Towards a standardization of biomethane potential tests

Production of biogas from different organic materials is a most interesting source of renewable energy. The biomethane potential (BMP) of these materials has to be determined to get insight in design parameters for anaerobic digesters. Although several norms and guidelines for BMP tests exist, inter-laboratory tests regularly show high variability of BMPs for the same substrate. A workshop was held in June 2015, in Leysin, Switzerland, with over 40 attendees from 30 laboratories around the world, to agree on common solutions to the conundrum of inconsistent BMP test results. This paper presents the consensus of the intense roundtable discussions and cross-comparison of methodologies used in respective laboratories. Compulsory elements for the validation of BMP results were defined. They include the minimal number of replicates, the request to carry out blank and positive control assays, a criterion for the test duration, details on BMP calculation, and last but not least criteria for rejection of the BMP tests. Finally, recommendations on items that strongly influence the outcome of BMP tests such as inoculum characteristics, substrate preparation, test setup, and data analysis are presented to increase the probability of obtaining validated and reproducible results.info:eu-repo/semantics/publishedVersio

Impact of household demographic characteristics on energy conservation and carbon dioxide emission: Case from Mahabad city, Iran

This study explores the impact of different household demographic characteristics on energy conservation and carbon dioxide (CO2) emission in Mahabad city located in the northwest of Iran. The structural model adopted was composed of six variables, including household age, household size, educational qualification, income quintile, gender, and energy conservation concerning demographic characteristics and energy sources and consumptions. To compare predictability power of effects of these variables concerning households’ energy conservation and CO2 emissions, a crisp instruction on how to evolve a statistical technique for analyzing data was provided by partial least squares structural equation modeling (PLS-SEM). To verify the reliability of the PLS-SEM technique, the statistical significance test was performed by investigating path coefficients. The study revealed that households consume approximately 89.71% on liquefied petroleum gas (LPG), 9.87% on electricity while the rest 0.43% on kerosene, petrol, and diesel monthly. Eventually, the results of this study showed that household age, household size, and carbon dioxide emissions, except education background and income level, are significantly correlated with energy conservation

Towards a standardization of biomethane potential tests

ABSTRACT Production of biogas from different organic materials is a most interesting source of renewable energy. The biomethane potential (BMP) of these materials has to be determined to get insight in design parameters for anaerobic digesters. Although several norms and guidelines for BMP tests exist, inter-laboratory tests regularly show high variability of BMPs for the same substrate. A workshop was held in June 2015, in Leysin, Switzerland, with over 40 attendees from 30 laboratories around the world, to agree on common solutions to the conundrum of inconsistent BMP test results. This paper presents the consensus of the intense roundtable discussions and cross-comparison of methodologies used in respective laboratories. Compulsory elements for the validation of BMP results were defined. They include the minimal number of replicates, the request to carry out blank and positive control assays, a criterion for the test duration, details on BMP calculation, and last but not least criteria for rejection of the BMP tests. Finally, recommendations on items that strongly influence the outcome of BMP tests such as inoculum characteristics, substrate preparation, test setup, and data analysis are presented to increase the probability of obtaining validated and reproducible results