Real-time Wobbe Index Determination of Natural Gas. J.C. Lötters Bronkhorst

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1 Real-time Wobbe Index Determination of Natural Gas J.C. Lötters Bronkhorst

2 Real-time Wobbe index determination of gas mixtures Joost Lötters Professor Chief Technology Officer Microfluidic handling systems

3 Introduction Problem huge variation in the composition and quality of the natural gas in national gas grids (Wobbe Index [MJ/m 3 ]) Causes blending of natural gas from different countries the addition of biogas periodical variations in both gas types

4 INTRODUCTION WOBBE INDEX

5 INTRODUCTION WOBBE INDEX

6 INTRODUCTION Current gas quality variations in the German gas grid

7 Monitoring the gas quality

8 Monitoring the gas quality Requirements: - Small size < 20 x 10 x 10 cm - Low cost < Fast response < s - Low gas consumption < 1 liter - Provide real-time information about the composition - Accuracy < 5 % Application: any Point-of-use and Point-of-Produce!

9 Monitoring the gas quality Solutions: We can determine the calorific value of the gas by: - Combustion (Wobbe index meter) - Correlation (Multiparameter system) For both solutions we need a Coriolis flow meter suited for accurate measurement of gas - Flow - Density

10 Monitoring the gas quality 3 types of Coriolis flow meters: We can determine the calorific value of the gas by: (1) Industrial (2) OEM (3) Consumer

11 The smart gas grid

12 The smart gas grid

13 Micro Coriolis Flow Sensor Sensor structure and basic operating principle

14 Micro Coriolis Flow Sensor Sensor structure and basic operating principle Lorentz force actuation Movement due to Coriolis force Resulting movement of flow tube

15 Density measurement possible! Theory and modelling

16 Fabrication University of Twente Transducers Science and Technology Prof. Elwenspoek

17 Assembly, interconnection & packaging - glass cover over chip -

18 27 March 2015 Coriolis Chip Packaging 18

19 Product roadmap Cori-Flow mini Cori-Flow micro Cori-Flow ~ 1000 kg/h ~ 1 kg/h ~ 1 g/h Currently, demonstrators are available

20 Demonstrator of the microcoriolis flow meter

21 Error [%RD] Measurement results M10 performance water vs. weighing scale (Mettler Toledo AX205) %RD and 0.002g/hZS Water mass flow by M Mass flow [g/h] Measured accuracy: ± 0.5 % of reading ± g/h zero-stability

22 Error [%RD] Error [%RD] Measurement results Performance M10 Air vs. calibration tube Air M %RD en g/hZS -0.5%RD en g/hZS Pressure ca. 7 bar at max. flow volumetric flow [ln/min] Mass flow (g/h) Measured accuracy: ± 0.5 % of reading ± g/h zero-stability

23 Error [%RD] Measurement results CH4 M10 performance with Helium vs. calibration tube volumetric flow [ln/min] Mass flow [g/h] Helium CH4 M %RD en g/hZS -0.5%RD en g/hZS Pressure ca. 7 bar at max. flow Measured accuracy: ± 0.5 % of reading ± g/h zero-stability

24 Error [%RD] Error [% RD] Measurement results H2 M10 performance Argon vs. calibration tube volumetric flow [ln/min] Mass flow [g/h] H2 Argon M %RD en g/hZS -0.5%RD en g/hZS Pressure ca. 7 bar at max. flow Measured accuracy: ± 0.5 % of reading ± g/h zero-stability

25 Reduced pressure drop by on-chip by-pass channel Ratios ranging from 20 to 100 have been designed, realised and characterised CleWin mask design

26 Frequency [Hz] Frequency (Hz) Density of (fuel) gases Measurement results y = x R 2 = density (kg/h) [kg/m 3 ] Density (kg/m 3 ) Frequency (Hz) Min/Max (Hz) Argon Air Helium Hydrogen y = x R 2 = density [kg/m^3] Density (kg/m 3 ) Frequency (Hz) CO Argon N CH He Min/Ma x (Hz)

27 Micro Wobbe Index Meter Basic Structure Chip Size ca. 15 x 15 mm Coriolis mass flow sensors reaction chamber with heaters pre-heaters exhaust tube air gas thermally isolated island exhaust

28 Mixing of fuel gas and air Air Methane Air Scientific questions: - Mixing - Clogging - Flame arrester - Heat supply

29 Measurement results Flow pulses 10 s on, 90 s off

30 Multiparameter Flow Measurement System

31 Multiparameter Flow Measurement System (1) (2) Two ways of modelling: (1) Composition determination via n equations with n unknowns (n 4) (2) Wobbe index determination via correlation with the measured parameters

32 Envisioned MEMS Multiparameter Systems M10 Multi parameter Coriolis and thermal Coriolis and pressure Coriolis, thermal and pressure

33 Multiparameter Flow Measurement Set-up Differential pressure sensor Density sensor Coriolis flow sensor Thermal flow sensor

34 Multiparameter Flow Measurement Results Composition determination based on heat capacity; modelling and measurement results of a binary gas mixture (CH 4 / CO 2 ) are within 1%

35 Multiparameter Flow Measurement Results 3 equations with 3 unknowns Composition determination of a ternary gas mixture (CH 4 / C 3 H 8 / N 2 ) based on the heat capacity and density; modelling and measurement results are within 5% Correlation between WI and 2 parameters Wobbe Index determination of a ternary gas mixture (CH 4 / C 3 H 8 / N 2 ); modelling and measurement results are within 5%

36 Multiparameter Flow Measurement Results 3 equations with 3 unknowns Composition determination of a ternary gas mixture (CH 4 / CO 2 / N 2 ) based on the heat capacity and density; modelling and measurement results are within 5% Correlation between WI and 2 parameters Wobbe Index determination of a ternary gas mixture (CH 4 / CO 2 / N 2 ); modelling and measurement results are within 5%

37 THE PROOF OF THE PUDDING Field test at a supplier to the German gas grid

38 IS IN THE EATING Field test at a supplier to the German gas grid

39 Summary We realised an: - Integrated micro Wobbe index meter, and a - Multiparameter flow measurement system for the energy content measurement of fuel gases such as natural gas, biogas and hydrogen Based on a microcoriolis mass flow meter, suitable of measuring flow rate and density of gases First measurement results have indicated the feasibility of the concepts Further research will focus on the integration of the micro Coriolis mass flow meters, and performing more on-site field tests.

40 Differential pressure sensor Density sensor Coriolis flow sensor Thermal flow sensor Thank you for your attention!