ARUN TECHNOLOGY UVF Total Sulfur Analyzer by Ultraviolet Fluorescence

Overview

The ARUN TECHNOLOGY UVF Total Sulfur Analyzer is a bench- or field-deployable analytical instrument engineered for precise, real-time quantification of total sulfur content in gaseous and liquid hydrocarbon streams using ultraviolet fluorescence (UVF) detection. Based on the ASTM D5453, ISO 20846, and UOP 971 standard methodologies, the analyzer subjects sample matrices to high-temperature oxidative combustion in an oxygen-rich environment—ensuring quantitative conversion of all organic and inorganic sulfur species (e.g., mercaptans, sulfides, disulfides, thiophenes, H₂S, SO₂, and elemental sulfur) into sulfur dioxide (SO₂). The resulting SO₂ is then carried into a reaction chamber where it is excited by pulsed UV light; subsequent fluorescence emission at 394 nm is detected by a low-noise photomultiplier tube (PMT). This principle delivers inherent selectivity for sulfur, eliminating interferences from carbon-, nitrogen-, or halogen-containing compounds commonly present in refinery, petrochemical, and syngas streams.

Key Features

• Ultra-fast response: Achieves stable measurement output within ≤5 seconds after sample introduction—enabling closed-loop process control and rapid compositional feedback.
• Quantitative sulfur oxidation: Combustion zone operates at >1050 °C with precisely controlled oxygen stoichiometry, ensuring ≥99.9% conversion efficiency of total sulfur to SO₂—validated per ASTM D5453 Annex A1 calibration protocols.
• Intrinsically safe architecture: Certified to ATEX II 2G Ex db IIB T4 Gb and IECEx Ex db IIB T4 Gb for Zone 1 hazardous areas; utilizes compressed air as the sole oxidant—eliminating hydrogen gas handling, storage, and associated safety audits.
• Modular outdoor deployment: Compact footprint (W×D×H: 600 × 500 × 1800 mm) supports direct-mount installation in NEMA 4X-rated outdoor cabinets adjacent to sampling points—minimizing transport line length (<2 m recommended), reducing adsorption losses and lag time.
• Low-maintenance design: No moving parts in the optical path or combustion train; quartz reaction furnace and PMT detector are rated for >20,000 hours of continuous operation under industrial conditions.

Sample Compatibility & Compliance

The UVF analyzer accommodates a broad range of sample types—including natural gas, LNG vapor, naphtha, diesel, jet fuel, coke oven gas, syngas, hydrogen, helium, argon, and food-grade CO₂—without matrix-specific recalibration. It complies with regulatory and industry requirements for sulfur monitoring: EPA Method 1664 (for wastewater extracts), ASTM D7167 (for gasoline), ASTM D7039 (for middle distillates), ISO 8217 (marine fuels), and EN 15940 (paraffinic diesel). Data integrity meets FDA 21 CFR Part 11 criteria when integrated with optional audit-trail-enabled software modules supporting electronic signatures and user-level access controls.

Software & Data Management

The embedded firmware supports Modbus TCP/IP, Profibus DP, and 4–20 mA analog outputs for seamless integration into DCS/SCADA systems. Optional ARUN Analytical Suite v3.2 provides real-time trend visualization, automated calibration scheduling, QC flagging (e.g., drift >2% over 24 h), and CSV/PDF report generation compliant with GLP/GMP documentation standards. All raw spectral data, calibration logs, and system diagnostics are timestamped and stored locally for ≥18 months—facilitating traceability during third-party audits.

Applications

• Petroleum refining: Monitoring sulfur breakthrough in hydrotreater effluents, FCC feedstocks, and finished gasoline/diesel per Tier 3 and Euro 6 specifications.
• Natural gas & LNG: Ensuring pipeline-quality compliance (<4 ppmv) and custody transfer verification at liquefaction terminals and regasification plants.
• Coal and steel industries: Quantifying sulfur in blast furnace top gas, coke oven by-product streams, and desulfurized flue gas for environmental reporting (e.g., EU IED Directive).
• High-purity gas production: Verifying sulfur impurities <0.1 ppb in semiconductor-grade H₂, He, and N₂—critical for epitaxial wafer fabrication.
• Food & beverage: Confirming SO₂ residuals in wine, dried fruits, and packaged meats per Codex Alimentarius STAN 192–1995 limits.

FAQ

What sulfur species does the UVF method detect?
All organosulfur and inorganic sulfur compounds—including mercaptans, sulfides, disulfides, thiophenes, benzothiophenes, dibenzothiophenes, H₂S, SO₂, COS, CS₂, and elemental sulfur—are fully oxidized to SO₂ and measured as total sulfur.
Is carrier gas purity critical for accurate results?
Yes—high-purity synthetic air (≥99.999% O₂-free, hydrocarbon-free) is required for the combustion and carrier gas streams; ARUN supplies certified gas filters and inline purifiers as optional accessories.
Can the analyzer be used for liquid samples without vaporization?
No—liquid samples must be introduced via heated vaporizer (200–350 °C) with precise flow-controlled nebulization; optional liquid autosampler modules support ASTM D7167-compliant injection protocols.
How often is calibration required under continuous operation?
Initial calibration uses certified SO₂ standards (0.1–100 ppmv); drift verification is performed every 8 hours using zero air and span gas—automated by built-in calibration sequencer.
Does the system support remote diagnostics and firmware updates?
Yes—via secure TLS-encrypted Ethernet connection; ARUN’s Remote Support Portal enables real-time health monitoring, predictive maintenance alerts, and over-the-air firmware patches validated per IEC 62443-4-2.