Organic chloride content in crude oil is an important characteristic of oil quality.
Organic chloride species are potentially damaging agent for refinery processes. Hydrochloric acid can be produced in hydrotreating or reforming reactors and the acid accumulates in condensing regions of the refinery. Unexpected concentrations of organic chlorides cannot be effectively neutralized and damage can result.
Organic chlorides determination in petroleum and petroleum products
There are three methods of organic chlorides determination: method covers the determination of organic chloride in the washed naphtha fraction of crude oil by sodium biphenyl reduction followed by potentiometric filtration; another method – by oxidative combustion followed by microculonometric titration, and thirth method – X-ray fluorescence analysis.
All methods include sampling, naphtha distillation at 204 oC, naphtha washing from hydrogen sulfide and non-organic chlorides.
XRFA method has some advantages:
Internal standard (5000 ppm Bismuth solution in non-polar solvent) is mixed with washed naphtha fraction.
Two sample cups are filled with the mixture, covered with film and measured in a spectrometer.
Mass content of organic chlorides is determined with a preliminary obtained calibration equation.
All methods include sampling, naphtha distillation at 204 oC, naphtha washing from hydrogen sulfide and non-organic chlorides.
XRFA method has some advantages:
- no interfering factors;
- minimal consumables required;
- minimal influence of human factor;
- the time for concurrent samples analysis is about 15 minutes.
Internal standard (5000 ppm Bismuth solution in non-polar solvent) is mixed with washed naphtha fraction.
Two sample cups are filled with the mixture, covered with film and measured in a spectrometer.
Mass content of organic chlorides is determined with a preliminary obtained calibration equation.
