Several decades ago, when humanity was raving about space exploration, the enthusiasm for rocket science was rampant. Both schoolchildren and adult men enthusiastically designed rocket models from improvised materials in garages and kitchens. Now the excitement has subsided a little, but what could be more exciting than launching an aircraft made by yourself? How to make a rocket take off? The most affordable and practical is to use caramel fuel, a mixture of nitrate and carbohydrate.
What is required
The set of components is not so great.
1. Sugar or sorbitol - raw materials for caramelization.
2. Nitrate (you can use different, more on this below).
3. Metal container - usually take ordinary cans, although it is preferable to take dishes with thick walls - for more uniform heating. Even better - enameled or stainless steel, so that there is no reaction of the solution with the material of the dishes.
4. Electric stove - it is impossible to cook fuel on a gas stove!
5. Newspaper or other paper with good absorbent properties (if your goal is to make not just caramel fuel, but caramel paper). It is also used in rocket engines, impregnating with finished "caramel" and drying (without heating).
6. Protective equipment: glasses and gloves.
7. Ventilation.
Three manufacturing methods
There are many ways to make caramel fuel. The easiest thing is to simply mix the components. Another "caramel" is boiled - simply or with evaporation. During normal mixing, the fuel is poured into a glass jar and shaken several times, then tightly closed to prevent absorption of water. When used directly in rocket engines, this type of fuel must be well sealed, otherwise an explosion may occur.
Caramel fuel is boiled, or rather melted, at a temperature of 120-145 degrees until the sugar is completely converted and mass is formed, similar in texture to liquid semolina. Pre-grind the components is not necessary. It is very important to constantly interfere with it so that air bubbles do not form. Cooking with evaporation involves the addition of water followed by its evaporation. The disadvantages of this method: moisture remains in the fuel, and this reduces its burning rate.
Recipe number 1
Caramel fuel from potassium nitrate (potassium nitrate) is the best option. The ingredients are taken in the following proportions: sugar or sorbitol - 35%; saltpeter - 65%. Saltpeter is dried in a flat wide pan about 100-150 degrees for about two hours. Then grind for about 20 seconds - you can use a mortar or coffee grinder.
Lay in equal portions, 50 grams. In order not to bother with grinding sugar, it is better to buy ready-made icing sugar. For "boiled" caramel fuels, neither grinding nor drying is necessary. To enhance efficiency, 1% iron oxide (Fe
2 O
3 ) can be added to the mixture.
Recipe number 2
Caramel fuel from sodium nitrate. Features of this mixture - it is more hygroscopic. It will require 70% saltpeter, 30% sugar and two volumes of water (200%).
Recipe number 3
Using it is not recommended. This is caramel fuel based on ammonium nitrate (ammonium nitrate). Why is it better to pay attention to other recipes? Because it is an unstable compound, and when heated, anything can go wrong. As a result, the venture is likely to end in a fire!
In addition, in the manufacture of "caramel" from ammonium nitrate extremely toxic fumes are released. Therefore, all recipes using ammonium nitrate contain additional components for converting it to sodium or potassium. The easiest option is with sodium. We take 40% saltpeter, 45% baking soda and 200% water. We mark the liquid level and evaporate until the smell of ammonia disappears. Then we add water to the initial level (it partially evaporated), add 15% sugar and wait for its dissolution.
Catalysts
To increase the effectiveness of "caramel" in it add various catalysts. The most popular is iron oxide. Less well known is caramel fuel with aluminum. Attention! A mixture of aluminum and nitrates can ignite in the presence of water. Especially dangerous is the presence of any alkaline impurities that may be present in nitrate that is not pure enough or made independently. Therefore, in the fuel based on nitrates with aluminum as a catalyst, it is necessary to add 0.5-1% of some weak acid, and not the fact that this amount is enough - it all depends on the quality of nitrate. Boric is the best option. Oxalic and acetic are not suitable - aluminum reacts with them. If during cooking the mixture heats up very much, foams and emits a pungent smell of ammonia - you need to immediately remove it from the tile and immerse it in water.
In general, it is better for experimental rocket engineers who have mastered the simplest types of fuel to experiment with catalysts. Yes, and learn chemistry does not hurt: to use ready-made tips is simple, but much more valuable knowledge and understanding of what you are doing and what reactions occur in the mixture.
Aluminum is added to the potassium caramel. Allowable variations are from 2.5 to 20%. A different amount gives a different change in the burning rate of the fuel. It is recommended to use spherical aluminum ASD-4.
How to stay whole and healthy
The most dangerous thing is to cook caramel fuel by melting sugar and saltpeter, but this option is the most effective. The container in which the "caramel" is cooked must be perfectly clean - foreign substances can cause a fire.
There should not be sources of open flame near - explosions in the kitchen are useless to us. It is very important to monitor the temperature of the mixture - it should not rise above 180 degrees under any circumstances!
When stirring, it is better to use a wooden stick to avoid adverse reactions. It should be mixed very carefully, but evenly: air bubbles in the finished fuel, when used, lead to a rocket explosion. When pouring this fuel into forms, you also need to ensure that there are no bubbles. It is necessary to work with an extractor hood or in the fresh air, especially for a recipe with ammonium nitrate.
Do not grind sugar and saltpeter in a coffee grinder together! Grind separately, mix, shaking, in a glass bowl.
Beginners should not get involved with ammonium nitrate: first try the simplest and safest (based on potassium nitrate) caramel fuel. The manufacture of any home-made fuel must undergo careful control of the quality of ingredients, temperature, moisture content and in compliance with all safety measures!
Where to get the ingredients
Nitrate is sold in agricultural stores and departments for summer residents as fertilizer. Sorbitol is a sugar substitute for diabetics. Sold, respectively, in a pharmacy. Fe 2 O 3 - iron oxide - used to be sold under the name "iron minium." You can try to do it yourself by studying the relevant literature. The hematite mineral is also iron oxide. Aluminum is sold by chemical manufacturers.