Canadian Biomass Magazine

Developing solid standards for biomass

November 25, 2016
By Staffan Melin Maurice Douek and Sebnem Madrali

November 25, 2016 - The use of solid biomass - in the form of wood chips, pellets, briquettes, firewood, sawmill residues, bark, or insect-killed trees - for fuel production is rapidly growing worldwide, with the global market for biomass pellets expected to nearly double from $4.5B in 2014 to $8.3B in 2020. Applications range from home heating, to greenhouses, schools, combined heat and power (CHP) plants, district heating stations and co-firing with coal in industrial power plants.  

As of 2016, Canada has 45 operating pellets plants (and another 20 in the planning stage), producing close to 2 million tonnes annually, over 70% of which is exported to Europe, 20% to the US, and only about 5% is consumed in Canada. However, the use of biomass in Canada for residential, commercial, institutional and industrial applications is expected to increase in the coming years, driven by more stringent emissions requirements and the need to reduce our environmental footprint.

The varying quality and different applications of the feedstock have created a need for standardization of these materials both for local consumption and to facilitate international trade. In addition, product quality certification schemes have been introduced in order for biomass suppliers to demonstrate compliance with national and international regulations on the quality and sustainability of their products. 

ISO Technical Committee (TC) 238 was established in 2007 to develop International Standards on solid biofuels. Many of these Standards are based on existing CEN (European Committee for Standardization) TC335 Standards, while others are entirely new ones, all of which intended to reflect current needs and priorities of the solid biofuels industry. The Standards specify and classify all types of biomass such as woody, herbaceous, fruity and aquatic. The Standards also provide specifications for graded solid biofuels traded in the market, including wood pellets, wood briquettes, wood chips, firewood, as well as non-woody pellets and briquettes.

This article provides an overview of Canada’s involvement in making significant contributions to the development of standards for solid biofuels, both at the International and National levels, and of the benefits to the Canadian solid biofuels industry. Since the inception of ISO/TC238, Canada has taken on a leadership role to ensure that these standards are technically sound, do not discriminate against Canadian markets, and that the Canadian solid biofuels industry is well positioned  to compete effectively in the global market place. The importance of using relevant standards and reliable emission accounting methods for assessing the sustainability of solid biofuels is also highlighted in the article.


I. International Standardization Activities
ISO Technical Committee 238  consists of the following working groups (WG’s):
WG1: Terminology
WG2: Fuel Specifications and Classes
WG3: Quality Assurance (currently inactive)
WG4: Physical and Mechanical Test Methods
WG5: Chemical Test Methods
WG6: Sampling and Sample Preparation
WG7: Safety

Currently, the committee is comprised of 36 member countries (24 Participating, including Canada; and 12 Observing). Canada holds the convenorship of Working Group 4 on physical and mechanical test methods (Staffan Melin, convenor). So far, 26 Standards have been published. Several others are in various stages of development. 

One of the objectives of the Canadian Mirror Committee to ISO/TC 238 is to ensure harmonization of methods between North America and Europe as well as Asia, to avoid any potential barriers to Canada’s trade.

The examples below illustrate the importance and benefits to Canada of selected standards, in three main areas, namely fuels specifications, test methods, and safety.

Fuels specifications 
For each class of solid biofuels, the specifications for key parameters, such as calorific value, ash, sulphur and chlorine levels are such as to accurately reflect the levels that can be achieved commercially for production of high quality biofuels. Without such rigorous standards, production and trading of biofuels of lesser quality could create unfair competition in markets of interest to Canadian producers and increase air emissions as a result of poor combustion in boilers. 

Emerging technologies for producing thermally-treated and densified pellets, by processes including torrefaction, steam explosion, or hydrothermal carbonization are also showing great promise for producing solid biofuels with unique properties. As such, some European countries have recently made a strong plea for introducing international standards based on these technologies in order to accelerate their entry into the market. However the proposal was turned down, largely based on arguments by Canada that these technologies have not yet been commercialized and validated, and that introducing new standards prematurely could seriously distort global markets and cause considerable confusion among stakeholders. The proposed standard was instead converted into an ISO Technical Specification (TS). This is intended to be a temporary measure to allow for more frequent revisions until the technologies become sufficiently mature to qualify for adoption as ISO Standards.    

