I have carried out pyrolysis of biomass. Now I am in need of calculating the biomass efficiency (in terms of mass and energy conversion). Kindly help me with a formula.
Heating values is defined at a temperature usually 60 F sometimes 15 C or 25 C. There are two types of heating values Low Heating Value(LHV) assumes water remans a liquid , High Heating Value (HHV) assumes water condenses as the name suggests HHV is higher than LHV by the heat of vaporization of water. If you have data for combustion gas temperature when you burn your biomass by mixing with air or oxygen at 15 C and you know the composition of the flue gas you can calculate the heat required to cool the flue gas from combustion temperature back to 15 C, If you burn it at a different temperature you will need to estimate the heat capacity of the biomass and adjust the balance by the amount of heat added or removed to get to the reference temperature. Here is a link to HHV of some typical "biomass"
https://www.engineeringtoolbox.com/biomass-fuels-hhv-d_1818.html
You can find the heating value of most types of biomass with a simple google search.
Efficiency is usually defined as the amount of heat you can usefully recover divided by the heating value. You need to specify HHV or LHV basis and the temperature (if it is different than 60 F).
You can calculate the thermal efficiency by dividing the energy content (calorific values) of the output gases (essentially a mixture of CO and H2) from the pyrolysis of biomass by the input energy content of the biomass feedstock to the pyrolyzer. The denominator of the thermal efficiency equation is merely the primary energy if you were to directly combust the biomass.
I'd recommend that you use a process simulation software like Aspen HYSYS or AspenPlus to model the biomass pyrolysis process. The simulation will give the mass and energy balance of this process.
Hope this helps answer your question and good luck.
Heating values is defined at a temperature usually 60 F sometimes 15 C or 25 C. There are two types of heating values Low Heating Value(LHV) assumes water remans a liquid , High Heating Value (HHV) assumes water condenses as the name suggests HHV is higher than LHV by the heat of vaporization of water. If you have data for combustion gas temperature when you burn your biomass by mixing with air or oxygen at 15 C and you know the composition of the flue gas you can calculate the heat required to cool the flue gas from combustion temperature back to 15 C, If you burn it at a different temperature you will need to estimate the heat capacity of the biomass and adjust the balance by the amount of heat added or removed to get to the reference temperature. Here is a link to HHV of some typical "biomass"
https://www.engineeringtoolbox.com/biomass-fuels-hhv-d_1818.html
You can find the heating value of most types of biomass with a simple google search.
Efficiency is usually defined as the amount of heat you can usefully recover divided by the heating value. You need to specify HHV or LHV basis and the temperature (if it is different than 60 F).
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