Debarking from Energy Plantation Wood, Is It Necessary?

Debarking machine

Wood pellet target market is an important thing that needs attention. If the power plant is the main market for wood pellets, the quality standard of wood pellet products follows the technology used by the power plant. Meanwhile, if wood pellets for households who want premium quality, wood pellets that are produced also follow these quality standards. The wood pellet market for electricity generation needs large, different from the wood pellet market for households that are sold in small packages or the retail market. Electricity generation technology also needs to be monitored so that all wood pellets produced can be absorbed. Pulverized and fluidized bed combustion technology is the technology most widely used for electricity generation. In pulverized combustion technology generally wood pellets cannot be used 100% (except with a number of modifications), while fluidized bed technology can use wood pellets or biomass pellets from various raw materials.

What is debarking? Why do need debarking? Debarking is the separation of bark from log, with the aim of reducing ash content. That means that if the ash content of the log with the bark can be accepted by the user, of course debarking is not necessary. For power plants usually can accept wood pellets up to 2% ash content for standard pellets and 6% for utility pellets. Meanwhile, if the user wants a wood pellet product with very low ash content, premium pellet (less than 1%), then debarking must be done. The wood species used also affects the ash content. Almost all energy plantations use fast rotation plants and coppice such as gliricidia with ash content of more than 1% so that it is more suitable for electricity generation and do not need debarking.

CFB Powerplant in Japan

Another thing to note is ash chemistry. The potassium and chlorine content in the ash is a critical point that needs attention. Fast rotation plants in general have a high potassium content than wood biomass in general. This makes the use of power plants in particular pulverized combustion increasingly limited to cofiring applications. Whereas in fluidized bed combustion because the operating temperature is lower then it can be tolerated and is considered not to cause problems. This means that wood pellets from energy plantation wood are compatible with biomass power plants with fluidized bed technology and can be used for cofiring with a certain percentage of pulverized combustion.