A short report on the operation of the “new” gasifier:
- the basic purpose of this construction was to be able to use wood of different sizes and shapes without any problems, which moves downwards without jamming or bridging, which ensures the same cross-section of the interior
- a large cross-section of 50 cm entering the hot zone allows for a lot of power and low resistance
- the lower central nozzle supplies air directly above the limiting opening, thus maintaining the active layer of charcoal until the end of the conversion, in this way all the charcoal is used until ash is formed, which simply retreats into the ash space with the gas flow
- after a few years of using wood gas to power a tractor, I have found that all processes are endothermic and require energy to proceed, well, the temperatures are different
- drying wood,… here it is necessary to heat and maintain the wood at a high temperature (150°C) in order for the moisture to evaporate from the interior, this process represents a consumption of approximately 5% of the energy of wood (wood with 15-20% moisture)
- pyrolysis,… here the wood is exposed to a temperature of 200 to 500°C, relatively moist but very calorific gases are released, thermal decomposition of the wood occurs and charcoal is produced, which represents a consumption of approximately 4% of energy
- the reduction of moist gases in charcoal “consumes” the most energy, this is estimated to be approximately 13%
A classic gasifier covers all these heat needs by burning wood, which represents more than 22% of the energy of the wood, the result is gas with a relatively low energy of approximately 1.5 kWh/pm.
If we include the heat recovery of wood gas in the calculation, it does not cover the energy for drying and pyrolysis, but when we add the energy of the exhaust gases, this is sufficient to cover these needs and also for preheating the cooled - dried gases that enter the reduction zone,… so here we can save 5% for drying, 4% for pyrolysis and we help the reduction process with 5% savings,… the gas becomes much more powerful and has at least 2 kWh/pm, an engine that runs on such gas reaches power and torque equivalent to diesel fuel
