Micro Carbon Residue

The carbon residue of a petroleum crude oil is proportional to the asphalt content, normally measured by Conradson Carbon ASTM D 189. In most cases the lower the carbon residue, the higher the value that can be placed on the crude oil. 

Nitrogen species in crude oils can cause catalyst poisoning. ASTM D 3228 or ASTM D 4629 normally determines nitrogen content. Either a syringe inlet or boat inlet analyzes distillate cuts by Oxidative Combustion and Chemiluminescence detection. Whole crude, atmospheric and vacuum 

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D4207, Sustained burning test by wick method D4530, Micro carbon residue X X X X... 

Note 9—Precision data and Conradson carbon testdite/micro carbon residue coirelation data were generated by a task force in 1983. The round robin involved 18 laboratories, six petroleum materiak in duplicate analysis for both micro method and Test Method D 189 tests. Range of values for samples was from 0.3 % to 26 %. 

The University of Tulsa (Volk et al., 2002) conducted a series of delayed coking tests for various straight-run residues (MCR, micro-carbon residue content from 16 to 29 wt%) in a... 

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. 

In the microcarbon residue test (ASTM D4530, IP 398), a weighed quantity of the sample placed in a glass vial is heated to 500°C (932°F) under an inert (nitrogen) atmosphere in a controlled manner for a specific time and the carbonaceous residue carbon residue (micro)] is reported as a percentage (% w/w) of the original sample. 

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. 

D4S30 Test Method for Determination of Carbon Residue (Micro Method) ... 

Report the value obtained as carbon residue, micro method, to the nearest 0.1 % (m/m). 

XI.1 A correlation (see Fig. 4) has been derived between the carbon residue test by the micro method and the Conradson carbon residue test (Test Method D 189) in a cooperative program involving 18 laboratories and six petroleum materials. 

FIQ. 4 Corralation Of Conradson and Carbon Residue (Micro) Tetto... 

The uncertainties for the analytical methods are as follows ash by combustion residue, 0.3% absolute C, 0.05 mg C H, 0.3% absolute and N, by Dumas, 5 /A or by micro-Kjeldahl, 1 g (18). The large uncertainties in the measurements of carbon and hydrogen limit the usefulness of data for these elements for very small samples. 

Sodium Tantalales.—4 3 Sodium tantalate, 4Na20.8Ta206.25H20, is prepared by fusing tantalum pentoxide with caustic soda in a silver crucible excess of caustic soda is removed by washing with water, and the residue is crystallised from hot water. Another method consists in adding a concentrated solution of sodium chloride to the aqueous extract from a fused mixture of tantalum pentoxide and potassium carbonate, when the salt separates as a dense, micro-crystalline powder. It forms six-sided plates, a c=l 1-0167. It loses most of its water of crystallisation between 105° and 110° C., but the remainder (apparently five molecules) appears to be water of constitution, as its removal takes place only at much higher temperatures, with decom-... 

Quantitation of Napelline.—The pharmacological activity of napelline (35)38 has prompted the development of a method for the quantitation of this alkaloid in raw plant materials.39 This method consists of the extraction of the total alkaloids, chromatographic separation, and a micro-scale acid-base titration of the napelline eluate in a non-aqueous medium. The total alkaloids were exhaustively extracted from a sodium carbonate suspension with chloroform. This extract was concentrated, dissolved in acetone, and chromatographed on silica-gel plates, with a standard reference of napelline as a marker. The appropriate bands were quantitatively removed and extracted, and the extracts were concentrated to dryness. These residues were dissolved in glacial acetic acid and titrated with 0.01N perchloric acid. The standard deviation of this method was 3.39 x 10 3. No limits of detection are reported. 

However, most fuel cell systems can tolerate methane concentrations up to at least 1% in the reformate, no special purification reactions are required. In contrast, hence, removing small residual amounts of carbon monoxide from pre-purifled reformate applying the methanation reaction may be considered as an alternative to the preferential oxidation of carbon monoxide, provided that the CO concentration is low enough to have no significant impact on the hydrogen yield. However, no applications of methanation for CO clean-up in micro structured devices appear to have been reported, hence the issue is not discussed in depth. Finally, during hydrocarbon reforming all hydrocarbon species (saturated and unsaturated) smaller than the feed molecule may be formed. 

Kawahara [156] introduced pentafluorobenzyl esters, prepared by the following procedure. A mixture of four acids (0.8 mg of each) was dissolved in 100 ml of acetone, and 250 mg (25-fold excess) of a-bromo-2,3,4,5,6-pentafluorotoluene and 50 mg (10-fold excess of potassium carbonate were added (it can be replaced with an ethanolic solution of potassium hydroxide). After refluxing for 3 h, the mixture was diluted with 500 ml of diethyl ether and 20 ml of ethyl acetate, washed with 10 ml of water and dried with 8 g of anhydrous sodium sulphate. After filtration, the sulphate and the filter were washed with 50 ml of diethyl ether, the solvent was removed and the residue was dried at 40°C and 50 mmHg it was further dissolved in 100 ml of -hexane and, after an additional 100-fold dilution, 6 /il were injected. The ECD response to pentafluorobenzoate was almost the same as that to aldrin. A method for the preparation of p-substituted benzyl esters of lower monocarboxylic acids on the micro-scale [157] is based on the same reaction scheme. A 10-pl volume of an ethanolic solution of carboxylic acids (ca. 1 pg/pl)... 

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