catalytic reforming-design and operation of nht strippers

8/10/2019 Catalytic Reforming-Design and Operation of Nht Strippers

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Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / ShutdownActivation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & MassBalance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst PerformanceCharacterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /Process Technology Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology PetrochemicalsSpecializing in the Development & Commercialization of New Technologyin the Refining & Petrochemical Industries

Web Site: www.GBHEnterprises.com

GBHE Technical Bulletin CTB #55

Catalytic Reforming

Design and Operation of NHT StrippersTo Protect Catalytic Reformers

Information contained in this publication or as otherwise supplied to Users is believed tobe accurate and correct at time of going to press, and is given in good faith, but it i s forthe User to satisfy itself of the suitability of the information for its own particular purpose.GBHE gives no warranty as to the fitness of this information for any particular purposeand any impl ied warranty or condit ion (statutory or otherwise) is excluded except to theextent that exclusion is p revented by law. GBHE accepts no liabilit y resulting from relianceon this i nformation. Freedom under Patent, Copyright and Designs cannot be assumed.


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Table of Contents

Common Reformer Problems

Purpose of NHT Stripper

Typical Design

Instrumentation of NHT Stripper

Other Design Issues

Indications of Problems in the NHT

Response to Reformer Upsets


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Common Reformer Problems

H2S in feed to reformer

Water in feed to reformer

Bad H2O:HCl control

Feed quality (High EP, low N+A)

Low H2:Oil

Organic Sulfur Compounds in feed to reformer

Purpose of NHT Stripper

Remove the following to protect Reformer: H2S Light Ends Water

Typical Design

Number of Trays

20-35 Trays

Reflux to Feed Ratio

0.25 0.35 More Reflux = More Reliability

Feed Tray Location

5-10 trays from top of tower

More Rectifying Trays can be added if needed


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Instrumentation of NHT Stripper

Other Design Issues

Fired Reboiler vs. Heat Exchanger Reboiler

Better heat input control with Fired Reboiler

Overhead Pressure

Set by the vapor pressure of the liquid in the overhead receiver


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Other Indicators in Reformer

Yield decreases Recycle gas purity decreases LPG make increases Coke make increases

Response to Reformer Upsets

Cut Temperature on Reformer

~900F Hold until H2S is back down

Increase Chloride Injection

Double or Triple normal rates Hold until H2S is back down


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catalytic reforming-design and operation of nht strippers

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