we give impulses south westphalia university of applied sciences

We give impulsesSouth Westphalia University of Applied Sciences

Dr.-Ing. Jörg HoFolie 2 (9.10.2014)

Gasification of Biomass with external heat supply

Introduction Gasification, but why? Germany‘s socio-economic background The technology Where‘s the gap? The basics for designing a new gasifier

Pyrolysis of residues Gas cleaning via conversion Gasification or combustion

One out of three – the concept of an integrated reactor

engineering a reactor from the basics

SEMINARIO DE USO ENERGETICO SOSTENIBLE DE BIOMASA RESIDUALOctubre 9 y 10 de 2014

Content


Gasification of Biomass with external heat supplyIntroduction

Energy demand of Germany

Industry G, Trade, D Household

Electricity demand = 28 % of total energy demand

Source: Energieflussbild der Bundesrepublik Deutschland 2009, Arbeitsgemeinschaft Energiebilanzen


Gasification of Biomass with external heat supplyGasification, but why?

Energy from biomass

153 TWh

electricity

318 TWh

total energy

Source: Entwicklung der Erneuerbaren Energien in Deutschland im Jahr 2013, Bundesministerium für Wirtschaft und Energie

133 TWh

Solid biomass has a heat

electricity efficiency of 12 %

Solar

Solar

Wind

Wind


10 100

0.01

0.1

1

10

100

Hu / GJ/m³

Gasification of Biomass with external heat supplyGasification, but why?

Energy density (lower energy content per storage volume)

Hardwood, pieces: 7,1 GJ/m³ Softwood, pieces: 5,1 GJ/m³ Hardwood chips: 4,2 GJ/m³ Softwood chips: 3,0 GJ/m³ Wood pellets: 9,7 GJ/m³ Sawdust: 2,9 GJ/m³ Straw, round: 1,5 GJ/m³ Straw, big block: 2,1 GJ/m³ Straw, chopped: 0,9 GJ/m³ Rape seed oil 34,1 GJ/m³ Alcohol (ethanol) 21,2 GJ/m³ Natural gas (H): 0,04 GJ/m³ Biogenic gas: 0,02 GJ/m³ Hydrogen: 0,01 GJ/m³

liquid fuel

wood

straw

gas

Hu / GJ/kg

Hu/

/

GJ/

m³


Gasification of Biomass with external heat supplyGermany‘s socio-economic background

Political support

1991: law to rule delivery of energy fom renewable sources to the privat eletric grid Grid companys had to buy the eletrical energy to reasonable prices

2000: law for renewable engergy production Grid companys had to buy the eletrical energy to fixed prices above market price

Law for renewable engergy production renewed in: 2004: higher prices, included combined heat and power 2009: special bonus for combined heat and power 2012: bonus for special technologies for biomass conversion

Prices for energy from wood: 13,88 €ct/kWh to 10,55 €ct/kWh (≤ 5 MW) 5,85 €ct/kWh (> 5 MW)

Combined heat and power boni: 3 €ct/kWh Boni for technology: 2 €ct/kWh


Gasification of Biomass with external heat supplyThe technology

Range of size

Source: Wiest, Dezentrale Stromerzeugung aus Biomasse, 21.12.2011

0,01 0,1 1 10 100

Fixed bed

Rotary kiln, (twin-)screw

Fluidized bed

Entrained flow

MWHm u /



Co-current dowdraft gasifier Spanner Re² Holzenergie Wegscheid REP Urbas Pyroforce

Source: Spanner wood gasifier, www.holz-kraft.de

The technology

Types of gasifiers available in Germany

gasifier

feederfilter

Source: Eckermann, Alte Technik mit Zukunft, 1986

Spanner Re² gsifier 30 or 45 kh/h



Co-current updraft gasifier Burkhard GmbH Stadwerke Rosenheim

Source: www.oelmuehle-moeriken.ch Source: Patent Burkhardt Vergaser DE 102008043131B4.

