Details

Title:

Micro-CHP Based on Biomass Gasification in a Downdraft Gasifier and Stirling Engine

Author(s):

Pieniniemi, K., Muilu, Y., Lassi, U.

Document(s):

Abstract:

The aim of this work was to study Stirling engine as a part of a micro­CHP power station to produce heat and electricity simultaneously and compare the emission levels of the Stirling engine to a micro­CHP based on wood gasification and internal combustion (IC) engine. Stirling engine can be used together with traditional solid wood or wood chip boilers. Unfortunately the flue gas of the direct combustion of biomass contains impurities like particles, ash, soot and moisture, which can cause problems e.g. fouling of the heat exchanger coils during operation. Moreover two stage combustion is needed for the combustion of the volatiles and for the combustion of charcoal. Fouling of Stirling engine heat exchanger lowers efficiency of the engine quite rapidly and can even block the whole exchanger and promote risk of destruction or corrosion of the coils. We have found that burning wood gasification product gas in a gas burner produce no such risk at all mainly because of the burning take place in the gas phase. In addition the level of contaminants in the flue gases of the wood gasification product gas burner is low and much lower than that of the internal combustion engine based micro­CHP and accordingly the emission levels are also rather low. Using wood gasification product gas as fuel for Stirling engine we can overcome all the possible problems faced when using direct combustion of the wood as a source of heat in the Stirling engine.

Keywords:

combined heat and power generation (CHP), downdraft gasifier, NOx emissions, small scale application, stirling engine

Topic:

R&D on Biomass Conversion Technologies for Heating, Electricity and Chemicals

Subtopic:

Gasification for power, CHP and polygeneration

Event:

21st European Biomass Conference and Exhibition

Session:

2CV.3.21

Pages:

814 - 819

ISBN:

978-88-89407-53-0

Paper DOI:

10.5071/21stEUBCE2013-2CV.3.21

Price:

FREE