Code IOCL-ERU Customer IOCL - Panipat Plant / Location Panipat, India Process Product Olefins Production From RFCC And DCU Off Gases And Integration With NCU C2 (Ethylene + Ethane) Streams Feedstock RFCC And DCU Off Gases Capacity 81.9 KTA PRE-FEASIBILITY REPORT ON PRODUCTION OF OLEFINS FROM RFCC AND COKER OFF GASES AT PANIPAT NAPHTHA CRACKER COMPLEX INDIAN OIL CORPORATION LTD. (IOCL)
S.No. Content Page No. 1.0 INTRODUCTION 3 2.0 BASIS OF STUDY 4 2.1 Need for the Proposed Project 4 2.2 Production Capacity 4 2.3 Design On-Stream Time 4 2.4 Overdesign 4 2.5 Overall Material Balance 4-5 3.0 PROCESS DESCRIPTION 6 3.1 Block Flow Diagram 6 3.1.1 Block Flow diagram for ERU Feed Treatment and Recovery 6 3.1.2 Block Flow diagram for ERU integration with NCU 7 3.2 BFD/PROCESS DESCRIPTION 8 3.2.1 ERU Process Description 8-12 4.0 RAW MATERIAL, PRODUCT & UTILIT 13 4.1 Raw Materials 13 4.1.1 Raw Material Quality 13 4.1.2 Raw Material Battery Limit Conditions 13 4.2 PRODUCT 13 4.2.1 Production Capacities 14 4.2.2 Product Battery Limit Conditions 14 4.2.3 Additional Storage 15 4.3 Flare System 15 4.3.1 Flare load from ERU Equipment located in Refinery Complex 15 4.3.2 Flare load from ERU Equipment located in NCU Complex 15 5.0 SOCIAL BENEFITS 16 5.1 Social Upliftment of the Region 16 5.2 Employment Generation 16 6.0 SAFETY AND POLLUTION CONTROL MEASURES 17 6.1 General 17 6.2 Environmental Protection 17 6.3 Highlights of Effluent generated in ERU 18 6.3.1 Effluent Summary 18 6.3.2 Gaseous Effluents 18 6.3.3 Acqueous Effluent 18 6.3.4 Solid Effluent 18 CHAPTER 1 2
INTRODUCTION 1.0 INTRODUCTION Indian Oil Corporation Ltd. (IOCL) intends to build an Ethane/Ethylene Recovery Unit (ERU) for Olefin Production from RFCC and DCU Off-gases and integrate with existing Naphtha Cracker Unit (NCU) located in Panipat, India. This project utilizes Lummus Low Pressure Recovery (LPR) Technology and consists of ISBL process units and supporting facilities designed to produce C2 and C3+ product streams from ERU that are being integrated with the existing NCU and other by-products. Owner Plant Location : Indian Oil Corporation Ltd. (IOCL) (Refineries Division) : Panipat, Haryana, India 3
CHAPTER 2 BASIS OF STUDY 2.0 BASIS OF STUDY 2.1 Need for the Proposed Project The ERU is designed to maximize the recovery of Ethylene and Ethane from RFCC and DCU off-gas feeds. Three main products are recovered from the Refinery offgas. Ethylene and ethane recovery is maximized in the ERU and recovered in the NCU via the overhead of the ERU Deethanizer. Fuel gas from the ERU Demethanizer overhead is recovered and returned to the fuel gas line near the Utility Boiler (Panipat Refinery End) Out Side Battery Limit (OSBL). The C3+ product from the ERU Deethanizer bottoms is sent to the NCU for recovery/ processing. 2.2 Production Capacity The plant design is based on following production capacities: Product Capacity (KTA) Total C2 Stream to NCU 81.9 Contained Ethylene (in total C2 Stream) 16.7 Contained Ethane (in total C2 Stream) 64.7 2.3 Design On-Stream Time The total C2 (Ethylene + Ethane) capacity is based on 8000 hours operation per calendar year. 2.4 Overdesign Unit / Section % of Design Capacity ERU 110 Enhanced Binary Refrigeration (EBR) 115 2.5 Overall Material Balance ERU Overall Material Balance Feeds TPH Design Case KTA 4
RFCC Dry Gas 9.41 75.30 Coker Dry Gas 19.00 152.00 Total ERU Feeds 28.41 227.30 Products Design Case TPH KTA Demethaniser Net Overhead as Refinery Fuel Gas 11.71 93.7 C2 Product to Ethylene Fractionator 10.24 81.9 C3 Plus Product to Depropanizer 4.64 37.1 Acid Gases & Water 1.82 14.5 Total ERU Products 28.41 227.3 For recovering C2s and C3s in ERU, off gas from Resid Fluid Catalytic Cracking (RFCC) and Delayed Coker Unit (DCU) dry gas will be combined upstream of the ERU. The ERU MDEA/Water Wash Tower and ERU DGA/Water Wash Tower will be located inside the refinery complex for integration with the refinery Mono Di-Ethanol Amine (MDEA) regenerator system. The combined off-gas stream is first amine washed in MDEA/Water Wash Tower using 30 wt% MDEA, N-methyl-di-ethanolamine, nonproprietary solvent. Rich amine acid gas loading is limited to 0.4 moles of acid gas per mole of MDEA as per design of amine regenerator system for the refinery complex. Lean amine for the MDEA /Water Wash Tower will be supplied from refinery amine regeneration facilities with acid gas loading of 0.02 moles of H2S per mole of MDEA. After the MDEA amine wash, the off-gas is further amine washed in the Di-Glycol Amine (DGA) / Water Wash Tower before being routed to NCU block through an approximately 7.0 km long pipe line for further feed treatment of ERU. ERU Amine Treatment system equipment (MDEA absorber, DGA absorber and DGA regenerator system) to be located inside Refinery complex. ERU Integration with existing NCU facility: The ERU will be integrated with the existing Naphtha Cracker Unit (NCU). Integration with the NCU allows the Ethane and Propane recovered in the ERU to be recycled back to cracking heater and converted to ethylene and propylene. 5