The technology

Types of gasifiers available in Germany

http://www.oelmuehle-moeriken.ch/


Counter-current gasifier Vølund at Harboøre Denmark Xylowatt

Source: Babcock & Wilcox Vølund, Biomass gasification plants


Further types of gasifiers



Further types of gasifiers

Fluidized bed Agnion GmbH Steenova

TU Wien, Güssing

Source: nach Karl, et.Al., Allotherme Wirbeschichtvergasung –

Möglichkeiten zur Realisierung des Wärmeeintrags. Velen2000

Source: Hofbauer, Fluidized Bed Gasification – State of Technology, presented at: reNnet Austria


Rotary kiln, skrew feeder DTU

REW Regenis PYREG

Source: Gøbel, et.Al., High performance gasification with the two-stage gasifier. In: Proceedings of the 12th Europeanconference on biomass for energy, industry and climateprotection, Amsterdam, 2002

Source: Das innovative PYREG®-Verfahren, www.pyreg.de


Further types of gasifiers/pyrolyzers


Technical problems solved with: Standarizised fuel

Pellets Sieved wood chips

→ high costs for the fuel

→ competing with hosehold heaters for the fuel Exessive gas cleaning

wood chips als fuel

→ high costs for the gas cleaning Rentability only with goverenmental support

Germany: supported refund for energy Further improvement necessary

Gasification of Biomass with external heat supplyWhere is the gap?

Gasification at the edge of rentability?


Technical problems solved with: Inderect heating

Rotary kiln Screw feeders

Burners for the pyrolysis gas

Technical problems not solved

Gasification of in-homogenic material Gas cleaning of pyrolysis gas

The gap is the conversion of the tar the heating of pyrolysis by autothermal gasification

Gasification of Biomass with external heat supplyWhere is the gap?

Pyrolysis/Gasification at the edge of relyability?


Gasification of Biomass with external heat supplyThe basics for designing a new gasifier

Biomass – options

ResiduePyrolysisFastpyrolysis

Gasification

Dry biomass

Conditioned biomass

Wet biomass

Wood char

Pyrolysis oil

Gas

Wet biomass

Fermentation

Gas

Dry biomassCombusti

onSteam process

Seed oil engine

Gasturbine

Gas engine

Stirling engine

Flue gas

SqueezingOil seeds Seed

oilSource: Wiest, Dezentrale Stromerzeugung aus Biomasse, 21.12.2011



Biomass – characterizing the fuel

Source: Wiest, Energy Technology 1

BIOMASS

water contentfragmented size,size distribution

Density,

bulk density

Ash content,

ash quality

micro structure,

porosity

composition

(hemicellulose, cellulose, lignin, starch, extractibles)

(carbon, hydrogen, oxygen, nitrogen, sulfur)



Choosing process characteristics and type of reactor

Biomass

Fuel quality

Characteristics

By-producs

Type of reactor

Plant size

Emissions


Relyable technology: Inderectly heatead rotary kiln Inderectly heatead screw feeders

Choice:indirectly heated rotary kiln



Pyrolysis

char

gas, oilheating

bulk fuel bed

biomass,nitrogen


Investigation of pyrolysis in a rotary kiln:

Axial temperature distribution from the pyrolysis of corn, heating at 800 °C, solids residence time of 20 min.


Pyrolysis

Source: Wiest, Zur Pyrolyse von Biomasse im Drehrohrreaktor. Dissortation, Kassel. 1998


Bed movement in the rotary kiln :


Pyrolysis

Source: Schinkel, Zur Modellierung der Biomassepyrolyseim Drehrohrreaktor. Dissortation, Kassel. 2002

collapse cascade

slide

roll

Fill

fac

tor

k F


Reasons for choosing an indirectly heated rotary kiln: Inderect heating: independent on calorific value and water content Rotary kiln:

moves anything Good mixing leads to good internal heat transfer One moving part, no friction with a screw

Disadvantage: big seals

Dimensioning:

Solids residence time: with and Heat transfer: with and (assuming the wall to be thin)

Head demand: with and


Pyrolysis of residues


State of the art: Hot gas filtration and scrubber with gasoline or alike Thermal conversion, hot gas filtration and katalytic cracking

Disadvantages: Loosing the calorific value of the tar 1 – costs handling and disposing the tar 2 – operation and degradation of katalyst

