1. Boiler Technology for Biomass Residues
ERK Eckrohrkessel GmbH
Alexis Hellwig, Commercial Director
Conference of the AHK Germany, Vietnam Bioenergy in Vietnam
September 16, 2013

2. Background of Eckrohrkessel
History and references
Eckrohr boiler technology was developed in the mid 1940s
first licensees started to build Eckrohr-boilers worldwide; ERK offers engineering only
outsourcing of the ERK technology from La Mont Kessel GmbH in 1977
today more than 30 licensees worldwide (from small boiler manufacturers to turn-key suppliers for example in Thailand BIB, Getabec and DGA)
>5.900 boiler and heater references with thermal outputs of MWth all over the world
references for biomass (>450), waste (>580), cogeneration (>200), fuel mixtures (>350) as well as coal, oil and gas (>4,000)

3. Background of Eckrohrkessel
Licensees all over the world (currently 31)

4. combustion (grate and fluidised bed)
Energy From Biomass
Conversion technologies
fuels
combustion (grate and fluidised bed)
gasification
ERK has references for all aforementioned conversion technologies
choice of firing system depends on fuel quality, process and efficiency requirements as well as commercial constraints

5. Energy From Biomass Target of efficient combustion
1.) total burnout of fuel
 no carbon content in the ash
 no CO or pyrolytic gases in the flue gas
 for higher efficiency and environment
2.) low NOx emission in flue gases, less effort for secondary DeNOx treatment
 for the environment
3.) low dust content in flue gases
 less fouling and corrosion in the boiler
 for a higher availability of the boiler

6. Grate System With Boiler
meltic eutectic
with corrosion
evaporator
economiser
fine dust
secondary
air
superheater
secondary
air
high temperature corrosion
slagging

7. Boiler Weight

8. Grate System With Boiler
Advantages:
very low demands to fuel treatment
Disadvantages:
cooled mechanical grate for higher calorific values
(higher plant and operation costs) ( scuffing of grate bars)
smooth packed bed hard to ensure
areas with cold streaks with CO and high dust loads
higher central excess air for sufficient burnout
→ boiler and flue gas treatment unit larger due to type of incineration (excess air)

9. Types of Gas Generators

10. Energy From Biomass Gasification – Two Stage Combustion Principle:
generation of carbon monoxide and hydrogen under sub-stoichiometric conditions in the first stage (gasifier)
high temperature combustion in the second stage (torsional chamber)
low gasification temperatures keep complicated fuels, e.g. chlorine and potassium, in the ash, thus reducing fouling and corrosion
Advantages
higher steam parameters due to absence of complicated substances; higher plant efficiency
reduced maintenance & small plant components
low investment and complexity
Disadvantages
not proven for highly contaminated wood waste yet
no existing references larger 70 MWth yet

11. Direct Relation of Two Systems
excess air: ~ 0,5
excess air: 1,4
NOx
high temperature
combustion
excess air: 1,2
DeNOx
alkaline
condensation (Na, K)
CO streak
low temperature
CO streak
low temperature
gases to burner controlled
burnout
high velocity
with high dust content
(alkaline metals: Na, K)
air
gasifier hight
fuel
ash
low dust
content
ash
cooling
cool
ashes
air
high ash heat loss
fuel
air pre-
heating
air for carbon
burnout
air for degasify-ing and pyrolysis
air for drying
air for drying
air for gasifying
and pyrolysis
air for carbon
burnout in ash

12. Advantages of Counter Current Flow Gasification
Spatial separation of drying and gasification from the combustion process leads to uniform flue gas burnout.
Little excess air (20 %) in the subsequent combustion system leads to a smaller boiler (~25 %) and a smaller flue gas treatment unit.
Simpler and more robust gasification reactor less prone to interference
Little loss of fuel due to extremely low carbon levels in the ash and cold ash removal
Concentration of nitrous oxide in the flue gas at a minimum even at a high concentration in the fuel due to low gasification temperature
Low levels of dust and contaminants, since the gasifier‘s fixed bed serves as a filter in the counter flow
→ higher efficiency factor for the entire plant, since the boiler runs with higher steam parameters at low facility costs

13. Energy From Biomass Gasification references
>100 references for biomass gasification plants (1-70MWth)
Simple scale-up to 40MWel
>40MWel plants possible, but unusual for biomass; gasifier adaptation necessary
MWth 5 25 40 70
130

14. Gasifying Plant With Eckrohrkessel Boiler

15. 40 MW Gasifying Plant Villacanas

16. Contact Prof. Dr.-Ing. Udo Hellwig, General Managere:
Alexis Hellwig (M.A.), Commercial Director e:
Address:
Am Treptower Park 28-30
Schuckert-Höfe, Haus A
Berlin
Germany