Fuels perchlorates

Rocket propellants -ammonium perchlorates as fuel [PERCHLORIC ACID AND PERCHLORATES] (Voll8)... 

By World War II, perchlorates were used mostly for solid rocket motors, which account for most of the emerging perchlorate problem in this country. Besides rocket fuel, perchlorates are used in 3-inch and 4.2-inch mortar shell illumination rounds, perimeter illumination booby traps, artillery simulators used in training, signal flares, smoke pots, artillery tracers, and railway torpedoes. 

On the right end is chlorine, which surrounded by four oxygens is perchlorate. Perchlorate reacts so readily that it is used in rocket fuel. Perchlorate is related to the molecules in chlorine bleach. Like arsenate, it is poison, not food. Some fascinating microbes eat chlorate molecules, but they do not appear to build with them. 

Polymer-based rocket propellants are generally referred to as composite propellants, and often identified by the elastomer used, eg, urethane propellants or carboxy- (CTPB) or hydroxy- (HTPB) terrninated polybutadiene propellants. The cross-linked polymers act as a viscoelastic matrix to provide mechanical strength, and as a fuel to react with the oxidizers present. Ammonium perchlorate and ammonium nitrate are the most common oxidizers used nitramines such as HMX or RDX may be added to react with the fuels and increase the impulse produced. Many other substances may be added including metallic fuels, plasticizers, stabilizers, catalysts, ballistic modifiers, and bonding agents. Typical components are Hsted in Table 1. 

Fig. 1. The postulated flame stmcture for an AP composite propellant, showing A, the primary flame, where gases are from AP decomposition and fuel pyrolysis, the temperature is presumably the propellant flame temperature, and heat transfer is three-dimensional followed by B, the final diffusion flame, where gases are O2 from the AP flame reacting with products from fuel pyrolysis, the temperature is the propellant flame temperature, and heat transfer is three-dimensional and C, the AP monopropellant flame where gases are products from the AP surface decomposition, the temperature is the adiabatic flame temperature for pure AP, and heat transfer is approximately one-dimensional. AP = ammonium perchlorate.

The perchloryl fluoride [7616-94-6] FCIO, the acyl fluoride of perchloric acid, is a stable compound. Normally a gas having a melting poiat of —147.7° C and a boiling poiat of —46.7°C, it can be prepared by electrolysis of a saturated solution of sodium perchlorate ia anhydrous hydrofluoric acid. Some of its uses are as an effective fluorinating agent, as an oxidant ia rocket fuels, and as a gaseous dielectric for transformers (69). 

Pyrotechnic mixtures may also contain additional components that are added to modify the bum rate, enhance the pyrotechnic effect, or serve as a binder to maintain the homogeneity of the blended mixture and provide mechanical strength when the composition is pressed or consoHdated into a tube or other container. These additional components may also function as oxidizers or fuels in the composition, and it can be anticipated that the heat output, bum rate, and ignition sensitivity may all be affected by the addition of another component to a pyrotechnic composition. An example of an additional component is the use of a catalyst, such as iron oxide, to enhance the decomposition rate of ammonium perchlorate. Diatomaceous earth or coarse sawdust may be used to slow up the bum rate of a composition, or magnesium carbonate (an acid neutralizer) may be added to help stabilize mixtures that contain an acid-sensitive component such as potassium chlorate. Binders include such materials as dextrin (partially hydrolyzed starch), various gums, and assorted polymers such as poly(vinyl alcohol), epoxies, and polyesters. Polybutadiene mbber binders are widely used as fuels and binders in the soHd propellant industry. The production of colored flames is enhanced by the presence of chlorine atoms in the pyrotechnic flame, so chlorine donors such as poly(vinyl chloride) or chlorinated mbber are often added to color-producing compositions, where they also serve as fuels. 

May 4, 1988, explosions leveled a Pacific Engineering Production Co. (PEPCO) plant, at Henderson, NV, one of only two U.S. plants producing 20 million lb/ year (maximum of 40 million Ib/year - see Table 7.1-2) ammonium perchlorate for solid rocket fuel. It was the principal supplier for the space shuttle and sole supplier for the Titan rocket and several military missiles. 

An important class of expl materials contains metallic fuels and inorganic oxidants. Examples are Tritonal (TNT/A1, 80/20), Amatols (TNT/AN, 28/80 80/20), and Minol-2 (TNT/AN/A1, 40/40/20). Oxidants other than nitrates, such as chlorates and perchlorates, may be employed. Water solns containing these cations are highly corrosive to metals. Alkaline metal salts, for example, in the presence of moisture, will pit A1 quickly (Ref 6)... 

Paraplex Propallants. A series of JATO proplnts (the PF-series) developed by the Aerojet Engrg Corp, Azusa, Calif using Paraplex P-10 resin-styrene mixt as a fuel ingredient in the amt of approx 26.5%. Other ingredients are AN or K perchlorate, 73.0%, and small amts of t-butyl-hydroperoxide or benzoylperoxide, 0.1 to 0.5% (as a polymerization catalyst) (Ref 2)... 

Hall, Perchloric Acid Flames. I. Premixed Flames with Methane and Other Fuels , in 10th Symposium (International) on Combustion , The Combustion Inst (196S), 1365... 

In addition to adding nitrocompds to PA to lower its mp, other substances could be added, such as oxidizers (K nitrate, Na nitrate, AN, Ba nitrate, Pb dioxide, Amm dichromate, K chlorate, K perchlorate, etc), fuels (such as sawdust,... 

