Gas analysis for the process control of biogas plants

Gas analysis for the process control of biogas plants Dr. agr. Markus Schlattmann 27.06.2013 Folie 1

Agenda AWITE Bioenergie GmbH Gas analysis technology Process control using gas analysis technology It s time for you to take control. Folie 2

AWITE Company History 2000 2001 2009 2011 2012 2013 Company foundation first gas analysis system for H 2 S meas. in biogas First office with integriated production~20 m² New office and workshop building ~700 m² 1000. Gas analysis system AwiFLEX Cool+ 1500. Gas analysis system 1600 Gas analysis systems 30 Employees Folie 3

AWITE - Scope of Work Gas analysis systems Development Planning Production Startup Maintenance/Service/ Support Automation Process control, visualisation and software development Switching cabinets (Subcontractor) Cabeling on site Service Measuring equipment Planning Installation Startup Service Folie 4

AWITE - Impressions Folie 5

Agenda AWITE Bioenergie GmbH Gas analysis technology Process control using gas analysis technology It s time for you to take control. Folie 6

Gas analysis systems AwiFLEX Cool+ and AwiECO Folie 7

Gas analysis systems AwiFLEX Cool+ and AwiECO AwiFLEX Cool+ Personalised, versatile, expendable Individual sensor equipment Any number of measuring points Profibus, Profinet, Ethernet, RS232, RS485, USB, analog, GPRS/UMTS Gas cooling (drying) Desulfurization, autocalibration, remote control Connection of additional sensors Calculations AwiECO Reliable, affordable, standardised CH 4, H 2 S, O 2, one measuring point or 2 x H 2 S, two measuring points Analog outputs, Ethernet, (Profibus) USB-interface and software AwiView Discontinuous measurement Folie 8

Internal Construction 1: Power section (incl. AwiProtect) & Profibus module 2: AwiMox & SPS-Modul AwiCore 3: Gas cooler AwiCool 4: Infrared sensors (CH 4 & CO 2 ) & electrochemiacl sensors (H 2 S, O 2, H 2 ) 5: AwiConnect (incl. press. sensor) 6: H 2 S filter,valves, water sensor and gas pump Folie 9

Sensors (1) Folie 10

Sensors (2) Gas Measuring Range Measuring Principle Repeatability Drift/Year CH 4, CO 2 0-100 Vol.-% Infrared double beam P. and T.-correction ± 0,2 Vol.-% ± 1,5 Vol.-% O 2 0-25 Vol.-% Electrochemical ± 0,1 Vol.-% ± 2,5 Vol.-% H 2 S H 2 0-20 0-5.000 ppm (0-50.000ppm) 0-2000 0-50.000 ppm (0-100 Vol.-%) Electrochemical (Indirectly by dilution) Electrochemical (Indirectly by dilution) ± 0,5 bis ± 50 ppm ± 25 bis ± 500 ppm ± 2,5 bis ± 300 ppm ± 65 bis ± 1.500 ppm Folie 11

Infrared Sensor Measuring signal IR Emitter Reference signal Folie 12

Electrochemical Sensor Electrolyte Elektrolyt Counter electrode Gegenelektrode Membrane Membran Gas Gas Reference electrode Referenzelektrode Working electrode Arbeitselektrode Folie 13

Internal Gas Flow Folie 14

Gas Analysis System Implementation Folie 15

Gas Analysis System Implementation Folie 16

Gas Analysis System Implementation Folie 17

Gas Analysis System Implementation Folie 18

Gas Analysis Operation 7 Touch-Panel Different tabs and sub-tabs Operation mostly intuitively Folie 19

Gas Analysis Data Folie 20

Gas Analysis In Practical Use Folie 21

Gas Analysis Research Application Folie 22

Agenda AWITE Bioenergie GmbH Gas analysis technology Process control using gas analysis technology It s time for you to take control. Folie 23

The Anaerobic Digestion Process (COD-flow) Partikul ä res Particulate organisches organic Material matter (100% CSB) Disintegration Inerts Kohlenhydrate Carbohydrates Proteine Proteins Fette Lipids Hydrolysis Monosaccharides Aminos acids ä uren Long langkettige chained Fetts fatty ä uren acids Acidogenesis Zwischenprodukte Intermediates HPr, HBu, HVa Acetogenesis Acetate Wasserstoff Hydrogen Methanogenesis Methane 90% Folie 24

