,
The production process of carbonization
Carbonization, also known as coking, is a process whereby coal, coke or tar is heated in the absence of oxygen and in the presence of steam, water or carbon dioxide in order to producea mixture of solid, liquid and gaseous products. The principal products of carbonization are coke, tar, light oils and condensates. Carbonization can also be split into two processes, thermal carbonization and catalytic carbonization.
Thermal Carbonization
Thermal carbonization uses the heat generated by coal and coke to decompose the coal and coke into these products. The most common temperatures used range between 300 to 450°C. Generally, higher temperatures result in higher reactivity and increased yields of gases, liquids and coke. There are two types of thermal carbonization; direct and indirect heating. Direct heating uses direct flame, usually from a furnace. Indirect heating uses hot gases and vapours which move passed the coal.
Catalytic Carbonization
Catalytic Carbonization uses a catalyst and catalyst bed to control and direct the reaction. The catalyst aids in breaking the bonds within the coal or coke resulting in a faster reaction rate. The most common catalysts used are nickel, iron oxide, potassium oxide, and sodium oxide. Temperatures used in catalytic carbonization are significantly lower than that used in thermal carbonization and are typically within the range of 250 to 350°C.
In both thermal and catalytic carbonization processes, the environment in which the reaction is taking place is carefully controlled and monitored. These control parameters include temperature, time, pressure, and catalysts. The ultimate products of the reaction depend on the working conditions which will vary for different materials and different processes.
Applications
Carbonization is used for a variety of industrial applications. The production of coke, which is essential for the smelting of metals, is the most common and most widely recognized form of carbonization. Carbonization is also used to produce charcoal and activated carbon which are used in the food industry for their smokeless flavour and their purifying capabilities. Other uses for carbonization include the production of fuel oils, lubricants and road tar. Carbonization is also widely used to produce metallurgical coke for the production of steel.
Conclusion
Carbonization processes are essential in many industries such as food, fuel and steel production. Carbonization produces a range of products such as coke, tar, light oils and condensates. Two primary processes are used in carbonization, thermal and catalytic. Temperature, time, pressure and catalysts are carefully monitored and controlled in order to ensure a successful reaction.
