Fuel briquettes from sunflower husks for heating. Advantages and disadvantages

Fuel briquettes from agricultural waste are becoming more and more popular. Husks (hulls) of sunflower, buckwheat, rice are used for their manufacture, straw, nut shells, etc. are processed. Features of modern technology are such that most often the formation of a fuel briquette occurs only due to pressure without additional binding elements. During pressing, one of the components is released from the raw material - lignin, which provides strength to the briquette.

With all the variety of raw materials, briquettes from sunflower husks are more popular. This is due to the large amount of heat that such fuel releases during combustion.

Advantages and disadvantages of husk briquettes

In addition to a large amount of heat, their density attracts in briquettes. Why is it so good? Firstly, you save on shipping (they usually charge for volume). Secondly, the more compact the fuel, the easier it is to store. Thirdly, when compared with firewood, when laying the same amount of firewood and briquettes (it is unlikely that you measure firewood in kilograms, because the boiler is laid by volume, and firewood is sold by cubic meters), you get more heat from briquettes than even from the best firewood. According to VNII TP, the heat from burning 1 kg of sunflower husk briquettes can heat an area of ​​50 m 2 within 1 hour.

In the table below you will see how much heat the fuel gives off. It must be said that fuel briquettes are far from last, but from the husk they are practically out of competition.

It is convenient to put briquettes in the firebox: their surface is smooth, unlike firewood, you won’t drive yourself a splinter, you won’t get your hands dirty, as when working with coal. There is another advantage: there is no need to improve or remake the boiler. Burnt with wood? Just buy briquettes and use instead of firewood.

Another plus of sunflower husk briquettes is the duration of burning: they burn for one hundred to one hundred and thirty minutes, and smolder for six or even eight hours. A considerable plus is the low ash content: after burning a kilogram of this briquette, ash remains from a matchbox or a little more (depending on quality, but normal briquettes have an ash content in the range of 4-7%), hence the large amount of heat that a unit of fuel emits: it burns out it is complete. The ash formed after combustion is an excellent fertilizer and can be taken out to the beds.

Now for the disadvantages. There is, in fact, one drawback: any briquettes (including husks) are afraid of moisture and can crumble when wet. Therefore, they are demanding on the place of storage: they must hide under a roof, in a dry room.

Often referred to as a disadvantage is a high price. If you look at the cost of a kilogram, then the price is really considerable. But if we calculate the cost of one kilowatt of energy, the picture is different. Want to make sure? Find out the price of a kilogram of firewood, coal, briquettes, etc. Divide this value by the number of kilowatt / hours from the table. Get the cost per kilowatt of heat for each type of fuel. We could do it ourselves, but the prices in different regions are different, and the situation on the market is changing rapidly ...

You can meet the opinion that fuel briquettes of sunflower husks clog the chimney as they contain a lot of oils. If it is not designed correctly or is defective, it is possible. In the presence of normal draft, the boiler works no worse than with firewood and you need to clean the chimney no more often.

If we consider the use of sunflower husk briquettes from the point of view of ecology, then this is also an obvious benefit: when burning husks, the same amount of carbon dioxide is released as when wood decomposes. When burning gas, CO 2 is released 15 times more, when burning coke - 30 times more, and coal - 50 times more. Emissions of other harmful substances are very small, because they simply should not be in a product grown under normal conditions, and the technology does not provide for extraneous additives.

Types and forms of briquettes. Is there a difference and what determines the quality

Fuel briquettes are produced in three different forms, which are usually named after the company that was the first to supply equipment for briquetting each of the forms to our market: NESTRO (nestro), RUF (raf), Pini-Kay (pini-kay). Briquettes are distinguished by the principle of pressing.

Extruder briquettes. This type is the most popular in the domestic market: it is convenient to put fuel produced using this technology into the furnace manually. They are characterized by the presence of a hole inside and a melted outer surface. The thing is that the pressing takes place at a sufficiently high temperature (up to 350 ° C), as a result, the outer surface of the briquette is melted, forming a rigid film, which increases the strength of the briquette. Therefore, they are better tolerated by transportation. Briquettes of this type made from sunflower husks have a dark glossy surface. High quality products do not have cracks on the outer surface.

Cylindrical briquettes. Raw materials are compacted by shock-mechanical presses. It leaves the installation as a continuous strip, which can then be divided into washers, pieces, etc. The shape can be any - round, square, polygonal (selected according to customer requests). On briquettes of this type, zones of higher and lower density are clearly visible (due to the peculiarities of the press operation).

Rectangular briquettes. They are obtained as a result of the operation of hydraulic presses, their density depends on the degree of friability of the feedstock.

The main indicator of the quality of a husk briquette (and any other one too) is its density. The denser the fuel, the more heat it produces. For example, a briquette with a density of 750 kg / m 3 will give out 14 MJ / kg of heat, a density of 1300 kg / m 3 - 31 MJ / kg.

The humidity of the feedstock also plays a role. At a moisture content of 4-10%, fuel with optimal strength characteristics is obtained, at high humidity, cracks appear on the surface and the briquette can fall apart. Therefore, when choosing, pay attention to the integrity of the outer surface: the presence of cracks indicates poor quality and insufficiently high calorific value.

Equipment for the production of briquettes from husks of seeds

The technology for manufacturing fuel briquettes from biomass (which includes sunflower husks, rice, buckwheat, etc.) is as follows:

• The material is washed and dried.
• They grind.
• Compress.
• Cool down.
• They pack.

Accordingly, the equipment is selected. You will need a dryer and a crusher (hammer or shredder), but the main thing is a press (piston, extrusion or screw). You may also need funds to transport raw materials and finished products to the workshop, a cooling plant, and packaging equipment.

The main equipment for the production of any briquettes is a press

How to make a press for self-production of briquettes

Do-it-yourself equipment for the production of fuel briquettes using extrusion (pressing at high temperatures) is hardly possible, but an ordinary press can be built even from improvised means.

This video demonstrates the original approach. Making such a press is not the most difficult task, and the yield of the product from one tab is decent. It can be easily adapted for pressing sunflower husks, only it will need to be crushed beforehand.

In general, our people are generous with all sorts of inventions. The culture of implementation is different for everyone, but whoever can do it does it. Here is a selection of photos, which also show home-made presses for the manufacture of fuel briquettes, including from sunflower husks.