The Anaerobic Digestion Process Disintegration Degradable, particulate organic matter Carbohydrates, lipids, proteins Inerts Hydrolysis Acidogenesis Acetogenesis Methanogenesis Folie 25

The Anaerobic Digestion Process Disintegration Degradable, particulate organic matter Carbohydrates, lipids, proteins Inerts Hydrolysis Acidogenesis Monosaccharides, disaccharides, amino acids, SC peptides, LC fatty acids, glycerine Acetogenesis Methanogenesis Folie 26

The Anaerobic Digestion Process Disintegration Degradable, particulate organic matter Carbohydrates, lipids, proteins Inerts Hydrolysis Acidogenesis Acetogenesis Monosaccharides, disaccharides, amino acids, SC peptides, LC fatty acids, glycerine Volatile fatty acids (acetate, propionate, butyrate), aldehydes, alcohols, ketones, hydrogen sulfide, ammonia, carbon dioxide, hydrogen Methanogenesis Folie 27

The Anaerobic Digestion Process - NH 3 Nitrogen urea ammonia proteins peptides amino acids ammonia 2 Alanine 2Glycine 2H O 3ADP 3P 3Acetate CO 3NH i 2 4 3ATP NH NH 4 3 H Folie 28

The Anaerobic Digestion Process - H 2 S proteins peptides amino acids hydrogen sulfide sulfur ~ 500 ppm life-threatening within 30 minutes ~ 1.000 ppm life-threatening within several minutes ~ 5.000 ppm fatal in a few seconds Folie 29

The Anaerobic Digestion Process - H 2 S Toxicity => personal injury => magnitude, monitoring (safety) Corrosion => engine damage => desulfurisation (biological, chemical) => check of desulfurisation performance Folie 30

The Anaerobic Digestion Process Disintegration Degradable, particulate organic matter Carbohydrates, lipids, proteins Inert Hydrolysis Acidogenesis Acetogenesis Monosaccharides, disaccharides, amino acids, SC peptides, LC fatty acids, glycerine Volatile fatty acids (acetate, propionate, butyrate), aldehydes, alcohols, ketones, hydrogen sulfide, ammonia, carbon dioxide, hydrogen NH 3 H 2 S Methanogenesis Folie 31

The Anaerobic Digestion Process - Acidogenesis C 6 H 12 O 6 + 2 H 2 O 2 CH 3 COOH + 2 CO 2 + 4 H 2 C 6 H 12 O 6 3 CH 3 COOH C 6 H 12 O 6 CH 3 (CH 2 ) 2 COOH + 2 CO 2 + 2 H 2 C 6 H 12 O 6 + 2 H 2 2 CH 3 CH 2 COOH + 2 H 2 O C 6 H 12 O 6 CH 3 CH 2 COOH + CH 3 COOH + CO 2 + H 2 C 6 H 12 O 6 + H 2 O CH 3 CH 2 OH + CH 3 COOH + 2 CO 2 + 2 H 2 C 6 H 12 O 6 2 CH 3 CHOHCOOH C 6 H 12 O 6 CH 3 CHOHCOOH + CH 3 CH 2 OH + CO 2 Folie 32

The Anaerobic Digestion Process - CO 2 Acidification processes Check measurement against methane measurement Folie 33

The Anaerobic Digestion Process Disintegration Degradable, particulate organic matter Carbohydrates, lipids, proteins Inerts Hydrolysis Acidogenesis Acetogenesis Methanogenesis Monosaccharides, disaccharides, amino acids, SC peptides, LC fatty acids, glycerine Volatile fatty acids (acetate, propionate, butyrate), aldehydes, alcohols, ketones, hydrogen sulfide, ammonia, carbon dioxide, hydrogen Acetate, carbon dioxide, hydrogen H 2 H 2 S NH CO 2 3 H 2 CO 2 CO 2 CO 2 H 2 Folie 34

The Anaerobic Digestion Process - Acetogenesis butyrate CH 3 (CH 2 ) 2 COO - + 2 H 2 O 2 CH 3 COO - + H + + 2 H 2 propionate CH 3 CH 2 COO - + 3 H 2 O CH 3 COO - + H + + HCO 3 - + 3 H 2 ethanol CH 3 CH 2 OH + H 2 O CH 3 COO - + H + + 2 H 2 Folie 35

