FUZZY LOGIC MODELING AND OPTIMIZATION OF ENZYMATIC HYDROLYSIS OF LIGNOCELLULOSIC MATERIALS

ALDO RODOMIRO VECCHIETTI; JULIO ROLANDO FLORES; RAFAEL ROQUE ALEJANDRO VARGAS

Foz Do Iguacu

Conferencia; 5th International Conference on Engineering Optimization; 2016

In recent decades there have been great advances in the production of bio-ethanol from lignocellulosic materials. In present are being installed industrial capacity plants, such as is the case of plant in Piracicaba (Brazil) of Raizen company. In this plant the bagasse of sugarcane is utilized for obtain bio-ethanol. Obtain a high conversion of carbohydrates in fermentable sugars, is critical to the success of this type of projects.The combination of a dilute acid pretreatment followed by enzymatic hydrolysis has been the technologythat more progress had in last years for decomposing the feedstock into fermentable sugars. It is important to properly modeling these steps for performing an optimization process, since the conversion efficiency is determined mainly in the pretreatment and enzymatic hydrolysis stages. The thermochemical pretreatments, such as dilute acid, have received many studies. Has been reported to the decomposition of the constituents of lignocellulosic materials follow first order kinetics in this type of process. In the literature there are several studies on the determination of decomposition rates for different materials of interest (Aguilar, Ramírez, Garrote, & Vázquez, 2002).Moreover, the step of enzymatic hydrolysis has also received a large amount of research. In which is identified a large number of variables related to the performance of enzymatic conversion. Obtain a model that accurately represents the process of enzymatic hydrolysis of cellulose is a highly complexproblem, because it includes a variety of phenomena (Bansal, Hall, Realff, Lee, & Bommarius, 2009). There are two major groups of works on the enzymatic hydrolysis process. On the one hand, experimental work to determine conversion yields for certain raw materials and specific pretreatments. And on the other, they are works oriented to establish the relevance of the various phenomena in determining the enzymatic conversion under certain circumstances. But obtaining a general model is still distant. Against this background is considered the alternative of modeling the enzymatic hydrolysis step using Fuzzy Logic. This tool has proven useful in the field of control of complex systems that do not have a suitable model (Gupta, Dey, & Sinha, 2012; Takagi & Sugeno, 1985). Fuzzy logic can utilize the knowledge of experts to determine what the system behavior and how to control it. An important aspect is that fuzzy logic allows working with certain levels of inaccuracies or ambiguities in the values of the variables of interest.In this work is developed an optimization model of the stages of pretreatment and enzymatic hydrolysis of lignocellulosic materials. Using Fuzzy Logic for modeling the enzymatic process. Particularly are studied the case of treatment of sugar cane bagasse, using bibliographic information. The model was implemented in Matlab and the results have been compared with data reported in experimental researches.