UNION Instruments. Biogas Upgrading

Transcription

1 UNION Instruments 1 Biogas Upgrading Overview of technologies Measurement technology for process optimizing Feeding biogas in the gas grid Requirements for gas quality Fiscal Measurement technologies

2 Company 2 UNION Instruments Founded 1919 in Karlsruhe Locations in Karlsruhe and Lübeck Development and production of measuring devices Gas analysis : gas properties, energy Gas analysis: gas composition Pressure und temperature recorders (gas and water) Main customers Industries: Steel, Glas, Oil and gas) Worldwide distribution

3 Topic 3 How can existing plants install biogas upgrading facilities? Overview of different German technology options for upgrading biogas to Biomethane Comparison single level and multi-level methods Feeding Biomethane into the natural gas grid requirements on gas quality Matching measurement technology to optimize product quality and energy Requirements for the measuring technology of Biogas pipeline injection according G260/262 related to Energy measurement, Gas quality and Gas conditioning to pipeline quality

4 General Information Biogas 4 Where does it comes from? What is it? What can I do with it? In an anaerobic environment and with the presence of bacteria, organic material will undergo a physical, chemical and biological Process. With the right temperature, the bacterial Anaerobic Digestion will take place while converting the complex organic matter into much simpler gaseous compounds. Anaerobic digestion generates Biogas with a high fraction of CH 4 and CO 2 and a small portion of some other gases (NH 3, H 2, H 2 S, etc.). Cleaned Biogas (removal of H 2 S, NH 3, dust and water) can be used for power or heat generation on site

5 Biogas qualities 5 Component Raw Biogas Landfill gas Methane CH % % Hydrogen H 2 < 200 ppm 0 0,2 % Carbon Dioxide CO % % Nitrogen N % 2-25 % Oxygen O % 0-6 % Trace Elements Hydrogen Sulphide H 2 S < 300 mg/m 3 n.a. Siloxanes SiOx < 100 mg/m³ n.a. Hydrocarbons C x H y < 100 ppm v n.a. Water H 2 O saturated saturated Energy Characteristics Gross Calorific Value H S,N 5.0 7,7 kwh/m 3 3,8 5,5 kwh/m 3 (Dry gas) Btu/ft³ Btu/ft³ Wobbe Index W S,N 4, kwh/m 3 3,5-6,1 kwh/m Btu/ft³ Btu/ft³

6 Natural Gas Grid From biomass to electrical power & biomethane 6 Conventional Direct Electrification Grid Injection & Decentralised Utilisation Biogas Upgrading Biomass Slurry Biogas Production Biogas Biomethane Off-gas + Heat Export CNG Vehicle fuel Power Heat CHP On site CHP Disadvantages: Marginal/No Heat Concept Low CHP-Efficiency High CHP-emissions Low energy utilisation High CHP-methane loss (2-5%) Energy wasted (>30%) Industry & households Power Heat CNG Vehicle fuel CHP Better Heat Concept High energy utilisation Highest added value Advantages: Grid Injection Highest CO 2 -reduction potential Lowest emissions High CHPP-Efficiency Schmack Biogas

7 Options: Usage of Biogas 7 Energy production at the site from Raw biogas Upgrading and gas grid injection Energy production at the site from Biomethane Biogas CHP Cogeneration (local) Upgrading CNG fuel CHP Cogeneration (local) Power Heat Bio natural gas Power Heat Heat demand on site often to low or non-existent Gas grid Injection Heat fuel CHP Cogeneration (local) High energy efficiency Power Heat High energy efficiency

8 Requirements for biogas upgrading 8 Raw biogas quality must be suitable for upgrading Oxygen and nitrogen concentrations will increase costs for upgrading High concentrations of trace components like siloxanes will increase costs for Raw biogas cleaning and gas analyzers Natural gas grid must be in vicinity Capacity of the gas grid must be higher than Biomethane production at all times CNG fuel market must exist

