Technical Challenges

Transcription

1 Technical Challenges Caused by impurities in raw biogas Reflections in CEN Standards Arthur Wellinger EBA Workshop for the promotion of BIOSURF in Sweden

2 Overview Biogas from AD Syngas from gasification Removal of critical compounds Biomethane Standards

3 Status of biomethane plants in % of all plants upgrade to biomethane 3

4 Production capacities 4

5 Comparative biomethane production from AD Gross biogas production: ~ 15,7 B m 3 biomethane = ~ 28.6 B m 3 biogas ~ 3% of NG consumption > 3% of total fuel consumption BioCH 4 production in: AT, CH, DE, DK, ES, FR, FI, HU, IS, IT, LX, NL, NO, SE, UK BioCH 4 production: ~ 1,2 B m 3 biomethane ~ 1,8 B m 3 capacity installed Roughly 7.5% of all biogas is converted to biomethane

6 Gasification: Syngas In total there are 53 biomass gasification plants in operation (including P&D plants) - 41 thereof are for CHP production - 10 for synthesis purpose - 2 for biomethane production Source: IEA Bioenergy Task 33

7 Biomethane potential 10 9 m 3 /year Source: Kovacs, EBA

8 Biogas conditioning: Requirements of utilizers Application H 2 S CO 2 H 2 O Siloxane Heating yes no eventually no Cooking yes no no Biogas Engine (CHP) < ppm no no condensation yes High pressure compression yes recommended Grid and fuel quality yes yes yes yes yes no Hot fuel cells yes No No condensation yes

9 Gasification: Syngas Syngas has more components than biogas: Hydrogen (H 2 ) Carbon monoxide (CO) Methane (CH 4 ) Short chain hydrocarbons May also contain inert gases: Nitrogen (N 2 ) Carbon dioxide (CO 2 ) Steam (H 2 O)

10 Gasification: Syngas Contains also more impurities: Dust and/or tar (function of temperature) (Organic) Sulphur Nitrogen heavy metals Chlorine compounds alkali salts Source: IEA Bioenergy Task 33

11 Hydrogene Sulfide Removal Air/Oxygen dosing into the digester (gas phase) Biological oxidation on a filter bed Iron oxyde sponge Iron chloride dosing into the digester (liquid phase) Activated carbon Washer (water, amines or glycoles) Sodium hydroxid

12 Biological Oxidation H 2 S + ½ O 2 = H 2 O + S H 2 S + air = H 2 O + S +N 2

13 Biological Oxidation Air/Oxygen dosing into the digester (gas phase)

14 Physical/Biological Oxidation Source: Pacques

15 Precision Cleaning

16 (Organic) Sulfide Removal Benfield process (precipitation with K 2 CO 3 ) Source: wiki.olisystems.com

17 Tar Tars are highboiling and highly viscous organic compounds, which condense at ~ C. Gas wash with special solvents (such as biodiesel) Condensation in a wet electro filter Catalytic conversion

18 Siloxanes What are siloxanes? silicon dioxide SiO2 What is the effect of siloxanes?

19 Siloxanes Where do siloxanes come from? Sanitary products like tooth past, coating of razor blades Cosmetics (glossy products like lip stick, eye colours, etc. Hydraulic oils Antifoaming agents Fire extinguishers

20 Siloxanes At low concentrations and low flows (< 500m3 per hr) siloxanes are removed with activated carbon. At higher concentrations and volumina by a combination of cooling and activated carbon

21 Biogas upgrading: CO2-removal Adsorption Absorption Permeation Membrane Cryophilic upgrading PSA Physical Absorption (Water) High pressure (ca. 8bar) Physical Absorption (org. solvent) Low pressure (ca. 2bar) Chemical Absorption (KOH) Chemical Absorption (org. Amine)

22 Haase Water washer Washing with organic/physical scrubbing

23 Amine washers (MEA, DEA, MDEA) Pressure Swing Adsorption (PSA)

24 Membranes

25 GtS upgrading, Lidköping Paintair Haffmans; METHApure

26 National Biomethane Standards Source: GGG

27 European Biomethane Standards EN EN

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29 CEN TC 234 WG11

30 CEN TC 234 WG11

31 pren : Specifications for biomethane for injection in the natural gas network

32 The limit for conventional determination is at > 0.5mg/m3 pren : Requirements, limit values and related test methods for natural gas and biomethane as automotive fuels with normal MN grade Curently the gas industry can provide NG only with 30mg/m3 (incl. odorant)

33 Sweden s Super Biomethane EN EN Higher MN, lower Si and S concentrations, etc.

34 Arthur Wellinger

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