Presentation on theme: "Systems and methods for the determination of"— Presentation transcript:
1 Systems and methods for the determination of odorants and other sulfur components in natural and liquid gasAxel Semrau GmbH & Co KGDipl.-Ing. Frank Sasse
2 Topics Axel Semrau GmbH & CO, the company Odorization ODOR handy ODOR on-lineField Study
3 The companyAxel Semrau®, a company of 44 employees, with a technical staff of 34, comprising mostly chemists (PHD) and also some electronic and information technology engineers.Since 1973 Axel Semrau as a person later his company is involved in sales and support for analyzers of odorant sulfur compounds
5 Axel Semrau GmbH & Co services Hardware service, repair and maintenanceSupply of calibration gasTraining on site and in the AS training centerSeminars on all topics related to the analysis and monitoring of odorants in gas.
6 OdorizationMethane CH4 (major component of natural gas) is without any smell.Natural gas is also often without any smell.If it smells, that is caused by natural sulfur.The concentration of natural sulfur is continuously changing.For a constant and typical smell an odorant is added.Main reason: Everybody should be able to detect (smell) any leak in a house installation.
7 Gas production sometimes strong smell, very high sulfur content (sour gas) Desulfurization not always necessaryTransportOdorizationDistribution
8 OdorantsStrong and typical smelling organic sulfur components of the substance classesSulfides R-S-RMercaptans R-S-H
9 Odorants for natural gas THT (Tetrahydrothiophen)TBM (Tertiary butyl mercaptan)BlendsScentinel® E and Spotleak® (TBM 75%, IPM 16%, NPM 8% )Scentinel® TB (50% TBM, 50%THT)
11 German Regulation G280 Level of odorant intensity
12 German Regulation G280Gas should reach a warning smell (level 2) before it reaches a concentration of 20% from LEL (lower explosion limit).Similar regulations in other countries
13 Calculation of the minimum odorant concentration in gas K C = mg/m % * LEL(LEL = Lower explosion limit)Example: TBM in natural gas ,03 mg/m³ C= = 3.8 mg/m³ TBM Minimum conc ,20 * 0, entration in Germany
14 Why do we have to check the odor level at all? Odorization controlWhy do we have to check the odor level at all?
15 Mechanical problems Odorant rate is not correct Bypass odorizer (difficult to adjust)Injection pump (mechanical failure)Pump injects only airPump is getting no impulseRemote control brokenFailures caused by operators
16 Chemical and physical problems Chemical oxidization (especially mercaptans) and adsorption (specially THT)The loss of odorant is depending on the flow and temperature. New PE pipes can also cause a problem.=>This means you have a big loss of odorant from the point of injection to the households!e.g: Injection 20mg/m³ THT Concentration at the last point 9mg/m³=>It is very important to measure the concentration at the end point of the distribution net!
17 Measuring methods Smell the gas Advantage: You smell it!Disadvantages: different results from different peopleLower results after several measurement in a short timeInaccurateGood as an additional backup.In European Countries are not used any longer
18 Measuring methods Measuring tubes Advantage: simple to handle, low investment costsDisadvantage: Many cross sensitivities, Very inaccurateDue to low accuracy not allowed in Germany any longer
20 ODOR handyProofed by extensive testing by many well recognized gas institutes, DVGW institute (Germany Gas Institute) for instanceProofed by hundreds of companies, using it in daily routine work all over the World eg. (Italy, Spain, France, Poland, Czech Rep., Mexico, Argentina, Brazil, Chile, Bolivia)Several customers have more than 20 units in use
21 Differences between THT and Mercaptan version ODOR handy TBMDisplay 00.1Measuring range 0 to 50 mg/m³For all mercaptans and blends with a high mercaptan concentrationSpecial version with US units (lbs/MMFC) and display 0.01 availableODOR handy THTDisplay 000Measuring range THT 0 to 100 mg/m³For THT and blends with high THT concentration
22 ODOR handy in the fieldConnect direct to the gas pipe if pressure is 20 mbar (approx. 15 inch of water, 0.5 psi) or with a rotameter if the pressure is higher.Wait just a few minutesRead the resultReady for next measurement after 10 minutes
23 Odorant concentration direct in mg/m³ Mercaptane ansprechen
24 Operation state No OFF switch Sensor should always have voltage In case of empty battery or new sensor: => let the sensor stabilize up to 12h => then calibrate the ODOR handy
25 ODOR handy Ex-proof Can be used everywhere on site Easily connected to the gas pipe by means of a very short non adsorptive tubeWeight approx. 100gSelective alarm levelsSimple calibration procedureEx-proof battery (6 months continuous work)Rechargeable battery ex-proof optional
28 Calibration Battery check Zero point check, adjust if necessary (screw 7)Pure calibration gas pressure regulatorConnect calibration gas to ODOR handyWait till the reading is stableIn case of differences: - adjust span/amplification (screw 8) - disconnect calibration gas and wait 10 minutes. - Repeat in case of bigger differences.