The most significant use for HTPB propints is in ballistic missiles (Refs 12 13). The most unique usage is in the functioning of a laser by means of the chemical exhaust species-generated by a HTPB-Xmm Perchlorate fuel matrix (Ref 9)... 

Polyglycidyl Nit rata (Polyurethane) Propellants (PGN). A series of proplnt compns developed by both JPL of Cal Tech and the Aerojet-General Corp in the late 1950 s (Refs 2 3), using as the binder fuel a polyurethane resin prepd from PGN. JPL used either Amm Nitrate or Amm Perchlorate as the oxidizer (Ref 2), while Aerojet used Amm Perchlorate with plasticizers such as 4-Nitrazapentanonitrile (NPN) and 2,2-Pentanoate (TNENP) in a plasticizer-to-binder wt ratio of 0.6 (Ref 3). 

PMMA finds ordn usage in several areas in ballistic or impact shields for missiles or airplanes also as windows, windshields or canopies in aircraft (Refs 7 and 22) as a Laser Q switch host using an organic Ni complex dye (Ref 22) and in proplnts as fuel (with A1 and NG as cofuels — Ref 20) and Amm perchlorate or K perchlorate as oxidizers (Refs 2, 4, 8—11, 13,14 16—20). Also see under Aeroplex Propellants in Vol 1, A108-R and under Composite Propellants in Vol 3, C464-L to C474-L Refs 1) Beil 2, [398] and (1279 1283 ... 

Composite proplnts, which are used almost entirely in rocket propulsion, normally contain a solid phase oxidizer combined with a polymeric fuel binder with a -CH2—CH2— structure. Practically speaking AP is the only oxidizer which has achieved high volume production, although ammonium nitrate (AN) has limited special uses such as in gas generators. Other oxidizers which have been studied more or less as curiosities include hydrazinium nitrate, nitronium perchlorate, lithium perchlorate, lithium nitrate, potassium perchlorate and others. Among binders, the most used are polyurethanes, polybutadiene/acrylonitrile/acrylic acid terpolymers and hydroxy-terminated polybutadienes... 

The influence of metal type on the specific impulse of propints has been described previously in this article (Table 16). The max theoretical specific impulse and density impulses (ISp x p ) for the oxidizers AN, AP and hydrazinium nitrate with 15 weight percent -fCH2)- binder have been calculated for various fuels (Ref 24). These data are in Tables 49-51. The ISp performance of nitronium perchlorate, lithium perchlorate and potassium perchlorate and metallized fuels with 4CH2>- binder are given in Table 52 (Ref 43)... 

Table 9 lists the chief performance characteristics of the most important delay compns. In general, the bum time is controlled within the stated limits by adjustment of the fuel fraction. Other variables are the particle size of the fuel and the presence of additives such as Pb chromate, silica and Viton. Many perchlorate containing mixts are friction and spark sensitive,... 

Photo flash powders are loose mixts of powdered oxidizers such as Ba nitrate and K perchlorates with metallic fuels, principally Mg, A1 and Zr. These ingredients have such small particle sizes that they bum with expl violence for durations of less than 0.1 sec. At present photoflash powders are used exclusively in military aerial photography, whereas civilian applications are served by electrically ignited Zr or Hf wire containing flashbulbs. Since 1970. non-electric, pyrotechnically functioned, flash cubes have appeared on the market (USPs 3535063,3540813 3674411)... 

L.3 The solid fuel in the booster stage of the space shuttle is a mixture of ammonium perchlorate and aluminum powder. On ignition, the reaction that takes place is 6 NH4C104(s) +... 

One spectacular example of the oxidizing ability of perchlorates is their use in the booster rockets of space shuttles. The solid propellant consists of aluminum powder (the fuel), ammonium perchlorate (the oxidizing agent as well as a fuel), and iron(III) oxide (the catalyst). These reactants are mixed into a liquid polymer, which sets to a solid inside the rocket shell. A variety of products can form when the mixture is ignited. One of the reactions is... 

Calculate the heat released when ammonium perchlorate (1.00 kg) reacts with aluminum powder (1.00 kg) as rocket fuel 3 NH4C104(s) + 3 Al(s) - Al20,(s) + AICI3(s) +... 

Another groundwater contaminant that can be removed by reduction reactions is perchlorate. Ammonium perchlorate is a solid rocket fuel, and wastes from its manufacturing have contaminated some irrigation and drinking water sources, among them the lower Colorado River in the American Southwest. Elevated perchlorate levels have been linked to human health effects, and because perchlorate has been found in vegetable crops such as lettuce, there is concern that this contamination could have serious consequences. 

Fhosphoric acid does not have all the properties of an ideal fuel cell electrolyte. Because it is chemically stable, relatively nonvolatile at temperatures above 200 C, and rejects carbon dioxide, it is useful in electric utility fuel cell power plants that use fuel cell waste heat to raise steam for reforming natural gas and liquid fuels. Although phosphoric acid is the only common acid combining the above properties, it does exhibit a deleterious effect on air electrode kinetics when compared with other electrolytes ( ) including such materials as sulfuric and perchloric acids, whose chemical instability at T > 120 C render them unsuitable for utility fuel cell use. In the second part of this paper, we will review progress towards the development of new acid electrolytes for fuel cells. 

The third type of propellent explosive, the composite type, is a more recent development, the purpose of which is to provide rocket propellants of increased thrust, compared with the ordinary varieties. Composite propellants are based on an oxidising solid, commonly a perchlorate, together with an organic binder which both acts as fuel and gives adequate mechanical strength to the mixture. The search for even more energetic compositions continues, but because of the military importance of the... 

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