The only thing that is known about fuel briquettes is that they can compete with traditional wood or coal. What is a solid fuel material of a modern sample? What is really better: fuel briquettes or firewood?
Solid fuel, known as Eurowood, is produced industrially, so each individual element has the same size and regular shape. Briquettes can be burned in solid fuel furnaces of all types, including stoves, fireplaces and heating boilers.
In the production of heating briquettes, waste is used that is generated at the enterprises of the woodworking industry. They are formed from the husks of cereal plants, straw or peat. To obtain the desired material, small particles are pressed under high pressure and dried at high temperatures. This method allows you to completely abandon the adhesive compositions and other binders. A densely formed mass during combustion does not emit toxic substances, so the fuel is absolutely safe for people and animals.
The main advantages of the material and its disadvantages
The main advantage of pressed briquettes is a high level of heat transfer during combustion, almost two times higher than that of firewood. At a standard moisture level of 20%, firewood gives 2500–2700 kcal / kg of heat, sawdust briquettes - 4500–4900 kcal / kg. The explanation is simple: heat transfer directly depends on the amount of moisture, and for eurodra, which have undergone thermal drying, it does not exceed 8%.
The briquette has a higher density. For example, oak burns much longer than birch, as oak firewood for each cubic centimeter contains more combustible matter (0.81 g / cm3) than birch, therefore the increased burning time. The briquette density is even higher and is equal to 0.95–1 g / cm3.
Among other advantages, it should be noted:
- Compact size for easy storage
- uniform burning and high calorific value;
- low soot emission due to low moisture content;
- ecological purity of raw materials.
Wood fuel briquettes have disadvantages, which are very conditional. Compressed firewood is more expensive than conventional lumber, but you need to consider the cost of a unit of heat, which is clearly not in favor of ordinary firewood. Briquettes are afraid of moisture, which destroys their structure, but wood should not be stored in a humid environment.. A significant drawback is that it is impossible to determine the quality and composition of fuel briquettes by eye.
Types of briquettes
There are several varieties of Eurodroves. It depends on the form and composition of the product. Manufacturers distinguish three main forms of products:
- Pini-kay Such euro-woods have a maximum density (1.08–1.40 g / cm3) They are made with square or hexagonal briquettes with holes inside for air circulation and better combustion.
- Nestro They have a cylindrical shape and differ in average density (1–1.15 g / cm3).
- Rufus (ruf). Such briquettes are produced from sawdust in bricks of low density (0.75–0.8 g / cm3) and compact size.
Table 1: Prices for RUF and Pini Key
Name | Volume | Cost, rub. | Calorific value, kcal / kg | Ash content,% |
Evrodrova RUF | 1 ton | from 5500 - 7500 | 4800 — 4900 | less than 0.3 |
Pini Kay | 1 ton | from 7500 to 9500 | 4850 — 5000 | less than 0.3 |
In addition to differences in shape and density, eurowoods differ in their constituent components that directly affect the ash content, the amount of soot produced, the calorific value and the degree of combustion. For example, peat products cannot be used to heat domestic foci due to the high content of ash and harmful fractions in their composition. Such material is intended exclusively for industrial needs. The table shows the types of fuel briquettes with comparative characteristics of products from different raw materials. These tables are collected on the basis of test reports obtained experimentally.
Briquette material | Ash% | Moisture% | The highest calorie content, kcal / kg | The lowest calorie content, kcal / kg | Density, g / cm3 |
Straw | 7,3 | 7,8 | 4740 | 3754 | 1,08 |
Husk seeds | 3,6 | 2,7 | 5161 | 4480 | 1,15 |
2,92 | 8,51 | — | — | — | |
Tyrsa | 0,7 | 7,5 | 4400 | 4200 | 1,37 |
Rice husk | 20,2 | 7,1 | 3458 | 3161 | 1,16 |
Sawdust | 0,8 | 4 | — | — | — |
1,1 | 10,3 | 4341 | 3985 | — | |
1,16 | 4,1 | 5043 | 4502 | 0,79 |
Decoding tables for each material
- Sunflower seeds. Due to the low ash content and the high energy value of vegetable oil, this type of compressed material shows the best calorific value (5151 kcal / kg), however, such samples emit more soot, which will lead to flue contamination.
- Wood. At a moisture content of 4%, pressed sawdust takes an honorable second place in calories with an indicator of 5043 kcal / kg, only slightly inferior to the previous sample from the husks of seeds. If the humidity of wood briquettes for heating rises to 10%, the calorific value drops to 4340 kcal / kg.
- Straw. By efficiency, straw briquettes take the third place after seeds and wood, but they have excellent heat transfer indicators (4740 kcal / kg). Ash content is high.
- Tyrsa (grass). Production is based on the use of perennials. With a sufficiently low ash content, the heat transfer of the briquette is 4400 kcal / kg, which is very good.
- Fig. High ash content and low heat transfer (3458 kcal / kg).
Two samples made from the same raw material can have different ash and moisture indicators, as is the case with straw briquettes. Ash consists of minerals with low energy value, and if there are too many of them in fuel, then one should not expect long burning and high heat transfer from it.
Different ash content in briquettes of identical composition signals different production processes and the initial quality of the raw materials. If the manufacturer has not cleaned the straw from dust and dirt or deliberately added foliage to increase the volume of finished products, then such fuel material at the outlet will be of low quality. And it doesn’t matter whether wood, husk from seeds or thyrs is included in its composition. The same applies to the humidity of the product, on which the heat transfer of the euro-woods depends: the higher it is, the worse the room will be heated.
Briquettes or firewood: which is better and more economical?
In fuel, weight and price are not so important as the cost of a unit of heat - you can’t do without calculations. One cubic meter of firewood weighs about 550 kg on average. With the same volume, briquettes for furnace furnaces weigh a ton and cost more than three times more. It would seem very beneficial to heat a stove or fireplace with ordinary wood, because it costs much less, but this is not entirely true. A cubic meter of wood is almost half the amount of real fuel in briquettes. If we evaluate the watts of heat received from each of these samples, then the difference will be a penny, which means that their efficiency is almost the same.
We must not forget about quality. If the wood is excessively wet, it weighs more, but its effectiveness is less. Yes, and to store bulky firewood you need a lot of space, not to mention the cost of delivery.
Combustion period
Most people living in villages know how to properly heat a stove. The burning time of any of the materials, whether it is firewood, regular coal or briquette, depends on the same factors: traction and ignition method. If the air supply to the furnace is excessive due to the untimely closing of the draft damper, the fuel will burn out very quickly.. If you correctly melt the euro-woods, correctly stacking them in the oven and supplying a minimum of oxygen, then due to the low moisture content and high density they will burn longer.
Selection rules
It is better to give preference to wood in briquettes consisting of sawdust. They give off heat well, and such material burns for a long time.
Briquettes for stoves, created from cereal husks, are characterized by good calorific value, but due to the oil content they quickly pollute the chimney with soot, which may require frequent cleaning. The same applies to resinous conifers, of which it is better not to buy fuel briquettes for a bathhouse, stove or fireplace.
When buying, it is advisable to look at the seller's documents for the goods. They contain information about the data of the test report with a detailed description of the product. Choose a good wood material with maximum density.
If you plan to carry out heating with briquettes and need a large batch of goods, take them for testing in a small amount. At home, you can check how solid the briquette is, whether it is crumbling from excessive moisture. Appreciate the fever so that you do not have to regret the unsuccessful purchase in the future.