9 Biogas Biogas upgrading Flow comparison 9 Process Compression & Cooling H 2 S Removal Methane enrichment Gas Drying Off-Gas treatment prior disposal Water Air Heat Water Scrubber 8-10 bar Scrubber Regen. Tower Heat Gas Dryer Biomethane H 2 S Scrubber Off-Gas Cleaning System Chemical Scrubber PSA Membrane bar 3-5 bar 8-16 bar Activated Carbon Activated Carbon Activated Carbon Scrubber PSA 2 or 3-Step Membrane Regen. Tower Gas Dryer Biomethane Biomethane Biomethane Off-Gas Cleaning System Off-Gas Cleaning System Off-Gas Cleaning System

10 Flow diagram Evonik Membrane Biogas upgrading 10 Biogas Cooling Pre-compression and drying Desulfurization Compressor Particle filter Control filter Temperature control Biogas production Membrane Stage I Membrane Stage II Biomethane > 98 % CH 4 Pre-treatment Compression Purification Membrane Stage III Off-gas CO 2 < 0.5 % CH 4 Gas separation Off-gas treatment option TO, KO, RO Purified gas 0.0 % CH 4

11 Membrane technology 11 Gas permeation using selective membranes made from high-performance polymers Design of membrane module Biogas: Biomethane: CH 4 (retentate) Off-gas: CO 2 (permeate) CH 4 + CO 2 (feed) Function of the highly selective membrane EISENMANN Hollow fiber membranes Separation of CO 2 and CH 4 based on differing permeation velocities CH 4 slow CO 2 fast

12 Membrane technology 12 Gas separation with highly selective membranes Compressor Membrane Stage I Membrane Stage II Biomethane > 98 % CH 4 Membrane Stage III Off-gas CO 2 < 0.5 % CH 4 EISENMANN

13 Membrane technology m 3 m EISENMANN Machine room compressor (Ex-II), membrane room gas separation (Ex-II), gas analysis room, switch cabinet

14 Selexol scrubber 14 Schwelm Anlagentechnik GmbH

15 Selexol scrubber 15 Schwelm Anlagentechnik GmbH

16 PSA (pressure swing adsorption) 16 Gas molecules: CH 4 N 2 / O 2 H 2 O/ H 2 S CO 2 Biomethane Power needed kwh el /m³ 0,25 0,20 0,15 Carbon Molecular Sieve (CMS) % CO 2 -Biogas Biogas Compressor Vacuum Pump CH 4 / CO 2 / N 2 / O 2 / H 2 O / H 2 S CO 2 / N 2 / O 2 / H 2 O / H 2 S / CH 4 Main Characteristics: Separation through molecular sieve effect. Biomethane production at elevated pressure CMS regeneration at low pressure. Selective & simultaneous separation CO 2, H 2 O, H 2 S, NH 3, partially N 2 & O 2 Operational pressure range 1 7 bar Upgrading process at ambient temperatures 5 35 C CMS fully self-regenerated Carbotech (Viessmann Group)

17 PSA (pressure swing adsorption) 17 Carbotech (Viessmann Group)

18 PSA (pressure swing adsorption) 18 Carbotech (Viessmann Group)

19 PSA (pressure swing adsorption) 19 Carbotech (Viessmann Group)

20 Monoethanolamin scrubber 20 MT Biomethan

21 Monoethanolamin scrubber 21 MT Biomethan

22 System comparison (1/2) 22 Properties of different gas cleaning and methane enrichment technologies Attribute Water Scrubbing Polyglycol Scrubbing Amine Scrubbing Pressure Swing Adsoption Membrane Process Air intake into Biomethane by stripper column O 2 -/N 2 - enrichement by CO 2 -Removal yes yes no no No yes yes yes no yes CH 4 -losses medium medium very low medium medium Product gas post drying step yes yes yes no no H 2 S-pre cleaning necessary no (yes) yes yes yes yes

