Extraction and Refining of Slack Wax from Residual Fuel Oil from Tema Oil Refinery to Produce Petroleum Wax (Paraffin Wax) for Industrial Application

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
Residual fuel oil from Tema oil refinery was fractionally distilled under reduced pressure of 0.001 maHg and two fractions with boiling points range 32-33oC and 33-42oC was collected. The distillates were subjected to urea dewaxing process. The urea adduct was separated into semi-solid hydrocarbon phase (alack wax) and an aqueous urea phase. An appreciable quantity of the slack wax was isplated from the distillate by solvent dewaxing technique using methyl ethylhetone (MIX) – toluene mixture (4:1 v/v). The slack wax was then deoiled using the same solvent system. The deoiled crude wax was subjected to various methods of purification or refinement. The sun bleaching method (as suggested by Root) (36) caused virtually no change in the colour. The wax was, however, successful refined by contact filtration and percolation techniques using carbon tetrachloride, xylane and benzene as solvents. The acid-fuller’s earth’s contact filtration method changed the original pale brown colour to pale yellow with a yield of 47.2%. The wax was, however, balance to white by separately percolating through bauxite, activated charcoal and fuller’s earth. The yield ranged from 75 to 81%.The physiochemical characteristics of the leaches waxes were determined by (ASTN D87); drop melting point (ASTN D127) and congealing point (ASTN D938) methods. The values obtained for the waxes bleached by the different methods differ slightly and ranged from 61-640C; 61.5-64.50C, 60.9-63.9 respectively. The oil content of the wax was determined by ASTN D72 method and the value for the bleached waxes were calculated and found to range from (0.282-0.469). Test for carbonizable substances was carried out on the bleached waxes using D612 method and were found to pass the carbonizable test. The specific gravity was determined by floating wax method and by Archimedes principles employing a sinker. The values for the various waxes ranged from (0.899-0.915; 0.897-0.914) for the above methods respectively. The refractive index was determined on the molten or liquid form of the wax at 800C using Abbe’s Refractometer. The readings ranged from 1.4281-1.4285 for the waxes bleached by the various methods.The molecular weight was determined for all the bleached waxes by means of cryoscopic (freezing point depression) method, - Rest method. The values ranges from (392.85 – 401.0), average being 396.9 g per mole. The physiocochemical property compare better with those of paraffin wax than those of microcrystalline wax.
A thesis in partial fulfillment of the requirement for the M.Sc Degree (Industrial Chemistry) of the University of Science and Technology, Kumasi Ghana. 1991