Alternative: Conversion of tar with hot activated carbon

Activated carbon is produced within the process

Conversion of tar to CO, H2, CH4, CO2 thus keeping the calorific value

Cheap ‚katalyst‘ and no handling of the tar


Gas cleaning


Gasification of wet beech wood and tar conversion on beech wood char:


Gas cleaning via conversion

Source: Ho, Vergasung feuchter Biomasse unter indirekter Wärmezufuhr. Dissortation, Kassel, 2012


Experimental setup for tar conversion on coke:



Source: Ho, Wiest, Heterogene Degradation von Pyrolyseölen an Kohlenstoff-Aktivaten. DGMK, Gelsenkirchen 2010


Results of tar conversion on coke:

Mass distribution, normalized Tar conversion, semi-logarithmic

Activate is coke with approximately 290 m²/g

total surface area



Source: Ho, Wiest, Heterogene Degradation von Pyrolyseölen an Kohlenstoff-Aktivaten. DGMK, Gelsenkirchen 2010

Residence time / sTa

r co

nte

nt

/ m

g/m

³


Calculating the reaction rate: Tar consists of many species One apparent reaction rate for

‚tar‘ as a represatative for all Assuming a quasi-homegenous

reaction of first order

Calculating EA via the slope(differential method)

Calculating k0 with the reaktion rate

Activate is coke with approximately 290 m²/g

total surface area



Residence time / sTa

r co

nte

nt

/ m

g/m

³


GASIFICATION Pro:

Enhances gas energy content Dilutes tar contamination Reduces Tar via conversion Gas is easy to use Gas burner is state of the art No fly ash

Contra:

With H2O: endothermic

With air: dilutes gas Reduces net efficiency


Gasification or combustion

COMBUSTION (for heating) Pro:

Best net efficiency No extra reactor volume Char is storable No other fuel for start needed

Contra No state of the art for local

burners Fouling of heat transfer

surfaces


Rotary kiln

Achimedes type reactor:

Heating by external burner and moderate exothermic internal gasification

Gasification of Biomass with external heat supplyOne out of three – the concept of an integrated reactor

The three components

Source: Ho, Wiest, Reaktor mit archimedischem Schraubenförderer, Deutsches Patent DE102008038570B4



The Archimedes principle



Process sheme

dryer

pyrolysiscooler filter

autothermal gasifier

kondensergas

engine

bio filter

biomass

air


conversion

conversion



Process data


D L l d

mm mm mm mm

Rotary kiln 139,7 1600 1260 129,7

Archimedes screw 219,1 1260 1260 211,1

A V t_v v_g,l

cm² l min.s m/s

Rotary kiln 132,1 16,6 35

Archimedes screw 350 44,1 '15 1,12



Finally

Thank you for your attention



Jörg Ho Studies of Mechanical Engineering at the University of Karlsruhe, Germany Graduation in 2012 ant the University of Kassel , Germany

About the gasification of wet biomass under external heat supply Lecturer at the University of Kassel, Germany

Department of Civil and Environmental Engineering Air cleaning technologies – particles Air cleaning technologies – gases

Assistant Professor at the South Westphalia University of Applied Sciences Department of Engineering and Economics

Sub-Department Thermodynamics and Energy Technology

Inventor

Introduction

About me



Location: western part of North Rhein Westfalia Part of Germanny with the greatest number of inhabitants Coal mining region

5 departments at 5 locations Iserlohn: applied computer science, mechanical engineering, Hagen: electrical engineering, information technology and technical econnomics Lüdenscheid: plastics technology, medical technology Meschede: Department of Engineering and Economics Soest: agricultural engineering, electrical engergy technology, mechanical

and automation engineering 12500 Students Meschede:

50 Jears Aniversary

Introduction

The South Westphalia University of Applied Sciences



Prof. Dr.-Ing. W. Wiest Teaching

Thermodynamics Energy Technology

Laboratory Heat pump cycle Testrig for wood fired domestic heaters Calorimetry Analysis of combustibles (in progress) New laboratory to be finished in 2015

Research: Wood fired domestic heaters: energy balance, combustion, pollution Pyrolysis and gasification of biomass: tar conversion, external heat supply Archimedes type rotary kiln demonstration plant (in design)

Introduction

Thermodynamics and Energy Technology

we give impulses south westphalia university of applied sciences

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