US3361834A - Method of preventing propagation of dinitrobenzenoid compound detonations - Google Patents

Description

United States Patent ABSTRACT OF THE DISCLOSURE Method of preventing detonation propagation while transferring molten dinitrobenzene or dinitrotoluene througha pipeline by adding 2l00% by weight of alkanol having 1-3 carbon atoms, using a pipeline having an inside diameter of not more than 18 inches and maintaining sufficient pressure to keep the alkanol in the liquid phase.

Background of the invention This invention relates to a method of preventing propagation of dinitrobenzenoid compound detonations and more particularly to a method of stabilizing dinitrobenzene and dinitrotoluene against propagation of detonations.

Dinitrobenzenoid compounds, such as the dinitrobenzenes and toluenes, are valuable intermediates used in large quantities by the chemical industry. Being normally solid and explosive in nature, these compounds present special handling problems in large scale operations. Although these materials can be transferred through pipelines in the molten state, there are serious limitations on the diameter of the pipes used. For example, in the case of dinitrobenzene, the inside diameter of the pipe cannot be more than about 1.25 inches. Otherwise, dinitrobenzene detonations, when they occur, tend to propagate through the pipeline and eventually reach bulk storage tanks. In the case of dinitrotoluene, the maximum safe pipe diameter is believed to be about inches. These limitations, particularly in the case of dinitrobenzene,

place serious restrictions on the ability to handle these materials on a large scale.

It is an object of this invention to provide a method of preventing propagation of dinitrobenzenoid compound vdetonations in pipelines having inside diameters up to about 18 inches. Another object is to provide dinitrobenzenoidcompositions which will not propagate detonations in pipelines having inside diameters up to about 18 inches. These and other objects will become apparent from the following description of this invention.

Description of the invention It has now been discovered that detonation propagation by molten dinitrobenzenoid compounds selected from the group consisting of dinitrobenzenes and dinitrotoluenes at temperatures of about 30 to 130 C. in pipelines having inside diameters up to about 18 inches can be prevented by maintaining a molten composition containing the dinitrobenzenoid compound and 2 to 100% by weight, based on the dinitrobenzenoid compound, of alkanol of 1 to 3 carbon atoms and maintaining suflicient pressure to keep the alkanol in the liquid phase.

It is quite surprising that relatively small amounts of these alkanols, which themselves are flammable or explosive, are effective arrestors of dinitrobenzenoid compound detonation propagations. Moreover these alkanols do not interfere with subsequent processing of the dinitro 3,361,834 Patented Jan. 2, 1968 ICC compound such as its reduction to the corresponding amine. Because of their volatility, these alkanols are readily stripped from the dinitrobenzenoid compound when desired.

The dinitrobenzenoid compounds which can be stabilized in accordance with this invention are dinitrobenzenes including ortho-, metaand para-dinitrobenzene and dinitrotoluenes including 2,3-, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-dinitrotoluene. The dinitro compound can be a single isomer or a mixture of isomers such as the technical meta-dinitrobenzene made by the process described in Cossaboon et al. in U.S. Patent No. 3,185,738.

In accordance with this invention, at least about 2% by weight, based on the dinitro compound, of alkanol having 1 to 3 carbon atoms is used as stabilizer for the dinitro compound. The stabilizer is generally used in an amount of about 2 to 20%. Larger amounts up to about by weight, based on the dinitro compound, may be used if desired, but they provide no special advantage and they greatly increase the handling costs.

2-propanol is the preferred stabilizer since it is highly effective in relatively low concentrations, preferably about 2 to 5% by Weight, based on the dinitrobenzenoid compound. Methanol, ethanol and n-propanol are normally used in somewhat higher proportions, preferably about 5 to 10% by weight.

To prepare the novel stabilized compositions of this invention, the stabilizing alkanol is intimately mixed with the dinitro compound. Heat may be applied where necessary. Conveniently the components are mixed at ambient temperature and then heated to produce a molten homogeneous mass or the stabilizer is added to the molten dinitro compound and intimately mixed. Such compositions have been found to be stable against detonation propagation at temperatures as high as about C. and are readily and safely transported through pipelines having inside diameters of up to about 18 inches.

When the dinitro compound is dinitrobenzene, the inside diameter of the pipeline is preferably not more than about 10 inches, and most preferably not more than about 4 inches. When the dinitro compound is dinitrotoluene, considerably larger pipeline diameters can be tolerated. With dinitrotoluene, inside diameters of about 18 inches provide a large margin of safety.

The pressure of the system is not critical provided it is sufilcient to prevent the stabilizer from vaporizing away from the dinitro compound at elevated temperatures. In pipelines and storage tanks, pressures of up to about 100 p.s.i.g. and usually about 40 to 50 p.s.i.-g. are sufiicient to keep the alkanol in the liquid phase in stabilizing proportions at elevated temperatures.

The material of construction for pipelines and storage tanks is not critical and may be any material inert to the dinitro compound and the alkanol. Ordinary iron and steel are suitable, as are aluminum and plastics. Polytetrafluoroethylene is particularly suitable since it is itself a detonation arrestor as has been described in the art.

