An Acoustic Analytical test for Quality Control on Granular Activated Carbons for Rum Production: Case study of Catalytic activity towards Acetal-Acetaldehyde formation

Abstract

This work presents the preliminary results of evaluating the potentialities of the acoustic emission method (AE) as a rapid analytical tool for quality assessment of granular activated carbons (GAC) used in the rum production process. A new commercial GAC-2 from a new supplier was under technological assessment in a pilot scale rum factory facility for research purposes. The GAC-2 was evaluated for ethanol-water solution refining operation in a fixed bed adsorption system. After a nonstationary operational test period of about 60 days, a significant deviation of the sensory quality (ethereal odor and untypical flavor) of the outlet filtered ethanol solution was detected. According to headspace (HS) and liquid SPME-GC/MS and TD-GC/MS analyses performed on the refined ethanol solution and GAC-2/U (GAC-2 after being used for ethanol solution refining) respectively and based on previous case studies, it was found, that the GAC-2 catalysed the ethanol conversion into acetaldehyde and its acetal (1,1-diethoxyethane) thus provoking undesirable sensory characteristics of the rum. GAC-2 was texturally and chemically compared with a traditionally used granular activated carbon for rum production: i.e., GAC-1 as reference which has an extensively proved satisfactory organoleptic performance in rum production. Although the commercial information about technical and physicochemical parameters of GAC- 2 and GAC-1 reported by the suppliers suggests that both materials are texturally comparable, differences were found between GAC-2 and GAC-1 based on BET, TGA, Digestion-ICP and AE. This study points to the possibility of applying AE method as a very sensitive and rapid complementary analytical test to detect differences between GACs with potential practical applications in the industrial sector.