Test methods
Standards have been developed within this group for the measurement of key parameters, including moisture, ash, calorific value, durability and several others. Two new standards, proposed by Canada, are under development for determining grindability and absorptivity characteristics of solid biofuels. Grindability is of fundamental importance during solid fuel preparation since it affects energy consumption and particle size distribution. Too large particles or too wide a distribution can result in feeding problems as well as un-burnt fuel passing through the conversion process. The new method will be a valuable tool for biomass power plants for accepting or rejecting pellets based on their grindability characteristics.The absorptivity method will assess the degree of water absorption and resulting durability loss of pellets and briquettes. It will be of particular relevance for plants using steam explosion pellets. The latter are getting considerable interest due to their high mechanical durability and hydrophobicity; and are thus particularly well-suited for use in converting coal plants without additional investment in large scale handling and storage facilities.   

Ash melting behaviour is another critical parameter. This standard is under development by Working Group 5 on chemical testing. The method is designed to assess the fusion and melting behaviour of mineral compounds remaining as residues in the combustion process. If the sintering or melting temperature of these residues is low, formation of slag or clinker occurs which can cause damage or breakdown of combustion equipment. Specifications of ash melting properties is mandatory for fuel quality assurance systems, such as ENplus in Europe. No internationally-validated method exists at the present time that can be used in case of litigation, thus this proposed method is of high economic relevance. Canada has made a significant contribution to this standard by 

advocating a lower ashing temperature of 550oC instead of 815oC proposed previously, on the basis that the higher temperature does not reflect the actual melting temperature of low melting salts in the ash. Salts that are generated during combustion well before 815oC can cause serious fouling and slagging problems, and could represent a serious problem for industrial pellets buyers, power plants and end-users. 

ISO/TC 238 is also currently developing a comprehensive series of standards on “Safety of Solid Biofuels”. These will include specifications for safe handling and storage to suppress fire and explosion; and for reducing the risks of self-heating, off-gassing, and oxygen depletion in pellets plants and storage facilities. The standards will be published within the next two years, and CSA intends to adopt these standards as well as they become available. This is a timely initiative since – according to the Wood Pellet Association of Canada (WPAC) – provincial governments in Ontario, New Brunswick, BC, Alberta, Quebec and Northwestern Territories, are looking for guidance and standards on safe handling and storage of biofuels.

Canada, largely through work conducted at WPAC and UBC has made significant contributions towards international safety regulations, including:
– Development of MSDS (Materials Safety Data Sheets) for wood pellets around the world and more recently an upgrade to the new Safety Data Sheet (SDS) format;
– Development of the International classification of wood pellets under the International Maritime Organization (IMO) Code for safe transportation of wood pellets;
– Currently developing “Best Practices Guidelines for the Wood Pellet Industry” with participation with the ISO/TC 238 working group on safety; and
– Development of methodologies for determination of self-heating, off-gassing and oxygen depletion.

II. National standardization activities
Canada is promoting replacement of coal with renewable biofuels in residential, commercial, institutional and industrial applications. District heating systems have been installed in Quebec, Ontario, B.C., New Brunswick, and Northwest Territories. In Ontario, the OPG Atikokan generating station was converted from coal to “white” wood pellets. The OPG Thunder Bay generating station is testing “steam exploded” wood pellets for production of electricity as a replacement for coal. A major study is also underway in Alberta to assess how much electricity produced by coal can be replaced by pellets or wood chips. These endeavours have been driving requests for fuel specifications and quality standards – in Ontario, New Brunswick and BC – by government agencies and local authorities responsible for certification of combustion equipment and emission regulations. This has prompted the Canadian Standards Association (CSA) Group to consider adopting ISO Standards as National Standards. As a result, out of 24 published ISO Standards on solid biofuels, 16 have now been adopted by CSA Group as Canadian Standards, and 6 more will be adopted in 2016-17. Fuel specifications are all based on ISO standards. One of the main benefits of adopting them as National Standards is that provincial regulators can more easily incorporate them into regulations, guidelines and/or individual site permits. 

According to the Ontario Ministry of Environment and Climate Change (MOECC) and the Ontario Ministry of Natural Resources and Forestry, “the MOECC has proposed a new draft guideline for the control of air emissions from small wood-fired combustors (with an energy input of less than 3 megawatts) that includes wood fuel specifications.  

Solid biofuel standards for wood pellets, chips and briquettes, initially published by ISO and subsequently adopted into Canada by CSA Group, feature prominently in the new draft guideline.  Other options are also available in addition to the CSA-ISO standards, but ungraded wood fuel that does not conform to any wood fuel specification will not be permitted under the guideline.

