Methods of decreasing the volatiles content of coke obtained by the delayed coking process

Conclusions

To obtain coke of minimum volatiles content and maximum mechanical strength by the delayed coking process, the following measures are necessary:

• 1) Preheating of the feed to a sufficiently high temperature so that its temperature at the reactor inlet will be not lower than 480°C.

• 2) Effecting “cementation” of the coke in the reactor by use of coker gas oil vapors or superheated steam at 500°C or higher, a “cementation” time of 3–5 h, and gas oil and gas oil vapor consumption rates of 20–25 and 3–5 tons/h, respectively, or a saturated steam consumption rate of 0.3–0.6 tons/h;

• 3) Adding 3.8 ppm (based on converted feed) of polymethyl siloxane (or polydimethylsiloxane) liquid over a 2–3 h period until all the feed has been supplied to the reactor.