The test unit is a pilot plant scale FCC unit which replicates of anexisting unit in an operational refinery, and consisted of a hybrid feedsection to accommodate for the nonconventional feedstock, the catalystdosification module, the riser reactor module, the product collectionand separation modules and the inert gas distribution system. The catalyst regeneration unit was specifically removed from the present superstructure since the viability of use of spent FCC equilibrium catalystwith low activity was sought in the present work. The reactor moduleis made up of an atomization sub-module on which is mounted theriser reactor. The riser reactor, which was a replicate of an existing reactor in an operating refinery, was a tubular type with diameter 25 mmand effective length 2000 mm. The atomization sub-module housedthe section of the reactor containing the feed atomizer, and serves as apre-heat zone for the atomized VGO–LDPE blend. In order to avoid thethermal degradation of the feed blend and premature coke formationon the inner walls and discharge orifice of the atomizer (a commoncause of FCC atomizer plugging), the temperature of this module iskept just below the degradation temperature of the blends polymercomponent, specifically, 723 K. Similarly, additional measures weretaken to avoid coke build-up via pre-mature catalytic degradation onthe atomizer orifice through the introduction of the hot catalyst150 mm above the atomizer apex. The product collection and separation modules consist of the catalyst–gas disengagement system (cyclonic separator), vapour condenser and the liquid gas collection andsampling sub-units. The design, construction and operational analysisof the FCC pilot plant have been described elsewhere[11].AsimplifiedHysys® simulation processflow diagram of the FCC unit is given inFig.
đang được dịch, vui lòng đợi..