15 Solid fuel small combustion installation (in particular for heating) (Lot 15)

Environmental Screening and Evaluation of Energy-using Products (EuP) Final Report

15.1 Background
15.2 Environmental screening based on the Ecoinvent database
15.3 Ecolabel requirements
15.4 Technology and market trends
15.5 Conclusion
- 15.5.1 Environmental impact in a system and life-cycle perspective
- 15.5.2 Regulation

15.1 Background

The background documents on the EuP preparatory study on Solid fuel small combustion installations (in particular for heating) can be found on www.ecosolidfuel.org.

The project is ongoing. According to the preliminary documents on the website, the working group will focus on the size of the combustion installations, the combustion efficiency (and the climate change aspects of the combustion). Furthermore, the growing concerns of small particles are mentioned.

15.2 Environmental screening based on the Ecoinvent database

The Ecoinvent database contains a range of processes that are relevant for the product group “Solid fuel small combustion installation (in particular for heating) (Lot 15)“. The following processes have been analysed in this screening:

Heat, anthracite, at stove 5-15kW
Heat, hard coal briquette, at stove 5-15kW
Heat, hard coal coke, at stove 5-15kW
Heat, lignite briquette, at stove 5-15kW/RER U
Heat, hardwood logs, at wood heater 6kW
Heat, softwood logs, at wood heater 6kW
Heat, wood pellets, at furnace 15kW

When analysing the results (see Figure 15.1 to Figure 15.7) the results are quit clear:

The combustion of anthracite, hard coal briquettes, hard coal coke and lignite briquettes is the absolute largest contributor to most of the environmental impacts.
For wood, the contribution to global warming is negative for the forest production due to the forest uptake of CO2 during growth.
The extraction and production of the coal products are also significant.
The production of the stove itself (and the materials for this) has relatively small significance for most of the environmental impacts.
However, the production of the stove itself has significant contributions to the impact category “Mineral extraction”, mainly due to the consumption of iron, nickel, aluminium and copper
When weighting the environmental impacts (not shown), the contributions to Global Warming is the most significant, however, the contributions to “Respiratory Inorganics” and “Photochemical ozone (impacts on vegetation)” are also considerable.
The contributions to “Respiratory Inorganics” are dominated by sulphur dioxide, nitrogen oxides and “small particles”. For the wood products, it is mainly “small particles”
The contributions to “Photochemical ozone (impacts on vegetation)” are totally dominated by the emissions of carbon monoxide (CO).

Click here to see: Figure 15.1 Environmental impacts from the production and use of a stove (including the combustion of anthracite) (Heat, anthracite, at stove 5-15kW).

Click here to see: Figure 15.2 Environmental impacts from the production and use of a stove (including the combustion of hard coal briquettes) (Heat, hard coal briquette, at stove 5-15kW).

Click here to see: Figure 15.3 Environmental impacts from the production and use of a stove (including the combustion of hard coal coke) (Heat, hard coal coke, at stove 5-15kW).

Click here to see: Figure 15.4 Environmental impacts from the production and use of a stove (including the combustion of lignite briquettes) (Heat, lignite briquette, at stove 5-15kW).

Click here to see: Figure 15.5 Environmental impacts from the production and use of a stove (including the combustion of hardwood logs) (Heat, hardwood logs, at wood heater 6kW).

Click here to see: Figure 15.6 Environmental impacts from the production and use of a stove (including the combustion of softwood logs) (Heat, softwood logs, at wood heater 6kW).

Click here to see: Figure 15.7 Environmental impacts from the production and use of a stove (including the combustion of the wood pellets) (Heat, wood pellets, at furnace 15kW).

15.3 Ecolabel requirements

In the Nordic Ecolabelling programme there is a criteria document for Swan-labelling of Closed Fireplaces [NE2006].

In the Ecolabel document the definition is:

“A closed fireplace is located in the room that is to be heated, and may also distribute heat as a supplementary function via a water or ventilation system. It is fired on solid biofuel, that is wood, wood pellets or, in some cases, an alternative biofuel. In everyday speech, closed fireplaces are known as stoves, tiled stoves, inset fireplaces and even sauna stoves. The fuel can be fed manually or automatically. Wood is generally fed manually while pellets are fed automatically. A closed fireplace contains the fire. Air is supplied through special ducts and the flow can often be controlled. As a rule, a closed fireplace does not provide the majority of a building’s heating requirement; rather it usually supplements another heat source. In energy efficient houses, however, a closed fireplace may well cover all heating needs”.

The main focus points of the Swan Ecolabel criteria document are:

Air emissions of organic carbon, CO and particles (limit values).
Energy efficiency
Additives in plastic parts: Heavy metals (Cadmium (Cd), Lead (Pb), Mercury (Hg) or their compounds), phthalates and flame retardants (especially polybrominated biphenyls (PBB), polybrominated diphenyl ethers and high-chlorinated short-chained chloroparaffins).
Additives in paints and other surface treatment agents: Heavy metals (lead, cadmium, chromium, mercury or their compounds.) and organic solvents.
Additives in metal coating (chromium, nickel or their compounds).

15.4 Technology and market trends

The product group uses a wide range of fuels such as mineral, manufactured mineral and biomass.

It is possible to use torrefaction, a process usually associated with coffee production, to increase the energy content of some crops by up to 20 per cent. Torrefaction is a mild temperature pyrolysis process that removes moisture, causes partial endothermic decomposition of cell wall composites and alters the chemical structure of wood polymers causing biomass to develop more favourable fuel properties. Not only would it lead to an increase of the energy extracted from some of these crops, it would also lead to solid products, easier to store and transport than raw biomass. Engineers have used reed canary grass, wheat straw and willow for their study. [Piq2008].

15.5 Conclusion

15.5.1 Environmental impact in a system and life-cycle perspective

The physical installations have only minor environmental impacts relative to the impacts from the combustion taking place in them. Accordingly, only little attention needs to be put on the materials used for manufacture of the stoves and furnaces.

Air emissions of small particles, which is probably the most important environmental aspect of this product group in addition to air emissions of NOx, SO₂ and CO.

The emissions of small particles and CO are very depending on an optimal combustion, which is to a large degree depending on the design of the installation and the knowledge of the user.

15.5.2 Regulation

As the EuP preparatory study focus on improving the combustion efficiency and reducing emissions of NO_X, SO₂, CO and small particles, which will cover the most important issues regarding the environmental impacts from solid fuel small combustion installations.