GB1500401A - Process for the formation of pumpable slurries from waxy hydrocarbon mixtures - Google Patents

Abstract

1500401 Pumpable waxy hydrocarbon slurries MARATHON OIL CO 25 April 1975 [17 June 1974] 17302/75 Heading C5E A pumpable slurry is produced from a waxcontaining hydrocarbon mixture by separating the mixture into at least two fractions, viz: a liquid low pour point fraction and a high pour point fraction, the latter containing the major proportion of the wax, introducing at least a portion of the high pour point fraction as a stream of discrete liquid droplets into a column of liquid having a density greater than the high pour point fraction, allowing the droplets to rise through the column to solidify therein, recovering the solidified particles from the top of the column and redispersing the solidified particles in a hydrocarbon carrier liquid comprising at least some of the low pour point fraction at a temperature below the solution temperature of the particles therein to form the slurry, the column of liquid comprising a first body of liquid at the bottom of the column into which the high pour point fraction is introduced which is maintained at a temperature above the pour point of the high pour point fraction, and a second body of liquid having a density less than that of the first body of liquid and positioned in the column above the first body and maintained below the melting point of the high pour point fraction to effect the solidification of the droplets as they pass therethrough. The waxy hydrocarbon mixture may contain 1-80% by weight of wax. Wax is defined as the precipitate which forms after one part by weight of the hydrocarbon mixture is dissolved in 10 parts by weight of methyl ethyl ketone at 80‹ C. and the mixture cooled to -25‹ C. The first body of liquid preferably has a temperature below that of the high pour point fraction, suitably at least 140‹ F., and the colder less dense liquid may be at ambient temperature. The difference in density between the two liquids may be at least 0À2 g./c.c. The coolants may be halogenated hydrocarbons but are preferably water containing water soluble agents imparting increased density, e.g. potassium alum, potassium metaphosphate, aluminium acetate or strontium fluoride. A surfactant, e.g. sorbitan monolaurate or a petroleum sulphonate may be added to the molten wax. A liquid and/or gaseous diluent may be admixed with the liquid hydrocarbon carrier before, during or after the slurrying operation. The final slurry may contain 1-60% by weight of the wax particles.