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

Author(s): Harold Crespo Sariol, Noemí del Toro del Toro, Donia Hernández Guisado, Jeamichel Puente Torres, Jan Yperman, Robert Carleer, Wouter Marchal, Dries Vandamme

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.