1. Ash content represents the incombustible components of fuel. It contains inorganic minerals like sodium, chlorine, potassium etc.
  2. The high ash content of fuel means that less volatile matter is present in the given fuel.
  3. High ash also increases the slagging and clinker formation, which could affect the system’s performance.
  4. Steamax developed new and innovative biomass fuels for the Indian market, “Astillas”.
  5. Astillas have a high calorific value (>4200 Kcal/kg), low moisture content (<10%), and ash content (<2%).


Ash content is an essential parameter for fuel as it is a byproduct of combustion. Ash content of the fuel refers to the measure of non-combustible materials it contains. It is crucial to know the amount of ash contained in fuel as its chemical composition contributes to slagging and corrosion in the combustion equipment. Depending on what is burned, it consists of different chemical components. In the Biomass, ash-forming elements are present as salts, bound in the carbon structure, or as mineral particles from dirt and clay introduced into the biomass fuel during harvest or transport.

In the reducing conditions and the high temperatures inside and on the surface of burning char, a small fraction present as refractory oxides, such as SiO2, CaO, and MgO, may be converted to more volatile SiO2, Ca, and Mg and get volatilized. Thus, when released as vapours, these elements form tiny primary particles in the boundary layer of the burning char particles due to reoxidation and subsequent nucleation.

How high is ash content % detrimental?

Many factors must be consider when selecting the right fuel for your system. One of the critical factors is the ash content of the fuel.

  1. High ash content means that less volatile matter is present in the given fuel quantity. Therefore, more fuel is needed to generate the same amount of heat.
  2. It also has erosive effects on the system and increases its maintenance, handling and operating costs.
  3. It also increases the slagging and clinker formation, which could affect the system’s performance.
  4. Ash is usually removed from the chamber at a high temperature. Thus, it carries heat, reducing the reactor’s efficiency.
  5. Suspended fly ash in the air acts as a global warming agent and heats the earth’s surface.
  6. All the heavy metals in fly ash—nickel, cadmium, arsenic, chromium, lead, etc.—are toxic. As a result, they leech into the surrounding soil and can enter food chains.
  7. Fly ash can be ingested through respiration, which causes many diseases such as asthma and neurological disorders.
  8. At last, ash generation ends up in the landfills, leading to increased land pollution.

Ash content in different Biomass fuels

Here is the list of some fuel and their ash composition-

Biomass FuelAsh content %
Rice Husk7.5-17.5
Pine Wood Pellets4-5
Groundnut shell2.8-6
Ash composition of Biomass Fuels

Astillas– A cleaner biomass fuel

Steamax has been developing new and innovative biomass fuels for the Indian market since 2015. We, therefore, developed an innovative biomass fuel blend, “Astillas”. The blend generates lesser emissions as compared to other fuels. Thus, it burns clean and has better combustion characteristics than any other biomass fuel on the market.

Astillas- A Clean Biomass Blend
Astillas- A Clean Biomass Blend

How is Astillas different from other Biomass?

Astillas recently acquired interest from many processing and manufacturing industries. They are finally looking for a new environmentally friendly fuel source. Its key features include:

  1. Firstly, it is manufactured from natural products like cashew shells, de-oiled cashew cake, sawdust, groundnut shell, and seasoned wood chips.
  2. Secondly, it burns more efficiently than any other fuel due to lower bulk density and high calorific value.
  3. The fuel is manufactured using low-cost local biomass sources at minimal processing.
  4. Different sizes and constituents are customized as per your location and requirement.
  5. Also, the fuel blend has no anacardic acid and phenol content.

There is an urgent need to switch to cleaner fuel, and Steamax is here to help. So, if you have any questions about Astillas, please feel free to contact us today. At last, which fuel would you prefer for your industry?