Sawdust dryers play an important role in enabling the production of biomass energy in that they solve the problem of high quantity of moisture deposited on newly produced sawdust. Sawdust being in nature of a byproduct of woodworking and logging industry is easily accessible, and carries a great amount of energy. Although it is a preferred material due to its variable thickness, it has high moisture content that poses a problem to energy consumption. In order to increase the efficiency of energy output from this feedstock, drying technologies like sawdust dryers are crucial given the growing trends in the use of biomass energy.
Drying Sawdust Is Essential for Producing Biomass
An organic material from a live or recently deceased organism that has the ability to produce energy and can be used is known as biomass or bioenergy. Biomass feedstock can be simply described as substances obtained from plants and animals or wastes from plants and animals; sawdust which is a fine wood particle produced as a result of cutting, grinding, or sanding wood is a typical biomass feedstock.
All the same, given its moisture content it is not very energy efficient as it can contain between 30% and 60% moisture depending on its stage of readiness. The water content in biomass lowers the combustion and conversion efficiency to biofuel because much of the energy is spent in converting water to vapor.
High moisture biomass also comes with complication on storage and transportation as compared to low moisture bio mass. Sawdust becomes easily biodegradable when wet and this causes a breaking down of the material and many health risks to human beings. In addition, excess of water within the biomass raises the density and volume of those biomass hence the transportation cost will be high. This is because many of the applications of sawdust require it to be dried before use, and this has several benefits such as; increasing the calorific value and therefore the efficiency of the combustion process, as well as tipping the transportation costs at the application end. This is where sawdust dryers come into picture.
How Sawdust Dryers Work
Depending on the type of use that is required for sawdust after it has been produced, so that it is not used merely for seasoning logs, a special tool called sawdust dryer to get rid of the moisture in sawdust needed for its subsequent use, such as energy. Among the two most common types of these dryers are the belt dryer and the rotary drum dryer. Other variations are also available. The main basis of operation of sawdust dryers is to bring in to contact with hot air or gas the wet material, the moisture is expelled leaving behind dry biomass which is easier to undertake subsequent processes on.
Rotary Drum Dryers
It is prescribed that rotary drum dryers are one of the most widespread kinds of dryers applied in biomass production. They comprise a big drum on which adapt from top to bottom and that leans slightly towards the discharge end. The moisture laden sawdust is then introduced into the drum, here it is subjected to blast of hot air. The method involves the use of a drum that has the sawdust placed on it such that as the drum rotates the sawdust is lifted through a hot air stream that dries the moisture.
This way, there is constantly movement as well as circulation of hot air, which ensures that the food item in question dries up uniformly. It is then further dried and when the temperature gets hot inside the drum, the sawdust is discharged out of the drum. Rotary drum dryers are one of the effective drying equipment that has the capabilities to handle large quantity of material to be dried. They are particularly suited for use in large biomass production industries where there is always a large volume of sawdust which requires to be processed within a short duration.
Belt Dryers
However, it is important for one to understand that belt dryers work in a different mechanism than the rotary drum dryers. In these systems, water-soaked sawdust is spread uniformly on a belt having small holes and this belt moves slowly through a drying room. Air is passed over or through the sawdust thus removing the moisture in the process as the material moves on the belt. Belt dryers, on the other hand, are used for drying of biomass in small quantities or occasions where gentle drying is necessary in order not to harm the biomaterials fed in the process.
But belt dryers are slower than the rotary drum dryers and they are more accurate as well in controlling the drying process. For this reason they are well suited for use in a system where the biomass requires gentle handling and should maintain a consistent form throughout the system.
Effects of Sawdust Dryers on Biomass Efficiency
Dryers are therefore very significant in the process of biomass energy production since they have the ability to drastically lower moisture content in sawdust. The following points show how sawdust dryers play an important role in improving biomass efficiency.
Increased Calorific Value
The amount of energy produced in the process of combustion of biomass is expressed in its calorific value. This means that the calorific value also depends on the moisture; the higher the moisture the lower calorific value is because a lot of energy has to be used to remove the moisture. If sawdust is dried before burning or converting, it will provide more heat and be a more effective fuel. Sawdust dryers it possible to bring the Moisture content back to the desirable levels which are for instances to be around 10% or less so that most of the energy generated from the combustion process is put to work in the production of heat rather than evaporation of moisture.
Improved Combustion Efficiency
Besides, elevating the calorific value, the sawdust dryers also improve the combustion process. Unlike dry biomass which burns rapidly with little smoke and emissions such as carbon monoxide and particulate matters, wet biomass burns inconsistently and produce more smoke and pollutants. This is because combustion is not complete and hence a lot of energy is wasted and there is emission of pollutants into the atmosphere. When sawdust is pre-dried before combustion, it can be burnt in a cleaner manner and has a higher heat value as well as lesser emission. This is especially so where biomass is used in large scale heating or electricity generation like is the case in industries.
Improved Production Efficiency on Pellet and Briquette Manufacturing
Biomass pellets, sometimes referred to as briquettes, are densified biomass products that are simpler to handle, store, and burn when made from sawdust alone. The description above makes clear how important feedstock moisture content is to the production efficiency of pellets or briquettes. When the sawdust is wet the pellets or briquettes produced will be so weak, and might crumble as they are being handled or burned. The proper moisture content is important to achieve prior to compaction and hence, sawdust dryers enable this to happen thereby resulting in improved quality of boards that are denser and more durable as well.
Enhanced Biogas and Biofuel Yield
Apart from combustion, sawdust can also be used to produce biogas or bio fuels particularly through techniques such as anaerobic digestion and pyrolysis. These processes also have high moisture sensitivity. For instance, anaerobic digestion is a process that involves the use of bacteria to reduce the complex of organic material under no access to free oxygen and generates biogas in the process.
High moisture content may have a negative impact on biogas production in that it slows down the rate of digestion and lowers feedstock concentrations. In the same way, pyrolysis, which involves the process of heating biomass in the absence of O2 to yield bio-oil and biochar, high water content decreases the biofuel quantity and quality. Sawdust dryers are useful in these processes since they make sure that the feedstock has the right moisture level for the conversion processes.
Some of the most useful devices that help in improving the potential of biomass energy are the sawdust dryers. The sawdust dryers also enable the reduction of moisture content of sawdust hence increasing calorific value and combustion efficiency of the biomass and cutting down on transportation and storage costs and optimizing production of pellets, briquettes, biogas and bio fuels.
In this process, Kerone, the manufacturer and supplier of innovative drying equipment, has a significant role of providing exclusive and effective sawdust dryers to fulfil the demand of the biomass energy market. With the increasing rate at which the globe is turning to renewable energy, Kerone’s sawdust dryers have a crucial role to play in expanding the capacity of feedstocks biomass. The use of Kerone’s advanced drying technology is ideal for any biomass producer who wants to improve energy efficiency as part of a more sustainable energy path.
