2020 REFINING PROCESSES HANDBOOK PROCESS CATEGORIES COMPANY INDEX HYDROPROCESSING Hydrogenation, CDHydro® benzene in reformate Hydrogen recycle CW Offgas Application: The CDHydro catalytic distillation technology processes reformate streams from refineries to reduce benzene to levels required by low-benzene gasoline specifications. Description: The patented CDHydro process hydrogenates benzene to cyclohexane in a catalytic distillation column. Hydrogenation reduces benzene in the gasoline pool. This process combines the three unit operations of reformate splitter, benzene hydrogenation and product stabilization in one unit operation. Selective hydrogenation: Reformate and hydrogen (H2 ) are fed to the catalytic distillation column. Hydrogenation of benzene to cyclohexane can exceed 99%. Benzene conversion can easily be limited to lower levels through control of H2 addition. Washing action of the reflux minimizes oligomer formation, flushes heavy compounds from the catalyst and promotes long catalyst life. Treated C6 product is taken as overhead. Excess H2 and lights are recycled and vented from the overhead drum. The C7+ product is taken as bottom with essentially full recovery of heavy aromatics. The unique catalytic distillation column combines reaction and fractionation in a single unit operation. This constant-pressure boiling system ensures precise temperature control in the catalyst zone. Low reaction temperature and isothermal operation enhance safety. Economics: Capital costs are considerably lower than conventional hydrotreaters, since the single-column design eliminates costs associated with fixed-bed systems and operates at low enough pressure to avoid the need for a hydrogen compressor. The CDHydro process is typically installed in a benzene-toluene splitter, either as a retrofit or in a new column. Overhead drum Low-pressure hydrogen C5 - C9 reformate Reflux Treated C6s Benzene-toluene splitter MP steam C7 + * * * * * Low benzene reformate Low benzene in reformate All carbon steel construction No H2 compressor Isothermal operation Reduced plot area. Installation: There are seven licensed units, with the first one licensed in 1995. Licensor: Lummus Technology Contact: Technology@lummustech.com Advantages: * Lower capital cost * High conversion * Simple operation * Low operating pressure * Low operating cost * Low capital cost Copyright © 2020 Gulf Energy Information. All rights reserved.http://www.hydrocarbonprocessing.com/