Introduction to Pre-reformer Flowsheet Options

Introduction Pre-Reformer Flowsheet

Options By:

Gerard B. Hawkins

Managing Director, CEO

Steam Reforming Section - Pre-reformer

Single adiabatic reactor • upstream of the steam reformer • uses high activity Ni based catalyst

Converts hydrocarbons to methane, CO, CO2 and H2 • Eliminates C2 and higher hydrocarbons

from feed • Makes life easy for the steam reformer

!!

Steam Reforming Section - Pre-reformer: Why ?

High efficiency/low energy plants Low steam export – benefit if steam not

required Smaller and high heat flux reformers

• Lower reformer capex (offset by pre-reformer capex)

Simplified and robust steam reformer operation

Means to deliver feedstock flexibility (not only means) between lighter and heavier feeds

Steam Reforming Section - Pre-reformer: Why Not ?

Additional equipment • Capex (offset by smaller reformer ?) • Opex (catalyst; maintenance; ….)

Complicated and delicate pre-reformer operation • Easily damaged expensive catalyst

Low steam export – problem if steam export valued/required

Economics suggest that pre-reformer is not the only solution if feedstock flexibility is required

Process Steam

Hydrocarbon Feed

HDS

Reformed Gas

Fuel

ZnO

Steam Generation and Superheating

Combustion Air

Pre-heat

Pre-reformer

Steam Reforming Section - Pre-reformer: Scheme without Re-heat

Process Steam

Hydrocarbon Feed

HDS

Reformed Gas

Fuel

ZnO

Steam Generation and Superheating

Combustion Air

Pre-heat

Pre-reformer

Steam Reforming Section - Pre-reformer: Scheme with Re-heat

Steam Reforming Section - Pre-reformer: Why or Why Not Re-heat ?

Endothermic steam reforming at inlet (both beds) Methanation causes exotherm with naphtha

525 500 475 450 400 350

Tem

pera

ture

(oC

)

Natural Gas

Inlet Exit

947 932 887 842 752 662

Temperature ( oF)

Naphtha

Inlet Exit

Summary

High level review of syngas flowsheets

Key differences and options highlighted

Increased awareness but many further layers of detail exist