23 System comparison (2/2) 23 Properties of different gas cleaning and methane enrichment technologies Attribute Water Scrubbing Polyglycol Scrubbing Amine Scrubbing Pressure Swing Adsorption Membrane Process Overall Utility demand: power, water, heat, cooling water, activated carbon, washing medium medium medium high - No high Power demand (kw electr ) (autarkic System) ~ 0,26-0,32 kw/m 3 Raw gas ~ 0,24-0,28 kw/m 3 Raw gas ~ 0,08-0,12 kw/m 3 Raw gas ~ 0,16-0,22 kw/m 3 Raw gas ~ 0,26-0,34 kw/m 3 Raw gas Heat demand (kw therm ) none ~ 0,1 kw/m 3 Raw gas ~ 0,7-0,8 kw/m 3 Raw gas none none CO 2 -footprint from utilities consumption ~ g/m 3 Raw gas ~ g/m 3 Raw gas ~ g/m 3 Raw gas ~70-97 g/m 3 Raw gas ~ g/m 3 Raw gas

24 System optimisation frequent reasons of energy losses 24 Technical hardware problems in the upgrading facility Methan losses in the gas compressor (to atmosphere) Leackages in valves (increase off gas losses) Wrong process settings Wrong adjustment of washing liquid flows, temperature and pressures. Incomplete stripping of CO 2 caused by low temperatures in the stripper column Blockage in the process Blokage of the adsorber by H 2 S Decomposition of the washing liquid (to high temperatures in the stripper

25 System optimisation methane losses 25 How can we detect methane losses? Methan losses can be detected by balancing the methane flows in the system. How can we balancing the methane flows? For balance we have to measure the flows and the methane concentrations in the flows. All measurements for the balance must be done with a high accuracy.

26 Measuring points for system optimisation (example membrane) 26 Biogas Cooling Pre-compression and drying Desulfurization Compressor Particle filter Control filter Temperature control Membrane Stage I Membrane Stage II Biomethane > 98 % CH 4 Methane balance Energy and quality optimisation Membrane Stage III Off-gas CO 2 < 0.5 % CH 4 Reliability option TO, KO, RO Purified gas 0.0 % CH 4

27 Biomethane to grid injection Typical natural gas qualities 27 Component German G260/G262 Gas Pipeline Tariff TETCO (Texas Eastern) Methane CH 4 n.a. % > 75 % Hydrogen H 2 < 5 % n.a. Carbon Dioxide CO 2 < 6 % < 3 % Nitrogen N 2 n.a % < 1 % Oxygen O 2 < 3 % < 0.2 % Trace Elements Hydrogen Sulphide H 2 S < 5 ppm < 8 ppm Siloxanes SiOx n.a. n.a. Water H 2 O Non condensing under pipeline conditions Energy Characteristics Low Calorific Value H u,n 8,4 13,1 kwh/m kwh/m Btu/ft³ Wobbe Index W S,N 12,8 15,7 kwh/m 3 n.a. kwh/m 3 n.a. Btu/ft³

28 kwh/m³ MJ/m³ Biomethane to grid injection 28 Defining the Quality of the gas Adjustment of Energetic Properties: Wobbe Index and Calorific Value Addition of LPG / Air / CO 2 (if necessary) Targets to be accomplished for the injection of biomethane into the grid: Matching Wobbe index and Calorific Value Dew point - gas dryness CO 2 -fraction limit (%) Free of dust or any foreign particle O 2 / N 2 -fraction limit (%) Matching pressure Trace limits: H 2, H 2 S, Siloxanes, CFHC, etc. Adding odour

29 Biomethane to grid injection 29 Fundamentals Biomethane to the Grid Injection Matching the operational pressure: Common Network Pipelines Type Pressure (bar) Int. Long-Distance Transport Grid Local Transmission System (LTS) Medium / Intermediate Pressure 1-7 Low Pressure (LP) < Monitoring of the Bio-Natural Gas (Conditioned Biomethane) Oxygen Monitoring (redundant, Paramagnetic Sensor) Gas quality Adjustment Unit (Calibratable) CV, Density and CO 2 -concentracion is measured Gas meter (Screw type gas meter)

