HYDROGEN PURIFICATION IN REFINERIES
Problem
Refinery processes producing hydrogen-rich off-gas
(processes where membrane solutions are available are highlighted)
Refinery hydrogen requirements are growing due to the increased use of hydrotreating (to remove sulfur) and hydrocracking (to convert heavy hydrocarbons to lighter, higher-value fuels). Residual gas from these processes contains a significant amount of unused hydrogen at pressure, and membranes provide an economical method for recovery and purification of this hydrogen. MTR's hydrogen-permeable
VaporSep®-H2 membranes can provide 90% to 99% pure hydrogen and greater than 90% recovery.
VaporSep® Solution
Hydrogen recovery from refinery hydrotreater or hydrocracking purge stream
VaporSep-H2 offers a simple method for recovering H2 from refinery streams. In a typical system, the feed gas is first cooled to remove condensable hydrocarbons, and then heated before entering the membrane. Hydrogen permeates preferentially through the membrane, producing a purified hydrogen “permeate” stream and a hydrocarbon-enriched “residue” stream. The available pressure for the purified hydrogen depends on the feed conditions, but can be as high as 1500 psi. The hydrocarbon-enriched “residue” is recovered at close to the feed pressure, and can be sent to directly to fuel, or first treated for liquefied petroleum gas (LPG) recovery if these components have value.
Benefits
VaporSep-H2 unit for H2 recovery
- Efficient and economical hydrogen recovery: typically 80% to 98% recovery of feed H2 with a purity of 90 vol% to 99 vol%
- Handles high feed pressures up to 2500 psia
- Reduce flaring and correct refinery fuel balance
- Proven performance and long membrane life: more than 50 references, including operating lifetimes of up to 20 years without replacement; typical membrane life is 5 to 10 years or more
- Simple, reliable, flexible unit; easy to install and operate:
- Integrates into existing operations with minimal modification
- Simple installation and operation with compact skid-mounted construction
- Minimal utility usage: Low pressure steam, instrument air, instrument power, N2
System Description
- Complete skid-mounted unit includes all necessary instrumentation and controls
- Typical size: 20 ft (L) x 8 ft (W) x 18 ft (H); 15,000 lb
System Performance
- Feed pressure: up to 2500 psi
- Feed: 1 to 200 MMscfd; 30% to 95 vol% H2
- H2 recovery: greater than 70% to 95+%
- Recovered H2 purity: 95% to 99 vol%
- Modular construction: 1 or 2 skids, each 20 ft (L) x 8 ft (W) x 18 ft (H)
Application Areas
- Refinery fuel/flare gas
- Hydrodesulphurization purges
- Hydrocracker purges
- Catalytic reformer net gas
- Pressure swing adsorption (PSA) tail gas
- Fluidized catalytically cracked (FCC) overhead gas