METHOD FOR ASSESSMENT OF STABILITY OF LOW-TEMPERATURE PUMPABILITY OF FUEL OIL Russian patent published in 2021 - IPC G01N33/22 G01N11/02 C10G47/00 

FIELD: technological processes.

SUBSTANCE: invention relates to methods of controlling fuel quality, in particular, to control of stability of low-temperature pumping ability of fuel oil. Invention relates to a method for assessment of stability of pour point of fuel oil, which includes heating of fuel oil sample to 373 K, cooling to 295 ± 2 K and holding at this temperature with aliquot collection through time intervals (τ_i) 1 day and 7 days. Heated to 373 K sample of fuel oil in volume of 250 ml is thermostatically controlled in sealed conditions for 2 hours with fixation of the temperature-controlled termination time, and from cooled to 295 ± 2 K aliquots are taken in addition to the selected aliquots in 1 day and 7 days after 10 and 14 days, each of which is heated to 323 ± 3 K and cooled at a rate of (υ) 0.53 ± 0.05 K/min to achieve effective viscosity of 10.0 ± 0.1 Pa⋅with fixation of effective viscosity values (μ) and temperature (T) through every 5–6 minutes of cooling, from which value of activation energy of viscous flow E_i(υ) of each aliquot by formula:

where E_i(υ) is viscous flow activation energy, kJ/mol; i is an aliquot number; R is universal gas constant (8.314 J/mol⋅K); ln is the natural logarithm; μ is effective viscosity, Pa⋅with; T is temperature, K, plotting E_i(υ) of temperature values (T_i) obtained during recording of effective viscosity, from which the maximum value E_i(υ)_max, graphic dependence E_i is plotted (υ)_max from each sampling time interval (τ_i) a given aliquot, from which the rate of change of activation energy is determined, which is adopted as a criterion of stability of low-temperature pumping ability of fuel oil, and at value K_r ≤ 0.346 kJ/(mol⋅day) make a conclusion on stability of low-temperature pumpability of analyzed fleet fuel oil.

EFFECT: higher reliability of evaluating stability of low-temperature pumping capacity of fuel oil while reducing duration and labor input of testing fuel.

1 cl, 3 dwg, 4 tbl, 1 ex