The Anaerobic Digestion Process - H 2 Acidification processes 1 3 2 Folie 36

The Anaerobic Digestion Process Disintegration Degradable, particulate organic matter Carbohydrates, lipids, proteins Inerts Hydrolysis Acidogenesis Acetogenesis Methanogenesis Monosaccharides, disaccharides, amino acids, SC peptides, LC fatty acids, glycerine Volatile fatty acids (acetate, propionate, butyrate), aldehydes, alcohols, ketones, hydrogen sulfide, ammonia, carbon dioxide, hydrogen Acetate, carbon dioxide, hydrogen Methane, carbon dioxide H 2 NH CO 2 H 2 3 CO 2 CO 2 CO 2 H 2 H 2 H 2 S CO CO 2 2 H CO CO 2 2 2 H 2 Folie 37

The Anaerobic Digestion Process - Methanogenesis Acetoclastic methanogenesis acetate CH 3 COO - + H 2 O CH 4 + HCO - 3 Hydrogenotrophic methanogenesis hydrogen HCO - 3 + H + + 4 H 2 CH 4 + 3 H 2 O Folie 38

The Anaerobic Digestion Process - CH 4 Monitoring of methane formation Folie 39

The Anaerobic Digestion Process - CH 4 Methane: value adding component of the biogas Transfer of the value to higher-level master control Folie 40

The Anaerobic Digestion Process - Methanogenesis Acetoclastic methanogenesis Acetate CH 3 COO - + H 2 O CH 4 + HCO - 3 Hydrogenotropic methanogenesis Hydrogen HCO - 3 + H + + 4 H 2 CH 4 + 3 H 2 O Folie 41

The Anaerobic Digestion Process - H 2 (2) Acidification processes Shifts in the balance of methane formers acid formers 1 3 2 Folie 42

The Anaerobic Digestion Process Disintegration Degradable, particulate organic matter Carbohydrates, lipids, proteins Inerts Hydrolysis Acidogenesis Acetogenesis Methanogenesis Monosaccharides, disaccharides, amino acids, SC peptides, LC fatty acids, glycerine Volatile fatty acids (acetate, propionate, butyrate), aldehydes, alcohols, ketones, hydrogen sulfide, ammonia, carbon dioxide, hydrogen Acetate, carbon dioxide, hydrogen H 2 H 2 S NH CO 2 H 2 3 CO 2 CO 2 CO 2 H 2 H 2 CO CO 2 2 H CO CO 2 2 2 CO CH 2 4 CH Methane, carbon dioxide CH CO 4 2 4 CH 4 H 2 Folie 43

The Anaerobic Digestion Process Disintegration Degradable, particulate organic matter Carbohydrates, lipids, proteins Inerts Hydrolysis Acidogenesis Acetogenesis Methanogenesis Monosaccharides, disaccharides, amino acids, SC peptides, LC fatty acids, glycerine Volatile fatty acids (acetate, propionate, butyrate), aldehydes, alcohols, ketones, hydrogen sulfide, ammonia, carbon dioxide, hydrogen Acetate, carbon dioxide, hydrogen O 2 N 2 N 2 H 2 H 2 S NH CO 2 H 2 3 CO 2 CO 2 CO 2 H 2 H 2 CO CO 2 2 H CO CO 2 2 2 CO CH 2 4 CH Methane, carbon dioxide CH CO 4 2 4 CH 4 O 2 H 2 N 2 Folie 44

The Anaerobic Digestion Process - O 2 Digester and substrate surface: H 2 S + O 2 2 H 2 O + S With gas analysis system: Control of desulfurisation (Fuzzy Logic) No manual aeration No overdosage Dilution of the biogas No underdosage Too high H 2 S-content Corrosion damages Aeration permanently controlled according to actual measurements of H 2 S und O 2 Folie 45

The Anaerobic Digestion Process - O 2 Check of the anaerobic process, tightness Check/correction in research applications Folie 46

