Apparatus and Method for Measuring the Properties of Petroleum Factions and Pure Hydrocarbon Liquids by Light Refraction

An apparatus for measuring the chemical, performance, perceptual or physical properties of a hydrocarbon sample which comprises at least on of the following properties:

• the API gravity at 15° C.,
• the specific gravity,
• the density at 20° C.,
• the average boiling point,
• the Watson characterization factor,
• the molecular weight,
• the critical volume,
• the Reid vapor pressure,
• the kinematic viscosity at 37.8° C. and 98.9° C.,
• the true critical temperature,
• the pseudocritical temperature,
• the true critical pressure,
• the pseudocritical pressure,
• the acentric factor,
• the net heat of combustion at 25° C.,
• the isobaric liquid heat capacity at 15.6° C.,
• the isobaric vapor heat capacity at 15.6° C.,
• the liquid thermal conductivity at 25° C.,
• the research octane number,
• the motor octane numbers,
• the heat of Vaporization at the Normal Boiling Point,’
• the carbon to hydrogen content,
• the true vapor pressure,
• the flash point,
• the freezing point,
• the surface tension of the liquid,
• the aniline point,
• the cloud point,
• the critical compressibility factor,
• the solubility parameter, and
• the compositional analysis for paraffins, napthenes, aromatics, sulfur, mono-aromatics, poly-aromatics;
• which comprises:
• a) placing said hydrocarbon sample in a refractive index apparatus;
• analyzing a of said sample by refractometry, under suitable and repeatable conditions, to determine the refractive index of the of said hydrocarbon in the refractive index apparatus;
• b) determining the API gravity of the hydrocarbon sample by calculation form the first set of data of step (a) or by analyzing the hydrocarbon sample by a suitable method, under suitable and repeatable conditions;
• c) applying at least the first set of data of step(a) or by analyzing the hydrocarbon sample by a suitable method, under suitable and repeatable conditions to determine the average boiling point of the hydrocarbon sample;
• d) inputting the values of a least one set of data from the first set of data of step (a), the second set of data of step (b), and the third set of data of step (c) into a computational model;
• e) applying a computational method to said sets of data of step (d) comprising a mathematical model wherein the computation method further performs a correlation between the amounts of the detected values of said sets of data to the properties of the hydrocarbon;
• and
• g) determining the physical and chemical property that is derived from the hydrocarbon as a function of that least the refractive index of its components in-situ or in real time.