Q & A > Question Details
I am working in VGOHDT. We are facing flaring issue intermittently in Fractionator overhead drum. We are using split range controller for maintaining pressure using fuel gas and excess pressure will release in LP flare.
But we found that the overhead gas composition consist about 51% hydrogen ,23% methane and 14% nitrogen respectively which are non condensable gases. We increased HP steam in stripper column and reduce the pressure in Cold LP separator for removing it but problem persist. Kindly give suggestion to reduce H2 and methane to reduce flaring in Fractionator?
We are operating fractionator pressure at 1kg/cm2 and top temperature at 106 deg c.Overhead Finfan outlet temperature at 45 deg.
 
Answers
11/09/2018 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Confirm the stripping steam flow rate by making overall component balance and/or comparing with overhead water flow rate. If that is O.K, the stripping steam may not be dispersed across the cross-section of the column, or the liquid hydrocarbon may be channeling.
03/09/2018 A: Rajasekaran R, HMEL, Rajaskrn.89@gmail.com
We are maintaining H2/HC ratio as per licensor recommendation.There is no issue in Reactor.How Hydrogen slippage in Fractionator over head drum is related to reactor issue?
03/09/2018 A: Rajasekaran R, HMEL, Rajaskrn.89@gmail.com
we are maintaining HHPS inlet temp @ 285 deg C and stripper bottom temp @ 272 deg C.From where hydrogen and methane slippage was happening?
24/08/2018 A: Bhavesh Kanani, Saudi Aramco, bhavesh.kanani@gmail.com
You may look into the reducing HHPS temperatures is feasible with is stripper feed.
As CLPS pressures is already reduced which will remove lighter to off gas. As stripping is done by HP steam, reduction of stripper bottom temperature to be checked.
24/08/2018 A: Bruce Carr, Suncor Inc, bcarr@suncor.com
That much slippage sounds more like a reactor issue.... have you tried adjusting your reactor temps.... recycle ratio?