Experience with Ultrasonic meters for Biogas

Transcription

1 Products Solutions Services Experience with Ultrasonic meters for Biogas Gastekniske Dage Billund Slide 1

2 What is Biogas? Biogas typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops. Biogas comprises primarily methane (CH 4 ) and carbon dioxide (CO 2 ) and may have small amounts of hydrogen sulphide (H 2 S) and moisture. Component Concentration (Vol%) Methane (CH 4 ) 50 to 75 Carbon dioxide (CO 2 ) 25 to 45 Water (H 2 O) 2 (20 C) 16 (55 C) Nitrogen (N 2 ) <1 Oxygen (O 2 ) Hydrogen Sulphide (H 2 S) Hydrogen (H 2 ) <5000 ppm <5000 ppm <5000 ppm Slide 2

3 Biogas market drivers The Biogas market is being driven by two factors Waste handling Green house Gas reduction. Methane s global warming potential is 21 times greater compared to CO2 Increasing demand for Energy Many governments have requirements regarding the percentage of energy that must be derived from renewable sources. Among the European countries there is a general strong political tendency towards supporting renewable energy, especially after the Kyoto agreement. 20% of Europe s energy should be from renewable sources in % of the fuel used for transport must be biofuel based by 2020 Slide 3

4 Biogas energy in the EU Slide 4

5 Typical measurement points on Biogas plants Slide 6

6 Prosonic Flow B200 Product highlights Designed for wet biogas measurement. Innovative industry optimized flowmeter for biogas. Measurement accuracy and reliability unaffected by changing gas composition, moisture content of the gas, and can measure under low flow and low pressure conditions. Integrated methane measurement. Enables process optimization via the integral in-line measurement of biogas methane content.. 2 wire platform Easy integration, as per any other loop powered device; 4 20 ma HART protocol. Reducing complexity and standardizing integration. Slide 7

7 Prosonic Flow B200 Methane measurement To calculate the methane content of biogas the B 200 measures the time taken for the ultrasonic pulse to travel through the gas. As the path length is know the speed of sound in the gas can be accurately determined. As the speed of sound in a gas is dependent on the gas composition the B 200 can use the sound speed to calculate the methane content of the biogas. Slide 8

8 Prosonic Flow B200 Methane measurement Because the speed of sound in gas is a function of the square root of temperature, the B 200 uses an integrated PT1000 to measure the biogas temperature; this measurement is then used to compensate the effect of temperature on sound speed. As biogas is typical saturated with moisture the temperature measurement is also used to calculate the moisture content of the gas. This is then used to compensate of the water content effect on sound speed. Slide 9

9 Prosonic Flow B200 Methane measurement The speed of sound in biogas (60% CH 4 40% CO 2 ) at 40 C is m/s Temperature Methane Carbon dioxide Speed of sound C CH 4 CO 2 m/s % 100.0% % 90.0% % 80.0% % 70.0% % 60.0% % 50.0% % 40.0% % 30.0% % 20.0% % 10.0% % 0.0% Slide 10

10 Prosonic Flow B200 Methane measurement Pressure however has very little effect on the sound speed. g = P g = Sound speed, = heat capacity ratio, P = operating pressure, = density Even though the effect of pressure on the methane calculation accuracy is limited, it can be compensated either by using the dynamic pressure compensation via current input(recommended) or by manually entering a static line pressure. If static pressure compensation is used it should be noted that any deviation in the actual operating pressure will result in a slight error in the methane calculation. Slide 11

11 Prosonic Flow B200 Methane measurement This direct measurement of the methane content of the biogas is unique and enables the monitoring of gas flow and gas quality around the clock. This can for example allow the operator of a biogas plant to detect disturbances in the fermentation process to respond quickly and effectively. Slide 13

12 Prosonic Flow B200 Dynamic Pressure Compensation Prosonic Flow B200 offers multivariable solution with current input allows compensated standard volume flow reading on the device Slide 14

13 Prosonic Flow B200 HART 7 Categorization of device status according to Namur NE107 Simple and uniform diagnostic information for operators Device failure Out of Specification Maintenance required Check function Slide 15

14 Prosonic Flow B200 Heartbeat Technology Heartbeat Technology Highest functional reliability = Safety Greatly reduced maintenance = Quality Flexible instrument access = Availability Compliant self-monitoring and testing without service interrupt Slide 16

15 Prosonic Flow B200 What Heartbeat Technology can do PDF Heartbeat Diagnostics Continuous self-monitoring, NE 107 status information Heartbeat Verification Effortless testing on demand, without service interrupt Heartbeat Monitoring Device and process supervision for preventive maintenance Slide 17

16 Prosonic Flow B200 Scope of tests Heartbeat Technology for Prosonic B200 Sensor integrity Main Electronics System Status I/O module Sensor connection Transducer resonance Signal quality Synchronous run of dual frequency reference (detects drift) Transmitter circuit check Coverage of entire signal processing chain Current output loopback test Amplifier circuit check Measuring circuit check Slide 18

17 Prosonic Flow B200 Flowmeter summary Diameters DN 50 to DN 200 Size 2" to 8" Pressure rating PN 10 Process connections Lap joint flange acc. EN1092-1, Lap joint flange acc. ANSI B16.5 Process temp. 0 to +80 C (32 to 176 F) Volume accuracy Volume repeatability Methane accuracy Methane repeatability ± 1.5% o.r. (3 to 30 m/s) ± 0.5% o.r. ± 2% abs. ± 0.5% o.r. Environment temp. 40 C to +60 C ( 40 to 140 F) Measuring tube /316L Protection class Compact: IP 66/67 (NEMA 4X) Temperature accuracy 0.6 C T C Temperature repeatability 0.3 C T C Number of ultrasonic paths Mechanical approvals Hazardous area approvals DN 50, DN 80 1 path system DN 100, DN 150, DN path system PED ATEX, IECEx, Ex ia IIC T6-T1 Gb, Ex d[ia] IIC T6-T1 ccsaus Class I Div. 1 Groups ABCD, Class I Div. 2 Groups ABCD Slide 19

18 Products Solutions Services Questions? Slide 20

19 Products Solutions Services Thank you very much for your attention Slide 21