How to choose quality briquettes and pellets

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In the run-up to the heating season the Energy and Biomass Project presents some advice on how to test the biofuel quality by using readily available tools.
Please follow these steps to make sure you buy quality briquettes and pellets that match the type of biomass boiler installed in your dwelling.

Recommendations to check the quality of pellets:
• Place a small quantity of pellets in a glass of water. Quality pellets shall preserve their shape for longer time. If the pellets dissolve immediately in the water then their quality is doubtful;
• Qualitative pellets are smooth and rigid at touch;
• Those pellets that are crumbly at touch have high moisture content and, therefore, would have low heat output;
• Qualitative pellets have the ash content of 4% at most after being burned. The remaining ash is a good fertilizer for plants. High ash content is an indicator of pellets poor quality.

Recommendations to check the quality of briquettes:
• Place some briquettes in a vessel with water for several minutes. Quality briquettes shall sink in the water, reaching the bottom of the vessel, and would dissolve harder. Briquettes with low density would float on the water surface and dissolve easily;
• Throw some briquettes on the floor/ground. If they break apart then the briquette density is low, and you would have to use larger quantities to reach the desired indoor temperature;
• Lower density briquettes have less energy: they burn more rapidly and release less heat;
• Qualitative briquettes have the ash content of 6% at most after being burned. Briquettes with high ash content have a smaller heat output;
• If you have to collect and dispose the ash more frequently than every four days then the fuel quality could be a source of concern.

Choosing qualitative biofuel that is suitable for the type of the installed boiler is a key precondition for the efficient operation of biomass heating plants.

The biofuel heat output and, respectively, its price may vary depending on the biomass source it is made of:
Briquettes/pellets with moisture content not exceeding 10% Gross Heat Output (MJ/kg)
Walnut shells 20
Sunflower husks 19
Sawdust 18
Straws 15

Please note that so far the Republic of Moldova does not have yet a laboratory in place to test the biofuel quality, although in accordance with Government Resolution No. 1070 dated 27.12.2013, biofuel certification is binding as of January 2015. The authorities are currently searching for solutions to establish the first laboratory that would test the quality of briquettes and pellets manufactured in the Republic of Moldova. The development partners shall provide the necessary support in this regard.

The Energy and Biomass Project will buy modern equipment to test the quality of solid biofuels (briquettes, pellets) manufactured in the Republic of Moldova. The costs of equipment shall be covered out of European funds appropriated for this purpose. It is envisaged to buy the equipment by the end of this year based on an international tendering process launched by the Energy and Biomass Project.

The Energy and Biomass Project 2 is a three-year project implemented during 2015-2017. The Project budget totals EUR 9.41 million, allocated by the EU, and it is implemented by the United Nations Development Programme.