Otimização no processo de hidrólise ácida dos tubérculos da erva daninha Cyperus esculentus visando a obtenção de etanol

Abstract

Ethanol consumption in Brazil increases every year, but the conditions for obtaining this product are still hampered by the lack of new raw materials that do not compete with the food chain. Brazil is one of the largest producers of ethanol through sugarcane. In 2005, Brazil led the world production of ethanol with an amount of 3,989 million gallons but over the years some events that occurred worldwide caused ethanol ceased to be exclusive to Brazil becoming a source of huge acceptance of fuel in the consumer market world. It was then that the United States has increased its technological advances and their areas of crops for the production of ethanol from maize. In 2007 the United States overtook Brazil in ethanol production and has occupied the first place in world production of ethanol until the past few years. In 2014 the United States managed to produce 14,300 million gallons of ethanol. However this annual exponential growth causes a major problem for both the United States and in Brazil which is the rising prices of raw materials used for the conversion of ethanol fuel. Against this backdrop Brazil seeks new alternatives to produce ethanol without reaching the productive food chain. This work used as an alternative in production ethanol one plant was called Cyperus esculentus which was study material for biodiesel production in previous studies providing a quantity of 17% oil. This plant also provides a amount of starch is about 30% being studied for the production of ethanol by enzymatic route. The way that ethanol produced in this work was the acid route used four different acids and using variables like temperature and three different times. For better optimization of the method used to the experimental design with the software design Expert® and the answer were the amount the amount of reducing sugar and alcohol content. For the characterization of the ethanol produced were performed by infrared (IR), ultraviolet (UV-VIS), calorific value and physicochemical tests. The results indicated that the catalysis using phosphoric acid and hydrochloric acid obtained better results in reducing sugar and alcohol content. Phosphoric acid has better results in alcohol characterization tests. A kinetic study was also designed to identify the order of reaction, activation energy and pre-exponential factor applied by acid catalysis. The kinetic study showed that both the hydrochloric acid and the phosphoric acid showed characteristic of first-order reaction. The activation energy and pre-exponential factor had a high difference between the catalysis of acid. On the issue of cost applied to industrial process using hydrolysis as phosphoric acid showed better results. Compared to hydrolysis with phosphoric acid and enzymatic hydrolysis performed in past studies highlight that the enzymatic hydrolysis is impractical to present a very high production cost since the production using hydrolysis with phosphoric acid indicates a beneficial framework to apply the production of ethanol fuel with a margin of profitable income. The hydrolysis of phosphoric acid to ethanol production using the plant tubers C. esculentus can be an alternative for the production of biofuel.