Biomass energy advantages and disadvantages

06 Jan.,2025

 

Biomass energy advantages and disadvantages

Biomass energy advantages and disadvantages

Biomass energy refer to the energy from plants and animals, mainly composed of organic matters. It is the chemical form of solar power deposited in organisms. Generally, it has 4 sources, agriculture biomass, forestry biomass, urban solid waste, and energy crops.

Link to Tiantai

These biomass materials can be molded into pellets or briquettes under high pressure. They are called biomass molding fuel. These biomass fuels has high density and heat efficiency, widely applied in heating stoves, boilers and power plants.

Advantages of biomass fuel

Good burning effect

Biomass fuels have high heat value. For wood pellets, the heat value is - kcal/kg. For crop pellets, the heat value is - Kcal/kg. Although they don't reach the coal&#;s kcal/kg, with less ash and slag residues, their heating effects are similar with medium coals.

According to industrial analysis, the biomass fuels contains high volatiles content. In terms of corn stalks and sawdust, their volatiles content can be 70-90%. This means biomass fuels have high ignitability.

Clean and less pollutant emission

Burning coals will generate large quantities of NOx, CO2, SO2, as well as suspended particulate matter, ash and slag. They are pollutant to the environment and have been restricted in many placed.

Burning biomass fuels can significantly reduce CO2 emission. As biomass contains little sulfur, there is no SO2 emission. Besides, biomass fuels has less fly ash, slag, or heavy metal discharge. Therefore, biomass fuel is known as clean and green energy.

Rich resources and low price

Biomass energy is the world&#;s 4th largest energy. As estimated by biologist, the land generate 100-125 billion tons of dry biomass every year, and the ocean generate 50 billion tons of dry biomass. Farms and forestry can provide abundant biomass resources that we can make use of.

In this regard, biomass energy is a renewable energy with large output and stable supply. Meanwhile, as the biomass materials cost low, and the manufacturing cost is much lower than coal and oil, it has significant price advantages and promotes more easily.

Mature processing technology and equipment

To make use of biomass energy, we usually mold the bulky materials into briquettes or pellets. Pellet mill and briquette press is used to mold the biomass materials with high pressure and temperature. They can soften the raw materials and squeeze them into a die or mold, so as to increase the density dramatically.

The molding process includes raw material crushing, drying, molding, cooling and packing, etc. First, we need to crush the raw material to reduce the size to under 5mm, then lower the moisture content to 15-20% with a drum dryer or in the sunlight. After that, we can use the molding equipment to make biomass fuels.

According to different molding structure, the molding equipment can be classified into 4 types: stamping briquette press, screw extruding briquette machine, ring die pellet machine, and flat die pellet machine.

Disadvantages of biomass fuel

Unevenly distributed and low density

Although biomass resources are abundant, they distributed unevenly all over the world. With irregular shapes and low density, the biomass materials usually take up large places, costing high for storage and transportation.

Taking rice husks for example, its natural stacking density is only 83-160kg/m3. The fixed carbon content is 10-15%, and the heat value is kcal/kg, equal to half of 1kg coal. So the energy density is rather low. To mold it into briquettes or pellets can increase the density to &#;kg/m3. But the molding equipment and process will increase the use cost.

These defects hinder the application of biomass fuel. Currently, to increase the energy density is a key project in the development of biomass energy.

Ash and slag deposition and corrosion

Biomass materials usually contains high alkali metal (Na&#;K&#;Ca&#;Mg) and metalloid content (Si&#;S&#;Cl&#;P), which lower the ash fusion point and cause ash and slag deposition. They not only impair the heat exchanging efficiency, but cause corrosion and abrasion to the boilers.

So it is usually added with Al2O3, MgO and kaolin or other biomass materials with high ash fusion point (like rice husks) to increase the softening temperature, increase the ash fusion point, and lower the burning temperature.

Poor water resistance

Most biomass molding fuels has poor water resistance. Once contacting with water, the biomass pellets with become damp and loose, and crumble into powders. Therefore, the wood pellets must be packaged in water-proof bags and stored in dry rooms above the ground.

Deficiencies of molding equipment

Although the biomass molding technology has developed for decades of years and the equipments have matured, there are still have many deficiencies, such as high power consumption, quick wear of the die and roller, short working life, and too simple molding process. So if you want to make biomass fuel, it is better to choose a reliable pellet machine manufacturer with warranty and after-sale service.

*Gemco is an reliable biomass molding equipment manufacturer and supplier. We provide flat die and ring die pellet machine, briquette press, and complete wood pellet production line. Our machinery features high durability, long working life, and high molding rate. Also, we provide 1 year warranty and life-long instruction and maintenance. If you have demand or questions, please leave us a message in the form below.

Get In Touch

A Guide to: Sawdust Briquettes

One of our favourite products, they are so useful.

