BACKGROUND
Biofilters can be used to eliminate different gaseous pollutants including alcohols (e.g. methanol, ethanol) and methane (CH4) individually or in a mixture. In this regard, the biofilter adaptability to feed composition variation is an industrial requisite. Inlet gas composition changes also give a better insight about carbon input and end‐points in biofilters. In this study, the gradual conversions of two biofilters from methanol and ethanol to CH4 were investigated.
RESULTS
Both biofilters reached 100% removal efficiencies for the alcohols with no initial inoculation. Keeping the total inlet load constant (30 ± 1.3 g m−3 h−1), CH4 was progressively substituted in the feed with corresponding alcohol:CH4 mass ratios of 3:1, 1:1, 1:3 and 0 galcohol:gCH4. Maximum CH4 removal efficiencies of 52% and 29% were obtained (respectively) for biofilters started with methanol and ethanol. By moving from alcohols to CH4 biofilters, the gas phase output carbon increased from 273 to 666 gcarbon day−1 and from 377 to 681 gcarbon day−1 respectively for the methanol‐ and ethanol‐based biofilters.
CONCLUSION
This study showed a successful treatment based on inlet pollutant alteration from methanol or ethanol to CH4 in two separate biofilters. However, the methanol‐based biofilter displayed a better performance and a shorter acclimation time for CH4 conversion. © 2019 Society of Chemical Industry