FLOWSIC100 Flare Challenges in Ultrasonic Flare meter field installations. History of Evolution

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1 FLOWSIC100 Flare Challenges in Ultrasonic Flare meter field installations Mart Gloudemans, Sebastian Stoof, Sven Holzbächer SICK Germany History of Evolution 1

2 Introduction SICK FLOWSIC100 has track record in flare metering since 10 years Identifying flare gas measurements Novy Urengoi Gas flow measurement at Oil processing plant Ultrasonic flow meter FLOWSIC 600 Typical measurement range m/s Meter is out of work 5 2

3 Identifying flare gas measurements Possible reasons: Dirty transducers High liquid contents Noise disturbance Electronic or Sensor faults 6 Identifying flare gas measurements Reason for meter malfunction: Typical flare gas application Associated petroleum gas Velocity of gas approx. 85 m/s Blowing away effect 7 3

4 Flare gas the unavoidable by-product What is flare gas? :! Waste gas from chemical and petrochemical processes :! Associated Petroleum Gas from oil exploration Flare gas the unavoidable by-product Challenge: Process waste gases are not emitted directly into the atmosphere. Typical velocity of gas m/ s at ambient pressure 95% of process working time velocities < 1 m/s Varying gas composition Unit A Unit B FT_Q Molecular weight is important for leakage detection and process control Factory II Factory 1 4

5 Flare gas the unavoidable by-product System depressurizing in emergency situations Significant amounts of gas leads to velocities up to 100 m/s Requirement for avoiding pressure drops High pressure condition Pipe sizes ( mm) Flare gas measurement Quo vadis? For emission and CO 2 reduction many countries have been defining regulations and standards Annually volume of CO 2 certificates emitted by flaring: 370 Mio! APG flaring causes 1.2% of total global CO 2 emission Russian Government Decree No.344 with emission fee for flaring of APG Emission trading of CO 2 certificates Global trend to flare gas recovery There are anti-flaring legislations with defined legal flaring limits + escalating penalties in most countries. COMMISSION DECISION of EG/589/

6 Flare gas measurement Quo vadis? For economic and environmental reasons: :! Recovery of flare gas becomes increasingly important. :! Various technologies for flare gas recovery available :! Taxes and fees for flaring of hydrocarbons are raising all over the world :! CO 2 is going to be the most important value for GHG measurements :! Raising world energy prices makes flaring uneconomical. 19 Purpose of flare gas measurement :! Calculation of CO 2 emissions for compliance with government regulations. :! Monitoring of abnormal process changes. :! Reduction of gas wastage. :! Process optimization and accurate mass balance calculation. :! Optimization of steam usage. 6

7 Challenge of flare gas measurement Gas velocity m/s Extraordinary low flow performance required Turn-down ratio 4000 : 1 Contamination by liquids and pollutions Strong variation of gas mixtures Harsh ambient conditions No pressure drop allowed 21 Challenges of flaregas metering The measurements companies view Requirements on the flaregas measurement 1.! Low flow performance To fulfill process optimization task and identification of valve leakage 2.! High flow measurement Availability of measurement in shutdown conditions. 3.! Measurement availability in difficult gas compositions Light + heavy gas. Sound absorbing gas. 4.! Adapted installation capabilities Long-term plant operation. Limited accessibility to piping. (Extraction Tools) Offshore installation. 7

8 Operation in low flow conditions Challenge 1: Low Flow condition < 1 m/s :! Strong reduced measuring effect smallest transit time difference. :! Very unstable flow conditions + backflow. :! Thermal stratifications. Extreme stability requirements Operation in low flow conditions SICK transducer technology 1.! Time resolution :! System +/-5ns in practise conditions 2.! Measurement stability, ensured by: :! Precise transducer signals :! Broadband system :! Highly accurate signal algorithm :! Highly stable elctronics 3.! Special verification procedure for zero point stability 8

9 Operation in low flow conditions SICK Performance verification using special zero flow check 0,001 Trend VOG [m/s] 0,0005 Zero flow stability of 0.6 mm/s 0-0,0005-0, Time [s] Operation in low flow conditions SICK field verification of meter :! Several local regulations recommends a meter performance check every year Field verification procedure needed :! Field test box: -! On-site capable -! Zero point adjustment -! Factory standard 9

10 Operation in low flow conditions SICK field verification of meter :! Closed box with minimal influence of temperature and fluctuations :! Data acquisition and evaluation with FLOWSIC FAD tool Challenge 2: Operation in high flow conditions High Flow condition 100 m/s or more :! Disturbing noise in the pipeline and at the sensor :! Signal is blown away, received signal amplitudes are reduced :! Signal beam an optimization task -! Wider signal beam angle distributes energy over a larger area -! Small signal beam might not hit the receiving sensor Limited Signal Noise Ratio (SNR) 1 0

11 Operation in high flow conditions Investigations in Signal Noise Ratio (SNR) 300 Noise Level undisturbed flow 80 khz p ambient 250 Sensor B Receiving Amplitude [digit] Sensor A VOG [m/s] The sensor inside the gas flow becomes to a significant source of noise! Operation in high flow conditions Aerodynamic probe design Probe design with ultrasonic sensor embedded in an aerodynamic shape Noise reduction at sensor Significant improvement of Signal Noise Ratio (SNR) Path angle of

