Rocket fuel problem

Since the early work of Stock, other boron hydrides have been synthesized. Some of these compounds have been used as fuel additives, and they have found some application in high-energy rocket fuels. However, because B203(s) is a product of the reaction, the use of these materials in that way causes some problems. The boron hydrides will all bum readily to produce B203 and water,... 

The use of ethyl nitrate as a component of rocket fuel involves the problem of thermal decomposition. Levy [16] has studied the decomposition of ethyl nitrate in the gaseous phase, in the temperature range 161 and 201°C under a pressure of a few centimeters of mercury. He found that ethyl nitrite is the main decomposition product. By-products include methyl nitrite, nitromethane, nitrogen dioxide and nitrous oxide. 

It s time to face reality. The theoretical yield is never obtained, for reasons that are largely uncontrollable. For one thing, although the major reaction predominates, many reactant mixtures also proceed through one or more side reactions that form smaller amounts of different products (Figure 3.9). In the rocket fuel reaction in Sample Problem 3.10, for example, the reactants might form some NO in the following side reaction ... 

Problem Hydrogen peroxide is a powerful oxidizing agent used in concentrated solution in rocket fuels and in dilute solution as a hair bleach. An aqueous solution of H2O2 is 30.0% by mass and has a density of 1.11 g/mL. Calculate its... 

Most of the elements of the periodic system occur in waters, including the elements of rate earths. However, these concentrations are very low and do not cause any hygienic or technological problems. Recently, attention has been paid to the remarkable toxicity of beryllium. The compounds of beryllium are used in the production of rocket fuels, fluorescent lamps and they occur in wastewaters from beryllium processing works. 

Extensive experience has been gained in the safe handling of liquid hydrogen, both in physics laboratories and, on a tonnage scale, for use in the space industry as a rocket fuel. No insuperable technical problems are encountered. The specialized equipment is, however, very costly and is one reason why liquid hydrogen has not been seriously considered as a fuel outside the space industry, where its low density is a particularly valuable property. Experimentally, liquid hydrogen has been employed as a fuel in automotive applications and there has been some preliminary consideration of using it as an aircraft fuel see Section 7.3, Chapter 7. 

Problem 4.7. Calculate the mass percentage of nitrogen in the rocket fuel hydrazine, N2H4. 

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. 

A simulated rocket fuel, comprising a urethane-based binder of undisclosed composition and a material simulating rocket fuel (without its pyrotechnic properties), was provided in uncured form by an industrial partner. The sample was held at a temperature of 55 C for approx. 27 hrs and mid-IR spectra were collected every two minutes by placing a Remspec fiber-optic probe with a zinc selenide ATR head in direct contact with the curing mass. During the experiment, two interruptions occurred the first when cooling of the MCT detector failed for a short time, and the second when a software problem (since corrected) led to non-storage of collected data. 

Urethane polymers are important in many fields other than home improvement and, in some of these cases, the ability to easily estimate the degree of cure can be very important. For example, in the manufacture of certain types of fuel for use in rockets, solid propellant is mixed with a urethane binder and very slowly cured in small batches. It is important for reasons of both safety and performance that the correct degree of curing is achieved. To illustrate the application of fiber optic mid-IR spectroscopy to this problem, a simulated rocket fuel mixture was obtained from an industrial partner. The material comprised a simulated propellant mixed with an uncured urethane precursor curing of this particular mixture is typically carried out batchwise at a temperature of 50°C over a period of several days. The use of a direct, in-situ probe capable of giving a clear indication of the state of cure of each batch would be of great utility. 

Example 2.10. Probably the best contemporary example of a variable-mass system would be the equations of motion for a space rocket whose mass decreases as fuel is consumed. However, to stick with chemical engineering systems, let us consider the problem sketched in Fig. 2.8. Petroleum pipelines are sometimes used for transferring several products from one location to another on a batch basis, i.e., one product at a time. To reduce product contamination at the end of a batch transfer, a leather ball or pig that just fits the pipe is inserted in one end of the hne. Inert gas is introduced behind the pig to push it through the hne, thus purging the hne of whatever hquid is in it. 

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