Biogas:Production, Conditioning, Upgrading, Injection

Martin Seifert Swiss Gas and Water Association

Biogas: Many sources – one product !?!

2 Martin Seifert

Content of my Speech

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Conditioning

Upgrading

Injection

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Biogas-It is a question of Origin and Age

Biogas: The Confusion

Biogas: A methane based energy gas?

Biogas or Biomethane?

Biomethane: Source dependent definition?

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The Definitions All but Clear!

Biomethane: Green Natural Gas Substitute

More than one road to Biomethane

Biomethane from anaerobic digestion (1. Generation)

Biomethane from wood gasification (2. Generation)

Biomethane from tailor made algae (3. Generation)

Biomethane from Power to Gas biological conversion (xx.Generation)

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Energy Policy Targets

More and more political quotas for renewable gases in the grid

Overestimation of allocatable educt ressources

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Most recent Literature

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Overview: Biogas Plants and Injection

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Biogas Plants and Injection into the gas Grid in Switzerland

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Biogas Plants and Injection into the gas Grid in the Netherlands

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The Biogas Chain: Anaerobic From Biomass to End user: The big link: The Gas Grid as an Enabler and Carrier

Biomass: Ecological value critical:

- Biomass from energy crops

- Biomass from waste

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Energy crops

Biowaste

Algae

Conditioning

Digestion Processes Wet digestion - up to 15 % dry solid content

Dry digestion -in the range of 25 - 35 % dry solid content

Waste water treatment plants Sewage sludge treatment

- Compost processes -Installations for energy crop digestion

Process temperature conditions: Mesophilic (30 - 35 oC) or thermophilic (50 - 60 oC))

Roppen, Österreich Martinique, Karibik (F) Kyoto, Japan

Rioja, Spanien Lustenau, Österreich

• >30 installations in Europe • >50 installations in the planningphase

Industrial biomass fermentation...

General processes in industrial digestion

Intermediate Storage

Biomass delivery

Magnetic separation

Separation

Digestion Water retrieval Post digestion

Industrial Digestion of Household Wastes and wastes from food industry

Mixing, conveying in the biogas reactor

The plant 10‘000 t/year

Hydaulic drive

Biogas from waste water treatment plants Gasometer Digester

Biogas from waste water plants: >100‘000 Inhabitants Biogasproduction: 1 - 2 Mio. m3 biogas Advantages of water treatment plants:

- Good biogas quality (>60%methane content) - low sulphur content

Cogeneration

Injection

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H2S cleaning

Dryer THT-

Odorisation

Odo

risat

ion

Quality requirements: Distribution: - Methane content: > 96 Vol. % - CO2-content: < 0.5 Vol % - Moisture: prevent condensation - H2S-Content: < 5 mg/Nm3 - Gasodorisation: 15-20 mg THT/Nm3

Bio

met

hane

Quality requirements: Transport Pipeline -Methane content > 60 Vol. % -O2-content: < 5 Vol % - Moisture: prevent condensation - H2S - Content: < 5 mg/Nm3 - Gasodorisation: 15-20 mg THT/Nm3

Bio

gas

(ca.

60%

Met

han,

40%

CO

2)

• Polyglykol Wash • Amine Scrubbing • Water Wash • Pressure Swing Adsorption • Membrane Separation

Des

ulfu

rizat

ion

with

ca

ltaly

tic fi

lter

Dyr

ing

of b

ioga

s

Com

pres

sor

Biogas Conditioning and upgrading

upgrading / CO2 Elimination

Biogas Conditioning

Main purpose: Separation of trace components and drying of the biogas/Pressurizing

- Separation of water/drying

- Desulphurisation/Reduction of total sulphur

- Removal of: Organic Silicon Components

Ammonia

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Biogas Upgrading

Processes and Systems

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Liquefaction: Facilitates transport from Remote biogas plants

Chemical absorption and Membrane upgrading: Good scalability! Easily adapted to different flow rates And compositional changes!

