Bitumen Certification using online instrumentation

[serendepidy]

Our refinery is searching for an online automated instrument to measure viscosity of its vacuum residue used for bitumen manufacture. We would preferably measure the viscosity straight off the Vacuum distillation column however the temperature at this measurement point would be around 400 deg C. I am unsure of it's viscosity at this temperature.

Alternatively we are also seeking a similar instrument for tank certification. We would be measuring the viscosity online, automated etc at around 140 deg C and a viscosity of 0.25 - 0.45 PaS.

Does anyone have experience using these types of instruments who may be able to recommend a supplier or could someone provide any information relating to their experiences with online viscometry ?

 

[jmw]

Yes, you can click the link below my name.
Bitumen is a great success story for the tuning fork viscometer which measures the density and viscosity at the operating temperature and then calculates the relevant values at the reference temperatures.

One user in North America claimed it was as good or better than his lab! (not sure just how far we should take this enthusiastic comment but it is certainly very good.)
The unit has been used with bitumen in installations in various countries including the US, the Uk and the Middle east.

These have also been used on road surface dressing vehicles with bitumen emulsions for heater control (though this is, measurement wise, a very simple application).

If installed in a sstem designed for the application they should provide trouble free maintenance free and calibration free operation i.e. virtually 100% onstream factor. Other applications include chalk slurries, PIB at high viscosity and high temperature, polymethyul methacrylate polymerisation end point spotting, quench oil heater control in refineries and many similar "difficult" applications along with easy applications such as residual fuel oil.

JMW

http://www.ViscoAnalyser.com

 

[jmw]

Not only am I having PC problems, the hotel internet service keeps messing with me!

I was going to go on to say:

Online measurement systems based on the 7827 digital viscometer (the sensor is manufactured by Mobrey, now part of Emerson) would comprise a pumped sample loop. This would include a heat exchanger to drop the temperature to 200degC or less. This may seem a problem but if your reference temperature is significantly different to your operating temperature of 400C you will need to do this anyway since the errors in calculation will become excessive otherwise.

You can see some information at

http://www.viscoanalyser.com/refineryapplications.html

and follow the link to systems from that page and visit this page

http://www.viscoanalyser.com/dualviscometer.html

to see a typical system layout.

You will recognise that there is no simple way to measure the viscosity, especially at 400C and you will require a system and to use the commissioning to calibrate the system against yoyur lab instrument (presumably a cone and plate viscometer or similar?).

The options can include rotational viscometers which can handle the temperature but would still need a sample flow stream and great care not to lose the flow or heating.

Tank measurement might seem a good option, especially due to the lower temperature, but there are other problems. You will be making a point measurement which will be vulnerable to a number of effects which would be more noticeable for a high viscosity fluid. It is feasible to use a tank sensor or to use a sensor to measure the flow in and out of the tank.

JMW

http://www.ViscoAnalyser.com