The released heat by fuel combustion increased in the order: methane, n-octane, and propane, with the maximum heat values being 12, 19, and 32 W, respectively.
The maximum lower heating value of the producer gas was approximately 3.6 MJ m−3 at standard temperature and pressure (STP) conditions and was obtained at an equivalence ratio of 0.165.
The maximum higher heating values (HHV) of biocrude oil from both algae were ∼37 MJ/kg.
Open image in new window Fig. 5 Total heating value versus maximum explosion pressure (reanalyzed NIOSH test results).
Performance parameters such as air factor, feeding point position and bed height are determined looking for a maximum gasifier efficiency and gas heating value and a minimum tar content in the gas.
The results show that for the maximum heat flux, the value of the cone angle (αc) with a high index is the top contributor to the both laminar and turbulent flow state, thus the geometric parameter αc should be considered firstly in the material design process of thermal protection system.
The maximum system efficiency based on lower heating value (LHV) is 37% at 120.7 W.
When CO2 mass percentage in the gasifying agent was 60%, the fractions of CO and CH4 in the producer gas reached the maximum, as well as the lower heating value and cold gas efficiency, so this was the optimal condition when the gasifier had the best performance.
Producing biogas, heat and power from chopped hemp has the highest overall energy efficiency, 84% of the theoretical maximum (based on lower heating values), providing that the maximum capacity of district heat is delivered.
A maximum efficiency of 45% based on the lower heating value of dodecane was calculated for a system that provides 2.5 kW for 40 h.