Biogas - Upgrading

Pressure Swing - Molecular sieves on carbon basis as adsorbent for CO2 (8-10 bar) Adsorption of CO2 at 8-10 bar, Desorption at 0.05 bar CH4 > 96 Vol. % Biogas Input 30 - 2000 m3/h Water Scrubbing - Water scrubbing under pressure (6-8 bar), CH4 > 96 Vol. % Biogas input normally > 300 m3/h Amine Scrubbing - pressureless or pressurized scrubbing

Amine-blend as absorbing liquid

Upgrading 99 Vol. % CH4

Biogasinput 30 - 100 m3/h Membrane Separation - Separation by non-porous polymer membranes

CH4 > 96 Vol. %

in pilotphase

Polyglycol Scrubbing - Upgrading by washing process under pressure (6-8 bar)

CH4>96%

Situation Schwitzerland

Upgrading Method Process

• Mainly used for upgrading • Two providers

Not applicable in Switzerland

7 plants in operation

Method in test phase Also small scale 2 Installations in operation

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Upgrading Technologies: The look‘s

Amine scrubbing

Washing tower

Heat managment Cooling

Washing tower

Glycole scrubbing

Pressure swing adsorption

Membrane separation

Biogas-Upgrading Technologies

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PSA Chemical Scrubbing

Water Scrubbing

Glycol Scrubbing

Membrane Separation

Other Methods

Upgrading Technologies in Europe

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Main Drivers: Germany, Sweden, Switzerland, The Netherlands, Austria

The characteristic Look of Scrubbing Upgrading of Biogas

Washing columns

Expansion columns

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Typical Layout of a Containerized Upgrading System (Scrubber –System)

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Odorization

Biogas/Biomethane Analyzer

Heating Pressurized Air

Electricity Supply

Scrubbing Columns Ex-Zone Environment

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Amine Scrubbing Membrane Technology

Gas Separation Chemical physical

Energy requirements [kWh/Nm3 Biogas]

Electr.: 0.1 – 0.3 Heat: 0.6 – 0.7

Electr.: 0.22-0.3 (p-dep.)

Methane grade 99% 97%

Methane Slip <0.1 % <0.5%

Capacity range 60 – 110 % 60 – 110 %

Comparison of Chemical and Membrane Upgrading

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Membranes: Hollow Fiber Technology

Membrane Separation Process with Hollow Fibres

Streams and definitions

Separation properties

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Selectivity: Typically: ca. 50 (CO2/CH4)

Pressure range: 10 – 20 barg Off Gas: < 1vol% CH4 Product Gas: >97 Vol% CH4

Applications for Membrane Upgrading

Biogasplant with membrane upgrading and commercial CO2-production

31 Speaker name Source: pentair/haffmanns

CO2-Value Chain: - Power to Gas - CO2 for Greenhouses

Liquefaction of Biomethane

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Gas Conditioning Upgrading Scheme

Off-Gas Aftertreament

Regenerative thermal oxidation: RTO

- Water scrubbing, PSA

Catalytic Oxidation: CO

- PSA, Membrane

Flameless Oxidation: FO

- PSA, Membrane

Co-firing in IC-engines/Microturbines: CF

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Off-Gas Aftertreatment Afterburner for off gases of the

Upgrading process

FLOX-burner cofired with natural gas

Off-Gas

Natural gas

Exhaust gas of the FLOX burner to The heat exchanger

Energy demand for Upgrading

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Eelectricity Deman [kWh/m3 BG]

Heat Demand [kWh/m3 BG]

Operation Pressure [bar]

Methane Slip [Vol%]

Off-Gas Treatment

Pressure Swing Adsorption

0.15 – 0.35 1 – 10 1.5 -8 Yes

Water Scrubbing

0.2 – 0.3 4 – 10 0.5 - 3 Yes

Physical Absorption (Glycole wash)

0.2 – 0.3 0.1 – 0.15 4 - 8 1.5 - 3 Yes

Chemical Absorption (Amine scrubbing)

0.1 - 0.2 0.4 – 0.8 Atmosph. – 8 0.1 No

Membrane Separation

0.18 – 0.35 7 – 20 1 - 10 Y/N

Upgrading Costs per m3 Biomethane

Cost in relation to upgrading capacity

The upgrading costs are almost constant at capacities >500 Nm3

The conditioning and compression process adds significantly to the overall costs of biomethane injection

The required biomethane quality measurment equipment adds significantly to the biomethane costs

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Upgrading costs versus Capacity

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Euro

Ct/

Nm

3 Bi

omet

hane

Conditioned Biogas Feed In [Nm3/h]

