Pellets from biomass pellet press vs coal, which one is better for fuel?

To meet energy demands, more and more companies, commercial groups and households are using biomass pellet press, and becoming wood pellet-oriented consumers. Pellet transition tendencies gain in their popularity as pellet fuel is a more sustainable source of energy than fossil ones.

RICHI biomass pellet press capacity ranges are from 300kg to 4.5 ton per hour. According to the characteristics of biomass fuel pelletizing, it is mainly designed for pressing combustible materials such as saw dust and grass into pellets. This pellet machine is usually equipped with 8mm and 10mm ring dies, because the 8mm and 10mm particle diameters are more favorable for combustion. Ring dies with other hole diameters can also be equipped according to different demands of users.

Main Characteristics of Biomass Pellet Press

• Driven by gear, so that the output is improved by about 20% when compared with that of belt drive.
• Advanced bearing and oil seal are adopted to ensure efficient, stable and low-noise whole machine operation.
• The feeder adopts variable-frequency and variable-speed motor to ensure the quality of discharged pellets.
• High-quality craft ring dies are adopted, so that the service life is long; the discharged pellets are smooth and the quality is high.
• Snakelike spring coupling has the properties of novel and compact structure, low noise and low fault rate.

RICHI Machinery makes detailed analysis of biomass wood pellet output rates to find out the cost and energy efficiencies of wood fuel in comparison with coal fuel to prove their cost-effectiveness.

Biomass pellets vs coal, which one is better for fuel

Calorific Value Comparison of Biomass Pellets and Coal

Biomass wood pellets are good candidates to change coal combustion, which is considered to be of high environmental influence having great emissions of the greenhouse gas. In comparison, wood pellets are considered to be carbon neutral fuel with relatively high output rates as compared to its counterparts.

According to the information provided by Richi Machinery, the energy outputs of wood pellets and coal do not differ considerably. The energy content highly depends on the content of moisture in the fuel, thus, wood pellets of high quality with relatively small moisture content rates, approximately 8-10% per unit, will show the efficiency of 19 Gj per tonne. At the same time, coal with no moisture content can produce 24.8 Gj per tonne.

Being relatively cheap, the sustainability properties of charcoal are much poorer than those of wood pellets. That is why a lot of big power stations, for example Drax, switch to wood pellets preferring them to the more environmentally unfriendly coal. Moreover, Drax will not only be ecologically cleaner, but the conversion will play a vital role in the future success of the power station. CPF or so called carbon price floor introduced by the government of the United Kingdom has significantly increased the prices for the fossil fuel for electrical power generation.

Hence, at the beginning the price for coal had been £0.44 ($0.75) per gigajoule, but rapidly increased up to £1.63 ($1.77) in 2016. That makes the combustion of coal very challenging in terms of economical efficiency.

Nearly all forestry and agro-waste material can be made into wood pellets by our ring die biomass pellet press, such as: Wood Chips, Shaving, Sawdust, Groundnut-shell, Sugarcane Biogases, Caster Shells/Stalk, Coffee Husk, Paddy Straw, Sunflower Stalk, Cotton Stalks, Tobacco Waste, Mustard Stalk, Jute Waste, Bamboo Dust, Tea Waste, Wheat Straw, Palm husk, Soybeans Husk, Coir Pitch Barks/Straws, Rice Husks etc. The final pellets can be used for industrial boilers and large power plants as well as home heating.

Comparison of Combustion Performance of Biomass Pellet & Coal

Theoretically speaking, the thermal value of biomass pellets made bu biomass pellet press is 10% lower than the thermal value of coal. But in actually working situation, biomass pellets can be fully burned, and on the contrary, coal normally can not be fully burned, there are always 10%-15% combustible components in the combustion residues of coal. Therefore, in actual using situation, the thermal value of biomass pellet and coal are equal.

The ignition time of biomass pellets is much lower than coal. Biomass pellets is made of biomass materials such as wood shavings, wheat straw, etc. Coal is a kind of combustible organic rocks. Biomass pellets made from biomass pellet press are much easier to ignite than coal, which means the start up time of the boiler is shortened by using biomass pellets.

