Sustainability has become a pressing priority for industries and governments worldwide, driven by the need to reduce carbon footprints, minimize waste, and transition to renewable energy sources. When it comes to industrial applications one can find out that the most energy intensive and carbon emitting step is drying of biomass. Bio-energy or bio-mass which comprises of crops residues, timber and animal waste is now one of the most important renewable sources of energy.
Nevertheless, its application in energy production and other related industries has need for drying, a process that was until recently highly energy-intensive. Biomass dryers present a technology that addresses this challenge by enhancing the feasibility of biomass as an energy source through efficient energy use, minimal wastage and enhancement of the whole process of biomass chain.
The Importance of Biomass Drying
Biomass drying is the process of removal of moisture content from biomass for its subsequent use in energy production, manufacturing of bio fuel and various other applications. Biomass has relatively high moisture content, which decreased the heat content and its effectiveness for combustion or gasification. Wet biomass is not only more difficult to combust but it also generates more pollutants resulting in deterioration of air quality as well as increased carbon emissions.
Taking water away from biomass increases its calorific value hence increasing the amount of energy that will be obtained when the biomass is burnt or when undergoing gasification. This is especially the case in the generation of bioenergy where the ability to convert the bioenergy depends on the moisture content of the biomass. The energy which can be derived is proportional to the moisture content, hence, the less the moisture content, the less the quantity of raw biomass required for energy production.
Besides increasing the calorific value, effective drying complicates the structure and makes the material more resistant and durable. The wet biomass due to high moisture content has susceptibility to decompose and to be acted upon by microorganisms, and hence, there is propensity for biomass material to breakdown and virtually loose viability. When biomass is dried, it is more manageable and lasts longer so that, unlike fresh plant material, it can be stocked and transported at appropriate conditions, and not spoil.
Types of Biomass Dryers
Biomass dryers are divided into several kinds for use in different industries due to the different kinds of biomass and moistures that it contains. Biomass dryers can be categorized in terms of technology options by the type of biomass, the level of dryness required, and the scale of the system and the energy sources employed.
Below are some of the most commonly used biomass dryers:
Rotary Drum Dryers
Among all of the biomass dryers used in the industry, the rotary drum dryers have always been popular and commonly employed. They include a large rotating drum in which the biomass is tumbled while heated air is passed through it. This design allows the continuous movement of the drum such that the biomass remain exposed to heat hence promoting efficient moisture removal.
The rotary drum dryer is also very flexible to use and can dry almost any biomass material such as wood chips, straws, stalks, animal manure among others. They are particularly suitable for large throughput volume as their operation in large manner is not significantly affected. However, they can also consume significant power, when they are not optimized to recover the energy delivered to them.
Belt Dryers
Flat belt dryers employ a conveyor belt design where biomass is taken through a heated drying zone. The biomass is regularly distributed on the belt and hot air is passed through the chamber and the moisture is evaporated from the biomass to both ends of the tunnel. These are commonly employed for biomass with reduced particle sizes such as saw dusts, or pellets and are famous for their gentle handling on biomass that is easily degradable.
A major benefit of belt dryers is that they use less energy than other conventional methods of drying and when coupled with heat recovery systems, which harvest heat from the drying process, then convey this heat to other natural processes, belt dryers provide a natural solution. Belt dryers are also easy to operate and easy to maintain and that is why they are ideal for medium to large biomass drying plants.
Flash Dryers
Flash dryers can be used for the fast drying of small particle size bio mass materials like saw dust, wood shavings etc and agricultural residuals. A feature of a flash dryer is that the biomass is passed through a hot air stream where evaporation of moisture is very fast. Flash dryers are characterized by high drying rates and low residence time; therefore, they are suitable for materials with high initial moisture levels.
As mentioned above, flash dryers can be used in combination with other drying systems; for instance, rotary drum dryers or belt dryers with a view of accomplishing the specific desired moisture level. There is also the fact that they are widely employed in industries where space is at a premium since they are relative compact compared to most other kinds of dryers that are out there.
Fluidized Bed Dryers
Biomass particles are supported in a hot airstream in fluidized bed dryers and move in the manner that resembles a fluid, improving the heat transfer and moisture removal rates. The biomass is fluidized so that all particles are subjected to the heated air hence uniform drying is achieved . Per batch, fluidized bed dryers are very efficient and can reduce moisture content in the given product to very low level using proportionate energy.
These dryers are best applied where the biomass material is in the form of fine powders such as saw dust or are in the form of pellets and are widely used in industries that require high turn around and are very sensitive to energy consumption. They may not be appropriate to handle biomass composed of large or non-uniform geometry particles as these will interfere with the fluidization.
Improving Sustainability with Biomass Dryers
Biomass dryers have a significant importance as regards the biomass sustainability, energy consumption minimization, and optimal biomass supply chain.
The most important advantage of biomass dryers is their contribution to enhancing the energy efficiency of biomass when it is being processed. As such, dryers help in enhancing calorific value of the biomass when it is being utilized for combustion or gasification procedures. This means that less raw biomass is going to be needed to generate the amount of energy needed thus the less demand for biomass harvesting and transportation.
Biomass dryers also help in managing waste in that wet biomass does not decompose during storage and transportation thus reduces on waste. Wet biomass can undergo microbial action and decay losses which can be very much substantial in value. The moisture content of biomass affects its potential for spoilage and as such, by controlling the moisture level in biomass, more of the collected biomass is available for usage in the generation of energy or in other processes.
The process of biomass drying also has a significant correlation with the carbon emissions related to the usage of biomass in energy generation. They are wet biomass which tends to burn less efficiently compared to dry biomass meaning that the emissions of CO2, particulate matter and other pollutant are higher than in the case of dry biomass. Through drying, biomass burners enhance combustion with reduced emission of gases to the atmosphere.
Furthermore, biomass dryers can also a reduce the absolute carbon footprint of biomass energy production. When biomass is dried with the heat, which is in excess or from renewable sources like solar or geo thermal then emissions of carbon are negligible. This has a positive bearing to general sustainability of biomass energy thus assisting the industries in achieving their carbon off-targets.
Maintenance of biomass dryers is one of the most critical aspects in the sense that it support circulatory economy to maximize resource utility and reap waste into good use. Essentially, a circular economy entails recycling material and using waste to manufacture products that would not come close to the market through conventional channels and thus with little or no degradation of the ecosystem. Biomass dryers facilitate the transformation of waste, for instance agricultural residues, food waste and forestry by products into energy.
In this context, dryers aid in the closing of the biomass supply cycle and assistance in reducing the usage of energy from raw materials from the more conventional chemical source by converting the waste materials into dry biomass appropriate for energy use. This combines well with the system of a circular economy where an element is repeatedly circulated in the economy rather than being disposed of on the first usage.
The utilization of biomass dryers is very important in enhancing the effective utilization of biomass materials in processing and energy production. Dryers play a crucial role of minimizing the moisture content of biomass, thus improving in the rate of combustion as well as gasification, low waste, and low carbon emission. Biomass dryers also conform with the principles of circular economy because waste materials can be converted to be of great use as energy sources.
Kerone is a prominent manufacturer with the durable and innovative biomass dryers having the capabilities of efficiently managing the moisture content besides controlling fuel consumption to produce high quality biomass materials. Due to advanced technology and innovative products, we make sure that every biomass dryer we offer fits well in different industries; hence making sustainable energy production possible and affordable. Companies can achieve high-performing drying systems for sustainable practices and increased output by collaborating with Kerone.