CHAPTER 3 BLOCK FLOW DIAGRAM and PROCESS DESCRIPTION 3.0 BFD / PROCESS DESCRIPTION 3.1 Block Flow Diagram 3.1.1 Block Flow Diagram for ERU Feed Treatment and Recovery 6
3.1.2 Block Flow Diagram for ERU Integration with NCU 7
3.2 Process Description 3.2.1 ERU Process Description RFCC and DCU Off-gas are fed to the Refinery Offgas Knock-out Drum. The refinery off-gas feeds contain primarily C1-C4 hydrocarbons but also contain significant impurities including: hydrogen sulfide, oxygen, carbon dioxide, nitrogen oxides, various metals, and various other contaminants. The levels of these contaminants must be significantly reduced before processing in the recovery section of the ERU. The process gas from the Refinery Offgas Knock-out Drum is sent to the bottom of the ERU MDEA/Water Wash Tower to reduce the amount of acid gases in the feed. Lean MDEA from the refinery (OSBL) is collected in the ERU Lean MDEA Feed Drum, then pumped through the ERU Lean MDEA Filters and fed to the top of two packed beds. The MDEA absorbs the bulk of the H2S and some CO2 from the process gas. As the vapour continues up the tower it passes through water wash section to prevent MDEA carryover to the next tower. Condensate from OSBL is used as wash water which is cooled in the ERU Condensate Cooler and collected in the ERU Amine Wash Water Feed Drum, and then pumped on flow control to the top of the tower. Spent wash water from this section is drawn off on level control and sent OSBL for treatment. After treatment with MDEA, the column overhead is sent to the lower section of the ERU DGA/Water Wash Tower. Rich MDEA from the bottoms of the ERU MDEA/Water Wash Tower is sent on level control to the refinery (OSBL) for regeneration. Any heavy hydrocarbons that accumulate in the tower bottoms sump are removed via manual valves to the ERU MDEA Oil Degassing Drum and are sent to the Amine Blowdown System. The ERU MDEA/Water Wash Tower overhead is sent to the bottom of the ERU DGA/Water Wash Tower to further reduce the amount of acid gases in the feed. Lean DGA from the ERU Lean DGA Filters is fed to the top of two packed beds and absorbs most of the remaining acid gases from the process gas. As the vapour continues up the tower it passes through water wash to prevent DGA carryover. Wash water is pumped on flow control to the top of the tower. Spent wash water and waste water from this section is drawn off on level control and split; a portion is sent as make-up water to the DGA regeneration system, while the rest is sent OSBL for treatment. After treatment with DGA, the column overhead is sent through an OSBL pipeline connecting the refinery complex to the ERU Caustic/Water Wash Tower in the NCU. Rich DGA from the bottoms of the ERU DGA/Water Wash Tower is sent on level control to the ERU Rich DGA Filters and ultimately to the ERU DGA Regenerator. Any heavy hydrocarbons that accumulate in the tower bottoms sump are removed via manual valves to the ERU DGA Oil Degassing Drum and are sent to the DGA Drain System. A pressure controller sends excess overhead vapor from the ERU DGA/Water Wash Tower to the fuel gas system in refinery complex on high pressure. IOCL has proposed to provide Fuel gas KOD in Fuel gas line from ERU DGA/Water Wash Tower to prevent carryover of any DGA solution in case of any upset into fuel gas system. Rich DGA from the bottoms of the ERU DGA/Water Wash Tower is sent to the ERU DGA Regenerator. The Rich DGA is filtered in the ERU Rich DGA Filters and is preheated against the hot bottoms (regenerated Lean DGA) of the regenerator in the ERU Lean DGA/Rich DGA Exchanger. The Rich DGA from the ERU DGA/Water Wash Tower is fed to the top of the packed bed section, and makeup DGA combined with makeup water is fed to the bottom of the regenerator. The gross overhead from the ERU DGA Regenerator is condensed against cooling water in the ERU DGA Regenerator Condenser and collected in the ERU DGA Regenerator Reflux Drum. 8
