Hydrogen recovery from ammonia purge gas by a membrane separator: A simulation study

Abstract

Summary In this study, a two‐dimensional mathematical model is proposed for modeling the hollow fiber membrane (HFM) separators for hydrogen (H2) recovery unit implemented in the Razi Petrochemical Company (Imam Khomeini Port, Iran) to capture hydrogen from ammonia (NH3) purge gas. In this regard, computational fluid dynamics is applied to solve the equations of momentum and mass transfer in the laminar flow conditions. Axial and radial diffusion for mass transfer inside the membrane fibers and axial diffusion within the shell side of separator were considered. The distributions of concentration, velocity, and mass transfer fluxes were achieved by the model. As the new insights, the effects of feed flow rate and feed gas concentration on mass transfer of H2 were investigated. Moreover, fluid velocity profile and H2 fluxes in the tube (fiber), membrane, and shell sides of the HFM separator were studied. The results of simulation were compared with the industrial data and showed that the present developed model has excellent agreement with the experimental data with a low mean deviation value of 3.5%.

Experimental study on water recovery and SO 2 permeability of ceramic membranes with different pore sizes

“…Xu et al 8 used porous metal organic framework (MOF)-205 to separate carbon dioxide from hydrogen and methane. Maarefian et al 9 used a hollow fiber membrane separator to separate hydrogen from ammonia. Absorption method, MOF, and hollow fiber membranes were used for dehydration and gas separation in above studies.…”

Green and Sustainable Chemical Looping Plasma Process for Ammonia and Hydrogen Production

“…The aluminium oxide produced in this reactor is then fed into the thermal plasma reactor to re-generate the reduced aluminium particles for completing the cycle and to provide the feed for the nitridation reactor. It is worth mentioning that in the hydrogen dominant operating region, still ammonia is produced, however, the mole fraction of the H 2 :NH 3 is 1:300 or (less than 0.3%) that can be separated from the hydrogen stream using a robust aqua-ammonia condenser already developed in the literature [40] or hydrogen/ammonia membrane separators [41]. It is worth mentioning that alumina has already been identified as an oxygen carrier in a two-stage chemical looping ammonia production at 1773 K and 0.1 MPa using steam hydrolysis reaction.…”

A Prospective Concept on the Fabrication of Blend PES/PEG/DMF/NMP Mixed Matrix Membranes with Functionalised Carbon Nanotubes for CO2/N2 Separation

“…Over the years, chemical separation using membrane technology has attracted enormous interest in fields such as gas separation, water purification, food processing, pervaporation, membrane contactors and reactors, and so on [ 53 , 54 ]. Membrane technology has lower overall and operational costs, thereby allowing it to compete with processes such as absorption, adsorption and cryogenic distillation [ 55 , 56 ]. In terms of economic viability in CO 2 separation, membrane technology has lower overall costs [ 57 ].…”