BioMatNet Item: FAIR-CT95-0682 - Abatement of emissions from small-scale combustion of biofuels

FAIR-CT95-0682
Abatement of emissions from small-scale combustion of biofuels

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FAIR Area 1.1 - Biomass and Bioenergy Chain : Solid Biofuels : Thermochemical Conversion : Wood (Lignocellulose)

	Type of Project	Shared Cost
	Contract No	FAIR-CT95-0682
	Total Cost	1,085,057 ECU
	EC Contribution	799,997 ECU
	Start Date	01/01/1997
	Duration	36 Months

Abatement of emissions from small-scale combustion of biofuels

Background

The use of biomass, in particular wood, as a fuel is increasing. There are numerous advantages with this non-fossil fuel and especially the fact that biofuels are CO₂ neutral. Lower costs associated with short transportation distances has increased interest in small-scale local heating plants (<100 kW_th) using various biofuels, such as cheap by-products from conventional and short rotation forestry. The problem is that the small-scale boilers and stoves have, in general, high emissions of soot, hydrocarbons and carbon monoxide and in some cases also NO_x. These emissions tend to be a health, as well as an environmental, problem especially for the local communities.

Objectives

The objective of the project is to reduce the emissions of NO_x, in particular, as well as unburned gases (such as VOC) from small-scale combustion of biofuels.

Technical Approach|

The methods adopted to obtain lower emissions include development of catalytic, as well as non-catalytic, small-scale ( between 15 and 35 kW) combustion equipment. Computer simulations will be used to develop non-catalytic, low-emissions stoves. A prototype catalyst will also be developed and tested. Tasks include:

Design of a low emission non-catalytic stove
Modification of existing boilers to reduce emissions
Adaptation of existing boiler to include catalytic reduction of emissions
Development of suitable catalysts for such applications
Evaluation of the lifetime of such catalysts
Development of a mathematical model for the catalytic step to be used for the optimisation of the system
Comparison of the non-catalytic and catalytic methods for reduction of emissions
Investigation of possibilities of combining non-catalytic and catalytic methods

Results to Date

A new stove design has been developed and built. Various existing wood fired boilers have been modified and equipped with catalysts. Better than 80% reduction of emissions of unburned products form a wood burning stove equipped with catalytic flue gas cleaning has been achieved. Several new combinations of catalytic active material and support have been developed and show good results in lab scale testing but only a few seems to be applicable to the wood burning stove. The target of finding a catalyst with lower concentration of noble metals, and thereby lower cost, seems to be met but at the expense of a somewhat lower conversion efficiency. A wood burning, low emission room heater has been developed and a commercial design has been developed. The integration of the catalyst will be optimised during the remainder of the project with the aim to further reduce emissions. In addition, a non-catalytic stove has been shown to give emissions well below regulation limits.

Prototype of wood burning, low emission room heater.

Sketch of wood burning boiler with catalyst for
reduction of emission of unburned gases.

Contacts

Coordinator

Niklas BERGE / TPS TERMISKA PROCESSER A.B. SWEDEN

Participant