The bottoms of the ERU DGA Regenerator, Lean DGA, is pumped and cooled by exchanging heat with Rich DGA feed in the ERU Lean DGA/Rich DGA Exchanger. The Lean DGA is cooled further against cooling water in the ERU Lean DGA Cooler before being filtered in the ERU Lean DGA Filter and recycled back to the DGA/Water Wash Tower. A provision is included the remove heat-stable salts formed in the DGA system via the ERU DGA Reclaimer. The exchanger is used in batch operation utilizing MP steam to evaporate the DGA solution, leaving behind DGA sludge to be drained to drums and sent for disposal OSBL. To maintain a concentration of approximately 10 wt% in the strong caustic compartment of the ERU Caustic/Water Wash Tower and to replace water that has evaporated from the circulating caustic into the process gas stream, makeup caustic solution from the NCU is continually added to the ERU Strong Caustic Circulation Pump suction on flow control. Make-up water is also added at the suction of the ERU Strong Caustic Circulation Pumps on flow ratio control to dilute the make-up caustic concentration to around 10 wt%. Make-up water is primarily spent wash water from the upper water wash section of the ERU Caustic/Water Wash Tower, and the balance is fresh wash water from the NCU. If any excess upper section spent wash water remains after dilution, it is sent on level control to the lower water wash section of the ERU Caustic/Water Wash Tower. The process gas is fed to the lower section of the ERU Caustic/Water Wash Tower and is washed with caustic to remove residual CO2, H2S, and SOx to very low levels. Caustic also removes most of the HCN and HCl that could be present. The process gas is then washed with water to prevent caustic carryover. The process gas is then sent from the lower section of the ERU Caustic/Water Wash Tower for further treating to the ERU Chloride Guard Bed. Wash water is sent by flow control to the tower on tray #3. Spent wash water is sent on level control to OSBL for treatment. Spent caustic from the lower section of the Caustic/Water Wash Tower is sent on level control to the NCU before being routed to OSBL for treatment. A small amount of high molecular weight polymer yellow oil may be formed in the ERU Caustic/Water Wash Tower. Provisions have been made to decant this oil from the bottom of the tower so it does not build up in the caustic circulation streams and cause fouling. The "yellow oil" is manually sent to the spent caustic line. The process gas from the lower section of the ERU Caustic/Water Wash Tower enter the top of the ERU Chloride Guard Bed. This non-regenerable bed is provided to remove any potential organic chlorides which can impair performance of the oxygen converter catalyst. The ERU Chloride Guard Bed consists of two vessels in a lead-lag arrangement to allow for maximum utilization of the adsorbent. The process gas leaving the ERU Chloride Guard Bed is filtered, and then preheated against the converter effluent in the ERU Oxygen Converter Feed/Effluent. Exchanger followed by HP steam in the ERU Oxygen Converter Feed Heater before being routed to the ERU Oxygen Converter. Catalyst selectivity is moderated by injecting Dimethyl Disulfide (DMDS) in the feed, which is eventually removed in the upper section of the ERU Caustic/Water Wash Tower. The catalyst in the ERU Oxygen Converter is Clariant OleMax 101 sulfided nickel catalyst, and is selective only in a certain range of temperatures. Due to coking of the catalyst, the operating conditions require gradually increasing temperature over time to maintain conversion. However, as the temperature increases, the selectivity decreases, and DMDS injection is required to maintain optimum performance. In the ERU Oxygen Converter, the oxygen reacts with the hydrogen present in the process gas to form water. Other contaminants, if present in the feed, are removed as follows: nitrides and nitriles are converted to NOx compounds; COS, H2S, DMDS, and other sulfur compounds are converted to ethylmercaptan; acetylene is converted to ethylene; and part of the ethylene is also hydrogenated to ethane. In addition, if C3 or C4 acetylenes are present, the methyl-acetylene and the propadiene are partially converted to propylene, and C4 acetylenes are converted primarily to butenes. NOx is also removed in the 9
