Biogas upgrading Technologies, framework and experience

Biogas upgrading – Technologies,

framework and experience

Owe Jönsson, E.ON Gas Sverige

Biogas as vehicle fuel – the driver for biogas injection in

Sweden

_y

_{14500 vehicles in Sweden 2007, 20% market increase}

y

Total sales 2007 - 53 Mm

y

53% biogas in the CNG in 2007

y

20% increase in biogas sales 2007

Marketing methane as a vehicle fuel

compressed natural gas and biogas at 20 public filling stations in the south of Sweden

y 6 busdepots

y 170 GWh/a replacing about 17 million liters of gasoline/diesel

y 25 % is biogas

Target:

y Supply 400 GWh/year in 2010, of which

Source: Swedish Gas

Methane filling stations in

Sweden

planned filling station 2008-2009

E.ON Sverige biogas production 2007

Laholm

20 GWh (grid

injection)

•

Norrköping

10 GWh (vehicle

fuel)

•

Kristianstad

15 GWh (local

gas grid)

•

Eslöv

5 GWh (grid

injection)

•

Bjuv

22 GWh (grid

injection)

72 GWh

Injection of gas into the gas grid I

y Laholm – 500 nm3_{/h, E.ON Gas}

y codigestion plant

y operation since 2000

y water scrubber

y Helsingborg – NSR and others y codigestion plant y 350 nm3/h, operation since 2004 y PSA y plants in 2008 - 650 nm3_{/h, and} 250 nm3_/h

y Göteborg, Göteborg Energi y injection into the town grid

y new plant (1600 m3_/h)in

operation 2007

Injection of gas into the gas grid II

y Bjuv - 600 nm3_{/h, E.ON Gas}

y start of operation in 2007

y PSA

y Malmö – 500 nm3_{/h, E.ON Gas}

y Operation since May 2008

y PSA (see picture)

y Falkenberg 600 nm3_{/h(oct 2008),}

E.ON Gas

y operation in october 2008

E.ON Bioerdgas - Biomethane plant Schwandorf

y Input material ca. 80.000 t/a (Maize and grass silage)

y Production of „raw“ biogas ca. 2.000 m³/h

y Annual biomethane productionca. 90 Mio. kWh/a

y Gas quality 11,1 kWh/m³ (H-Gas)

y Start of construction July 2007

y Start of production December 2007

Schwandorf – upgrading with PSA technology

y Connection of biogas plants

y Connection fee based on connection cost

y Connection limit (measurement, upgrading, odorisation)

y Transport fee

y Feed in in distribution grid results in reduced cost in transmission grid

y Quality of biogas injected into the grid

y Grid owner liable for gas quality in grid

y Grid owner measures quality

y Liability for pressure, quality, odorisation etc.

Political framework – Gas grid injection

y

Tax exemption for

biogas in the gas grid

y

Trading of biogas to

specific customers

y

CO

-based road tax

y

Reduced tax on

company

CNG/biogas-vehicles

y

Climate investment

program

y

Environmental policy for

governmental

organizations (85% env.

vehicles 2007)

Bugs in biogas ?

0,25m3 _{upgraded biogas 0,4 m0,4 m}33 _{natural gasgas}

1m3 _{air from school class}

Injection in gas grid

Large custom design upgrading plants

Biogas upgrading – getting bigger !

Standardised units

Upgrading plants in Sweden 2007

y Several plants under planning

Water scrubber systems

y

CO

-absorption in water

y

Suitable for sites with water readily

available

y

Methane losses has to be

controlled

y

Growth on packing requires

attention

Pressure Swing Adsorption

y Adsorption of CO₂ on active carbon

y System pressure around 4 bar

y Sensitive to sulphur and water

y Erosion in valves and other mechanical equipement

Chemical absorption systems

y Most common – Amine scrubber

y Regenerated by heating

y Low methane losses

y Can be operated at low pressure

y Handling of chemical on site

y Corrosion must be controlled

Membrane upgrading systems

y Multiple membranes necessary for NG –quality

y Demonstration plant in operation in Austria, 180 nm3_{/h, since 2007}

Cryogenic systems

y Technology still under development

y Potential for CO₂-recovery

y Methane may be produced in liquid form

Possibility for CO

-recovery

y CO₂ may be used for

y Cooling of trucks y Cooling in stationary applications y Greenhouses y Other applications Photo: BioMil

Small scale upgrading

y Small scale water scrubbing system

Upgrading plant investment costs

Investment cost (million SEK)

Total upgrading cost 11 – 25 €c/m

injected gas

Chemica l

Water PSA

Heat demand [kWh/m3 _{raw gas] 0,55}

0,12 0,16 150 0,6 <0,1 0 0

Electricity demand [kWh/m3 _raw

gas]

0,29 0,27 Service cost [€c/m3 _{raw gas] 0,16 0,16}

Maintenance, supervision [h/year] 150 150

Methane losses [vol-%] 1-2* 1-3*

Consumables, spares [€c/m3 _raw

gas]

0,4 0,4

Summary

y

Gas grid injection must be driven

by a market demand for biogas

y

Technologies for purification and

upgrading are available

y

Small scale upgrading

technologies are still not

commercial

y

Biogas can be injected without

any hazards to distribution grid

or public safety

y

General agreements between

the gas industry and biogas

producers are beneficial for the

development