Wood or Sawdust Briquettes are made by recycling the sawdust waste from sawmills etc. and compressing them into briquettes.

Are wood/sawdust briquettes safe to use in a stove?

Yes. They are a completely wood-based product, so can be used in wood burners and multi fuel stoves.

What are the advantages & disadvantages of burning wood/sawdust briquettes?

Advantages include;

  • Cost
    Briquettes are a relatively inexpensive fuel source and are usually cheaper to buy compared to logs and coal.
  • Heat output
    Briquettes burn hotter than logs but not as hot as coal.
  • Moisture content
    They usually have a moisture content of less than 10%, which means less risk of chimney problems.
  • A recycled, all-natural product.
    Due to briquettes being made from a waste product, you are making use of something that could have been thrown out otherwise.
  • Quick to light
    Gets your fire alight quickly and efficiently.

Disadvantages;

For more Sawdust Briquetting Machineinformation, please contact us. We will provide professional answers.

  • Can overheat stove easily
    We always warn our customers to exercise caution when using briquettes for the first time, as they burn hot. It can be very easy to overheat a stove unit by putting on too many.
  • Storage
    Briquettes expand and crumble apart when wet, so they must be stored in a dry environment.
  • Can burn quickly
    This is affected by size and density but be aware that some briquettes will burn quicker than others.
  • Treated wood, chemicals and other particles.
    Some of the cheaper briquettes can contain sawdust from treated wood and when burnt will release chemicals, the other thing to look is for is things like glue and other unwanted particles. A good briquette should only contain untreated sawdust particles.

What type of wood/sawdust briquette is best?

With briquettes becoming so popular, there are many different variations of briquettes available. Which is best for a customer depends on how they want to use the product. When choosing briquettes the following should be considered;

  • Shape & Size
  • Type of wood used
  • Density
  • Packaging
  • Chemicals, wood treatments and other particles.

Shape & Size

Briquettes come in all manner of shapes and sizes.

The most common shapes are;

  • Circular
  • Rectangular
  • Tubular

Briquettes can usually be grouped into three sizes:

  • Smaller Briquettes
    These are usually round; however, you can get some rectangular shaped small briquettes.
  • Medium Briquettes
    These are usually rectangular blocks; however, you can get some round as well.
  • Large Briquettes.
    These are more often tubular in shape; however, you can get large rectangular blocks.

The larger the briquette the longer the burn time. However, this is also affected by other factors such as the type of wood and density.

Type of wood used

This is similar to logs; the type of wood will provide different heats and burn times. Softwood sawdust will burn quicker than hardwood. Density will also effect burn time.

Check our types of wood section for wood types to avoid.

Also, ensure that the sawdust used is untreated and the briquettes only contain sawdust particles.

Density

The density of a briquette is affected by two main factors;

  • Size of sawdust particles.
    Smaller sawdust particles make a denser and tighter packed briquette.
  • The pressure used in the manufacturing process.
    The higher the pressure used, the denser the briquette will be.

The denser the briquette the longer it will burn. The larger and denser briquettes will behave more like solid logs when lit.

Packaging

If briquettes get wet then they will expand and crumble, which is why it is important to consider the packaging when looking at briquettes. Thin plastic packaging is more likely to tear, and the briquettes inside may have expanded. So, when purchasing check for any rips in the packaging.

If purchasing a bulk bag of briquettes check how they are stored and look for any signs of expansion when purchasing (or on delivery).

Chemicals, wood treatments and other particles.

When purchasing ensure you have a look at the product to ensure you are getting briquettes that are made from untreated wood, and the briquettes only contain sawdust particles.

How do I use briquettes?

Briquettes have a few uses, the most common are;

  • First lighting fire
    We advise all of our customers to use the smaller briquettes when first lighting a fire. This is because of the high heat output and high burn aid in getting your fire up to optimum temperature quickly.
  • Alongside slower burning logs
    Mixing them alongside slower burning logs such as oak gives a boost in the heat but also can help speed up the slower burning logs combustion.
  • Heat boost.
    If you just want a quick heat boost, then chuck a few of the smaller or medium-sized briquettes on.
  • Primary fuel source
    They can be used as a primary fuel source, but remember that the larger and denser the briquette, the longer burn time.

How do I store briquettes?

If briquettes get wet and expand and crumble. You will not get the same heat from expanded briquettes and tend to produce smoke when burnt. If your briquettes have gotten wet and expanded, we do not advise burning them.

Even if the briquettes have good quality packaging it can still be susceptible to damage.

Briquettes should be stored in a dry area such as;

Contact us to discuss your requirements of Straw Briquetting Machine. Our experienced sales team can help you identify the options that best suit your needs.

  • Watertight shed
  • Dustbin with Lid
  • Watertight storage boxes