ERU Oxygen Converter by hydrogenation to ammonia and water. The ERU Oxygen Converter is regenerable, with an expected run length of one year. A spare reactor is provided to allow for continuous operation. The ERU Oxygen Converter has the following expected performance: Effluent acetylene < 1 ppmv Effluent oxygen < 1 ppmv Effluent NOx < 10 ppbv The effluent from the ERU Oxygen Converter is cooled against the feed and then against cooling water and sent to the upper section of the ERU Caustic/Water Wash Tower. The ERU Oxygen Converter effluent is washed with caustic to remove the residual amount of acid gases remaining in the process gas. The acid-gas-free process gas flows to a water wash section that serves to prevent any caustic carryover. Wash water is fed to the upper section of the ERU Caustic/Water Wash Tower on flow control. Spent wash water is either sent on flow control and used for dilution of the caustic circulation or sent on level control to OSBL for treatment. Spent caustic from the upper section of the ERU Caustic/Water Wash Tower is sent to the lower section of the Caustic/Water Wash Tower on level control. The process gas leaving the upper section of the ERU Caustic/Water Wash Tower is chilled against Heavy EBR and directed to the ERU Dryer/Treater Feed Gas KO Drum to separate any condensed liquid, mainly water. The condensed liquid is routed on level control to OSBL for treatment. The process gas is then sent to the ERU Dryer/Treater, which is designed with selected adsorbents to remove water, mercaptans, methanol, nitrogen compounds and trace quantities of CO2, H2S, COS, and nitride/nitriles. The ERU Dryer/Treater consists of two units, one operating and one on standby or in regeneration to maintain the continuity of operation between cycles. The process gas from the ERU Dryer/Treater is then fed to the non-regenerable ERU Metals Treater for removal of trace amounts of mercury, arsine, and phosphine in the process gas. The ERU Metals Treater consists of two vessels in a lead-lag arrangement to allow for maximum utilization of the adsorbent. Effluent from the ERU Metals Treater is passed through the ERU Dryer Effluent Filters to protect the downstream process gas chilling equipment in the event of adsorbent fines carryover. The treated process gas from the ERU Dryer Effluent Filters are chilled in a core exchanger, the ERU Offgas Exchanger, against Demethanizer overhead, Demethanizer bottoms, and various EBR streams and sent to the ERU Demethanizer. In the ERU Demethanizer, fractionation is based on the absorption principle whereby the ethylene and ethane contained in the process gas is absorbed by Wash Liquid. A portion of the C3+ bottoms from the Deethanizer is chilled in the ERU Off-gas Exchanger against Demethanizer overhead, Demethanizer bottoms, and various EBR streams in the core exchanger and sent as Wash Liquid to the ERU Demethanizer. The C3+ stream absorbs ethylene and ethane from the process gas as it travels down the ERU Demethanizer. Some Wash Liquid is lost in the Fuel Gas; in order to reduce the losses an overhead condenser utilizing EBR is provided to partially condense the ERU Demethanizer gross overhead. Liquid from the ERU Demethanizer Reflux Drum is returned to the top of the ERU Demethanizer on flow control. The Demethanizer is reboiled by subcooling heavy EBR. The ERU Demethanizer net overhead product containing methane and lighter compounds, as well as some equilibrium C3+ components, is reheated in the ERU Off-gas Exchanger against process gas and C3+ Wash Liquid and is sent to the fuel gas line near the Utility Boiler (PR End) OSBL by the Fuel Gas Compressor. The ERU Demethanizer bottoms is pumped on flow control reset by level controller in the ERU Demethanizer and sent to the ERU Deethanizer. In case of hydrate formation in the ERU Off-gas Exchanger or ERU Demethanizer, provisions have been provided to inject methanol at the following locations to dissolve the hydrates: the ERU Demethanizer feed upstream of the ERU Off-gas Exchanger, Wash Liquid upstream of the ERU Off-gas Exchanger, and into the ERU Demethanizer Reflux Pump feed. 10