29 Life time sensor Sensor has to be replaced if: THT: Ce-value is higher TBM: Sensor has not enough sensitivity to adjust during calibrationH2S filter is saturated.Life time of sensors is about 1-2 years, depending on usage.(Sensors age, even if they are not been used.)
31 conform to ISO 19739 (German standard DIN 51 855-07-GC/ASTM D7493-08) gas chromatographic procedure for online measurement (stationary and mobile)for more than 30 years successful operatingsince 1996 with ODOR on-line systems are always on the latest technical standard2010 about 300 instruments on the market
32 Major applications1. Natural sulfur compounds (e.g H2S, mercaptans) in natural gasUnderground gas storagesGas power plantsTransmission pipesGas quality stationsH2S causes corrosion to pipes and turbines
33 Major applications 2. Odorization control City gatesPressure regulation stationsMobile measurementOdorants fade during transportation!
34 Installation In the field for on-line application In the lab for manual operation (analyzing of samples)
35 References E-on Ruhrgas (Germany) RWE (Germany) Fluxys (Belgium) Gas de FranceTIGF (France)Italgas (Italy)Gas Natural (Spain, Brazil)Peoples gas (USA)Kindermorgan (USA)Polish Oil and Gas Company (Poland)Société Tunisienne de l’Electricité et du Gaz (Tunisia)VCP Vychodoceska plynarenska, a.s (Czech Republic)Igdas (Turkey)EWE, Bayern Gas …… (Germany)
36 Stationary measurement On-line measurement in a pressure regulation station
37 Stationary measurement Processing with a special PC SoftwareODOR control
38 ODOR on-lineChromatograph designed to fulfill the demands of ISO (ISO 6326 T2)packed columnelectrochemical detector10 ml gas sampling loop
42 Electrochemical detection Explanation of the expression An electrochemical detector uses the oxidation ability of a substance as its proof. In the case of H2S and mercaptans the oxidation power of the chrome trioxide is used as the specific proof.
50 ODOR control Software Easy to operate Real-time chromato- gram User defined reports
51 ODOR control Software Database with all measure- ments Search filters Export function to Excel™
52 ODOR controlReportgeneratorUser specific reports
53 Data output: 3 x 4-20mA (standard) or Modbus (optional)
54 Option ModbusAll results with name of the substances, retention time, areas and …Groups of substances8 different alarmsStatus of the instrumentInformation about the last run:22: Update of Bus-Memory:22:24 File: F:\ODO Results.xml:22:24:22:24 Parameter: Substance name TBM:22:24 Value: TBM:22:24 Type: String:22:24 Start address: 0:22::22:24 Parameter: Retention time TBM:22:24 Value: 94:22:24 Type: Single:22:24 Start address: 10:22:24 Parameter: Peak area TBM:22:24 Value::22:24 Type: Int32:22:24 Start address: 20:22:24 Parameter: Concentration TBM:22:24 Value: 2.8:22:24 Start address: 30
60 Odor on-line Measuring range Carrier gas Automatic and manual injector THT mg/m³ - about 100 mg/m³H2S mg/m³ - about 100 mg/m³Mercaptans mg/m³ - about 100 mg/m³Carrier gasNitrogen or compressed oil free airAutomatic and manual injector
61 Advantages of the electrochemical detector The detector is not sensitive to other compounds in natural gasLow detection limits 0.1 mg/m³Linear within the normal measuring rangeExtremely robust and stable in on-line applications
62 Mobile measurement 12 V use Heated column No cross sensitivities Option: Electronically flow controllerDiesntleister mit bis zu 6 FahrzeugenGroße GVUs haben eigen Fahrzeuge
80 1. Stationary on-line measurement Data transmission to the central control stationRechter Bildschirm: StatusmeldungenLinker Bildschirm Messwerte5 Anlagen
81 2. Mobile measurement with a car Small pressure regulation stationfactorySampling point on the streetPublic building (school)
82 Summary field study Mark E Optimum control procedure for odorization level by:On-line measurement (24h) ODOR on-lineGood positioning of sample sitesFlexible through a mobile gas chromatographQuick results from new sites with the handheld instrument (ODOR handy)