Heating Value of Biogas 1

[magaguadavic]

Can someone tell me how to claculate the heating value of biogas given the following: 55% methane, 750 mbar, 47 degrees C, gas is saturated? Been using the lower heating value at STP but we're off setting more fuel oil than expected. Assume it is because gas is not at STP. Any help would be greatly appreciated.

 

[danw2]

Check out this paper:

http://www.dairyfarmenergy.com/DLtech_Publications/Heating_Value_of_Biogas.pdf

 

[25362]

Following danw2's given link, it seems that LHV drops by about 19% at the conditions submitted by magaguadavic. For that message danw2 merits a star.

 

[magaguadavic]

25362, I don't get the same. Using danw2's link and especially Figure 2, I get an increase in LHV due to the increase in P and T above STP. Am I missing something?

 

[25362]

Magaguadavic, I based myself on Table 1. The LHV values are tabulated at a given STP, which adjusted to the prevailing conditions you mentioned, means that every CF of gas has a lower heat value.