Hydrogen Recovery from Refinery Off-gases

Refinery Off-Gas as Feed to a Hydrogen Production Facility: Performance Lifting of the Steam Reforming Technique

“…In a typical refinery off-gas, there are 28% H 2 , 28% CH 4 , 24% C 2 + paraffins, 10% olefins, 3.5% N 2 , 3% CO 2 , and 3.5% CO, sometimes containing 25-250 ppm of sulfur (Dragomir et al, 2010). In another report by Faraji et al (2005), % molar composition of an industrial off-gas stream flowing at 5800 kg/h at 25 and 1.2 bara contains 45.74 C 1 , 5.46 C 2 , 3.84 C 3 , 0.98 iC 4 , 0.59 nC 4 , 0.18 iC 5 , 0.07 nC 5 , 0.04 C 6 + , 0.64 CO, 8.84 CO 2 , and 33.62 H 2 . Despite the fact that refinery off-gases containing minimal CO 2 cause greenhouse gas problems upon release, re-channeling them to recover CO 2 , CH 4 , and olefins will reduce this potential hazard to the atmosphere.…”

“…Among them, SMR is the best way to go based on the following reasons: it has the highest H 2 yield of all reforming strategies, it is currently the simplest and least expensive method of H 2 production, it has the highest efficiency (65-70%), it is the safest due to the lower operating temperature of the SMR technique, and cumulatively, its disadvantages are easier to overlook or address (Holladay et al, 2009;Olateju et al, 2017). Other techniques of separating H 2 from refinery off-gas, like pressure swing adsorption (PSA), membrane separation (MS), and cryogenic distillation (CD), are vividly explained in the literature, where cost and purity of the product recovery (i.e., H 2 ) are two major factors that must be considered in choosing a particular technique (Benson & Celin, 2018;Faraji et al, 2005;Hussain, 2023;Key & Malik, 2010;Mehra, 1988;Mperiju et al, 2023). In terms of purity, MS < CD < PSA, according to literature sources (Benson & Celin, 2018;Hussain, 2023;Mendez et al, 2000).…”

“…Increased demand for clean fuels will be a solid motivation to build new refineries having greater conversion and off-gas treatment capacity (Faraji et al, 2005). In addition to being used to remove metals, sulfur, and nitrogen (N 2 ) from various petroleum fractions, H 2 is desirable for the conversion and processing of heavy petroleum fractions into lighter products.…”

“…Based on this merit, we set an achievable objective of realizing approximately 40 kg/h of H 2 , to be manufactured taking refinery off-gas as feed. Off-gases formed at refineries regularly comprise of components such as olefins, diolefins, hydrocarbons, CO, CO 2 , H 2 S, and various organic sulfur speciesall of which are injurious to the environment and subject to ever more sterner protocols (Faraji et al, 2005). In a typical refinery off-gas, there are 28% H 2 , 28% CH 4 , 24% C 2 + paraffins, 10% olefins, 3.5% N 2 , 3% CO 2 , and 3.5% CO, sometimes containing 25-250 ppm of sulfur (Dragomir et al, 2010).…”

Metal-Induced Aminosilica Rigidity Improves Highly Permeable Microporous Membranes via Different Types of Pendant Precursors

“…Membrane-based gas separation processes are gaining a great deal of attention for carbon dioxide capture and separation, natural gas purification, hydrogen recovery, and molecular air filtration. − The primary advantages of membrane technology involve minimizing global energy demand and mitigating the effect of greenhouse gases from the consumption of conventional fossil energy resources, which is generally based on cryogenic distillation, solvent extraction, and evaporation. , Several studies have reported gas separation via the use of polymeric membranes such as polyaniline, polyimide, and polypyrrole and also via the use of porous inorganic membranes including zeolites, metal–organic frameworks (MOFs), carbon molecular sieve (CMS), and organosilica. Polymeric membranes have the advantage of flexible low-cost fabrication, but challenges include swelling, plasticization, and poor temperature and chemical stability .…”