Comparison of Combustion Performance of Biomass Pellet & Coal

The solid waste of biomass pellets is much lower than the solid waste of coal, which lower the slag discharge fee and the pollution of the environment. The solid waste of biomass pellets are ashes, the weight of biomass pellet solid wastes are about 0.4%-7% of the total biomass pellet weight. The solid waste of coal is the mixture of ash, alkali and residual coal, the weight of coal solid wastes are about25%-40% of the total coal weight.

Coal is one of the main sources of pollution to the atmosphere. There are a large quantity of granular carbon and toxic corrosive gas such as SO2 and CO. And the corrosive gas will cause the corrosion problem of the boilers, too. The main component of biomass pellets made by biomass pellet press  is C-H organism, there are no granular carbon in the smoke from burning biomass pellets.

The smoke from burning biomass pellets are mainly C-H volatile gas, the discharge of SO2 and CO is nearly zero. The smoke color from burning biomass pellets is lower than Ringelman emittance Grade one. Using biomass pellets made by biomass pellet press  can significantly reduce the carbon dioxide emissions which helps protect the environment. Biomass pellets is known as “the clean fuel” around the world.

Using biomass pellets as the fuel of industrial boilers is cheaper than using coal. Moreover, it can also save time by using biomass pellets. Take a 0.5 ton boiler as an example, if we use biomass pellets as the fuel, the cost is 11% lower than the cost of using coal, and the time is 34% lower than the time of using coal.

The continuous combustion time of biomass pellets is 8-10 times compare to the loose biomass materials, which is definitely enough for the continuous combustion of industrial boilers.

RICHI biomass pellet press machines are identifiable by the circular "ring" shape of their extrusion die. Generally small wheels in the center of the ring ride on the die and force the raw material through the extrusion holes.  Compared with flat die biomass pellet press machine, ring die biomass pellet press has three main advantages:

• It is highlighted with high efficiency and large capacity.
• Biomass pellets produced by ring die biomass pellet press are more solid and smooth.
• With its long service life and low-malfunction rate, it is really a cost-effective machine if you want to start medium or large size biomass pellet production line for commercial use.

For these reasons we suggest new mill operators to start out with a flat die biomass pellet press machine while large industrial pellets production with ring die biomass pellet press.

Ten Contrasts between Biomass Pellets and Fire Coal

1. Burn out rate comparison of biomass pellets and fire coal. Biomass pellet fuel has low density, loose texture and is easy to burn out. The density of coal is higher than that of biomass pellet fuel, which results in less residual heat of biomass pellet fuel than that of coal-fired carbon. Therefore, biomass pellet fuel burns more fully and has a higher utilization rate.

The nature of raw materials fed to the biomass pellet press greatly influences the output, for example: the output of saw dust pellets of hard wood is obviously lower than the output of saw dust pellets of soft wood; the raw materials should not all be powdery. Containing some cellosilk substances, powdery materials are more favorable for pellet forming.

2. Sulphur content comparison of biomass pellets and fire coal. The sulfur content of biomass pellet fuel is only 0.02%-0.12%, while the sulfur content of coal combustion is generally 0.5%-6%. So biomass pellet fuel is more environmentally friendly than coal, and there is no need to install desulfurization device.

3. Calorific value comparison of biomass pellets and fire coal. The carbon content of biomass pellet fuel made by biomass pellet mill is less, the highest carbon content of biomass pellet fuel is only about 50%, and the oxygen content of biomass pellet fuel is higher than that of fire coal, so the calorific value of biomass pellet fuel is lower than that of coal combustion.

Ten Contrasts between Biomass Pellets and Fire Coal

4. Ignition comparison of biomass pellets and fire coal. The hydrogen content in biomass pellet fuel is slightly higher, resulting in higher volatile matter. The carbon in biomass pellet fuel combines with hydrogen to form hydrocarbons with low molecular weight. After decomposition at a certain temperature, volatile matter is released. Therefore, biomass pellet fuel made by biomass pellet press is easier to ignite than fire coal.

5. CO2 emissions comparison of biomass pellets and fire coal. The carbon dioxide emission of biomass pellet fuel is almost zero, while that of power plant boilers range from 2.36 to 2.37 tons of carbon dioxide per ton of coal, and that of industrial boilers is 2.6 tons of carbon dioxide per ton of coal. So biomass pellet fuel emits less carbon dioxide harmful gases than fire coal.

