Quantitative Risk Assessment Study (QRA) Study Of IOCL, Haldia Refinery

The main objective of the Quantitative Risk Assessment study is to identify the potential hazards, assess the impact and frequency of all probable hazardous scenarios and if needed to suggest the mitigation measures to reduce the risk from the facilities under the scope of study to a tolerable limit.

Brief details of Process units, Offsite and Power & Utilities at IOCL Haldia Refinery (Crude processing capacity-8.0 MMTPA) –

A. Fuel Oil Block:

i) Crude Distillation Units (CDU-1 with revamp capacity 3.8 MMTPA & CDU- 2 capacity of 4.2 MMTPA)
(ii) Naphtha Hydrotreating (NHT) and Catalytic Reforming Unit (CRU)
(iii) Kerosene Hydro-Desulphurization Unit (KHDS)

C. DHDS Block:

(i) Diesel Hydro-desulphurization) Unit (DHDS)
(ii)Hydrogen Generation Unit (HGU-1)
(iii)Sulphur Recovery Units (SRU-II, III, IV Train-I & II)
(iv)Amine Treating Units(I/II) and Sour Water Stripping Units (SWS-I/II) (v)Vacuum Distillation Unit (VDU-2)
(vi)Resid Fluid Catalytic Cracking Unit (RFCCU)
(vii)MS Quality Upgradation (MSQ) Units:

Naphtha Splitter, Reformate Splitter and Naphtha Hydrotreating Unit
(viii) ISOM Unit
(ix)Gasoline Splitter and FCC Gasoline Treatment Unit & PrimeG+(quality revamped done under BS-VI)
(x)N2 Plant-1:1350 Nm3/hour N2 gas + 275 NM3/hr Liquid N2

F. BS-VI Block

(i) DHDT (Diesel Hydro-treating )
(ii) H2SO4 Plant (Sulphuric Acid plant)
(iii) ARU-4 (Amine Regeneration Unit)
(iv) SWS-4 (Sour Water Stripping unit)
(V) Plant Air, Instr. Air & N2 plant-3 (1100 Nm3/hr N2 gas)

B. Lube Oil Block:

(i) Vacuum Distillation Unit (VDU-1)
(ii)Propane De-asphalting Unit (PDA)
(iii)Solvent (Furfural) Extraction Unit (FEU) (iv)Lube Hydro finishing Unit (LHFU)
(v) Visbreaker Unit (VBU)

(vi)Catalytic Iso De-waxing Unit (CDWU)
(vii) New CDWU project (TOR application done before MoEF & CC)

D. OHCU Block:

(i) Once Through Hydrocracker Unit(OHCU)
(ii) Hydrogen Generation Unit (HGU-2) revamp
(iii)Feed Preparation Unit for CIDW(FPU)
(iv) N2 Plant-2: 1600 Nm3/hr. N2 gas + 400 NM3/hr Liquid N2

DYIP (Distillate Yield Improvement Project) Block:

(i) DCU (Delayed Coker Unit)
(ii) CGO-HDTU (Coker Gas Oil Hydrotreater unit) (iii) Coker LPG Merox Unit
(iv) SRU-V(Sulphur Recovery Unit)
(v) SWS-3 (Sour Water Stripping unit)
(vi) ARU-3 (Amine Regeneration Unit)

Apart from the Process units mentioned above, the refinery is also having the following operational facilities:


(i) 4 Nos Boilers (3 X 125 MT/hr and 1X 150 MT/hr)
(ii) 4 Nos Turbo Generators (3X 10.5 MW and 1X 16.5 MW)
(iii) 3 Nos Gas Turbines (3X 20 MW)
(iv) 3 Nos Heat Recovery Steam Generation Unit (1X100 MT/hr and 2X130 MT/hr) (v)Process Cooling Tower (PCT CT): 9 Nos cells of capacity 2300 M3 each
(vi) DHDS CT :7 Nos cells of capacity 3000 M3 each
(vii) OHCU + FPU CT: 4 Nos cells of capacity 3000 M3 each
(viii) TPS Cooling Tower (TPS CT): 3 Nos cells of capacity 3000 M3 each
(ix) GT Cooling Tower (GT CT): 8 Nos cells of capacity 125 M3 each

(x) DYIP CT: 3 Nos cells of capacity 4000 M3/hr each
(xi) BS-VI CT : 3 nos. cells of capacity 4000 M3/hr each
(xii) 5 Nos DM Water PLANT CHAINS

(xiii) Fire water tanks (3 x 9000 m3 each) and FW pump house
(xiv) 2 Nos Of Mixed Bed Resin System (MB-6/7) for Production of DM Water From TTP- RO Permeate.
(xv) DYIP- DM Plant 2 x 160 M3/hr
(xvi) Chlorine tonners and Chlorine dosing facilites near Cooling towers
(xviii) Other facilities:

  • Existing Flare: 54″ (HC Flare) / 16″ (acid flare)
  • DYIP Flare: 60″ (HC Flare)/ 16″ Staged/ 13″ (acid flare)


  • Effluent Treatment Plants (650m3/hr + 600 m3/hr)
  • TTP-RO of 1250 m3/hr capacity
  • LPG Storage & Dispatch (4 nos. Horton Spheres + 3 nos. Mounded bullets) – Propane Storage (3 nos. bullets)
  • Bitumen Drum Filling & Dispatch
  • TANK TRUCK Loading Gantry
  • TANK WAGON Loading Gantry
  • Petroleum final products & intermediate tanks (174 storage tanks)
  • Solvent Storage & Handling
  • Product Dispatch facilities through pipeline
    • PPL-HMR (2.5 MMT)
    • PPL-HBPL (1.0 MMT)
  • Coastal dispatch facilities – Barge /Tanker
  • 4 Nos. H2SO4 storage tanks & transfer system (i.e. Tanker & Barge Loading facilities through loading bays) under BS-VI