Micro carbon residue, commonly known as "MCR" is a laboratory test used to determine the amount of carbonaceous residue formed after evaporation and pyrolysis of petroleum materials under certain conditions.
The test is used to provide some indication of a material's coke-forming tendencies.
Heating is performed in a controlled manner, for a specific period of time, and under an inert (nitrogen) atmosphere .
The sample experiences coking reactions, with volatiles formed being swept away by the nitrogen.
Advantages of MCR include better control of test conditions, smaller samples, and less operator attention.