form of peel and bagasse is generated. This waste comes from orange juice factories and it is normally sent to landfills or open air dumps where they represent an important pollution source. This waste can be used to produce high added value chemicals such as L(+) lacticacid. This product is demanded in the food, pharmaceutical, and personal care industries or for the production of biodegradable plastics and organic synthesis. This research deals with a process for the production of lactic acid through solid phase bioconversion of orange peel and bagasse using Rhizopus oryzae. The product complies with the Food Chemical Codex (FCC) regulations. Three differenttechniques were evaluated for the separation of liquids and solids (mechanical pressing, centrifugation and vacuum filtration), determining the maximum water contents to carry out the lactic acid extraction from the biotransformed solid. The feasibility of using ion exchange to remove impurities was also evaluated. For the recovery of lactic acid, two processes were tested as possible routes forsecondary separation and concentration: (a) Esterification with 1-butanol, and (b) Evaporative crystallization of calcium sulfate salts. Based on the experimental results, a flow sheet was created to carry out theoretical mass and energy balances using the computer program SuperPro Designer® 6.0, supported which the packages Aspen Plus and Aspen Split® 11.1, to estimate physical and thermodynamicproperties and to carry out detailed phase equilibrium calculations in process units. Based on the simulation, a processing plant with capacity of 400 ton/year of orange peel and bagasse with 12% w/w moisture was identified as suitable for the transformation of the wastea from a medium size juice factory into a production plant for 5.5 ton/year of 14% w/w lactic acid.

RESUMEN El interés social porla conservación del medio ambiente ha resultado en el endurecimiento de legislaciones ambientales y cambios de política fiscal que buscan impulsar a la industria química y reducir su impacto ambiental. Por tal motivo, la utilización de residuos agroindustriales como materia prima de bajo costo, para la obtención de productos químicos finos por biotransformación está ganando interés. Esta opciónde transformar desechos en nuevas materias primas se perfila como una opción atractiva para reducir la dependencia del petróleo y, al mismo tiempo, obtener compuestos que son económica o técnicamente inviables de obtener por síntesis química tradicional. El sureste de México es una de las principales regiones productoras de cítricos del país, donde se genera un gran volumen de desechos sólidos...