A random pump: 4mn at 350W to lower a 20l enclosure to 2mbar. Or less than 120Wh per 100l: it is nothing compared to the calorific energy saved if it were necessary to provide the calorific energy by heating to 60 or 80 ° C.
It is a question of drying crushed biomass to prepare pellets.
Breathtaking !!
An enclosure that air of 20L is 20X1,3g) 26g of air without water !!
100l is 130g of air without water to dry !!!
100 liters of wood or 50kilos to dry at 50% humidity is 25 liters of water or 25kilos, to evaporate by pumping to give 25m3 (at random) of steam (not 100litres) and therefore (at random) 25kilos / 130g = 210 or 20m3 on 100L = 200 times more energy to consume (randomly because there is no point in wasting my time calculating the exact PV with a poor-performance pump, the best root pump!)
Even at 25% wet, it is 100 times more.
Finally it is useless to heat to 80 ° C, but to send dry air for a long time on a finely divided wood to evaporate.
If the air is completely dry, the drying is enormous at 20 ° C, even at 0 ° C if the air is completely dry (freeze-drying) !!! (verifiable by east wind coming from Siberia in winter)
Air can be dried by cooling a surface to condense water.
I repeat, a solar dryer is very good and not tiring and economical !!!
Another basic problem is that after drying, following elements of the hygroscopic salt type (such as sea salt), the wood takes up the humidity of the ambient air !!!!
Finally I think more and more that we can make stoves similar to those with pellets, not too expensive, but accepting a wide range of shredded wood, with a little imagination instead of having an armada of standards making captive with the granules !!!
) ... which will facilitate air circulation and therefore the drying of the wood.