In the pelletizing process of feed pellets a lot of frictional heat is generated, that is a well-known fact. Most often, the temperature difference (Delta T) is +10 ºC (see trend curve) in relation to the 81º C, which is prescribed in Danish feed legislation, to reduce salmonella. The knowledge of the core temperature of the pellets makes it possible to utilize the generated frictional heat, without compromising the heat treatment of the feed. At the same time, the inlet temperature can be lowered when the core temperature is known, i.e. the steam supply in the conditioner and thus energy / CO2 is reduced.

Trees do not grow into the clouds. Similarly, there are limits to how much the temperature can be lowered. It is the steam that softens the flour and helps to reduce friction and thus creates a more durable pill. If the steam supply is reduced too much, it will result in an increased power consumption on the pellet press’s main motor, which in turn will increase the CO2 emission of the production.  Therefore, it is crucial to find the balance between the pellet press’s power consumption and the steam supply.  The exact temperature reduction will depend on the individual conditions in the production, such as the composition of the recipe, the die thickness and the wear of the die.

Above is a trend curve where the conditioner’s temperature has been lowered to 74 ºC and where the temperature after the pellet press is 91 ºC.

Below is a simple calculation of what cost savings could look like:

• In this calculation 10 kg steam / hr – per. ° C are used, with which the temperature must be raised in the conditioner.
• The capacity of the pellet press will be 15 tons per hour.
• The cost of steam can vary as the energy sources differ from production to production. In addition, the efficiency of the steam boiler fluctuates due to age and make. In this calculation, the “rule of thumb” is used, which is DKK 1 per kg steam / hour.
• The calculation uses an average amount of working days of 216 days per year.

Another significant aspect of the start-up process is the lower amount of steam to be used before the flour reaches the right temperature. Partly because a lower temperature must be achieved, but also because the increased energy that is supplied to the matrix means that the feed pellets heat up to the right temperature faster than in the conditioner.

All this means that the product can be approved more quickly and less material is generated for repelletation, which also saves energy / CO2. In addition, it will be possible to run shorter series, as there is a shorter waiting time for the repelletation system to be empty and ready for the next batch. In connection with the reduction of the temperature of the feed pellets, less air will be needed to cool the pellets (m3 / hr). This in turn means a further reduction of energy / CO2.

It is generally crucial to know how the material is processed in the pelletizing process in order to know the production process. There may be e.g. changes in the raw material which help to increase the friction but which are not usually visible in the process. Or also a bad adjustment of the roll, which gives a longer pelletizing time, which increases the frictional heat.

All the heat that is added also helps to destroy the naturally occurring vitamins and enzymes in the raw material. However, a lot of artificial vitamins and enzymes are added to compensate, and also to increase nutrient uptake. However, in this case it is also possible to reduce the supply, as not everyone is equally thermostable. All this will of course require a more in-depth review of one’s production, but if there is a large temperature difference, it is advisable to investigate.

In connection with this article, it can be recommended to read the following:

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GreenUp Accelerator is Denmark’s most ambitious acceleration program for climate tech startups working with CO2 reduction. Our aim is simple: To scale up climate tech startups working with solutions and technologies that make a difference in reducing CO2 emissions.

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LAG MANK supports the establishment of mounting facilities.

The local action groups (LAGs) are funded by the European Agricultural Fund for Rural Development.

In a press release, they write:

Newly developed temperature sensor is to solve an old challenge in the feed industry.
Nomination: 200.000 kr
Contact: Lasse Jessen, tel. 22156512

Danish Feed Tech Solutions Aps specializes in technology solutions optimizing feed production. In the last few years, the company has developed a new type of temperature sensor, which measures the temperature of feed at a much more optimal time in the production process.
It is regulatory requirements that the feed, during the production, must be heated to at least 81 degrees, which requires large amounts of energy. The improved measurement method can reduce heating, and it improves both producers’ finances and CO² emission – and ultimately also the climate impact of consumers’ dinners. “In collaboration with Danish Agro in Skamby, we have tested the temperature sensor, and we are now ready to start the actual production”, says co-owner Lasse Jessen, who has an expectation that almost all major producers will be interested in their invention, as it is easy to integrate into the vast majority of production facilities and the energy savings are significant. LAG MANK supports the establishment of production facilities in Otterup, where the measuring device will be produced.

The Otto Bruun Foundation supports research in Danish industry as well as entrepreneurs’ and inventors’ development of industrial inventions and other purposes of general societal significance.

The Innovation Fund invests in the development of new knowledge and technology that leads to strengthening of research and innovative solutions for the benefit of growth and employment in Denmark. The foundation focuses on supporting solutions to specific societal challenges and increasing research and innovations efforts in companies.
www.innovationsfonden.dk