The ERU Demethanizer bottoms product is heated in the ERU Off-Gas Exchanger before being sent to the ERU Deethanizer. This column is reboiled against LP Steam and is partially condensed by Heavy EBR. The net overhead containing the C2 s (ethylene and ethane) recovered from the process gas is sent to Deethanizer overhead to the Ethylene Fractionator in the NCU. The Deethanizer bottoms product contains C3 and heavier components recovered from the process gas. The C3+ bottoms product is cooled by cooling water. Part of the bottoms product is sent to the ERU Demethanizer as C3+ Wash Liquid and the rest is sent to the NCU to recover the contained propane and propylene. The C3+ Wash Liquid is chilled by the ERU Off-gas Exchanger before being sent to the ERU Demethanzier. Regeneration of the ERU Dryer/Treaters is carried out using HP Methane Gas from the NCU. A oncethrough regeneration system is provided for the ERU Dryer/Treaters, where the regeneration gas undergoes controlled heating in the ERU Regeneration Gas Steam Heater against HP Steam. Additional heating is provided by the ERU Regeneration Gas Electric Heater. The regeneration gas returning from the ERU Dryer/Treaters is cooled against cooling water in the ERU Regeneration Gas Cooler. The cooled effluent is then sent to the Regeneration Gas Knockout Drum in the NCU. The ERU Oxygen Converter Regeneration Electric Heater is a dedicated electric heater provided for the ERU Oxygen Converter regeneration. The ERU Oxygen Converter is regenerated using nitrogen, steam, plant air, DMDS (for sulfiding), and hydrogen. The ERU Oxygen Converter regeneration effluent is either routed to atmosphere, to flare, or to the NCU Quench Tower (for depressuring). The Enhanced Binary Refrigeration Unit is a multi-component, mixed refrigeration system comprised of primarily methane, ethylene, and propylene, with a very small amount of hydrogen. It is a closed circuit, three-stage compression system utilizing a turbine-driven centrifugal compressor. It replaces separate methane, ethylene, and propylene refrigeration systems. The enhanced binary refrigeration provides the full range of chilling requirements for the IOCL ERU. The EBR Compressor 3rd stage discharge stream is cooled and partially condensed against cooling water prior to separation in the Heavy EBR Accumulator. Condensed liquid from this drum is designated as Heavy Enhanced Binary Refrigerant (Heavy EBR). The Heavy EBR from the drum is split; one portion is depressurized and then vaporized to provide chilling in the ERU Dryer/Treater Feed Chiller before returning to the EBR Compressor, while the other portion is subcooled in the ERU Demethanizer Reboiler. A portion of the subcooled liquid from the ERU Demethanizer Reboiler is further subcooled in the ERU Offgas Exchanger and then vaporized to provide chilling for the ERU Deethanizer Condenser, and is sent to the EBR Compressor. The remainder of the subcooled Heavy EBR liquid is vaporized to provide chilling in the ERU Off-gas Exchanger, before being returned to the EBR Compressor. The vapor from the Heavy EBR Accumulator is partially condensed against EBR and Fuel Gas in the cold box and then sent to the Medium EBR Accumulator. Condensed liquid from this drum is designated as Medium Enhanced Binary Refrigerant (Medium EBR). Overhead vapor from this drum is designated as Light Enhanced Binary Refrigerant (Light EBR). The Medium EBR is subcooled in the cold box against itself, Fuel Gas, and other EBR streams, and then split. One portion is depressurized and vaporized to provide chilling for process gas, Wash Liquid, and other EBR streams in the cold box before mixing with Heavy EBR and returning to the EBR Compressor 3rd Stage Suction Drum. The other portion is subcooled against Fuel Gas and Demethanizer Bottoms, as well as itself and other EBR streams, and is then depressurized and vaporized to provide chilling for process gas and C3+ Wash Liquid in the cold box. This vapor is then sent to the EBR Compressor 2nd Stage Suction Drum. 11
Light EBR is condensed and subcooled against other EBR streams in the cold box before entering the Light EBR Accumulator. Any non-condensables in the Light EBR are vented to flare from this drum. The liquid Light EBR from this drum is further subcooled against itself and Fuel Gas in the cold box and then enters the EBR Retrograde Drum. Any remaining noncondensables in the Light EBR are vented to flare from this drum. The liquid Light EBR from this drum is then depressurized and vaporized to provide chilling to the ERU Demethanizer Condenser and against process gas and C3+ Wash Liquid in the cold box. The vaporized Light EBR leaving these exchangers is then sent to the EBR Compressor 1st Stage Suction Drum. 12
