KY-0231 H₂S Content Analyzer for Liquefied Petroleum Gas (LPG) – Lead Acetate Chromatographic Method

Overview

The KY-0231 H₂S Content Analyzer for Liquefied Petroleum Gas (LPG) is a dedicated chromatographic gas analyzer engineered for quantitative determination of hydrogen sulfide (H₂S) in hydrocarbon fuel streams—specifically liquefied petroleum gas—using the standardized lead acetate impregnated silica gel column method. This instrument operates on the principle of selective chemical reaction chromatography: gaseous LPG samples are drawn at controlled flow rates through a calibrated glass reaction tube packed with coarse-pore silica gel pre-impregnated with lead(II) acetate. Upon contact, H₂S reacts stoichiometrically with Pb(CH₃COO)₂ to form insoluble black lead sulfide (PbS), resulting in a visible, sharply defined chromogenic band along the silica gel bed. The length (or volume) of the stained zone is directly proportional to the mass of H₂S introduced, enabling gravimetric quantification when combined with precisely measured sample volume data from the integrated wet gas meter. Designed in strict compliance with SH/T 0231—China’s petroleum industry standard equivalent in technical scope and procedural rigor to ASTM D4084 and ISO 8573-7 for trace sulfur compound detection—the KY-0231 delivers reproducible, field-deployable results without requiring carrier gases, detectors, or complex electronics.

Key Features

• Calibrated glass reaction tube with uniform packing density and documented void volume for consistent breakthrough length measurement
• Integrated 2-liter wet gas meter with temperature and pressure compensation capability (manual reading, ±1% full-scale accuracy)
• Stainless steel hollow sampling needle (φ1 mm OD × 0.2 mm ID) ensuring precise, low-dead-volume gas introduction and resistance to H₂S-induced corrosion
• Precision stainless steel needle valve enabling fine-tuned, stable flow regulation between 50–500 mL/min—critical for maintaining laminar flow and minimizing axial dispersion in the reaction column
• Corrosion-resistant sampling assembly constructed from fluoropolymer-lined stainless steel and perfluoroelastomer (FFKM) seals, compatible with saturated LPG vapor and trace acidic components
• Modular, benchtop design with rigid aluminum alloy frame and heat-strengthened borosilicate glass components for long-term dimensional stability under ambient laboratory conditions

Sample Compatibility & Compliance

The KY-0231 is validated for use with commercial-grade LPG mixtures containing propane, butane, and minor C₂/C₅ hydrocarbons, including those with up to 5 vol% propylene. It accommodates both vapor-phase and liquid-phase sampling modes (with appropriate vaporization control). Interference testing confirms negligible response to COS, mercaptans, and elemental sulfur under SH/T 0231-defined operating conditions. Instrument validation documentation supports GLP-compliant operation, and analytical procedures align with QA/QC requirements for refinery off-gas monitoring and custody transfer verification. While not intrinsically safe, the system may be operated in Class I, Division 2 environments when installed with proper ventilation and grounding per NFPA 58 and GB 50160.

Software & Data Management

The KY-0231 is a manually operated, analog measurement system with no embedded firmware or digital interface. All calculations—including H₂S concentration (mg/m³), mass loading (µg), and breakthrough front position—are performed using standardized worksheets derived directly from SH/T 0231 Annex A. Laboratory information management systems (LIMS) integration is achieved via manual entry or optional barcode-scanned worksheet templates compliant with ISO/IEC 17025 documentation traceability requirements. Audit trails for calibration records, column preparation logs, and operator sign-offs are maintained externally in accordance with GMP-relevant record retention policies (minimum 5 years).

Applications

• Refinery LPG desulfurization unit performance monitoring and amine absorber efficiency assessment
• Custody transfer verification prior to pipeline injection or marine loading
• Quality assurance testing for LPG used in petrochemical feedstock applications where H₂S-induced catalyst poisoning must be avoided
• Field-based compliance screening against national emission limits (e.g., China’s GB 17820-2018 Class II ≤20 mg/m³)
• Method validation reference for laboratories deploying GC-SCD or UV fluorescence analyzers

FAQ

What is the minimum detectable H₂S concentration using the KY-0231?
The lower limit of quantitation (LLOQ) is 5 mg/m³, determined by the smallest measurable chromogenic zone (≥2 mm) under optimized flow and humidity conditions.
Can the KY-0231 be used for natural gas or refinery fuel gas analysis?
Yes—provided the sample matrix contains <10% C₁–C₄ hydrocarbons and total sulfur compounds other than H₂S do not exceed 50 mg/m³; validation per SH/T 0231 Section 6 is required.
How often must the lead acetate silica gel column be replaced?
Column lifetime depends on cumulative H₂S exposure; typical service life is 20–30 analyses at ≤100 mg/m³ or 5–10 analyses above 300 mg/m³. Visual inspection for complete blackening beyond the 80% column length indicates exhaustion.
Is temperature control required during analysis?
Ambient temperature must be maintained between 15–30°C; deviations outside this range require correction factors for gas volume calculation as specified in SH/T 0231 Clause 7.3.
Does the instrument meet FDA 21 CFR Part 11 requirements?
No—since the KY-0231 generates no electronic records, it falls outside the regulatory scope of Part 11; paper-based records must follow ALCOA+ principles for data integrity.