The key difference between carbonization and graphitization is that carbonization involves the conversion of organic matter into carbon, whereas graphitization involves the conversion of carbon into graphite.
Carbonization and graphitization are two industrial processes that are different from each other, but both these processes involve carbon as either a reactant or as a product.
CONTENTS
1. Overview and Key Difference
2. What is Carbonization
3. What is Graphitization
4. Similarities Between Carbonization and Graphitization
5. Side by Side Comparison – Carbonization vs Graphitization in Tabular Form
6. Summary
What is Carbonization?
Carbonization is an industrial process where organic matter is converted into carbon. The organic matter that we consider here includes plants and dead animal matter. The process occurs through destructive distillation. It is a pyrolytic reaction which is considered a complex process in which we can observe many chemical reactions occurring concurrently. For example, dehydrogenation, condensation, hydrogen transfer and isomerization.
The carbonization process is different from the coalification process because carbonization is a faster process due to its reaction rate being faster by many orders of magnitude. Generally, the amount of heat applied can control the degree of carbonization and the residual content of foreign elements. For instance, at 1200 K temperature, the carbon content of the residue is about 90% by weight, while at about 1600 K temperature, it is about 99% by weight.
Typically, carbonization is an exothermic reaction, and we can make it self-sustaining, and we can use it as a source of energy that does not form any carbon dioxide gas trace. However, if the biomaterial is exposed to a sudden change in the heat, for example, in a nuclear explosion, the biomatter gets carbonized as soon as possible, and it turns into solid carbon.
What is Graphitization?
Graphitization is an industrial process in which carbon gets converted into graphite. It is a microstructural change that takes place in carbon or low alloy steel that is exposed to temperatures ranging from 425 to 550 Celsius degree for a long time, like a thousand hours. It is a type of embrittlement.
For example, the microstructure of carbon-molybdenum steels usually contains pearlite (a mixture of ferrite and cementite). When this material is subject to graphitization, it results in the decomposition of pearlite into ferrite and randomly dispersed graphite. This can lead to the embrittlement of the steel, and when these graphite particles are randomly distributed throughout the matrix, it can lead to a moderate loss of strength.
However, we can prevent graphitization by using more resistant material that is less sensitive to graphitization. In addition, we can prevent it by modifying the environment, e.g. by increasing pH or reducing the chloride content. There is another method of preventing graphitization which includes the use of coatings, e.g. cathodic protection of cast iron.
What are the Similarities Between Carbonization and Graphitization
- Both are important industrial processes that involve carbon as either a reactant or as a product.
What is the Difference Between Carbonization and Graphitization?
Carbonization and graphitization are two industrial processes. The key difference between carbonization and graphitization is that carbonization involves the conversion of organic matter into carbon, whereas graphitization involves the conversion of carbon into graphite. Therefore, carbonization is a chemical change whereas graphitization is a microstructural change.
The following infographic summarizes the difference between carbonization and graphitization in tabular form.
Summary – Carbonization vs Graphitization
Carbonization and graphitization are two different industrial processes. The key difference between carbonization and graphitization is that carbonization involves the conversion of organic matter into carbon, whereas graphitization involves the conversion of carbon into graphite.
Reference:
1. “Graphitization.” ScienceDirect Topics, Available here.
Image Courtesy:
1. “Carbonization Link Map – 1” By IUPAC – (Public Domain) via Commons Wikimedia