1. Water Gas Shift & Hydrogen Purification Section Flowsheet By: Gerard B. Hawkins Managing Director

2. Simplified Steam Reforming NH3 Plant H2O H/C feed H/C purification Removes impurities (S, Cl, metals) Steam reforming Converts to H2, CO, CO2 + H2O + CH4 H2O Shift WGS reaction: H2O + CO CO2 + H2 H2 Hydrogen purification Removal of CO, CO2 + maybe CH4 3. Shift & Hydrogen Purification Sections Consider shift + purification together design options are intimately linked Historically preferred designs linked to available catalyst/absorbent technology Not required on HyCO and MeOH plants 4. Shift & Hydrogen Purification Sections Water gas shift reaction Purification Either: CO2 removal and methanation (NH3 & old H2) COx + H2 => CH4 + H2O yields ~96 % H2 Or: PSA unit (newer H2) yields 99.9+ % H2 CO + H2O CO2 + H2 (+ heat) 5. Shift & Hydrogen Purification Sections Ammonia Plants Designs feature HTS and LTS beds in series with inter-cooling HTS From Steam Reforming Liquid CO2 Removal LTS H2O CO2 feed to urea plant Methanation H2 COx + H2 => CH4 + H2O 6. Shift & Hydrogen Purification Sections Ammonia Plants Design options Linde LAC process use tubular ITS followed by PSA unit From Steam Reformer PSA H2ITS H2O Purge gas to fuel 7. Shift & Hydrogen Purification Sections Hydrogen Plants Designs 1970s to mid-1980s LTS catalyst developed HTS and LTS beds in series with inter-cooling HTS From Steam Reforming Liquid CO2 Removal LTS H2O CO2 to vent Methanation H2 COx + H2 => CH4 + H2O 8. Shift & Hydrogen Purification Sections Hydrogen Plants Older plants built up to ~1970 pre-date LTS catalyst development two HTS beds in series with inter-cooling HTS From Steam Reforming Liquid CO2 Removal HTS H2O CO2 to vent Methanation H2 COx + H2 => CH4 + H2O 9. Shift & Hydrogen Purification Sections Hydrogen Plants Designs since mid-1980s PSA units improved significantly HTS followed by PSA unit From Steam Reforming PSA H2 HTS H2O Purge gas to fuel vent 10. Shift & Hydrogen Purification Sections Hydrogen Plants Design options include additional LTS before PSA unit favoured in some large new plants (>105 kNm3/h or 90 MMSCFD) HTS From Steam Reforming PSA H2LTS H2O Purge gas to fuel vent 11. Shift & Hydrogen Purification Sections Hydrogen Plants Design options use MTS followed by PSA unit From Steam Reformer PSA H2MTS H2O Purge gas to fuel vent