Patent ID: 6076961
Filing Date: 2000-06-20
Classification: G01N

Abstract:
A process for determining temperature stability of a hydrocarbon mixture liable to undergo phase separation, which comprises:a) in a first step, subjecting the mixture at ambient temperature, to accelerated cooling, either by quenching or by gradually decreasing the temperature at a rate of between about 10 and 0.05.degree. C./min., until the mixture has reached a predetermined temperature, and, continuously measuring loss of apparent weight (W) of a gravimetric detector b thermogravimetric analysis wherein a portion of the detector is immersed in the mixture, thenb) in a second step, maintaining the mixture at this temperature while continuously measuring an increase in apparent weight of the detector and simultaneously recording a curve of variation of the weight as a function of time, thenc) collecting the mass of solid and determining the rate of separation of the two phases from the curve of variation by determining, from the slope of this curve, an initial rate at break point corresponding to a substantial and continuous increase in the apparent weight W during step b), andd) determining the stability of the sample of the mixture by comparing the variations in weight and the initial rate with those of reference hydrocarbon mixtures, the low-temperature stability monitored over time between about 0 and -30.degree. C.