12 Operation in high flow conditions SICK innovative high speed sensor design :! Probe design with ultrasonic sensor embedded in an aerodynamic shape :! Noise reduction at sensor Significant improvement of Signal Noise Ratio (SNR) B A Considerations for gas composition Challenge 3: Gas composition :! Short term changes possible. :! Difficult compositions can reduce SNR by a changed transmission characteristics of transducers. Sound beam lobe Light gas SOS ~700 m/s Natural gas SOS ~400 m/s Heavy gas SOS ~280 m/s 1 2

13 Considerations for gas composition SICK transducers + signal algorithm :! Transducers with large bandwidth and amplitudes! gas composition do not have a significant effect on signal performance. :! SICK Flare measurement starting at compositions with MW 2 g/mol. SOS 934 m/s, MW 3.5 g/mol, ~90%H2, 10% CH4 SOS 611 m/s, MW 7.8 g/mol, ~60%, 40% CH4 SOS 349 m/s, MW 23 g/mol Meter installation requirements 2-path configuration :! Much less sensitive for flow profile deformations at instable flow conditions :! 2-path meter can reduce uncertainty down to 1 % 1 3

14 Meter installation requirements Optional 2-path configuration :! For higher accuracy demands. :! For representative measurement results also under difficult measuring conditions (disturbed flow, gas composition). Meter installation requirements Gas with liquids and pollutions :! Use of high power version FLOWSIC100 Flare EX-RE 1 4

15 Meter installation requirements Solutions: Flowmeter with and without meter body 1.! Device without meter body :! Hot tapping installation :! Nozzle installation tool / geometry calculator :! 1- or 2-path configuration 2.! Device with meter body :! System solution - plug&play :! Factory-sided parameterization - ready for operation :! Solution for higher uncertainty demands by optional: :! Highly precise 3D survey :! Flow calibration for uncertainty down to 0.5% Meter installation requirements 3D survey - Minimizing geometric uncertainty! < +/- 0.1 mm Meter body 1 5

16 Meter installation requirements Optional flow calibration :! Calibration on SICK test stand, approved and traceable to national standard, represented by the german PTB (Physikalisch Technische Bundesanstalt, Germany). :! Test benches is equipped with two electric fans with a total connected power of 70 kw. Measurement range 30! m"/h Meter installation requirements Offshore installations :! Highly robust device configuration with electronics housings in stainless steel :! Highly durable material configurations in Duplex or Hastelloy :! Special paintings 1 6

17 Business opportunities Example Offshore platform Norway Case Mass flow Annually Min 160 t/h 95% Normal 290 t/h 3% Max 504 t/h 2% Total amounts: Mass flow: ~ t/year Emission: ~ t CO 2 /year CO 2 tax Norway: 21$ /CO 2 t (15!/ CO 2 t) Costs CO 2 Emission total: 7.5 Mio!/year 1% accuracy increase: !/year per plant 64 FLOWSIC100 Flare solutions 1 7

18 Meter installation requirements Optional 3x1path configuration :! System solution to serve 3 different flare measurements with a single control unit. Flare 1 Flare 2 Flare 3 Meter installation requirements Remote installation of control unit up to 1,000 m (3,000 ft) from measurement location :! Installation of control unit in safe area. :! Safe costs of an expensive installation in hazardous area. 1 8

19 Meter installation requirements Single-sided installation :!Use of probe version FLOWSIC100 EX-PR up to 1,000 m Control unit non-ex or Ex-Zone 1 and 2 (ATEX), Cl I, Div2 (CSA) Safe or hazardous area FLOWSIC100 Flare Operation principle & devices FLOWSIC100 EX-S FLOWSIC100 EX FLOWSIC100 EX-PR -! Standard cross-duct - Retractable - ATEX Zone 1+2 -! CSA Cl I, Div.1/2 -! IEC Ex Ga/Gb Ex d [ia] IIC T4 -! High power cross-duct - Retractable - ATEX Zone 1+2 -! CSA Cl I, Div.1/2 -! IEC Ex Ex d IIC T4 -! Probe version - Retractable - ATEX Zone 1+2 -! CSA Cl I, Div.1/2 -! IEC Ex Ga/Gb Ex d [ia] IIC T4 1 9

20 FLOWSIC100 Flare Operation principle & devices Multi Control Unit MCUP :! Medium housing -! non-ex -! ATEX Ex zone 2 -! CSA Cl I, Div2 / zone 2 -! up to 3 measurement points -! optional conduit connection :! Flameproof housing -! ATEX Ex zone 1 -! up to 3 measurement points -! optional conduit connection Conclusion 2 0

21 Conclusion :! Leading transducer technology Best signal performance, shortest time resolution for reliable and precise measurement also in difficult gas conditions. Cross-duct measurement up 72 pipe size. :! Unique zero flow performance verified by special Zero Flow Test procedure. Fast and reliable process control + optimization. Trend VOG [m/s] 0,001 0, ,0005-0, Time [s] :! Innovative high speed sensor design High measurement availability also in High flow conditions up to 120 m/s. Conclusion :! Installation advantages: 1x1, 2x2 or 3x1 path configuration Remote installation of control unit up to 1,000 m from measurement location Installation in safe area safes costs of an expensive installation in hazardous area. Probe version for single flange mounting Single nozzle installation for pipes with access from one side only. Lowest installation expenditure. 2 1

22 :! Thank you for your attention. 2 2