3.6 Technical Questions:

1. Explain how crude quality affects the topology of refinery configuration?
Ans: This is a very important question.  Usually, refinery crudes are characterized as light, moderate and heavy crudes.  Light and moderate crudes are typically targeted for gas, naphtha, diesel, light and heavy gas oil fractions.  Heavy crudes are targeted for coke and residue product streams.  Therefore, the crude quality does affect the topology of the refinery configuration.  According to the choice of the crude available, refineries are classified into four types namely

1. 1. Those that target fuels. This is very prominent in a country like India
2. 2. Those that target coke.  This is very much targeted for refineries that supply coke as an important raw materials to other industries such as steel, catalysts etc.
3. 3. Lubricants. 
4. 4. Petrochemicals.

According to the desired product pallete, the refinery configuration and hence topology is affected with the crude quality.

Ans: A chemical process essentially involves streams whose composition is fairly known. As far as refinery processes are concerned, their chemical constituents are not exactly known but are estimated as functions of various measurable properties such as viscosity, cetane number, octane number, flash point, TBP/ASTM distillation etc.
Therefore, refinery process technology should accommodate the details pertaining to these issues in addition to the technology issues.