Ramsbottom

J. E. Ramsbottom, Fire Proofng of Fabrics, His Majesty s Stationary Office, London, 1947. 

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. 

Figure 2-6. Ramsbottom Carbon Residue versus Conradson Carbon Residue. (Copyright ASTM D-524. Reprinted with permission.)...

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. 

Ramsbottom, similar to Conradson Carbon, is a quantitative indication of carbon residue of a sample. 

As work began on the process, it quickly became apparent that the extraordinary catalyst properties required for the process were not then available, and even with a superior catalyst, consumption would undoubtedly be severe. Figure 3 shows how Ramsbottom Carbon and nickel plus vanadium vary in the same reduced crude oils. All levels are very high far beyond anything normally encountered in a gas oil feedstock. 

Because of the high coke-forming tendencies of reduced crude, mainly due to a high concentration of Ramsbottom Carbon, the adverse effects of nickel appear to be somewhat moderated in the trip up the riser. Therefore, nickel does not appear to be quite as harmful as first anticipated. 

RCC process catalysts with metals contents as high as 12,300 ppm nickel plus vanadium, plus 6,000 ppm of iron, have operated in the 200 B/D demonstration unit on feedstocks containing up to 84 ppm nickel plus vanadium.(4,5) Presently in our refinery, when metals levels are at still higher levels, the reduced crude is first processed in the Ashland ART unit, where some 85-95% of the metals and 75% of the Ramsbottom Carbon are removed.(6)... 

Two schools of thought still abide on this unresolved issue. The RCC unit operates with a significant partial pressure, gives rather low coke yields in relationship to Ramsbottom Carbon in the feed, and makes an unusually high research octane.(5)... 

G. HIGH CARBON VALUES FOR MICRO METHOD, CONRADSON, AND RAMSBOTTOM CARBON NUMBER DETERMINATIONS... 

The following information can be obtained from Micro Method, Conradson and Ramsbottom carbon values ... 

Residuum type 1000T (LV Gravity CAPI) Sulfur (wi. %) Nitrogen (wt. %) Ramsbottom carbon (wl. %) Metals (ppm) ... 

There are two older well-used methods for determining the carbon residue the Conradson method (ASTM D-189) and the Ramsbottom method (ASTM D-524). Both are equally applicable to the high-boiling fractions of crude oils that decompose to volatile material and coke when distilled at a pressure of 1 atm. Heavy oils and residua which contain metallic constituents (and distillation... 

Because of the extremely small values of carbon residue obtained by the Conradson and Ramsbottom methods when applied to the lighter distillate fuel oils, it is customary to distill such products to 10% residual oil and determine the carbon residue thereof. Such values may be used directly in comparing fuel oils, as long as it is kept in mind that the values are carbon residues on 10% residual oil and are not to be compared with straight carbon residues. 

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