Methods
Accurate measurement of BMP requires:
- The use of an accepted protocol and measurement method
- Application of standardized equations for calculating BMP from raw laboratory data
- Evaluation of results using accepted validation criteria, and elimination of results that are likely to be inaccurate
Below you can find practical documents that describe all of these components. All documents listed below are free and open-access, and should be cited in reports or papers in lieu of a detailed description of methods (see "Citing these documents" below or each individual document for citation information). Each has an associated approval list of researchers, showing that it describes widely accepted methods (to add your name, please contact us). For papers and other information related to these documents, see the Literature and Tools and Links pages.
Requirements for BMP measurement
All BMP tests should follow the guidelines given in the document below, which represents the consensus view of more than 50 biogas researchers. It includes both required components for any BMP protocol, as well as validation criteria. Use of validation criteria to eliminate results that are likely inaccurate is important for improving inter-laboratory reproducibility. Any test that does not meet the criteria listed in this document should be repeated. For a short summary of the validation criteria see document 101 instead.
Data processing
BMP calculations are relatively simple, but the level of detail given in peer-reviewed papers is often insufficient. Calculation of BMP should follow the steps given in the following document.
- BMP calculation (document 200) EN
Determination of the standardized volume of methane produced requires method-specific calculations. The following open-source documents provide detailed equations for four approaches, including two common variations for each.
Laboratory protocols
BMP can be measured using a variety of approaches. Commercial automated systems – typically volumetric – require the least labor and deliver the highest temporal resolution, but the initial cost is high. Manual methods are based on volumetric, manometric, or gravimetric principles. Any of these approaches can provide results just as accurate and precise as automated systems, but the gravimetric approach is not sensitive to leaks or other interferences. All measurement methods require separate gas analysis or removal of carbon dioxide. When gas analysis is not available, the gas density (GD) method can be used instead. The documents below provide detailed protocols for manual methods, with new additions under development.
Citing these documents
If you use these documents in your work, they should be cited. Doing so can help spread the word about the Standard BMP Methods site and contribute to standardization of BMP measurement. See the files listed below for recommended citation information. If you use Endnote, Zotero, or other reference management software, you can import the information in BibTeX file (either copy file contents to your clipboard for importing, or right-click on the link to save the file for later import). Please pay attention to version numbers when citing these documents. Changes (generally minor) will occur over time.
Recommended citations view online
BibTeX file for reference management software view online
Document approval
Each of the documents presented here has been approved by a number of biogas researchers. For details, see the following list (use the search box to filter by document number, name or country):
Document approval list view online
Document development
These documents represent the consensus view of many biogas researchers. Documents are developed and revised using Git and GitHub, which provide a means of tracking all changes and more. If you would like to contribute to the documents, send a message or visit the GitHub repository at https://github.com/sashahafner/BMP-methods