CHAPTER 4 RAW MATERIAL, PRODUCT and FLARE LOAD 4.0 RAW MATERIAL, PRODUCT and UTILITIES 4.1 Raw Materials 4.1.1 Raw Material Quantity Feed Design Case TPH KTA RFCC Dry Gas 9.41 75.30 Coker Dry Gas 19.00 152.00 Total ERU Feeds 28.41 227.30 4.1.2 Raw Material Battery Limit Conditions The ERU shall be designed to receive feed stocks to the battery limits at the conditions specified below. Feedstock Temperature ( C) Pressure (kg/cm²g) FCC Dry Gas 40 12.5 (Note 1, 2) Coker Off-gas 40 12.5 (Note 1, 2) Notes: 4.2 Product 1. Pressure at ERU battery limit located inside refinery complex. Amine absorbers and DGA regenerator system will be located inside refinery for integration with refinery MDEA regenerator system. Off-gas from the ERU DGA/ Water Wash Tower will be routed to NCU block for further treatment via approximately 7 km long pipeline. ERU pressure profile has been set accordingly. 2. RFCC Dry Gas tie-in for ERU will be upstream of existing pressure control valve 07-PV-4401 located on the off-gas KO drum overhead line, and Coker off-gas tie-in for ERU will be upstream of existing pressure control valve 78-PV-5501 located on fuel gas scrubber KOD overhead line. The feed gas lines from tie-in points up to ERU battery limit are considered OSBL. The feed gas lines will be combined inside ERU battery limit before being routed to the ERU MDEA/ Water Wash Tower. 4.2.1 Production Capacities Products Design Case 13
TPH KTA Demethaniser Net Overhead as Refinery Fuel Gas 11.71 93.7 C2 Product to Ethylene Fractionator 10.24 81.9 C3 Plus Product to Depropanizer 4.64 37.1 Acid Gases & Water 1.82 14.5 Total ERU Products 28.41 227.3 No change in NCU product quality is envisioned as part of ERU integration 4.2.2 Product Battery Limit Conditions The ERU shall be designed to deliver products to the battery limits at the conditions specified below. Products Temperature ( C) Pressure (kg/cm²g) Fuel Gas 34.0 5.1 (Note 1) C2 Product (-)14.0 17.7 (Note 2) C3 Plus Product 23.0 6.0 (Note 3) 4.2.3 Additional Storage One Horten Sphere of 2800 M3 capacity and one Mounded bullet of 2800 M3 capacity are considered at for Naphtha Cracker Complex for storage of C4 mix/c4h/c4r. 4.3 Flare System Depending upon temperature and composition of relieving load, the ERU flare system is categorized into 4 sections namely : Refinery HC flare, Refinery Acid gas flare, Dry flare & Wet flare. 4.3.1 Flare load from ERU Equipment located in Refinery complex: Sr. No 1 2 3 Equipment Details ERU MDEA/Water Wash Tower ERU DGA/ Water Wash Tower ERU DGA Regenerator Reflux Drum Table: ERU Flare load from Refinery complex Type of Flare Refinery Flare Refinery Flare Acid Gas Flare Governing Case Blocked outlet Without Instrumented shutdown Max Load (Kg/hr) MW With Instrumented shutdown Max Load (Kg/hr) MW 27696 20.5 27696 20.5 -- 0 0 0 0 Global power failure Remarks 2329 18.3 2329 18.3 Note-1 14
Notes: 1. From ERU DGA Regenerator a load of 797 Kg/hr is continuously flared to Acid gas flare system. 4.3.2 Flare load from ERU Equipment located in NCU complex: Table: ERU Flare load from NCU complex Sr. No Equipment Details Type of Flare Governing Case Without Instrumented Shutdown Max Load (Kg/hr) MW With Instrumented shutdown Max Load (Kg/hr) 1 ERU oxygen Converter Wet Power Failure -- -- 27083 20.4 2 ERU Caustic/ Water Wash Tower Wet Power Failure -- -- -- -- 3 ERU Demethanizer Dry Power Failure 45364 25.8 57074 25.8 4 ERU Deethanizer Dry Power Failure 54319 45.4 -- -- 5 EBR Compressor Wet Power Failure 171485 37.7 -- -- MW Total Relieving Load (Note-1) WET Power Failure 171485 37.7 198568 35.3 DRY Power Failure 99683 36.5 111393 35.4 Notes: 1. The maximum load for with Instrumented shutdown is based on considering failure of largest single SIS (Safety Instrumented Shutdown) system and other unmitigated loads resulting in largest flare load. 15
CHAPTER 5 SOCIAL BENEFITS 5.0 SOCIAL BENEFITS This project, besides general economic desirability, would result in substantial socio-economic benefit to the country in general and more specifically to the region. The socio-economic benefits are described hereinafter. 5.1 Social Upliftment of the Region This area of the country is undergoing rapid industrialization. Setting up of this project will be a boon to this region and will bound to improve living conditions and thereby result in further reduction of population below poverty line, which is one of the prime policy objective of the Government. It is expected that by creation of vast employment potential and industrialization of the area poor/weaker section of the society will see an upliftment in their living conditions. 