6. Ash and slag utilization situation comparison of biomass pellets and fire coal. The ash after burning biomass pellet fuel is a kind of high potassium fertilizer, which can make chemical fertilizer and realize the recycling of waste, while coal-burning cinder brings more hydrological and land pollution. So biomass pellet fuel has better ash and slag utilization than after coal combustion.

7. Combustion carrier comparison of biomass pellets and fire coal. In principle, biomass boilers specially designed for biomass pellet fuel can burn coal with higher combustion efficiency and lower emissions. Coal-fired boilers are generally backward in design and can not burn biomass pellet fuel without retrofitting. Moreover, the retrofitted coal-fired boilers have poor combustion efficiency and low utilization rate of biomass pellet fuel.

8. Comparison of thermal efficiency utilization of biomass pellet fuel and coal-fired boiler. The thermal efficiency of biomass pellet fuel boilers is as high as 85%, and that of coal-fired boilers is generally 65%. Therefore, coal-fired boilers waste more resources and have low utilization rate.

9. Price comparison of biomass pellets and fire coal. The price of biomass pellet fuel made by biomass pellet press is lower than that of high-quality anthracite and sulfur-less coal, and the price of biomass pellet fuel is higher than that of low-quality coal. Comparing the comprehensive cost, the operating cost of biomass pellet fuel is almost the same as that of coal combustion.

10. Biomass pellet fuel combustion belongs to waste utilization, realizing resource recycling, and is harmless to environmental protection, while coal combustion brings more waste pollution and air pollution.

5T/H Austria wood pellet plant project

Comprehensive Comparison of Biomass Pellets with Other Fuels

In order to confirm the economic and combustion performance of biomass pellets, we have compare the environmental protection property, heat value, boiler thermal efficiency, fuel consumption quantity, fuel price and operation cost of biomass pellets and other fuels. The boiler we used for the test is a one ton boiler, and the fuel price and operation cost is based on Chinese market. The result of this test has been placed in the following table. Hopefully, this contrast can help you get a visual understanding of biomass pellet fuel.

More and more industrial energy companies convert their basic source of energy in favour of biomass wood pellets. This can be explained by the economic viability of the renewable source of energy. Firstly, the energy content of pellets is about 5 kW/kg (depending on the pellet quality - better quality - more heat - less consumption). These figures prove that wood pellets can easily substitute coal.

Biomass pellet press is used to produce pellets for heating, cooking or animal bedding. It can process raw materials like wood, sawdust, bamboo, pine, alfalfa, straw, wheat bran, cotton stalk, rice husk, cotton stalk, and many other biomass materials.

Biomass pellets made by biomass pellet press are biofuels maded from compressed organic matter or biomass. Biomass pellet fuel calorific value is large, calorific value is about 3900-4800 kcal /kg. As biomass pellets don't contain sulfur phosphorus, combustion does not produce sulfur dioxide and phosphorus pentoxide, thus will not lead to acid rain, do not pollute the atmosphere, do not pollute the environment. Biomass pellet fuel clean sanitation, feeding convenient, reduce the labor intensity of workers, greatly improved the working environment, the enterprise adopts pellets will reduce the cost of labor.

The volume of pellets is compressed by biomass press, storage space is saved, and transportation is easy, reducing transportation costs. When biomass pellet combustion harmful gas composition content is extremely low, the emission of harmful gas is less, has the environmental protection benefit. And the ash after combustion can also be used as potash directly, saving money.

Richi Machinery, China leading pellet press manufacturer, supply high quality biomass pellet press for customer's increasing demand to make biomass pellets.

• It can make full use of your biomass waste. In the past you may just throw them away. But now, with biomass pellet press, you can turn waste into treasure!
• You won't worry about your fuel cost anymore! You might be quite clear that heating the home for a whole winter can cost a great sum of money if you use electricity. Even if you use raw wood, it cannot be fully used, since wood always can't burn completely. However, if made into pellets, the pellets can combust perfectly in the stove, and you don't need to worry about harmful air polluting gases!
• Our biomass pellet press machines are highly efficient. Every part is made by high quality materials and processed by advanced equipments and technology. You won't worry about its service life. You buy a biomass pellet machine and you can use it for years!
• It has been a trend to use biomass pellet press now all over the world. You may surprisingly find your neighbor using it right now!