mass2vol {biogas} | R Documentation |

## Calculate Biogas Production Gravimetrically

### Description

`mass2vol`

calculates biogas volume based on measured reactor mass loss.

### Usage

```
mass2vol(mass, xCH4, temp, pres,
temp.std = getOption('temp.std', as.numeric(NA)),
pres.std = getOption('pres.std', as.numeric(NA)),
unit.temp = getOption('unit.temp', 'C'),
unit.pres = getOption('unit.pres', 'atm'),
value = "CH4", headspace = NULL, headcomp = 'N2',
temp.init = NULL, std.message = TRUE)
```

### Arguments

`mass` |
reactor mass loss in g. A numeric vector. |

`xCH4` |
biogas mole fraction of methane. Must be normalised so xCH4 + xCO2 = 1.0. A numeric vector. |

`temp` |
the temperature of biogas as it exited the reactor. A length-one numeric vector.
Degrees Celcius by default (see |

`pres` |
the pressure of biogas as it exited the reactor. A length-one numeric vector.
Atmospheres (atm) by default (see |

`temp.std` |
standard temperature for presentation of biogas and methane results.
Default value is 0 degrees C.
Argument is passed to |

`pres.std` |
standard pressure for presentation of biogas and methane results.
Default value is 1.0 atm.
Argument is passed to |

`unit.temp` |
temperature units for |

`unit.pres` |
pressure units for |

`value` |
what should be returned?
Default is |

`headspace` |
(optional) reactor headspace volume in mL. Used to correct for effect of initial reactor headspace on mass loss. A numeric vector. |

`headcomp` |
(optional) composition of the initial reactor headspace.
Only required if |

`temp.init` |
(optional) initial headspace temperature in unit.temp units. Used to correct for effect of initial reactor headspace on mass loss. |

`std.message` |
should a message with the standard conditions be displayed? Default is TRUE. |

### Details

This function uses the method described in Hafner et al. (2015) to calculate biogas production from reactor mass loss.
It is essential that the only change in reactor mass is due to biogas removal!
Users are advised to read the original reference before applying the method.
This function is vectorized.
Instead of using this function directly when working with multiple measurements on multiple reactors, use the `cumBg`

function (which can call up `mass2vol`

).

Standard values and units of temperature and pressure can be globally set using the function `options`

.

### Value

volume of methane in mL as a numeric vector (if `value = "CH4"`

) or a matrix with columns for biogas, methane, and carbon dioxide volumes in mL.

`vBg` |
standardised volume of biogas in mL |

`vCH4` |
standardised volume of methane in mL |

`vCH4` |
standardised volume of carbon dioxyde in mL |

All volumes are standardised using `pres.std`

and `temp.std`

arguments (see `stdVol`

).

### Author(s)

Sasha D. Hafner and Charlotte Rennuit

### References

Hafner, S.D., Rennuit, C., Triolo, J.M., Richards, B.K. 2015. Validation of a simple gravimetric method for measuring biogas production in laboratory experiments. *Biomass and Bioenergy* **83**, 297-301.

### See Also

`vol2mass`

,
`stdVol`

,
`cumBg`

,
`options`

### Examples

```
# Volume of methane if measured mass loss was 3.1 g
mass2vol(3.1, xCH4 = 0.65, temp = 35, pres = 1)
# More details
mass2vol(3.1, xCH4 = 0.65, temp = 35, pres = 1, value = "all")
# Vectorized
data("massw")
massw$massloss <- massw$start - massw$end
massw$vCH4 <- mass2vol(massw$massloss, xCH4 = 0.65, temp = 35,
pres = 1)
massw
```

*biogas*version 1.23.2 Index]