2006 Spring Meeting & 2nd Global Congress on Process Safety
(99d) Fast Cycle Rotary Adsorption Bulk Separator at Low Pressure
Authors
The separation of gaseous mixtures at low pressures into their constituent components has been a challenge as it is energy intensive and costly. The paper addresses the technology of rotary adsorption to perform separations at low pressures, utilizing the partial pressure difference and a displacement purge (may also include inert purge) stream. This may be applied to hydrogen enrichment from syngas mixtures, where carbon dioxide is to be rejected with nitrogen-enriched air as the displacement purge stream containing residual oxygen/nitrogen. This technology has diverse applications like High Temperature Fuel Cell (HTFC, such as Molten Carbonate Fuel Cell and Solid Oxide Fuel Cell) off-gas, PSA off-gas, CO2 removal and other bulk separations.
Examples will be discussed such as the application to HTFC anode exhaust: · Enables bulk separation of CO2 from the HTFC anode exhaust stream and overall improved hydrogen recovery efficiency. · Utilizes external purging instead pressure-swing for adsorbent regeneration o Bulk separator H2 recovery of over 90% is achievable o Operates at near atmospheric pressure with low pressure drop
Benefits of Bulk Separation Rotary Adsorption Module will be examined: · Enrichment the H2 concentration in HTFC anode exhaust · Decreases in the down stream H2 purification PSA operating pressure · Bulk separation operation at < 3 psig and requiring minimal operating energy · Fast-cycle structured adsorbent bed and rotary valve technology increases the bulk separator's hydrogen production per unit volume and enables a small, efficient device