Composition of biogas Component Symbol Range Unit Methane CH 4 45-75 % Carbon dioxide CO 2 25-55 % Water vapour H 2 O 0-7 % Nitrogen N 2 0-8 % Oxygen O 2 0-2 % Hydrogen sulfide H 2 S 0-3000 ppm Hydrogen H 2 0-2000 ppm Ammonia NH 3 0-50 ppm O 2 N 2 N 2 H 2 O 2 H 2 S NH CO 2 H 2 3 CO 2 CO 2 CO 2 H 2 H 2 O CO H 2 CO 2 2 H CO CO 2 2 2 H 2 N 2 CO CH 2 4 CH CH CO 4 2 4 CH 4 Folie 47

Applications (1) Biological Control Desulfurisation Laboratory and research facilities Gas utilisation in motors Gas supply and gas sales Fuel cells CDM-applications Folie 48

Applications (2) Gas flow, normalised gas and energy calculations, autom. calibration Cont. measuring, data logging, limit monitoring, master control Folie 49

Applications (3) Gas flow, normalised gas and energy calculations, autom. calibration Cont. measuring, data logging, limit monitoring, master control Folie 50

Gas Analysis and Plant Control I Visualisation air CHP fermenter Folie 51

Gas Analysis and Plant Control II Alerts State detection Plant control Folie 52

Fuzzy Logic: Basics What is Fuzzy logic? unsharp, blurred, indistinct hazy logic Based on the fuzzy set theory Degree of membership B 1 B A A A: tall men ( 1,80 m) B: small men (< 1,80 m) 0 1,53 A: tall men B: small men 1,98 Height (m) Folie 53

Fuzzy Logic: Basics II Why Fuzzy logic + No math. Description of an issue or problem is necessary + Verbal description of the process understanding ( expert system ) + Systems can be controlled / regulated, even when a direct mathematical correlation can not be shown + Comparatively easy to understand + Robust even with gaps or outdated knowledge base + Fast calculation in real time possible + Low data requirements => Used for control and automation tasks: medical care, finance, consumer electronics, automotive engineering, voice / document recognition, biotechnological processes,... Folie 54

Fuzzy Logic: Fuzzyfication (Example: ph-value) Folie 55

Fuzzy Logic: Structure of a Fuzzy System Input variables R1 System states R2 Global measures/ strategies R3 Output variables,, ph-value: 6,3,, Fuzzification Rule base 1: IF c1_ph IS very_low THEN c1_state IS toxic; IF c1_ph IS low THEN c1_state IS overload; Rule base 3: IF c1_state IS overload THEN feed IS no_feed; IF c1_state IS shortage THEN feed IS more; Defuzzification, feed: 0,72, Folie 56

Fuzzy Logic: Defuzzification (Change of Feed Rate) COG: 0,72 Folie 57

Fuzzy Logic: Gas Analysis (Fuzzyfication H 2 ) Folie 58

Fuzzy Logic: Gas Analysis Within The Control System Rule bases: Fuzzification IF c1_ch4 IS high AND c1_h2 IS low THEN c1_state IS shortage; IF c1_h2 IS high THEN c1_state IS overload; IF d_c1_ch4 IS decreasing AND d_c1_h2 IS increasing THEN c1_state IS overload; IF H2S IS high THEN W_set IS high; Methane: ch4 Input variables Hydrogen: h2 Change of methane content: Δch4 Change of hydrogen content: Δh2 Hydrogen sulfide: h2s Oxygen: o2 Output variables:, CHP power, Feed rate, Aeration desulfurisation, Defuzzification Folie 59

Summary AWITE Bioenergie GmbH company presentation Gas analysis systems technology (AWITE AwiFLEX Cool+ and AwiECO) System implementation The anaerobic digestion process: gas formation, monitoring and control options with the implementation of a gas analysis system H 2 S: poison gas, corrosion, biological desulfurisation, monitoring of limit values CO 2 : acidification, check value against methane measurement H 2 : acidification, microbiol. balance => targeted process control & feeding, avoidance of failures & economical losses CH 4 : process end product, value adding component, value for master control, monitoring of limit values O 2 : desulfurisation, tightness of the system Gas flow: process monitoring Further gas analysis applications, fuzzy logic plant control Folie 60

Thank you very much for your attention! Awite Bioenergie GmbH Grünseiboldsdorfer Weg 5 85416 Langenbach/Niederhummel Folie 61

AWITE Distribution Partner UK Allison Engineering Capricorn Centre Cranes Farm Road Basildon Essex SS14 3JA Tel: +44 1268 526161 Fax: +44 1268 533144 www.allison.co.uk Folie 62