A lot of friends who want to do biomass particle production think that the particle density and hardness of wood pellet press have an impact on calorific value, but in fact, density refers to the mass per unit volume, and the calorific value refers to the unit inside A unit of mass fuel combustion completely released by the heat.An analogy: uncompressed woodchuck calorific value per kilogram is 4200 kcal, even if you compress it 100 times smaller, a kilogram of calories is 4200 kcal.
This issue can be referred to the question of which primary schooling is one kilogram of cotton and one kilogram of iron.
Biomass particle density
The mass per unit volume of a substance The density of a biomass particle is typically between 1.0 and 1.3, and the size of the density only determines the size of the volume, so biomass particles of a larger density do not affect their calorific value, Affect the size of the biomass particle size, that is, the density of the wood particles only in the same vehicle installed more.
The biomass calorific value: An important indicator of fuel quality. The amount of heat emitted per unit mass (or volume) of fuel when fully combusted. The amount of heat released by a kilogram of solid fuel for a particular type of solid fuel is called the calorific value of the fuel. Therefore, a kilogram of wood pellets, regardless of the density of the compression, have the same heating value, so that the heating value of the wood pellets has nothing to do with the density and therefore has nothing to do with the compacting density of the wood pellet machine. Misled by some comments online.
So what are the factors that affect the calorific value of biomass particles?
1, the internal factors: the most direct impact on calorific value is the internal factors, internal factors that affect the calorific value of the plant itself, mainly refers to the plant itself, the main body of the plant, mainly by the lignin, cellulose, starch, protein, Fat and other substances, and different material composition calorific value varies greatly, so different part of the plant tissue, root, stem, branch, leaf, skin calorific value has great differences.
Ash content studies showed that the ash content of plant samples directly affected the caloric value of plant dry weight, and those with higher ash contents had lower dry weight calorie values, whereas dry weight calorific values were higher.
Exogenous factors: The caloric value is not only affected by plant internal factors, but also affected by the environment in which plants are located. The results show that climate, soil, temperature and human disturbance have an important influence on the proportion of various organs of plants , And then affect the level of plant calorific value.The plant caloric value reflects the changes in plant life and plant activity and plant growth, the impact of various environmental factors on plant growth, to a certain extent, from the change in calorific value The caloric value can not only be used as an effective indicator of plant growth, but also the calorific value of the study is the basis for the study of energy flow and biomass size.
Therefore, whether it is wood pellets, straw particles and other fuels, the root cause of its calorific value is the calorific value of its vegetation itself, not by changing the density, shape, etc. It can be concluded that wood chips The pellet mill does not have the slightest relation to the calorific value of the produced biomass pellet fuel, and the density control is only for transportation and storage.