The proposed guideline is one element of the Supporting Biomass Heat Initiative led by the Ontario Ministry of Natural Resources and Forestry which aims to improve the business and policy environment for the use of solid biomass fuels for heat in Ontario.”

III.  Sustainability
In recent years there has been a growing emphasis on meeting sustainability requirements in all industry sectors, particularly bioenergy. There is also a proliferation of standards and regulations worldwide on bioenergy sustainability requirements. However, there is no consensus yet on which scheme(s) will become the norm. Sustainability of solid biofuels is not currently a requirement of ENplus certification, however, companies  need to provide some reference or evidence to demonstrate that their product is sustainable (such as FSC or PEFC certification). The European commission is planning for sustainability criteria for solid and gaseous biofuels to come into effect in 2020. There is no clear indication as to what criteria will be adopted.  The new ISO 13065 on “Sustainable Criteria for Bioenergy”, published in September 2015 may provide a common ground for demonstrating sustainability. 

Sustainability is also becoming a more pressing issue for users of industrial pellets. As such, a new sustainability certification under “Sustainable Biomass Partnership” (SBP) is starting to get implemented in Europe. This partnership was formed in 2013 by European utilities using pellets or chips in large generating plants. The objective is to demonstrate that biomass meets EU national requirements. It is based on existing certification schemes such as FSC and PEFC and complements these schemes by including a standard for greenhouse gas calculation. 

One of the main requirements in Europe for sustainability of solid biofuels is that the overall GHG savings from such fuels be at least 60% compared to fossil fuels. In 2015, the European commission released data (based on the use of emission accounting methods, taking into account use of fertilizer, processing energy, transport distance) showing over 60% GHG savings for electricity and heat for feedstocks from the EU, Russia, and Southern US, but well below 60% for feedstocks from Western Canada, particularly those used for heat generation. However, to our knowledge no rigorous validation of these emission accounting methods has been demonstrated. 

Another extensive study on “GHG performance of heat and electricity from wood pellet value chains – based on pellets for the Swedish market” was recently published by Hansson, J., Martinsson, F., and Gustavsson, M., from the IVL Swedish Environmental Research Institute (; DOI; 10.1002/bbb.1538; Biofuels, Bioprod. Bioref. (2015)). Wood pellet value chains from Sweden, Latvia, Russia and Canada were assessed using a Life Cycle Analysis (LCA). The study evaluated the impact of extraction/cultivation of raw material, pellet production, and transport on GHG emissions. 

Moisture content and transport-related GHG emissions were key factors; although natural gas vs. biomass-based drying has much greater impact on GHG emissions than transport. Pellets from Canada, particularly those that were biomass-dried instead of natural gas-dried, were found to meet the 60% reduction in GHG emissions and thus would well comply with the strict demand for sustainability from a GHG perspective. These results are also in line with GHG life cycle emissions reported in the “British Columbia Wood Pellets Sustainability Fact Sheet”, November 2013. However, they are in contrast with the European Commission report. These discrepancies show the importance for Canada to ensure the validity and credibility of assumptions for assessing the sustainability of its biomass.

The U.S. Clean Power Plan is also in the process of developing specifications for meeting CO2 targets, and it recognizes that biomass used for co-firing is a powerful mitigation strategy. The EPA’s emission accounting framework for assessing CO2 benefits has not yet been finalized. Only “qualified biomass” will be eligible for compliance with the Clean Power Plan. Compliance requires biomass from sustainably-managed lands and biomass that meets associated CO2 benefits. Since the majority of Canada’s forests are sustainably managed, it is anticipated that, in most cases, Canadian pellets would qualify under the requirements of the Clean Power Plan, provided that they have a relatively low moisture content, are biomass-dried, and that transport environmental footprint is minimized.

IV. Conclusion
This article has highlighted the importance and benefits of standards for the Canadian solid biofuels industry. It has also underscored the need for Canada to be vigilant in ensuring the validity and credibility of assumptions for assessing the sustainability of its biomass operations and products. Rapidly changing trends in international markets for pellets and wood chips, combined with new technologies for pellet production, and the growing demand for international standards and compliance certification, will need to be closely monitored and taken best advantage of, as they will have a profound impact on Canada’s domestic use and export markets of solid biofuels. 

Staffan Melin is Chair of the SCC Mirror Committee to ISO/TC238. Maurice Douek and Sebnem Madrali are co-chairs of the SCC Mirror Committee to ISO/TC238.

This article is part of the Bioheat Week 2023. Read more articles about bioheat in Canada.

Print this page


Stories continue below