Method and apparatus for quantitative determination of components in residual fuel oils

A method of determining a content of asphaltene in a residual fuel oil, the method comprising the steps of:

• (a) measuring absorbances of a sample solution having an aliphatic hydrocarbon insoluble matter suspended in the sample solution at two spaced wavelengths of light in a wavelength range from 500 nm to 1,000 nm;
• and
• (b) performing an operation to determine the content of the asphaltene in the sample solution by inserting the measured absorbances (K.sub.3 and K.sub.4 ) into one of two correlations:
• the content of asphaltene={a(bK.sub.3 -cK.sub.4)}'100/{d((K.sub.4 -K.sub.3).times.100/K.sub.3)+e}.times.{f((K.sub.4 -K.sub.3).times.100/K.sub.3)+g}/100
• where a is 0.015 to 0.035;
• b is 1 to 10;
• c is 0.5 to 7;
• d is -10 to -0.1;
• e is 50 to 300;
• f is 1 to 30;
• and g is -5 to 5;
• or
• the content of asphaltene={a(bK.sub.3 -cK.sub.4)}.times.100/{d(K.sub.4 .times.100/K.sub.3)+e}.times.{f(K.sub.4 .times.100/K.sub.3)+g}/100
• where a is 0.015 to 0.035;
• b is 1 to 10;
• c is 0.5 to 7;
• d is -800 to -500;
• e is 500 to 1,000;
• f is 450 to 550;
• and g is -600 to -300.

An apparatus for determining a content of an aliphatic hydrocarbon insoluble matter in a residual fuel oil, the apparatus comprising:

• a container for containing a sample solution which has an aliphatic hydrocarbon insoluble matter suspended in the sample solution;
• a measuring device for measuring absorbances of the sample solution by transmitting light at two spaced wavelengths in a wavelength range from 500 to 1,000 nm to the sample solution and for outputting electric signal in accordance with the measured absorbances;
• and
• a calculator for calculating the content of the aliphatic hydrocarbon insoluble matter from the electric signals, the calculator performing an operation with one of two correlations:
• the content of the aliphatic hydrocarbon insoluble matter={a(bK.sub.3 -cK.sub.4)}.times.100/{d((K.sub.4 -K.sub.3).times.100/K.sub.3)+e}
• where a is 0.015 to 0.035;
• b is 1 to 10;
• c is 0.5 to 7;
• d is -10 to -0.1;
• e is 50 to 300;
• and K.sub.3 and K.sub.4 are the absorbances at the two spaced wavelengths;
• or
• the content of the aliphatic hydrocarbon insoluble matter={a(bK.sub.3 -cK.sub.4)}.times.100/{d(K.sub.4 .times.100/K.sub.3)+e}
• where a is 0.015 to 0.035;
• b is 1 to 10;
• c is 0.5 to 7;
• d is -800 to -500;
• e is 500 to 1,000;
• and K.sub.3 and K.sub.4 are the absorbances at the two spaced wavelengths.

An apparatus for determining a content of asphaltene in a residual fuel oil, the apparatus comprising:

• a container for containing a sample solution which has an aliphatic hydrocarbon insoluble matter suspended in the sample solution;
• a measuring device for measuring absorbances of sample solution by transmitting light at two spaced wavelengths in a wavelength range from 500 to 1,000 nm to the sample solution and for outputting electric signal in accordance with the measured absorbances;
• and
• a calculator for calculating the content of the asphaltene from the electric signal, the calculator performing an operation with one of two correlations:
• the content of asphaltene={a(bK.sub.3 -cK.sub.4)}.times.100/{d((K.sub.4 -K.sub.3).times.100/ K.sub.3)+e}.times.{f((K.sub.4 -K.sub.3).times.100/K.sub.3)+g}/100
• where a is 0.015 to 0.035;
• b is 1 to 10;
• c is 0.5 to 7;
• d is -10 to -0.1;
• e is 50 to 300;
• f is 1 to 30;
• g is -5 to 5;
• and K.sub.3 and K.sub.4 are the absorbances at the two selected wavelengths;
• or
• the content of asphaltene={a(bK.sub.3 -cK.sub.4)}.times.100/{d(K.sub.4 .times.100/K.sub.3)+e}.times.{f(K.sub.4 .times.100/K.sub.3)+g}/100
• where a is 0.015 to 0.035;
• b is 1 to 10;
• c is 0.5 to 7;
• d is -800 to -500;
• e is 500 to 1,000;
• f is 450 to 550;
• g is -600 to -300;
• and K.sub.3 and K.sub.4 are the absorbances at the two selected wavelengths.