Seven Hills International Limited

Seven Hills Online Mercaptan Analyser


Seven Hills Online Mercaptan Analyser in kerosene / Jet Fuel
Real time Mercaptan Analyser – Coulombometry based


Seven Hills Mercaptan Analyser

Seven Hills Online Mercaptan Analyser is dedicated to continuously monitor the efficiency of your Kerosene treatment Unit.

Our on-line analyser able to measure the quantity of mercaptans in Kerosene with respect to ASTM norm

Increase your performance and cost saving with Seven Hills Online Mercaptan Analyser


Seven Hills Mercaptan Analyser - Measuring Principle

The mercaptan concentration is determined by means of a precipitation of mercaptans sulphide with Ag+ ions.
The Ag+ ions are generated with a coulombmetric method.
The production of Ag+ is controlled during the reaction of oxidation.
The evolution of the reaction is monitored using a potentiometric method with zero
At the balancing point, the number of Ag+ ions is equal to the number of moles of mercaptans.





Seven Hills Mercaptan Analyser – Analysis Area

The analysis unit consist of

Control unit
Analytical Unit
Electrolyte tank
Sensor, pumps, valves and regulators to ensure 24 x 7 smooth functioning of analyser.

Analytical unit comprises of specially build measuring cell, with combination electrodes, silver electrode and platinum electrode

Built in pneumatic agitator to ensure homogenous sample


Seven Hills Mercaptan Analyser – Control and Operation Area

The Analyser is controlled by a programmable logic control unit

Inbuilt MMI allows operators to set and operate the analyser at the local level.

Depending on the location, Service the analyser unit is custom build


MMI Trend display

Users can realise on line trend at their DCS or PLC control system displays using the data supplied by the analyser





Seven Hills Mercaptan Analyser –Application Area of Mercaptan Analyser

Seven Hills Mercaptan Analyser can be installed for measuring the quantity of sulphur in the form of mercaptans in the process. Primarily installed in the refineries at different sections of a kerosene / Jet fuel plant.

This analyser is available in single channel and dual two channels configuration.

In single kerosene plant, it is used in the inlet and outlet to monitor and (or) control it's operation.



Seven Hills Mercaptan Analyser –Repeatability Lab Vs Analyser result

There is an excellent correlation of Seven Hills Online Mercaptan Analyser results with Lab analysis

Seven Hills Online Mercaptan Analyser is able to measure the quantity of mercaptans in Kerosene with respect to ASTM norm.




Unique Characteristics of Seven Hills Mercaptan Analyzer
  • Real time on line measurement of jet fuel to ensure higher regulatory compliance.

  • Use of on line Mercaptan analyzer reduces off spec product and also optimises the kerosene unit operations.

  • The Control System will be able to anticipate the regulation requirements of the Kerosene unit in case of change in input(feed forward).

  • Laboratory sample analysis is reduced to the minimum, at the same time, more samples analysis is done at the unit level.

  • Seven Hills Online Mercaptan Analyser allows plant operators to mix treated and untreated Kerosene with a fine regulation which significantly reduces the cost of operation of the Kerosene Plant

  • The plant can still deliver an optimised final product according to the Jet fuel requirements while mixing the treated and untreated Kerosene.

  • Increases time between 2 maintenance operations and optimizes the planning of these operations.

  • Production without interruption of outlet flow even during maintenance operations of a unit ( in 2 units configuration).


Benefits of Seven Hills Mercaptan Analyzer
  • Real time Online Mercaptan measurement

  • Highly reliable and repeatable Measurement with respect to ASTM norm

  • Highest Reliability & Repeatability

  • Continuous Mercaptan Measurement available at any time

  • Measurement method is same as current Laboratory analytical method

  • Help refiners in optimising their process

  • Significantly reduces the cost of operation of Kerosene plant

  • Easy to operate and simple to maintain






RSH in the kerosene

Number of channels

1 (standard) or 2 (optional)

Range 40 and 300 ppm

Output signal

 0/4 – 20 mA (latched)

Analyser alarm :

Free potential contact

Analysing frequency

User  Programmable

Analyse time

5 mn (approximate)

Repetitive measuring

1 % of full scale

Protection level

ATEX Ex II 2G Ex « pdem» (ia) II C T

Ambient temperature 40°F to 105°F (5°C to 40°C

Electrical supply

230/110 VAC – 50/60 Hz

Power consumption


Air Pressure

Dry air 5/7 bars pressure

Air consumption during purging phase

50 m3/h


10/30 ml / analyse (depending range)

Nitrogen Air supply

N2 : 4/7 bars (ejector + pilot valve)


Minimum pressure

1 bar

Maximum pressure

2 bars

Sample filtered

5 μm


 5 to 40 degrees Celsius
Supporting Systems

Sampling Handling System

Sampling Multiplexing System

Sample Feed Line

Sample Probe

Analyser Shelter

Other accessories based on site conditions