Ramsbottom carbon test

Feed residue coke is the small portion of the (non-residue) feed that is directly deposited on the catalyst. This coke comes from the very heavy fraction of the feed and its yield is predicted by the Conradson or Ramsbottom carbon tests. 

Coke number used, particularly in Great Britain, to report the results of the Ramsbottom carbon residue test (q.v.), which is also referred to as a coke test. 

Ramsbottom coke test. A laboratory test for carbon residue in petroleum products. 

Tests for Conradson carbon residue (ASTM D-189, IP 13), Ramsbottom carbon residue (ASTM D-524, IP 14), the microcarbon carbon residue (ASTM D4530, IP 398), and asphaltene content (ASTM D-893, ASTM D-2006, ASTM D-2007, ASTM D-3279, ASTM D-4124, ASTM D-6560, IP 143) are sometimes included in inspection data on petroleum. The data give an indication of the amount of coke that will be formed during thermal processes as well as an indication of the amount of high-boiling constituents in petroleum. 

In the Ramsbottom carbon residue test (ASTM Test Method D524, IP 14), the sample is weighed into a glass bulb that has a capillary opening and... 

Thus the tests for the Conradson carbon residue (ASTM D-189, IP 13), the Ramsbottom carbon residue (ASTM D-524, IP 14), and the microcar-bon carbon residue (ASTM D4530, IP 398) are often included in inspection data for fuel oil. 

In the Ramsbottom carbon residue test (ASTM D-524, IP 14), the sample is weighed into a glass bulb that has a capillary opening and is placed into a furnace (at 550°C/1022°F). The volatile matter is distilled from the bulb, and the nonvolatile matter that remains in the bulb cracks to form thermal coke. After a specified heating period, the bulb is removed from the bath, cooled in a desiccator, and weighed to report the residue (Ramsbottom carbon residue) as a percentage (% w/w) of the original sample. 

Values obtained by the method of Ramsbottom Carbon Residue are not numerically the same as those obtained by ASTM Method D524, or Test for Ramsbottom Carbon Residue of Petroleum Products nor have satisfactory correlations been found between the results of the two methods for all materials which may be tested, because the carbon residue test is applied to a wide variety of petroleum products. 

Carbon Residue—amount left after evaporation and pyrolysis to provide some indication of relative coke-forming propensity (ASTM Test Method D189, Conradson Carbon Residue of Petroleum Products, ASTM Test Method D524, Ramsbottom Carbon Residue of Petroleum Products, or ASTM Test Method D4530, Determination of Carbon Residue (Micro Method)), ASTM Method D4530 having gained wide acceptance. 

D 524 Test Method for Ramsbottom Carbon Readue of Petroleum Products ... 

The Conradson carbon residue (CCR) results from ASTM test D189. It measures the coke-forming tendencies of oil. It is determined by destructive distillation of a sample to elemental carbon (coke residue), in the absence of air, expressed as the weight percentage of the original sample. A related measure of the carbon residue is called Ramsbottom carbon residue. A crude oil with a high CCR has a low value as a refinery feedstock. 

The Ramsbottom test (ASTM D-524) is also used to measure carbon residue. The test calls for introducing 4 grams of sample into a preweighed glass bulb, then inserting the bulb in a heated bath for 20 minutes. The bath temperature is maintained at 1,027°F (553°C). Af 20 minutes, the sample bulb is cooled and reweighed. Compared with the Conradson test, Ramsbottom is more precise and reproducible. 

Carbon residue the amount of carbonaceous residue remaining after thermal decomposition of petroleum, a petroleum fraction, or a petroleum product in a limited amount of air also called the coke- or carbon-forming propensity, often prefixed by the terms Conradson or Ramsbottom in reference to the inventor of the respective tests. 

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