In cost terms: all technologies very near to each other

Membrane

Biogas Quality Control/Metering

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Process controle -Biogasanalyzer NDIR-analyzers for CO2, CH4 el. chem. sensors H2S, 02 Metering Gas meters/p,T compensation Unconditional injection (exchange gas)) CH4-content > 96 Vol/o No other measurements necessary Conditional injection (add on gas) -Conversion CH4-content to calorific value -Calorimetric measurement of injected gas

Process controle -Biogasanalyzer NDIR-analyzers for CO2, CH4 el. Chem. sensors H2S, 02 Abrechnung (PTB-A 7.64) -Gas meters/p,T compensation - Gaschromatography - Calorimeter with authority approval

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On line: CH4-, CO2-, NDIR/ O2-Sensor

Datalogger

Odorisation Concentration Monitoring

Periodic: H2S-Sensor

Biogas injection: Quality control, Monitoring

Efficiency/Methane losses on upgrading

Target Values

- Maximum methane loss on cleaning/upgrading : 0.5 Vol/o

- Maximum energy input in cleaning/upgrading: 0.5 kWh/Nm3 biogas input

In Germany Grid acces ordinance #41: Till 2010: Acceptable methane losses 1% From 2010: Acceptable methane losses 0.5 % New EEG (renew.electr.act (from 1.1.2009): Acceptable methane losses 0.5% Clean air act (TA-Luft): Acceptable methane losses 0.01 - 0.2 % (according to plant size)

Methane loss assessment by balancing mass flow

Formation of balance zones Metering of all gas flows including internal recycling

Biogas Upgrading

Biogas Cleaning

Drying Desulfurization Filtering

Compensated metering

Raw biogas

Excess gas Exhaust gas

Biogas-What needs to be eliminated

Application H2S CO2 H2O silica-organic Halides NH3

compouns

Heating ≤ 500 ppm No No No No No

Cooking ≤ 100 ppm No No No No No

Combustion

engines ≤ 500 ppm No No Yes Yes No

condensation

Fuel Yes Recomm.. Yes Yes Yes Yes

Fuel-Cells HT BZ HT BZ

Natural Gas Yes Yes Yes possibly Yes Ye

grid

Regelwerk

Concentration limits for trace components of upgraded biogas including SNG

The new Swiss Biogas Injection Directive Includes biogases from themal gasification processes

European Standard for Biomethane Fuel Quality

CEN PC 408: Development of the necessary standard For Biomethane fuel quality under the EC Mandate E 475

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Main Discussion Items Biomethane Standardization

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Wood Gasification-Biomethane

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Lignocellulosic Biomass The Potential 2020 in EU 27

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The Wood Hemisphere

Process view of Wood Biomethane

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Methanization of wood gas (SNG) and Upgrading energy products: Biomethane > 96% CH4, power/heat

Gasification Repotec

Fluegases

Product- gas

H2, CO, CH4

Cogen 1

Exhaust

Heat Production Facility

Electric grid

Cogen 2

Cogen 3

Stea

m

Methani- zation

CH4 CO2

SNG Cleaning

Gas grid

SNG

CH4 H2, KW, CO2,…

Gasification Process

Product gas Flue gases

Air Vapour

Coke

Wood chips

Gasification Combustion

Wood gas reactor: Fluidized bed gasification FICFB (Fast internally circulating fluidized bed)

Heat Wood drying

Wood Gasification Definition of Scale

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Biggest Potential

Wood Gasification Selection of Technologies

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Power to Gas Biomethane

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Power to Gas Biomethane

General overview of process streams

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CH4

Biological Catalysis: Basic Processes

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4H2O 4H2 + 2O2 + Heat

CO2 + 4H2 CH4 + 2H2O + Wärme

Biomethane from CO2 and Hydrogen

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Power to Gas Biomethane

Two System Designs

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Efficiencies: 58 % (no heat recovery) Efficiencies: 67 % (no heat recovery)

System Design 1.0

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The Future

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Raw Biogas Sewage Plant Biogas

CO2 form Biogas Digester

Methanization Electrolysis

Natural Gas Vehicles (NGV‘s) AUDI TCNG-Version

Biomethane – The ultimate Fuel Commodity

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Chinese Proverb

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Some are building walls.....

We are building wind mills!

If the wind of change blows.......