5.2 Employment Generation During Construction phase of about 2 years, project on an average will provide employment to about 500 persons, of which significant portion is expected to be drawn from the surrounding areas. On commissioning and achieving successful trial runs, this project will provide direct employment to 40-50 persons out of which around one third of the local personnel would get employment. Indirect employment in the form of contractors, workers, transporters, marketing and general utilities services will provide employment to about 50 persons (mainly from the neighbouring areas) Employment associated through forward linkages in the small and medium scale industries expected to be set up on the basis of products available from this project is estimated to be in the region of 1000-1500 jobs. 16
CHAPTER 6 SAFETY AND POLLUTION CONTROL MEASURES 6.0 SAFETY AND POLLUTION CONTROL MEASURES 6.1 General Public concern over environmental pollution is increasing at a geometric rate. The concern stems from an awareness of the threats to health and welfare from the wastes of our society. It leads inevitably to pressure on industry to reduce the discharge of contaminants into the air and public waterways. Environmental monitoring plans will be prepared for the project to ensure all activities of the project are operated in an environmentally safe manner. A brief note on the various environment impacts of the project and the remedial measures are enumerated hereinafter: During construction, the activities that might cause adverse effects to the area are - Site preparation - Site filling, flattening and reinforcement of the foundation - Transportation of materials and equipment to the site - Construction of infrastructure - Installation of equipment and support facilities for the plant These activities will be controlled primarily by the construction contractor(s) under agreement(s) with LSTK contractor / IOCL to follow the requirements to be satisfied at site. During operations, the activities that have an adverse impact on the environment are - Operation of the production process - Gaseous waste and liquid waste Environmental impacts of these activities will be controlled. The ERU is designed to minimize the amounts of effluents generated and to control those streams which cannot be eliminated. 6.2 Environmental protection Prevention of Air Pollution 17
Emissions from the plant are minimized with the application of nitrogen blanketing for storage tanks, proper selection of pumps as per OSHA standard, proper selection of gaskets, etc. Prevention of Water Pollution Recirculating cooling water system is utilized in the ERU. The cooling water return will be cooled in the already existing Cooling tower, thus reducing the water requirement for cooling in the complex. As for process waste water, it will be routed to the already existing Effluent treatment plant, which is installed so as to comply as per Haryana State Pollution Control Board (HSPCB) and Central Pollution Control Board (CPCB) guide line. In order to prevent underground water pollution, the process area is paved with concrete. Oil, acid and rain water falling in the area is collected in a sump for further treatment. This waste water is discharged to the waste water treatment plant for treatment. Prevention of Noise Noise level of working place will be controlled within the limit as specified in the HSPCB standard. In the case that some areas might not satisfy the said standard, suitable countermeasures, e.g. addition of noise insulation, use of PPE etc., will be applied in order to satisfy the said standard. Noise level at plant boundary fence will be controlled to satisfy noise criteria. 6.3 Highlights of Effluent generated in ERU 6.3.1 Effluent Summmary The ERU is designed to minimize the amounts of effluents generated and to control those streams which cannot be eliminated. 6.3.2 Gaseous Effluents The following gaseous effluent streams will be produced by the ERU: 1. ERU Oxygen Converter Regeneration Offgas 2. ERU Di-Glycol Amine (DGA) Regenerator overhead to Refinery Acid Gas Flare The characteristics of these gaseous effluent streams are given below. ERU Oxygen Converter Regeneration Offgas ( Once in a Year) Prior to regeneration, hydrocarbons are purged to the quench tower in the NCU, then to flare. During steam/air regeneration, offgas is sent to atmosphere. Parameter Unit Value Offgas flow rate kg/hr 8780 18
