Resíduos lignocelulósicos qumicamente modificados para remoção de glicerol da água

Abstract

The traditional and most widely used process for biodiesel purification it is washing. This process can consume water up to three times the volume of biofuel produced, and the effluent generated in this process retains large amounts of glycerin, the main byproduct of the transesterification reaction of triglycerides. The search for efficient processes to recover water resources led us to propose the use of sugarcane bagasse as a biosorbent of glycerol in wastewater. Four types of fibers were used, two integrals and two with surface modifications: Brute Fiber (FB), Purified Fiber (FP), Carboxymethylated Fiber (FCM) and Iron (III) Complexed Carboxymethylated Fiber (FCMFe). Among the four fibers that presented more consistent results in the removal of glycerol from water was the fiber modified and complexed with iron (III), the FCMFe. The optimum conditions were as follows: temperature of 24 ° C, contact time of 72 hours, mass of 0.7 g of fiber dipped in 5 ml of 2% solution of glycerol, obtaining approximately 82% of adsorption. The experimental data of the adsorption isotherm of the FCMFe were adjusted to the Langmuir and Freundlich equilibrium models presenting the same linear correlation coefficients of 0.99. The statistical analysis of the experimental results were significant to the analysis of variance and the Tukey mean test at 1% of probability, which indicated differences between the variables and their respective combinations.The surface carboxymethylation and the complexation of sugarcane bagasse enhance the adsorptive properties of the biomaterial to glycerol.