Q & A > Question Details
Is there any limitation for taking Hydrogen rich off gases as feed to reformer? My doubt is whether excess hydrogen in the feed to reformer can it cause reversible reactions as steam methane reforming is reversible in reaction?
24/04/2019 A: Rajesh Nandanwar, Bharat Oman Refineries Limited, Bina, rajesh.nandanwar@borl.co.in
It depends on the H2 content of rich off gases. Normally excess H2 above that required for hydrogenation/desulphurinsation reactions about 0.25 mol/mol feed gas is normally taking free ride but required additional energy with little advantage of lower coking chances.
It is good practice to use H2 rich off gas as recycle H2 and rest of the H2 can be sent to PSA unit for purification This solves two purposes, one you do not use purified H2 for recycle requirement and also reduced loading of PSA.
26/10/2018 A: vijaykumar natarajan, BPCL, Mumbai Refinery, vijaykumarn@bharatpetroleum.in
Reply to your 1st Q: why you want to take Hydrogen rich gases inside a reformer?
Reply to your 2nd Q: excess H2% in Refeormer feed is good for reformer catalyst. Results- less coke formation, you can keep Low RGC flow to reactors by maintaining same H2/ HC ratio (provided your Packinox Lifing flow is satisfied). as an Operator of CCR unit, i can ensure no such reverse reacations takes place during excess H2% in RGC.
04/10/2018 A: Yongwen Wu, Manchester University, hawlcat@hotmail.com
"Any excess hydrogen in feed implies loss of energy and capacity limitations as the intent here is to produce hydrogen." (NS Murthy)
If hydrogen is originally purged to fuel, is it a good way to recover hydrogen by using those low purity hydrogen as reformer feed? Can it also reduce hydrogen production cost effectively since less fuel is required?
03/10/2018 A: NS Murthy, Suez, murthy.ns.ext@suez.com
I must say, it is good question. As such one would required to have some hydrogen in feed gas (may up to 25% vol.) so as to convert all S species in feed gas into H2S in the u/s feed gas hydrotreater. Any excess hydrogen in feed implies loss of energy and capacity limitations as the intent here is to produce hydrogen. There are lit available on kinetics which the refiner may like to go thru. Being a highly endothermic reaction of methane to carbon monoxide and hydrogen in first place, and that too when there is higher level of H2O (excess over stoichiometric need), the impact of hydrogen in feed could be minimal. Take up with M/s Linde the reformer licensor and they can optimize the unit.