Ash Content and Quality of Premium Grade Wood Pellets

Compared to industrial wood pellets, which have looser specifications, particularly regarding ash content, which can reach 6%, premium-grade wood pellets, for use in space heating, have stricter specifications, specifically a maximum ash content of 1%. Premium-grade wood pellets generally have a diameter of 6 mm, while industrial pellets are generally 8 mm. The color or appearance of premium-grade wood pellets also plays a role, with brighter colors generally preferred. This is why premium-grade wood pellets are naturally more expensive. Demand for premium-grade wood pellets increases during the winter due to the increased need for space heating.

Regarding ash content, several standards even stipulate ash content lower than 1%, such as DIN Plus with a maximum of 0.5%, ENPlus-A1 with a maximum of 0.7%, and Ö NORM M7135 which requires a maximum of 0.5%. This is why strict control of raw material selection and treatment is applied in the production of wood pellets to meet these specifications. Although the ash chemistry for premium grade wood pellets may not be as stringent as for industrial pellets because the application operation is at lower temperatures, the production of wood pellets with very low ash content requires high-quality raw materials.

In premium grade wood pellets, even a slight difference in ash content can significantly impact the selling price. For example, wood pellets with a maximum ash content of 0.55% can differ by around USD 30 per ton compared to wood pellets with a maximum ash content of 0.35%. Because they are used for space heating, premium grade wood pellets are generally packaged in small plastic bags, such as 15 kg, while ordinary industrial pellets are packaged in jumbo bags or even bulk due to the much larger volume requirements.
 

Wood Pellet Certificate Standards

As a trading commodity that is becoming a world trend, many wood pellet standards are implemented. Basically the wood pellet standard covers only two things, namely quality and sustainability which are mostly related to environmental aspects. Many aspects of quality are related to the technical aspects of the production of wood pellets and also the raw materials used. A number of countries or certain institutions apply the quality aspects that they can receive for these wood pellet products. The application of wood pellet quality standards is also related to the use of wood pellets or more specifically technology or equipment to consume or use wood pellets as fuel. Based on this, usually the market segments are also differentiated, namely for industries and households. The industry segment has its own specifications which are slightly different from households. Some quality standards are widely used today: ENplus, DINplus, PFI, ITEBE, Onorm and CANplus. Following are the quality tables:

The second type of standard is about sustainability and now it has also begun to be widely applied, especially for the trade in large quantities of wood pellets. Sustainability standards include the practice of cultivating trees whose wood is a source of wood pellets. In terms of its implementation there are a number of countries that buy wood pellets that are very concerned about this sustainability standard, but there are also those who do not pay much attention to it. Japan is an example of one of the countries in Asia that is very concerned about the issue of sustainability standards. Some sustainability standards that are widely used today: FSC, PEFC and so on.

Prospective wood pellet producers must pay attention to the problem above, because it is closely related to the market or trade in wood pellets. Without being able to map the market comprehensively, it is very possible that the production of wood pellets will be constrained. For example wood pellet producers will target their markets in Asia, especially in Japan and Korea, even though the market characteristics of wood pellets in Japan and Korea are different.