Mechanical Engineering - Thermodynamics - Discussion

1. Coal gas: It is also known as a town gas. It is obtained by the carbonization of coal and consists mainly of Hydrogen, carbon monoxide and various hydrocarbons. It is very rich among combustible gases and is largely used in towns for street and domestic lighting and heating. It is also used in furnaces and for running gas engines. Its calorific value is about 21000 to 25000 kJ/m3.

2. Producer gas: It is obtained by the partial combustion of coal, coke, anthracite coal or charcoal in a mixed air-steam blast. It is, mostly, used for furnaces particularly for glass melting and also for power generation. Its manufacturing cost is low and has a calorific value of about 5000 to 6700 kJ/m3.

3. Water gas: It is a mixture of hydrogen and carbon monoxide and is made by passing steam over incandescent coke. As it burns with a blue flame, it is also known as blue water gas.

The water gas is usually converted into carburetted (enriched) water gas by passing it through a carburetor into which a gas oil is sprayed. It is, usually, mixed with coal gas to form town gas. The water gas is used in furnaces and for welding.

4. Mond gas: It is produced by passing air and a large amount of steam over waste coal at about 650°C. It is used for power generation and heating. It is also suitable for use in gas engines. Its calorific value is about 5850 kJ/m3.

5. Blast furnace gas: It is a by-product in the production of pig iron in the blast furnace. This gas serves as a fuel in steel works, for power generation in gas engines, for steam raising in boilers and for preheating the blast for furnace. It is extensively used as fuel for metallurgical furnaces. The gas, leaving the blast furnace, has a high dust content, the proportion of which varies with the operation of the furnace. It has a low heating value of about 3750 kJ / m3.

6. Coke oven gas.: It is a by-product from coke oven, and is obtained by the carbonisation of bituminous coal. Its calorific value varies from 14500 to 18500 kJ / m3. It is used for industrial heating and power generation.

Water gas is a synthesis gas, containing carbon monoxide and hydrogen. It is a useful product but requires careful handling because of the risk of carbon monoxide poisoning. The gas is made by passing steam over a red-hot carbon fuel such as coke:

H2O + C → H2 + CO (ΔH = +131 kJ/mol).

The reaction is endothermic so the fuel must be continually re-heated to keep the reaction going. In order to do this, an air stream, which alternates with the vapor stream, is introduced for the combustion of carbon to take place.

O2 + C → CO2 (ΔH = -393.5 kJ/mol).

Theoretically to make 6 L of water gas, 5 L of air is required.
Or alternatively to prevent contamination with nitrogen, energy can be provided by using pure oxygen to burn carbon into carbon monoxide.

O2 + 2 C → 2 CO (ΔH = -221 kJ/mol).

In this case 1 L of oxygen will create 5.3 L of pure water gas.

It is a mixture of hydrogen and carbon monoxide and is made by passing steam over incandescent coke.

Definitions of incandescent : Emitting light as a result of being heated.

"plumes of incandescent liquid rock"

Synonyms: white-hot, red-hot, burning, fiery, blazing, ablaze, aflame, glowing, aglow, radiant, bright, brilliant, luminous, sparkling, fervid, lucent, igneous

Examples of incandescent : The metal flakes heat up until they are incandescent and shine brightly or, at a high enough temperature, actually burn.

As it burns with a blue flame' it is also known as blue water gas.

The water gas is usually converted into carburetted ( enriched) water gas by passing it through a carburetter into which a gas oil is sprayed . It is usually, mixed with coal gas to form town gas the water gas is used in furnaces and for welding.

Water gas, colorless poisonous gas that burns with an intensely hot, bluish (nearly colorless) flame. The gas is a mixture of carbon monoxide and hydrogen with very small amounts of other gases, e.g. , carbon dioxide, and is almost entirely combustible as a result. Water gas is so named because of the use of water (steam) in its preparation. This process involves treating white-hot hard coal or coke with a blast of steam; carbon monoxide and hydrogen are formed. The gas is manufactured in vast quantities for commercial use. It is of much importance in the preparation of hydrogen and as a fuel in the making of steel and in other industrial processes.

Water gas is formed by the steam passing through the red hot coal or coke in the furnace and it reacts to each other and to form a gas known as water gas. The gas consists of CO & H2O.

It forms the water gas this is widely used in the industrial applications for making steels&cast irons it is the by product of getting iron from ore in blast furnaces. It is poisonous gas cannot breath.

Bosch Process A German chemist Bosch, prepared hydrogen on a large scale using inexpensive raw materials such as water and coal by passing steam over red-hot coke (carbon) at about 1000°C a mixture of carbon monoxide and hydrogen known as water gas is produced carbon monoxide is separated from the mixture by converting it to carbon dioxide.

Water gas is produced by passing steam over red hot carbon fuel like coke. It is the combination of carbon monoxide and hydrogen. Approximately about 6 liters of water is required to produce 5 liters of water gas.

Dear friends.

The Water Gas is made by passing steam over a coke, containing carbon monoxide and hydrogen, a highly flammable and poisonous gas in industry it is used in production of steel.

The gas is manufactured in vast quantities for commercial use. It is of much importance in the preparation of hydrogen and as a fuel in the making of steel and in other industrial processes.

The Steam is passed through the burning bed of coal or coke above.

1000° Celcius.

6 litres of water is required to produce 5 litres of water gas.