Page 79 - Fluid Catalytic Cracking Handbook

FCC Feed Characterization 57

heavier crudes contain more nitrogen than the lighter crudes. In
addition, nitrogen tends to concentrate in the residue portion of the
crude. Figure 2-8 shows examples of nitrogen compounds found in
crude oil.

A. Neutral N - Compounds

N- H
Carbazole

B. Basic N-Compounds

'N' "N
Quinoline Acridine

o

COO Phenanthridine

C. Weakly Basic N-Compounds

*OH N--OH
IN
Hydroxipyridine Hydroxiquinoline

Deriviates with R = H, alkyl, phenyl-, naphthyl-

Nitrogen Distribution in Several Middle Eastern Oils (6)

Content: 20-25% of nitrogen in 225-540°C gas oil fraction.
75-80% of nitrogen in 540°C plus vacuum resid fraction.
Type: 225-540°C gas oil fraction: 50% of nitrogen as neutral nitrogen compounds;
33% as basic, 17% as weakly basic.
540°C plus vacuum resid fraction: 20% of nitrogen in asphaltenes, 33% as
neutral, 20% as basic, 27% as weakly baste.

Figure 2-8. Types of nitrogen compounds in crude oil [12].