Conradson Coke Residue

Conradson coke residue in the non-distillable part of the sample... 

Sample No. Softening Point R B Cc) Penetration at 25 °C (0.1 mm) Viscosity at50°C atl00°C (mmVs) (mmVs) Conradson Coke Residue (% wt)... 

The / 800 is always smaller than the Conradson coke residue CCR (DIN 51 551). A linear dependence exists ... 

The Conradson coke residue CCR of samples 6, 7,10, and 11 is within the limits of the other samples of this group. The corresponding temperatures with values of... 

The data for the residue at the temperature clearly exceed the corresponding data of / 800. On the other hand the values are comparable to the corresponding Conradson coke residues The same is valid if the temperature is ascertained from the TGA... 

Thus the equivalence of and as well as of and G has been proved. The statistical evaluation of results in a mean x = 585.9 X with a coefficient of variaton +V= 14.34 %. It is well known, that measurement of the Conradson coke residue exhibits a large scattering. DIN 51 551 speaks of a repeatability of 10 % and a reproducibility of 15 % of the values. 

The Conradson coke residue in the non-distillable part of the samples (CCR/ND) 100 is in the limits from 23 to 33 % for vacuum residues, bitumens, and atmospheric residues. The statistics result in a mean x = 27.3 % and a coefficient of variation V = 9.6 % (relative). The products from conversion processes scatter from 33 to 58 %. The furfural extract (sample 24) stands out because it does not possess any coke residue. 

Conradson coke residue in the simulated vacuum residue (%) residue at 800 °C in the simulated vacuum residue (%) residue in the extrapolated point of inflexion of the TGA curve in the simulated vacuum residue (%)... 

The Conradson coke residue in the simulated vacuum residue ((CCR/SVR) 100) for the vacuum residues and bitumens has a mean value x2l.6%( y= 7.01% relative). For the atmospheric residues the mean amounts to x = 13.8 % ( + y = 8.7 % relative). The products from conversion processes (samples 19, 20, and 22) have extremely high values demonstrating that they have been distilled exhaustively, whereas the distillate of the residue of a cat-cracker, sample 25, exhibits the extremely low value of 4.4 %. 

Residue at the end of experiment, with the Conradson coke residue, CCR ... 

Correlation of the Conradson coke residue or R800 with the non-distillable part of the samples does not give significant results, nor does correlation of the reaction rate with the average molecular weight. 

The relation of the different index numbers characterizing the coke residue to the simulated vacuum residue, SVR, does give useful results. The relation of the Conradson coke residue CCR to SVR results in ratios between 10.0 and 23.4 for vacuum residues and bitumens to ratios from 12.2 to 14.8 for atmospheric residues and the ratio for residues from conversion processes gives values of over 27 up to 43. 

The fact that the formation of coke is not complete at 600 °C in every case, has already been proved by other means. This is confirmed by comparing the data of / 600 and i 800, with the mean of the colloid component, but this calls in question to a certain extent the importance of the values of the Conradson coke residue. 

The Micro-method uses an analytical instrument to measure Conradson carbon in a small automated set. The Micro-method (ASTM D4530) gives test results that are equivalent to the Conradson carbon residue test (D189). The purpose of this test is to provide some indication of relative coke forming tendency of such mat al. 

Hydroprocessing reduces the Conradson carbon residue of heavy oils. Conradson carbon residue becomes coke in the FCC reactor. This excess coke must be burned in the regenerator, increasing regenerator air requirements. 

The third type is the additional coke related with the feedstock quality. FCC feedstock contains a dissolved carbon, polynuclear aromatic compounds, called Conradson carbon residue (CCR ASTM D-189). It is deposited over the catalyst surface during cracking reactions. In the FCC unit, this material is part of the coke remaining in the catalyst. Some researchers have investigated cracking of heavy feedstock and observed that, in particular cases, the amount of Conradson carbon is linearly related with the carbon-hydrogen ratio of the feedstock [3]. 

Coking processes have the virtue of eliminating the residue fraction of the feed, at the cost of forming a solid carbonaceous product. The yield of coke in a given coking process tends to be proportional to the carbon residue content of the feed (measured as the Conradson carbon residue see Chapter 2). The data (Table 7-11) illustrate how the yield of coke from delayed and fluid coking varies with Conradson carbon residue of the feed. 

Thermal coke the carbonaceous residue formed as a result of a noncatalytic thermal process the Conradson carbon residue the Ramsbottom carbon residue. 

Figure 7 summarizes the main relations, which determine the effect of coke on deactivation. Note that a poor coke selectivity (or low cat-to-oil ratio) will aggravate the poisoning effect of the fraction of the Conradson Carbon Residue which is converted to coke. 

While originally designed for cracking the overhead stream from vacuum distillation units, known as vacuum gas oil (4), most FCC units currently operate with some higher boiling vacuum distillation bottoms (Resid) in the feed. Table 5.1 illustrates the difficult challenges faced by refiners, process licensors and FCC catalysts producers the resid feeds are heavier (lower API gravity), contain many more metals like Ni and V as well as more polyaromatic hydrocarbons prone to form coke on the catalysts (Conradson Carbon Residue, or CCR). 

In resid cracking the high feed metals and Conradson Carbon Residue (CCR) require careful consideration when assessing both catalyst design and performance evaluation. This paper addresses the issues of the latter with respect to coke, delta coke and catalyst deactivation. 

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. 

The data produced by the nucrocarbon test (ASTM D4530, IP 398) are equivalent to those by the Conradson carbon residue method (ASTM D-189 IP 13). However, this nucrocarbon test method offers better control of test conditions and requires a smaller sample. Up to 12 samples can be run simultaneously. This test method is applicable to petroleum and to petroleum products that partially decompose on distillation at atmospheric pressure and is applicable to a variety of samples that generate a range of yields (0.01% w/w to 30% w/w) of thermal coke. 

Other test methods that are used for determining the coking value of tar and pitch (ASTM D-2416, ASTM D-4715), which indicates the relative coke-forming properties of tars and pitches, might also be applied to asphalt. Both test methods are applicable to tar and pitch with an ash content <0.5% (ASTM D-2415). The former test method (ASTM D-2416) gives results close to those obtained by the Conradson carbon residue test (ASTM D-189, IP 13). However, in the latter test method (ASTM D-4715), a sample is heated for a specified time at 550 10°C (1022 18°F) in an electric furnace. The percentage of residue is reported as the coking value. 

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