Wood pellets are refined and densified biomass fuel which are compressed into uniform shape,size and density by the pellet mill. They can apply in home wood stove, power generation, bio-energy and other applications which may take many benefits of efficiency, cost-effectiveness, convenience, renewability,
environmentally responsibility and energy independence. According the hardness, the wood pellets are classified into hand wood pellet and soft wood pellet, the differences between them mainly are as follows:
1. Price. The hard pellets are frequently sold as premier ones at a higher price than the soft pellets, the reason has little to do with quality and cost. Hardwood material is so much expensive than the softwood that the manufactures must sold at a high price to make up the same profits.
2. Hearting. Soft pellets can produce more 10 and 20 percent thermal than hand wood pellets, because the sap contained into soft pellets are more. This difference may be explain the higher hearting value of soft pellets.
3. Ash content. The ash content is non-combustible inorganic substance in biomass pellets which affects its energy content. The higher ash content, the lower energy content. The hard wood pellets contain about three times ash, at the same moisture, that is conducted by study. At the same time, the premium wood pellets only caused less than one percent ash content. The much ash content is involves in increasing buildup on the burn of stove surface, more bumping of it and restricting air flow. Also it refers the cleanness and environment side effect.
4. Emission. The study found the burn rate is comparative both hard wood pellets and soft wood pellets,, but the emission is drastic difference. At higher burn rate category,the emission is higher in hard wood pellets than soft wood pellets, however,at lower burn rate,it is opposite. Emission factor includes pyrolisis, densification and air flow rate.
From above description, we may choose different pellet type for wood stove on the basis of differences between them. Our company are abundant of various kind of pellets machine which can compress materials into hard and soft wood pellets as your demands.