Estudo de um sistema de recuperação de CO2 para uma cervejaria artesanal

Abstract

Beer is a product resulting from the alcoholic fermentation of wort (malted barley), which is carried out by the yeast Saccharomyces cerevisiae. This process produces several by-products, among them carbon dioxide (CO2) which plays a key role in the factory production of beer, but its elimination into the atmosphere can be harmful as it contributes to global warming. One of the proposals of the work is to unite the environmental and economic needs, through the study of the technical and economic feasibility of implementing a CO2 recovery system in an artisanal brewery. For this, a survey of fermentation data of Ale and Lager yeasts (the most used in the brewery) was carried out, to estimate the amount of CO2 produced during productions, associating the real values with the experimental ones, in comparison with the yeast generations. Possible errors in the methodology were discussed, the CO2 recovery system models on the market, the investment value linking the profit and cost of the operation, and the use of environmental indicators to parameterize the CO2 values prevented from being eliminated in the atmosphere. The case study was based on analyzes carried out in the Alcolyzer Beer DMA 4500 M equipment and with the pressure generated during the fermentation period. The results obtained were in terms of pressure, converted into mass units through concepts and values derived from scientific articles and books. The CO2 values produced were high for both yeasts, but they are still plausible in view of the study carried out by Venturini Filho et al. (2014). In the case study, several flaws were presented, such as: efficient data collection, volume inaccuracy, gas solubility in beer, headspace size, operating limit of maximum tank pressure, different production volumes, yeast stress, and accelerated fermentation. Taking into account the CO2 estimate of a CO2 recovery system manufacturer, he used the Payback tool to estimate the economic viability, resulting in the investment being more profitable when the factory capacity reached the volume of 600,000L. Thus, in order to make a more realistic estimate of CO2 production, errors pointed out during the study and future suggestions for better parameterization should be taken into account. Finally, he discussed the amount of CO2 that would be avoided from being emitted into the atmosphere if the CO2 recovery system were implemented.