The alkanol stabilizers of this invention also appear to be effective in retarding thermally induced detonations. Dinitrobenzene containing about 89% meta-, 9% orthoand 2% para-isomer begins to decompose explosively in heated pressure vessels at temperatures as low as about 320 C. 2-propanol, in concentrations of about 2 to 20% by weight, based on the dinitrobenzene, tends in general to reduce the decomposition rate of dinitrobenzene, measured as the change in internal pressure With time during decomposition. This alkanol also tends to increase the temperature necessary for explosive decomposition in some cases to as high as about 400 C.

The following examples, illustrating the method and compositions of this invention, are presented without 3 any intention that the invention be limited thereto. All percentages are by weight.

EXAMPLES 1-5 General prceaure.Molten dinitrobenzene containing 89% meta-, 9% orthoand 2% para-isomer with added stabilizer in the amount indicated in the following table was charged into a series of vertical 4-inch steel tubes, each open at the top, sealed at the bottom, and containing a wire support for a primer charge 35.5 inches from the bottom. The dinitrobenzene was added to a 36-inch depth and maintained at the temperature indicated in the table by means of electric heating tape wrapped around the outside of the pipe. Next a 95/5 RDX (sym.-trimethylene trinitramine/wax) primer rod, 3.875 inches x 6 inches weighing 1380 grams and contained in an aluminum foil cup, was inserted through the top of each pipe and rested on the wire support in contact with the dinitrobenzene. The primer was connected to a conventional explosion initiating device by placing on top of the primer rod a standard disc-shaped booster charge attached to an 80-foot-long low energy detonation cord attached at the other end to a standard blasting cap wired to an electrical detonation initiator. Each tube was completely enclosed in a loose fitting wooden box which was then covered With sand to a -6 foot depth to mufile the explosion and contain shrapnel. When the RDX primer rod was detonated, the dinitrobenzene did not detonate in any of the tubes in this series.

Several control runs, not within the scope of the invention, were carried out following the above procedure except that no stabilizer was present. In each case the detonation was propagated by the dinitrobenzene, as evidenced by pipe rupture along its entire length.

The data obtained in these examples is summarized in the following table in which DNB represents dinitrobenzene.

Molten dinitrobenzene as described in Example 1 at 100 C. without added stabilizer was placed in a tube similar to that described in Example 1, except that the tubes bottom seal was a .001-inch brass shim and the tube was immersed in a 100 C. molten composition comprising 95% dinitrobenzene and 5% 2-propanol contained in a storage tank having an 18-inch diameter, 20- inch depth and .375-inch thick walls. When the dinitrobenzene in the tube was detonated, the dinitrobenzene composition containing the alkanol stabilizer in the storage tank did not detonate.

This example shows that 2-propanol is effective in arresting a detonation even in an 18-inch vessel.

EXAMPLE 7 Molten dinitrobenzene as described in Ex-ample 1 at 100 C. containing 2.6% 2-propanol, based on the dinitrobenzene, was placed in the 18-inch storage tank described in Example 6. A /5 RDX charge, 18 inches in diameter, 3 inches thick and Weighing 14 pounds, was detonated in direct contact with the dinitrobenzene within the tank using a booster charge, detonation cord, blasting cap and electrical detonation initiator as described in Example 1. The stabilized dinitrobenzene composition did not detonate.

Although this invention has been described and exemplified by way of specific embodiments with particular regard for stabilization of dinitrobenzenes, it is also applicable to other dinitrobenzenoid compounds such as dinitrotoluenes. It is to be understood that the invention includes all modifications and variations coming within the scope of the following claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of preventing detonation propagation while transferring molten dinitrobenzenoid compound selected from the group consisting of dinitrobenzene through a pipeline and dinitrotoluene at a temperature of 30 to 130 C. which comprises passing a molten composition containing the molten dinitrobenzenoid compound and 2 to by weight, based on the molten dinitrobenzenoid compound, of alkanol having 1 to 3 carbon atoms through a pipeline having an inside diameter of not more than 18 inches and maintaining sufficient pressure to keep the alkanol in the liquid phase.

2. The method of claim 1 in which the composition contains 2 to 20% by weight of alkanol based on the dinitrobenzenoid compound, and the pipeline has an inside diameter of not more than 10 inches.

3. The method of claim 2 in which the composition contains dinitrobenzene and 2 to 10% by weight of alkanol based on the dinitrobenzene, and the pipeline has an inside diameter of more than 1.25 to 4 inches.

4. The method of claim 3 in which the composition contains 2 to 5% by weight of 2-propanol based on the dinitrobenzene.

5. The method of claim 2 in which the composition contains dinitrotoluene and 2 to 10% by Weight of alkanol based on the dinitrotoluene.

References Cited UNITED STATES PATENTS 2,362,743 11/1944 Crater 260-645 2,976,320 3/1961 Winstrom et al 260-580 3,032,5-86 5/1962 Dicrichs et a1. 260---580 OTHER REFERENCES Langes Handbook of Chemistry, 1946, pp. 468, 469, 472 and 473.

Vogel, A Text-Book of Practical Organic Chemistry, Longmans, Green and Co. New York, 1948, pp. 123, 508, 586 and 587.

CARL D. QUARFORTH, Primary Examiner.

L. A. SEBASTIAN, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,361,834 January 2, 1968 Fenn Laursen et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 28, for "dinitrobenzene through a pipeline and dinitrotoluene" read dinitrobenzene and dinitrotoluene through a pipeline Signed and sealed this 18th day of February 1969.

(SEAL) Attest:

Edward M. Fletcher, J r. EDWARD J. BRENNER Attesting Officer Commissioner of Patents