1a) Modern concept is that the refinery and petrochemical complex should be situated in the same campus - why? b) In a modern refinery coking and visbreaking concepts are losing ground - then what are the alternative routes to process the feeds to the said units? Why? 2a) Why water is added to the desalter? b) What is the function of pump-around reflux? 3a) Tray tower or packed tower - which one for ADU and VDU and why? If tray is used then which type of tray? Why? b) No reboilers are used in ADU or VDU, then how distillation can take place? 4a) Catalytic reformer generally consists of three reactors of unequal size in series with inter-stage heating arrangement - why? b) Describe the Fluid Coking process (Flowsheet not needed). 5a) Discuss how the reactor section of the FCC operates (Flowsheet not needed). b) One hundred percent conversion is possible in a distillate hydrocracker - how? 6a) Between NG and LPG - which one is a comparatively safer fuel? Why? b) Merox is a sweetening processes and not a de-sulfurization process - Comment. 7a) How can the petrochemical precursors C2 and C3 be obtained from natural gas? b) Will crosslinking convert thermoplastic to thermoset? Give proper reasoning