30 Biomethane to grid injection 30 Overview of the process scheme options Biogas Production & Upgrading biogas production biogas upgrading Biomethane Conditioning & Grid Injection Unit LPG / Air Flow Pressure Control PCV THT Safety Valve SAV Caloric Value Adjustment Unit Calibrated flow measurement PGC or Calorimeter Biogas Producer / Grid Company Odorizing Biomethane to the Grid Gas Grid

31 Energy metering system Raw biogas 31 Heated cabinet CWD2005 CT Biogas Gas pipeline T flowmeter Encoder 1 Vb SNK 971 Flow computer VCC Encoder 2 Heating value Modbus (RS232) Archive maintenance (CL) EX barriere K920 ESS Modbus RS232 Modem GSM Insolation Heated line 6 mm Signaling cable

32 Energy metering of Raw biogas calorimeter solution 32 Heated cabinet with calorimeter and flow computer Ultrasonic Flowmeter with fow computer Designed to measure wet gases up tp water dewpoint of 40 C High accurate calorimeter measurement better 0,5% of reading Automatic calibration 8 years calibration period of flow meter

33 Engergy metering system NDIR solution 33 NDIR analyzer in heated cabinet (50 C) Ultrasonic Flowmeter pressure and temperature sensors Eenergy metering control panel INCA analyzer control panel Designed to measure wet gases up tp water dewpoint of 45 C Cross sensitivity detection by dual wavelength NDIR measurement Automatic calibration with air and methane 8 years calibration period of flow meter

34 Gas measureing technologies 34 Calorimeter Direct energy measuring principle by burning the gas Gaschromatograph Selective gas analysis by using adsorption an desorption properties in seperation columns NDIR sensors Determination of gas concentrations by measuring the absorption of light in a defined spectral range

35 Fiscal natural gas analyzer Calorimeter (BTU analyzer) prinziple 35 Dry Calorimeter Cooling air + flue gas Cooling air Fuel gas

36 Calorimeter CWD2005 CT 36 Direct BTU measurement No cross sensitivities Fiscal approval for Natural gas and Biomethane One gas calibration Measured values Wobbe index Specific gravity Calculated values Heating value Air demand

37 Gaschromatograph Sitrans CV 37

38 Sitrans CV Geräteaufbau 38 Communication & Energy Analytic module Gas supply & probe Control module

39 Siemens Sitrans CV Analysemodul 39 Live- Switching Detector Columns Ofen Detector

40 Siemens Sitrans CV 40 Analytical configuration and seperation of components

41 NDIR non dispersive infrared 41 Measurement principle: Measuring the absoption in a defined spectral range IR-source heated chamber Detection Range filter + receiver signal CH vol.-% input pressure sensor output filter + receiver reference CO 2 C 2 + (C x H y ) vol.-% 0-15 vol.-%

42 Transmission [%] NDIR non dispersive infrared cross sensitivity detection 42 Principle: Detection of cross sensitivities by measuring in different spectral ranges. A drift between the values indicates a cross sensitivity in the process or calibration gas. Wavelength [mm] Measurement range [mm] Methan Ethan Propan Butan Measurement range [mm] 0

43 43 UNION Instruments GmbH Zeppelinstraße Karlsruhe

44 List of manufacturer Biomethane facilities 44 Water scrubber Amin scrubber PSA Membrane technology Greenlane (Flotech) Cirmac Carbotech Eisenmann Malmberg Purac (Läckaby Water) ETW Energietechnik GmbH Himmel Gastechnik MT Biomethan Mahler AGS Methapower Biogas GmbH Strabag AG Pentair Haffmans Bilfinger EMS MT Biomethane Borsig Membrane Technology GmbH Air Liquide Envitec Biogas Cirmac