Panipat Refinery is a technologically most advanced public sector refinery complex in India. It was Commissioned in 1998 and is located in the district of Panipat in the State of Haryana. The Integrated Panipat Refinery and petrochemical Complex, is the largest in India and third largest in South East Asia. The Refinery Complex comprises of Refinery, Aromatics Complex of Para Xylene/Purified Terepthalic Acid, Olefinic complex of Naphtha Cracker.
Earlier the capacity of the refinery was 6.0 MMTPA. In order to meet the ever growing demand of petroleum products, the capacity had been increased to 12 MMTPA in 2006 and subsequently to 15 MMTPA in 2010. Major secondary units includes Hydrocracker Unit (HCU), Delayed Coker Unit (DCU), Diesel Hydrotreating Unit, Hydrogen Generation Unit (HGU), Sulphur Block and associated auxiliary facilities.
The Scope of work is to carryout HAZOP (Hazard & Operability) Study for IOCL- Panipat refinery for 46 Process Units and 9 PX-PTA (Para Xylene – Purified Terepthalic Acid) Units which comprises of 1430 and 422 P&IDs respectively. Those Units are tabulated below:
Process Units:
| S.No | Unit No | List of Units covered in HAZOP study |
| 1 | 03, 04, 19 | CDU, VDU(AVU I) |
| 2 | 5 | OHCU |
| 3 | 6 | HGU |
| 4 | 7 | RFCCU |
| 5 | 33 | PSU |
| 6 | 8 | CRU |
| 7 | 52 | DHDS |
| 8 | 9 | VBU |
| 9 | 10 | BBU |
| 10 | 12 | Gasoline Merox |
| 11 | 13 | LPG Merox |
| 12 | 15 | ATF/SKO Merox |
| 13 | 22 | SRU |
| 14 | 44 | SSRU |
| 15 | 21 | ARU |
| 16 | 17 | SWS-I(Refinery) |
| 17 | 18 | SWS-IIII(Hydro processing) |
| 18 | OM&S + Offsite-LPG/Tank farm | |
| 19 | 61 | ETP-I |
| 20 | 62 | ETP-II |
| 21 | 257 | ETP-III |
| 22 | – | CPP |
| 23 | – | Utilities |
| 24 | 73 | AVU-II |
| 25 | 74 | VDU-II |
| 26 | 59 | NSU-2 |
| 27 | 75 | HCU |
| 28 | 76 | HGU |
| 29 | 77 | HGU |
| 30 | 78 | DCU Revamp |
| 31 | 79 | Cracked (DCU) LPG Merox |
| 32 | 72 | DHDT Revamp |
| 33 | 55 | SRU-I |
| 34 | 56 | SRU-II |
| 35 | 57 | TGU |
| 36 | 51 | ARU |
| 37 | 53 | SWS-I |
| 38 | 54 | SWS-II |
| 39 | 20 | SW Stripper (Hydroprocessing) |
| 40 | 25 | SRU |
| 41 | 26 | TGTU |
| 42 | 301 | NHT |
| 43 | 301 | PENEX |
| 44 | 302 | RSU |
| 45 | 303 | FCC GDU |
| 46 | 304 | MSQU (offsites) |
| 47 | 107 | NDHDT |
| 48 | 88 | Sulfur Handling Unit |
| 49 | 63 | Flare System |
| 50 | 39 | Prep Sour Flare System |
| 51 | 41 | IFO-Merox |
| 52 | 105 | TAME |
PTA Units:
| S.No | Unit No | List of units covered for HAZOP study |
| 53 | 201, 202 | NHT, CCR with REGTR |
| 54 | 204 | Shell Sulfolane |
| 55 | 205 | Parex |
| 56 | 206 | XFU |
| 57 | 207 | Isomer |
| 58 | 208 | Tatoray |
| 59 | 209 | BTF |
| 60 | 2 | PTA-Oxidation/ Purification |
| 61 | 37 | PTA N2 plant |
The objective of the HAZOP (Hazard & Operability) study is to provide required support in managing project risk through early identification of hazards and operability problems and to reduce the probability and consequences that would have an adverse impact on the personnel, plant, properties and environment.
The Steps involved in HAZOP study are as follows:
- Select the node (line, equipment or a system) on the Piping and Instrumentation Diagram.
- List the intention (Design intent) & process parameters, guidewords for the selected node.
- List all the deviations, apply the necessary deviation and ignore the deviations that are not relevant.
- Brainstorm and list all the possible causes for the deviation applied and ignore the causes that are not credible.
- Determine the Consequences for the listed deviation with the credible cause.
- Identify the Safeguards that are already provided in the system.
- Suggest recommendations/actions where the safeguards are found to be inadequate.
- Repeat steps 3 to 7 for each deviation.
- Repeat steps 1 to 8 in the next node until all nodes are covered.
Guidewords are the tools that are used systematically to direct the HAZOP Study. Guidewords are those Words or phrases, when put together with a parameter, form a deviation for the Team to consider. The basic guide words are: NO/LESS, MORE, REVERSE and OTHERS.
