SERVOTOUGH SpectraScan

Transcription

1 SERVOTOUGH SpectraScan Continuous, real-time analysis of light hydrocarbons Jan Hordijk - Servomex Hydrocarbon stream analysis 5 major technologies used in HydroCarbon land for gas: IR (Infra Red) Laser Paramagnetic Zirconia GC The rest is niche like UV, Mass Spec, Moisture, etc GC s : Very good in ppm and Hydrocarbon mixtures, BUT WHAT ABOUT MAINTENANCE AND RESPONSE TIME! Certain applications Tunable Filter Spectroscopy can replace GC GC land will change in the next 1 years!! 1

2 SpectraScan: Scanning IR Technology What is Spectrascan: Spectrascan is a Hydrocarbon Gas Analyser able to analyse C1 to C5 + CO with a response time of seconds without carrier gas and without calibrations but with GC specification. Measurement is based on scanning IR absorption spectroscopy with spectral chemometric analysis. Chemometrics the use of advanced mathematical modeling techniques to separate and understand the complex interactions on a chemical system as a hole (i.e. complex absorption spectroscopy). x What Spectrascan can NOT do: 1 - Gases other than hydrocarbons or CO 1 - Traces (ppm) hydrocarbons - Analysing an unknown gas. - Caloric value for custody transfer 1 SpectraScan: Scanning IR Technology Hydrocarbon Gas Analyser : Individual component concentration C1 C5 + CO Calculated BTU/CV/Wobbe index value Real time measurement : seconds response time Robust, Reliable, Low Maintenance No carrier gas No calibration gas or clean air requirement No Shelter or temperature controlled ambient No complicated sample system requirement Hi Accuracy, low cross sensitivity ATEX Zone, Class 1 DIV Offers breakthrough capability in HP Industry for instantaneous analysis of light hydrocarbons C1-C5 + CO + BTU

3 The Hydrocarbon Processing Industry Spectrascan will benefit clients in: -Gas processing -Refining -First level of processing BENZENE TOLUENE XYLENE Cumene Cyclohexane, Caprolactam, Terephthalic Acid* Nylon, PET Polystyrene, Resins, Fibres, Polyurethane Oil Coal METHANE BUTANE BUTENES BUTADIENE Methanol, Syngas Adiponitrile Formaldehyde* Resins, MEK, Neoprene, P Butadiene Styrene Rubber Natural Gas ETHYLENE Ethanol, Ethylene Oxide * Ethylene Dichloride*, Acetic acid* Polyethylene, Vinyl Chloride*, Polyvinyl Acetate Ethylene Glycol, Polyvinyl Alcohol PROPYLENE Acrylonitrile Adiponitrile* Acrylic Acid Polypropylene, Acrylic Fibres Nylon Styrene Acrylonitrile FUEL Difference between IR and TFS IR Reference filter Measure filter x Absorption Magnitude Wavelength (nm) Methane Ethane Propane n-butane iso-butane 3

4 SERVOTOUGH SpectraScan -Tunable Filter Photometer Tunable Filter Photometer An optical filter is rotated through an IR light source enabling spectral scanning of a broad range of frequencies, rather than just a narrow band point measurement x Frequency or 1/ λ = m c/ nl cos θ If you change the angle of incidence of light, you change the emitted wavelength Wavelength Scanning (C 1 to C 5 ) λ TFS Sensor Wavelength Scanning Technology Typical IR TFS IR Sample x 1-7 x 1-7 Absorption Magnitude Wavelength (nm) Wavelength (nm)

5 Challenges of Hydrocarbon Spectroscopic Analysis Servomex SpectraScan achieves precise separation and quantification by: - Absorption spectrum of each hydrocarbon compound is unique => this acts as fingerprint and can be used to speciate compounds - Intensity of the absorption is proportional to the concentration of the molecules => this can be used to compute concentrations: Chemometrics x 1-7 Absorption Magnitude Methane Ethane Propane n-butane iso-butane Wavelength (nm) 9 Sensor Design-SpectrScan (TFS TM ) Sample inlet Turning mirrors Sample outlet Light path Windows Spectrometer assembly light source, TFS and detector Advantages: Non-contact, flow-through cell Rejects window contamination and or changes in light intensity Easy to clean windows No carrier gas Wide range of flow (-1 l/min) Wide range of pressure (- barg) Heated cell to C Filter rotation overdesigned by 99% 1 5

6 Typical Configuration (with 7 Components) - Methane (CH ): -1% - n-butane (C H 1 ): 1% - Ethane (C H ): 5% - Propylene (C3H): 1% - Propane (C 3 H ): 5% - Ethylene (CH): 1% - iso-butane (C H 1 ): 1% 11 Direct Comparison with Single CH Component Equivalent Speciated Methane plots Concentration (ppm) Concentration (ppm) GC measurement Data point TFS measurement GC reading (ppm) IR VS GC readings, methane y = 1.9x R = IR reading (ppm) Standard Error (SE):.7% Data point

7 Hi Accuracy and Low Cross Sensitivity Typical Test Data, - 1% scale for all components Theoretical (%) Reading (%) Error (%) Methane Ethane Propane Iso-Butane N-Butane Mixture 1 Theoretical (%) Reading (%) Relative Error (%) Methane Ethane Propane Iso-Butane N-Butane Propylene Ethylene Mixture 13 Immune to Effects of IR Source Intensity Drift Change in Light Intensity does not affect accuracy Test Setup: Configured for C1 C alkane gas measurements Update rate: 5 seconds Sample gas:.5% calibrated CH, balance N Test Procedure: 1. Zero the instrument (with pure N ). Start data collection 3. Flow calibrated CH mixture (stop N flow). Reduced light source intensity by ~ 3% 5. Stop CH flow, start N flow. Stop data collection Results: Absolute accuracy error due to a 3% drop in light intensity:.15% Relative accuracy error:.35% Zero drift:.3% This is without re-zeroing the instrument Average value:.35% 1.%.%.%.%.% % Average value:.% => Error:.15% (due to a 3% drop in light intensity) 1.% C1 (%) Source Intensity (%) Zero drift: -.3% 7

8 -hour Pipeline Natural Gas: side-by-side test with a GC-TCD (CH values) % CH discrepancies:.3% Probably due to calibration gas differences 15 SERVOTOUGH SpectraScan Applications Natural Gas fractionation DeC1 (De-methaniser) to DeC (De-butaniser), tops and bottoms Ethylene plants Ethane or Propane feed analysis (not naphtha feeds as too variable Cracked gas analysis De-methaniser tops and bottoms (bottoms can be complex, check before going too far) PolyEthylene plants Methane (predominantly) sour gas analysis LNG & LPG processes multiple points in fractionation, conditioning and regeneration processes Waste gas boilers on plants BTU analysis and CH top-up Treated Tail Gas analysis from Claus process (HS removal) NG processing Refineries

9 SERVOTOUGH SpectraScan Ethylene Production Special flarestack application TYPICAL Hydrocarbon Speciation Flare Stack Application SpectraScan Offering CH : 1% C H : 5% C H: - 3% C 3 H : 5% iso-c H 1 : 1% n-c H 1 : 1% Iso Pentane - 1% C H : 5% C 3 H : 5% CO : 1% 9

10 Summary Industry-first all-optical hydrocarbon gas analyzer GC-like speciation performance C1 C5, alkanes, alkynes, alkenes and calorific value! Fast update rate ( seconds) No carrier gas or other consumables Proven technology & platform 15+ units throughout North America Versatile spectroscopic hardware platform UV IR analysis Rugged design, IP 5, Zone 19 ANY QUESTIONS? 1