UOP 678-04 PDF

Full title and description

Dissolved Molecular Oxygen in Liquid Hydrocarbons by Electrochemical Detection — UOP 678-04. This UOP test method describes an electrochemical sensor–based procedure for estimating dissolved molecular oxygen in liquid hydrocarbon streams, intended primarily for online process monitoring but also applicable in laboratory measurements. The method defines detection limits, typical interferences and sampling considerations for reliable oxygen determination.

Abstract

This standard specifies the use of an electrochemical detector to measure dissolved molecular oxygen in liquid hydrocarbons. The lower detection limit is 0.1 mass‑ppm; the upper measurable concentration is governed by the solubility of oxygen in the specific hydrocarbon matrix. The procedure notes common gaseous and chemical interferences (for example, carbon dioxide, ammonia, hydrogen sulfide and mercaptans at elevated concentrations) and highlights the importance of appropriate sampling and membrane/sensor maintenance for accurate online or laboratory results.

General information

• Status: Active.
• Publication date: Edition code -04 (2004); last updated / recorded as Jan 1, 2005.
• Publisher: Universal Oil Products (UOP).
• ICS / categories: 71.080; 71.040.40.
• Edition / version: UOP 678‑04 (2004 edition / revision indicated by “-04”).
• Number of pages: 8.

Key bibliographic/details taken from UOP product listings and document catalog entries.

Scope

The scope of UOP 678‑04 covers the estimation of dissolved molecular oxygen in liquid hydrocarbon streams using an electrochemical sensor (membrane‑type) technique. It is intended for continuous (online) process monitoring but may be applied in controlled laboratory sampling. The method provides guidance on detection capability (down to about 0.1 mass‑ppm), expected limitations tied to oxygen solubility in hydrocarbons, and typical chemical interferences that may affect the sensor response; it also addresses the need to tailor the sampling arrangement to the specific process unit.

Key topics and requirements

• Measurement principle: electrochemical (membrane) oxygen sensor for dissolved O2.
• Performance characteristics: lower detection limit ≈ 0.1 mass‑ppm; upper range limited by solubility in sample matrix.
• Sampling: recommendations for process sampling systems and sample conditioning to ensure representative, contamination‑free measurement.
• Interferences and limitations: CO2, NH3, H2S and mercaptans at elevated concentrations (specific threshold levels noted in the method) and materials that contaminate the membrane or react at the sensor electrodes.
• Maintenance and calibration: membrane care, sensor cleaning/replacement, and calibration procedures to ensure reliable online operation.
• Applicability: designed for hydrocarbon streams where dissolved oxygen measurement is needed for process control, corrosion monitoring, and safety management.

Typical use and users

Primary users include process control and instrumentation engineers, refinery and petrochemical laboratory analysts, pipeline and storage operators, and quality assurance teams who require continuous or periodic monitoring of dissolved oxygen for corrosion control, catalyst protection, and process safety. The method is used both for on‑line monitoring points and for laboratory confirmation measurements when appropriate.

Related standards

UOP 678‑04 is part of the UOP suite of test methods for hydrocarbon analyses and process monitoring. Users often reference other UOP methods and industry standards for gas and dissolved species analysis and for sampling system design when integrating oxygen measurement into process control systems. The method appears in published UOP catalogues and standard collections alongside related UOP procedures.

Keywords

dissolved oxygen, liquid hydrocarbons, electrochemical detection, membrane sensor, online monitoring, process sampling, oxygen sensor, interference, detection limit

FAQ

Q: What is this standard?

A: UOP 678‑04 is a test method that specifies an electrochemical (membrane) sensor technique for estimating dissolved molecular oxygen in liquid hydrocarbons, intended primarily for online process measurement and also usable in laboratory settings.

Q: What does it cover?

A: It covers the measurement principle, performance characteristics (including a lower detection limit around 0.1 mass‑ppm), typical interferences, sampling and conditioning recommendations, and maintenance/calibration considerations necessary to obtain accurate dissolved oxygen results in hydrocarbon streams.

Q: Who typically uses it?

A: Refinery and petrochemical process engineers, instrumentation and control specialists, QA/QC laboratory personnel, pipeline and storage operators, and others responsible for corrosion control, catalyst protection and process safety who need reliable dissolved oxygen data.

Q: Is it current or superseded?

A: The method is listed as active in UOP document listings under the designation UOP678‑04, with the edition indicated by “‑04” (2004) and a recorded update entry dated Jan 1, 2005. Users should check the publisher’s catalogue for any later revisions or replacement documents before purchase or implementation.

Q: Is it part of a series?

A: Yes. UOP 678‑04 is part of the broader set of UOP (Universal Oil Products) test methods and standards covering hydrocarbon analysis and process instrumentation; it is commonly listed alongside other numbered UOP procedures in UOP libraries and third‑party document collections.

Q: What are the key keywords?

A: Dissolved oxygen, electrochemical detection, membrane sensor, liquid hydrocarbons, online monitoring, process sampling, oxygen interference, detection limit.