Functions for calculating biochemical methane potential (BMP) from laboratory measurements and other types of data processing and prediction useful for biogas research. Raw laboratory measurements for diverse methods (volumetric, manometric, gravimetric, gas density) can be processed to calculate BMP. Theoretical maximum BMP or methane or biogas yield can be predicted from various measures of substrate composition. Molar mass and calculated oxygen demand (COD') can be determined from a chemical formula. Measured gas volume can be corrected for water vapor and to standard (or user-defined) temperature and pressure. Gas quantity can be converted between volume, mass, and moles. A function for planning BMP experiments can consider multiple constraints in suggesting substrate or inoculum quantities, and check for problems. Inoculum and substrate mass can be determined for planning BMP experiments. Finally, a set of first-order models can be fit to measured methane production rate or cumulative yield in order to extract estimates of ultimate yield and kinetic constants. See Hafner et al. (2018)
The biogas package is an R package for biogas research.
It provides tools for processing biogas data, predicting biogas production, making conversions, and planning experiments.
For example, the calcBgVol() function can be used for calculating biochemical methane potential from original measurements.
The calcCOD() function can calculate the chemical oxygen demand of a compound based on a chemical formula.
And the planBMP() function can suggest substrate or inoculum quantities for a biochemical methane potential (BMP) experiment based on multiple constraints.
Much of the biogas package is dedicated to processing of laboratory measurements, but those functions are difficult to demonstrate in a short example.
So, an alternative is the predBg() microbial stoichiometry function.
With it, the theoretical maximum BMP of, say, cellulose, could be calculated with
> predBg("C6H10O5")
[1] 413.7274
and we could get a lot more information, including an estimate of biogas composition as affected by pH, for a 5:1 mixture of waste paper and waste oil with
> predBg(mcomp = c(C6H10O5 = 5/6, C54H100O7 = 1/6), mass = 1,
fd = 0.8, fs = 0.1, conc.sub = 50, pH = c(6.5, 7, 8.5),
temp = 35, value = "all")
form mass mol.mass moles COD fs fe fd
1 C1.52618H2.61516O1.00000 1 36.9655 0.02705225 1.454303 0.1 0.9 0.8
2 C1.52618H2.61516O1.00000 1 36.9655 0.02705225 1.454303 0.1 0.9 0.8
3 C1.52618H2.61516O1.00000 1 36.9655 0.02705225 1.454303 0.1 0.9 0.8
conc.sub temp pH hydro fCH4 xCH4 vCH4 vCO2 vBg
1 50 35 6.5 0.09279292 0.5566161 0.5689900 365.8395 275.91411 641.7536
2 50 35 7.0 0.09279292 0.5566161 0.5864017 365.8395 256.90636 622.7459
3 50 35 8.5 0.09279292 0.5566161 0.8921576 365.8395 44.02904 409.8686
mCH4 mCO2 mCO2Bg mCO2.sol cTIC m.bio N.req
1 0.2624617 0.5735654 0.54543300 0.02813242 0.03196140 0.08225028 0.01018521
2 0.2624617 0.5735654 0.50785807 0.06570735 0.07465048 0.08225028 0.01018521
3 0.2624617 0.5735654 0.08703757 0.48652785 0.55274693 0.08225028 0.01018521
See the vignettes and help files for more details.
The biogas package is available from CRAN, and so can be installed directly in R with:
install.packages("biogas")
To see available vignettes, use
vignette(package = 'biogas')
and then, e.g.,
vignette('calcBgVol_function')
or
vignette('predBg_function')
Alternatively, download the vignettes from the CRAN page.