The Nelson Complexity Index (NCI)

The refinery utilizes below listed Basic processes to meet the above objectives:
1) Separation: Vaporizing fractions of crude feed & subsequent separation of fractions based on varying boiling points.
2) Reforming: Reconfiguration of molecules for better value added products.
3) Treating (Hydrotreating): Removal of salts of metal contaminants – Nickel, Vanadium, Sulphur, etc to give Clean Fuel as per environmental norms.
4) Cracking: Break down larger hydrocarbon molecular into smaller ones for further processing.
5) Coking: The Carbon rich Heavy Residues of other refinery processes are treated at high temperatures to produce lighter value adding products
Refinery Configuration
A refiner's choice of crude oil will be influenced by the
There are several measures of complexity for refineries. The most publicly used is the Nelson Complexity Index (NCI) developed in the 1960s by Wilbur Nelson in a series of articles for the Oil and Gas Journal. The NCI is a pure cost-based index. It provides a relative measure of refinery construction costs based upon the distillation & upgrading capacity a refinery has. The index assigns a complexity factor to each major piece of refinery equipment based on its complexity and compared with simple crude distillation, which is assigned a complexity factor of 1.0. The complexity of each piece of refinery equipment is then calculated by multiplying its complexity factor (Table Below) by its throughput ratio as a percentage of crude distillation capacity. Adding up the complexity values assigned to each piece of equipment, including crude distillation, determines a refinery’s NCI number. The higher the NCI number of a refinery, the more complex it is and costly to build and
On the other hand, the demand of Oil from Petrochemical Industry is expected to grow around 4 folds from current 8% to around 31% in the same period.
Crude Oil Production across the world is getting Sourer (increasing Sulphur Content)
These changes are creating more volatility in pricing, forcing refiners to adjust their feedstocks more frequently and dramatically than in the past, and making long-range planning more difficult than ever. The influx of heavier and sourer oils also puts pressure on less complex refineries that must consider investing in conversion units if they want to stay in the game.
Thus, refiners are looking towards downstream petrochemicals sector as a dawning sun on their horizon.
Refiners are now competing against Natural Gas (NGL) for basic petrochemical feedstock chemicals – Ethylene & Propylene.
Cracking of Naphtha feedstock (obtained from Crude Oil) gives these basic chemicals.
Further, the drop in margins between Ethane Cracking (NGL) & Naphtha Cracking (Crude Oil) have put Refiners in a Strategic Sweet Spot.
The stable crude price has brought down Naphtha Price to near Ethane prices, making operability