Nitration time

The original temperature of the mixture of acids also exerts its influence on the period of nitrating the lower it is the sooner the glycerine can be introduced into the nitrator. In winter, nitration takes less time due to this factor. 

In nitrators equipped with mechanical stirrers, as used in the U.S.A., 500 kg of glycerine are nitrated in 50 min. 

For several minutes after the nitrator has been fully charged, stirring is discontinued and then either the whole is allowed to remain in the nitrator which in this stage plays the part of separator, or it is transferred to a special separating funnel. In continuous production the mixture flows into the separator continuously. 

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Methylol-2-Butanone Mononitrate /3-Methyl-7-ketobutanol mononitrate). CH3.C0.CH(CH20N02).CH3, mw 147.13, N 9.52% (theory), 8.20% found OB to C02 -114.18% liq. Prepd by hitrating methylol-butanone with mixed acid (HN03 25.3, H2 S04 59.6 w 15.1%). The total nitration time was 1 hour at about —5°, and the yield was 54% of product contg 8.20% N. Although the product was carefully purified to be acid-free, it underwent decompn when allowed to stand for several days at RT (Ref 4)... 

In the pilot plant procedure, 50kg of finely powdered metriol was fed thru an endless screw (dosierschnecke) to a nitiator provided with cooling coils and an agitator, contg 175kg of mixed acid (65/35 nitric-sulfuric). The nitration time was about 20 minutes at 20°. 

An important aspect of nitrating toluene to nitrotoluene is the very low solubility of toluene and nitroioluenes in nitrating mix Is. Therefore the nitration proceeds in a two-phase system and the rate of nitration depends greatly on dispersion, which in turn depends on keeping the two phases efficiently stirred. This is emphasized in Fig 4, which gives the yield of MNT for a 11/64/25% nitric acid/sulfuric acid/water MA and a nitration time of 30 minutes as a function of stirring speed... 

Fig 5 shows the yield of MNT as a function of acid/toluene ratio for a MA of 27/55/18% nitric acid/sulfuric acid/water and a nitration time of 50 minutes at 30°... 

Effective temp control is an absolute necessity. Small scale nitration can be carried out at temps as high as 40°, but NG yield is reduced at these temps. Low temps favor yield but increase nitration time. In the older methods, temps in the 15-25° range are usually maintained... 

A nitrogen content of about 5.7% N can be attained after 1 hr on treating 5 parts of cellulose with 60 parts of dinitrogen tetroxide dissolved in 60 parts of carbon tetrachloride, mixed with 7 parts of anhydrous nitric acid. The relationship between the nitration time under the conditions mentioned above and the variation of nitrogen content of the product is shown in Fig. 128. 

Temperature coeffident of nitration. Experiments have shown that in a moderate range, e.g. from 0 to 45°C, temperature affects the degree of nitration very little. A decrease in temperature usually results in some decrease in degree of nitration on a technical scale, where nitration time is limited, but this is because equilibrium is not reached, and the rate of the reaction is the governing factor. From a knowledge of the heat of nitration it should be possible to predict the course of the reaction from the known equation ... 

The pot process of nitration is very simple, no elaborate plant is required, and it can be used for nitrating low grade cotton. Because of the long nitration time it is possible to make use of nitrating mixtures containing little nitric acid, thus reducing the hazards involved in nitration and centrifugation. 

Nitration. The nitration is usually carried out under conditions that promote the production of a low-viscosity product. Hence the process is carried out primarily with linters, at a relatively elevated temperature, commonly between 30 and 35°C. The clarity of nitrocellulose sulution increases, with nitration time to an optimum and then decreases [1]. 

Fig. 6-3. Seasonal sub-series plot of nitrate time series in the drinking water storage reservoir...

Using the nitrate time series example, the effect of a trend model with additive seasonality is shown in Fig. 6-7. 

Tab. 6-1. Seasonal differences in an additive model from the nitrate time series example...

Such analysis demands many cases in the series similar to multivariate model computations. Now a multiple regression analysis with the independent variables jan, feb, mar,. .., summ and the number variable num, and the nitrate time series as the dependent variable is started. 

Fig. 6-16. Autocorrelation function of the nitrate time series at the drinking water reservoir...

The nitrate time series of the drinking water reservoir is very complex and demonstrates the difficulty of identifying such models. A model with the shape ARIMA (p,d,f) (sp,sd,sf) shall be estimated. 

Next, one calculates the autocorrelation function, ACF, (Fig. 6-16) and the partial autocorrelation function, PACF, (Fig. 6-17) from the original nitrate time series. The autocorrelation function leads to the following conclusions ... 

Organic nitrate Time of onset Duration of action... 

Kunz Toth (Ref 22) found that nitration time for NS varies linearly with temp (Fig 2). Above 14°C nitration is very rapid... 

Nitrating temperature Drowning tank Nitration time... 

Reactions were carried out with potassium amide in 250 ml of liquid ammonia at -33°. The nitration time was 5 min. Reactions were carried out with potassium amide in 100 ml of liquid ammonia at -33°. The numbers in parenthesis represent recovered starting material. The yield was 47.0% when anion formation was carried out with potassium amide in THF at 65°, and the nitration at -33°. 

Fenn, J. (1995). The cellulose nitrate time bomb using sulphonephthalein indicators to evaluate storage strategies. In Postprints Tate Gallery conference From Marble to Chocolate . The Conservation of Modem Sculpture London, 18—20 September 1995 (J. Heuman, ed.) pp. 87-92, Archetype Books. 

Pentaerythritol trinitrate is prepared by a condensation reaction between formaldehyde and propionic aldehyde to pentaerythritol, which is farther nitrated by a mixed acid of nitric acid and sulfuric acid. The preparation condition is nitration coefficient of 5-6, nitration temperature of 20-25 °C, and nitration time of 25-30 min. The nitration yield at 10 °C with a mixed acid of 45 % nitric acid and 55 % sulfuric acid is 197-198 %, about 93 % of the theoretical yield. If 20 % fuming sulfuric acid is used, the yield can be increased to 97-98 % of the theoretical yield. The parameters of stability treatment with water-washing coefficient of 5 are listed in Table 5.56. 

One method for the manufacture of TMETN is to feed 50 kilograms of finely powdered metriol into a nitrator provided with cooling coils and an agitator. The nitrator contains 175 kilograms of mixed acid that consists of 65 percent nitric acid and 35 percent sulfuric acid. The nitration time is about 20 minutes at 20°C after which the contents of the nitrator are allowed to set for 15 minutes. The TMETN separates from the spent acid and is decanted and then washed at 40°C with an aqueous solution of soda and then with water. The yield is almost 100 kilograms of TM ETN with a nitrogen content of 16.32 to 16.36 percent. 

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