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Biomass grain drying systems: the solution for organic farming

 
28/03/2022

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By using biomass grain drying systems, the drying process can become greener and more sustainable. In fact, plants equipped with a biomass heating system can obtain bioenergy to heat the air needed to remove excess moisture from the crop without having to use traditional fossil fuels.

Biomass grain drying systems use natural and renewable fuels to replace traditional fossil and non-renewable combustion sources such as gas and oil. Economical, renewable and sustainable: solid biomass consists mainly of residues from agro-forestry and food industry processes.

But how do biomass grain drying systems work and what advantages do they offer? In this article, Mecmar illustrates the most efficient and high-performance solutions for drying your organic crops.

Why choose a biomass grain drying system?

The subject of biomass is certainly much discussed, but what exactly is biomass? Biomass is material of biological origin - generally waste from other activities - from which it is possible to obtain fuel for other processes, such as grain drying. Using a biomass grain drying system means making the most of what nature has to offer, while complying with the standards of the circular economy.

Biomasses can be of various kinds and come in the form of solid, liquid or gaseous fuel. But what are Mecmar's solutions for using biomass when drying your harvest? Let's see them together!

Let's start from the assumption that solid biomass from activities linked to agriculture and forest maintenance is the most widely used. Solid biomass is mainly divided into woody biomass, such as brushwood and prunings, and herbaceous biomass, such as straw and corn cobs. The main advantage of using them in the drying phase is their high degree of reusability.

In fact, by opting for a biomass plant you will be able to use an organic energy source, which therefore comes directly from the environment and nature. Not only will you save on fuel costs, but you will also be doing good for the environmental ecosystem.

For example, rice straw - a type of biofuel - contains silicon, an ingredient often used in the cosmetics industry. From the embers of burnt straw it is therefore possible to obtain elements that can be reused in other production cycles, thus contributing to the creation of new products.

According to the international standard UNI EN ISO 17225, biomass can be classified into four categories: A1+, A1, A2, B, depending on specific quality characteristics. But how do you actually recognise a quality biofuel? A biofuel produces a lot of heat with a small amount of biomass, but not only that. The smoke produced by a quality biofuel is much less polluting.

Mecmar's mobile and tower dryers can also be fitted with a biomass boiler, instead of the classic oil burner. The components of Mecmar's BM500 biomass boiler include a heat generator made of stainless steel, an electric fan to extract the smoke and a loading screw equipped with a system to reduce the risk of fire.

Mecmar's biomass grain drying systems generally burn 2-3 centimetre wood chips of A1 quality or pellets with a moisture content of no more than 13-15%. The heat resulting from biomass combustion can then be transferred directly to the air or water. 

Mecmar biomass systems can be equipped with a stainless steel lamellar air-to-air heat exchanger, which can send the smoke directly to a dedicated chimney. This ensures that only fresh heated air circulates inside the dryer. Alternatively, it is also possible to use a hot water biomass boiler: simply equip the dryer with a radiator to transfer the heat from the water to the system's air flow. 

 

                                 Wood chip pellet dryer - model D20                                                                     F75 with biomass heat generator

 

In the first case, thanks to the Mecmar biomass hot air generator it is possible to produce air capable of reaching a temperature of 100 °C. In the second case, on the other hand, if the customer already has a hot water generator that burns wood chips, the heat from the water is recovered to heat the air during the drying of the cereals.

When to opt for a biomass plant: 3 ways of using biofuels for drying

Mecmar organic grain dryers can also be fitted with a special water-to-air heat exchanger, which is particularly useful if your farm already has a biomass heat generator capable of heating water. Thanks to the Mecmar heat exchanger, the heat from the water is in fact recovered and transferred to the air: in this way the heat produced by the biomasses is exploited in an intelligent and profitable way.

 

 

But how are biofuels used for drying cereals? Let us now look at three different possible ways:

  1. Use a standard dryer equipped with a burner capable of burning biofuels, such as biodiesel or biogas. This is the sustainable solution with the lowest impact in terms of plant costs.
  2. Install a hot air generator capable of burning solid biofuel (wood chips/pellets). Compared to the first solution, the overall dimensions and costs of installation and maintenance increase while fuel costs decrease.
  3. Prefer a dryer equipped with a special boiler suitable for burning any biomass. Together with the boiler, a heat radiator is installed: hot water passes through the heat exchanger, generating hot air to be used for drying. The advantage? By installing a hot water radiator, the biomass system can be used both to remove excess moisture from the crop and for other purposes than drying. In this way, the cost of the system pays for itself in less time.

How economically viable is it to burn biomass? Comparing the calorific value of various fuels, to obtain the heat produced by burning a litre of diesel, it is necessary to burn 1 cubic metre of gas or 4 kg of wood chips. Taking into account the current fuel costs in Italy, the cost of using diesel or methane gas are almost equivalent, while, considering buying wood chips at market prices, the fuel costs are reduced by about 60% for the same amount of dried grain. Furthermore, it is important to remember that much biomass is generated from processing waste, so it is available at virtually no cost. 

Conclusion

In this article we have reviewed the reasons why it is worth choosing a biomass grain drying system, as well as 3 ways of using biofuels for drying.

Inspired by the circular economy, Mecmar's biomass systems allow you to save on fuel and promote more sustainable drying. How? By using organic combustion sources from previous processes that can be reused in future production processes.

But why should your company invest in a biomass plant? Our advice is to choose a biomass system if you already have a hot water generator in your company. In this way, you can use the biomass plant not only to efficiently dry your harvest, but also for other purposes, such as heating greenhouses.

Depending on the size of the dryer required, the amount of grain to be processed each year and the type of fuel, Mecmar will identify the best biomass drying system for you. Since 2010 our team has been active in developing more sustainable drying solutions to meet the needs of all farmers.

Would you like to purchase a biomass grain drying system through financing or learn more about our machines? Contact us: we are available to answer all your questions.

https://www.mecmargroup.com/en/lp/calcolatore-costi-essiccazione
https://www.mecmargroup.com/en/lp/calcolatore-costi-essiccazione

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