Naphtha Hydrotreating Unit скачать в хорошем качестве

Naphtha Hydrotreating Unit

The chemistry it’s very well known, the main goal to remove sulfur, nitrogen, oxygen and metals compounds; olefin & aromatic saturation and sulfur recombination occurs. 1. Reactor: Design T 370C to remain with 1¼ Cr - ½ Mo with SS347 lining as MOC Usually 1 catalyst bed, but can be fit with 3 beds, quench zone between beds; 6 m max catalyst bed depth, but also 1 (one) 10-12 m bed was used without any flow mall distribution If NHT is upstream Reformer a max outlet T of 340C is recommended to avoid sulfur recombination Inlet nozzle min 700 mm for internals installation and easy access Naphtha at reactor inlet is 100% vaporized then an inlet distribution tray is not necessary An inlet diffuser shall dissipate the feed high velocity avoiding attrition of topping layers and increasing of reactor delta p Inlet elbow on the manway cover shall be foreseen such that when removed shall be a min 1 m radial clearance from the manway centerline for access, no instrumentation on elbow Typical delta p per 1 m of catalyst bed around 0.03 bar calculated by Ergun equation / even if it’s for isothermal flow conditions, good accuracy is obtained using bed average fluid properties Bed support design loading is clean bed pressure drop + fouling allowance + dead load of catalyst where fouling allowance depends by Licensor, usually for top bed 2.0-2.5 bar and for bottom bed 1.0-1.5 bar Outlet collector design depends by each Licensor from simplest ones to very complicated, the main idea is to minimize delta p not causing flow maldistribution in the catalyst layer from above For outlet nozzle provide a 50 mm nominal bore blind flange connection to connect a nitrogen purge Multipoint thermocouple shall be provided for top, middle and bottom of catalyst bed and also the skin thermocouple outside the reactor to monitor heads and reactor wall. 2. Reactor Fired Heater: Floor fired vertical cylindrical type with air preheater and induced/forced draft fans / induced fan to control the furnace pressure and forced one to provide the combustion air The purpose of forced/induced system is to provide all the time oxygen to avoid explosive mixture accumulation Skin thermocouples are mandatory, remember that the furnace tubes are design per max 100000 hours strength corresponding to a max tube wall temperature, if the fired heater is operating at temperature higher with only 25C than the design the life could dramatically decrease to 20000 hours of even less Monitor heater delta T especially for transient phases, delta T affects skin temperature and remember that fired heater inlet T depends by reactor outlet T and during start-up the rector outlet T is lower than in normal operation meaning that the delta T shall increase, and corrected actions shall be taken. Enjoy! eBook: https://lnkd.in/evN6h_w https://lnkd.in/eF4KWM9 https://lnkd.in/eUcR2kk #innovation #sustainability #processengineering #research #energy #training #technology #business #engineering