ERU DGA Regenerator Overhead to Refinery Acid Gas Flare : Parameter Unit Value Offgas flow rate kg/hr 598 Temperature ⁰C 44 6.3.3 Aqueous Effluent The following aqueous effluent stream will be produced by the ERU: 1. Condensate from Refinery Off-Gas KO Drum 2. Spent Wash Water from MDEA/Water Wash Tower, DGA/Water Wash Tower, and Caustic/Water Wash Tower 3. Spent Caustic from Caustic/Water Wash Tower 4. Polymeric oil from ERU MDEA/Water Wash Tower 5. Polymeric Oil from ERU DGA/Water Wash Tower 6. Polymeric Oil from ERU Caustic/Water Wash Tower Condensate from Refinery Off-Gas KO Drum Condensate from Refinery Off-Gas KO Drum (17-V-9001) is directed to Amine Blowdown System. The possibility of condensate from 17-V-9001 is minimal. Composition: Since RFCC Off-gas does not contain heavy hydrocarbons, condensate mainly contains water and traces of amine (carryover from refinery) and heavy hydrocarbons. Parameter Unit Value Temperature ⁰C 44 Pressure kg/cm2g 11.5 Spent Wash Water from Amine Absorbers Spent wash water from the water wash sections of the ERU MDEA/Water Wash Tower and the DGA/Water Wash Tower is sent to treatment OSBL (in refinery complex). Spent wash water contains mostly water with traces of caustic and amine. Parameter Unit Value Flowrate kg/hr 2165 Spent Wash Water from ERU Caustic/Water Wash Tower Spent wash water from the ERU Caustic/Water Wash Tower and condensate from the ERU Dryer/Treater Feed Gas KO Drum is combined with spent wash water from NCU and sent to treatment OSBL. Spent wash water contains mostly water with traces of caustic. Parameter Unit Value Flowrate kg/hr 2010 19
Spent Caustic from Caustic/Water Wash Tower Spent caustic leaves the bottoms of the ERU Caustic/Water Wash Tower and is sent to the NCU to be combined with spent caustic from the NCU Caustic/Water wash tower The spent caustic from ERU has the following flow rate and characteristics: Parameter Unit Value Flow rate kg/hr 317 Temperature ⁰C 56 Pressure kg/cm2 6.0 Polymeric Oil from Amine/Water Wash Towers Some amount of polymeric oil (yellow or red oil) may be formed in the MDEA and DGA Amine/Water Wash Towers (17-C-9001 and 17-C-9002), particularly when high amine concentration and high operating temperatures are used. In most cases, some oil will be formed, and periodically this oil is decanted from the bottom of the towers to corresponding degassing drums (17-V-9002 for MDEA Tower, 17-V-9004 for DGA Tower). The oil is routed to the respective amine drain system for disposal. Polymeric Oil from Caustic/Water Wash Tower The possibility of polymeric oil (yellow or red oil) formation in the ERU is low; however provision is given in the design to skim off the Yellow Oil from the bottom section of the ERU Caustic/Water Wash Tower and recombined with the spent caustic. Spent caustic/polymeric oil stream from the ERU is combined with NCU and sent to the spent caustic pretreatment-gasoline wash system, where the polymeric oil is washed from the spent caustic before it is sent OSBL for treatment. 6.3.4 SOLID EFFLUENTS Spent Catalysts/Adsorbents The following spent catalysts/adsorbents will be produced: 1. ERU Oxygen Converter spent catalyst 2. ERU Chloride Guard Bed spent adsorbent 3. ERU Dryer/Treater spent adsorbent 4. ERU Metals Treater spent adsorbent When the catalysts and adsorbents can no longer be satisfactorily regenerated or are at the end of life, they will be sent offsite via drum or truck to landfill or returned to the vendor for reclamation. DGA Sludge Amine based solvents for CO2 and H2S absorption degrade over time due to reaction with acid gases, halogenated compounds and other impurities. Major degradation products include Heat Stable Salts (HSS), non-volatile organic compounds and suspended solids. Contaminants (heat stable salts, amine degradation products, solids, hydrocarbons, surfactants) cause reduced capacity, product quality and increased fouling. To remove the HSS and to recover the amine, a reclaimer has been included in the DGA regeneration system. The reclaimer is designed to convert a degradation product, N,N-bis(hydroxyethoxyethyl) urea (BHEEU) back to useful DGA. However, HSS and non-volatile impurities accumulate in the DGA reclaimer, which can upset the BHEEU conversion. The accumulation of HSS in the DGA reclaimer can lead to increased operating temperatures and the need to purge accumulated salts periodically. 20
The purging of 0.4 m3 of sludge can be planned to occur once per month. Disposal options may vary depending on local regulations and corresponding classification as hazardous or nonhazardous waste. However, assuming the sludge is classified as hazardous waste, typical disposal method is incineration. *** 21