1. UNIVERSITY OF JYVÄSKYLÄ 2006 Stirling-aided heat and power (10 kW) production from wood pellets and planning a miniature ESP for small scale combustion Martti Aho Research director, Renewable energy programmes, University of Jyvaskyla Evaluation of the Energy Research In Finland 1999 - 2005, 31.05.2006 in University of Jyväskylä

2. UNIVERSITY OF JYVÄSKYLÄ 2006 Goal of research  Demonstration of electricity production from wood pellets in 10 kWe size in minimum of 15% efficiency (from fuel energy) without operational problems

3. UNIVERSITY OF JYVÄSKYLÄ 2006 Stirling-aided power production: State of art  Routine from natural gas: Electricity can be produced with efficiency of about 25%.  Power production from solid biomass is in research stage because of ash related problems  Experiments in very small scale (1 kWe) has been conducted in the U.S.  Experiments in 37-75 MWe scale have been conducted by Technical University of Denmark (DTU) and Austrian research centres. No commercial products yet.

4. UNIVERSITY OF JYVÄSKYLÄ 2006 Traditional pellet boiler Concept under development Water

5. UNIVERSITY OF JYVÄSKYLÄ 2006 Example of CFD calculations: Fuel power 60 kW High landa (a) and fuel gas recirculation (b) with equal mass flow of flue gas λ=2,03, circ. 0% m= 48 g/s (λ=1,47, circ. 0%, m= 33 g/s) λ=1,47, circ. 46% m= 48 g/s sec+tert 558 o Csec+tert 345 o C T f =1245T f =1173T f = 1224 o C Clever air jet direction a b1b2

6. UNIVERSITY OF JYVÄSKYLÄ 2006 Vertical Furnace, fuel power 80 kW max Pellet burner Economisers Extract about 60 kW) Comb. air preheating & flue gas recirculation Stirling-engine 9-10 kWe

7. UNIVERSITY OF JYVÄSKYLÄ 2006 Co-operation  Technical Research centre of Finland  Helsinki University of Technology  Finnish industry (four companies)  International co-operation planned in a submitted EU proposal (ERA-NET)

8. UNIVERSITY OF JYVÄSKYLÄ 2006 Development of miniature electrostatic precipitator (ESP) for small scale combustion  Goal –To develop a miniature ESP for small scale combustion (< 200 kW thermal) capable to reduce particulate concentration in the flue gas by 80%  State of art: –High need in the markets –No commercial devices available –Prototype development in Austria, Norway and Switzerland since 2003 –Our version differs from those prototypes

9. UNIVERSITY OF JYVÄSKYLÄ 2006 Scheme of the collector (JYU) Examples of results obtained so far Particle charging principle (TUT)

10. UNIVERSITY OF JYVÄSKYLÄ 2006 Co-operation  Technical Research centre of Finland (VTT)  Tampere University of Technology (TUT)  Helsinki University of Technology (HUT)  Finnish industry (three companies)  A proposal has been submitted to extend this research (EU level)