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KHABAROVSK REFINERY HYDROPROCESSING PROJECT PROCESS DESCRIPTION. TRAINING COURSE. APRIL 29th – MAY 3rd 2013, MADRID, SPAIN. INTRODUCTION. TRAINING COURSE TO HIGHLIGHT THE MAIN PROCESS FEATURES, STARTING FROM THE BASIC KNOWLEDGE OF THE THEORY. BLOCK DIAGRAM OF SRU/TGT. MAIN SECTIONS.
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KHABAROVSK REFINERY HYDROPROCESSING PROJECT PROCESS DESCRIPTION TRAINING COURSE APRIL 29th – MAY 3rd 2013, MADRID, SPAIN
INTRODUCTION • TRAINING COURSE • TO HIGHLIGHT THE MAIN PROCESS FEATURES, • STARTING FROM THE BASIC KNOWLEDGE OF THE THEORY BLOCK DIAGRAM OF SRU/TGT
MAIN SECTIONS CLAUS SECTION TGT SECTION DEGASSINGSECTION PLANT SECTIONS: To remove H2S and sulphur compounds from acid gas producing elemental sulphur To remove H2S and polysulphides (H2Sx) from the produced liquid sulphur The tail gas is reduced so that all sulphur compounds and residual SO2 are converted to H2S AMINE SECTION To regenerate the rich amine containing H2S and CO2 and recycle the acid gas to the Claus Section
MAIN SECTIONS PLANT SECTIONS: AMINE REGENERATION SECTION To regenerate the rich amine containing H2S and CO2 and recycle the Amine Acid Gas to the Claus Section SOUR WATER STRIPPING SECTION To remove H2S and NH3 from sour water streams and recycle the SWS Acid Gas to the Claus Section
THERMAL STAGE CATALYTICSTAGE CLAUS SECTION • To remove hydrogen sulphide and sulphur compounds from acid gas, producing elemental sulphur. • As a second effect, NH3 content of the SWS stream will be highly reduced in the Claus Thermal Reactor. PURPOSE
CLAUS SECTION - Process Streams • The process streams involved in the Claus Section are: • FEEDS • Amine Acid Gas; • Sour Water Stripper Acid Gas; • Amine Acid Gas Recycle from TGT Regenerator • PRODUCTS • Tail Gas to TGT Section • Liquid Sulphur to degassing/storage PROCESS STREAMS
CLAUS SECTION - PROCESS FLOW DIAGRAM Amine Acid Gas Scrubber has the purpose to remove the NH3 in the AAG. AAG recycled from Regenerat. section is mixed with AAG coming from AAG header K.O. Drum installed to prevent any liquid drop going to the burner. Combustion Air is supplied by Blower.
CLAUS SECTION - PROCESS FLOW DIAGRAM SWSAG and part of the AAG are mixed prior to enter in the Claus Burner. AMINE AG SWS AG Thermal Reactor, WHB: residence time, gas cooling and heat recovered. COMB. AIR Any sulphur condensed in the Thermal Reactor Waste Heat Boiler is drained to Sulphur Pit via dedicated hydraulic seals.
CLAUS THERMAL REACTOR : Main Equipment • The concentration of H2S and the presence of impurities in the feedstock to Claus Unit play an important role for the selection of the more appropriate plant configuration • THERMAL STAGE • The minimum requirements for the Thermal Reactor in case of treatment of feedstock which contains impurities are: • Installation of a well proven high intensity burner • Appropriate residence time in the Thermal Reactor • Adequate temperature in the Thermal Reactor The Thermal Reactor has been designed with double zones configuration to achieve COMPLETE DESTRUCTION OF ALL IMPURITIES
CLAUS SECTION - PROCESS FLOW DIAGRAM • CATALYTIC STAGE • 2 Claus Reactors, filled with • alumina catalyst to complete • the Claus reaction between • H2S and SO2 • The first reactor has been • designed also for the use of • titania catalyst (to promote • Hydrolisis of COS, CS2). • Claus Heaters: • Hot gas by-pass for the first Claus Converter; • Electrical Heater for the second Claus Converter. • Steam side: • 1st, 2nd and 3rd Condensers • operating P = 4.5 kg/cm2 g • The produced Svap is condensed in each Sulphur Condenser and drained via hydraulic seals. • Condensation and removal of sulphur, before the inlet to first and second catalytic stage, • enables further conversion of sulphur in each catalytic reactor.
SULPHUR DEGASSING SECTION • To remove H2S and H2Sx from the liquid sulphur produced. • The removal is achieved by means of direct contact with air (Stripping Air from Combustion Air Blower) in a internal Degassing Column filled with catalyst. PURPOSE • The process streams involved in the Sulphur Degassing are: • FEEDS • Undegassed Liquid Sulphur with H2S content about of 300ppm wt. • Stripping Air • PRODUCTS • Degassed Liquid Sulphur with H2S content less than 10ppm wt. • Sweep Air to Thermal Incinerator PROCESSSTREAMS
SULPHUR DEGASSING – PROCESS FLOW DIAGRAM • Sulphur Pit is equipped with Undegassed Sulphur Section and Degassed Sulphur Storage Section. Air (hot)is fed from Combustion Air Blower through steam jacketed pipe.
SULPHUR DEGASSING – PROCESS FLOW DIAGRAM Sulphur Pit temperature The temperature inside the sulphur pit must be 135÷145 °C in order to control the viscosity of the liquid sulphur, which has to be easily pumped/ transferred (steam coils are provided). Sweeping the sulphur pit In order to ventilate the vapour space above the sulphur level - and thus maintaining the H2S concentration below the lower explosion limits – Steam Ejector is provided. The resulting Sweep Air is sent directly to the Incinerator.
TAIL GAS TREATMENT SECTION R.A.R. Technology (REDUCING, ABSORPTION, RECYCLE) The goal of the process is the reduction/hydrolysis into H2S of sulphur compounds (SO2, Sx, COS, CS2) and the selective absorption of H2S with the amine solution. The H2S released during the regeneration of the amine solution is recycled to Claus Unit. • To reduce all sulphur compounds contained in the tail gas from Claus Section into H2S, over a catalytic reactor. • After the reduction stage, there is the cooling stage, where the gas is cooled in the gas/gas heat exchanger and the water content is reduced by condensation. • Finally, the H2S contained in the quench tower outlet gas is absorbed along the TGT Absorber and recycled to the Claus Unit. PURPOSE
TAIL GAS TREATMENT SECTION – Process Streams • The process streams involved in the TGT Section are : • FEEDS • Tail Gas from Claus Unit • Lean Amine (MDEA 50%wt.) from Amine Regenerator • PRODUCTS • Tail Gas to Thermal Incinerator • Rich amine (MDEA 50%wt.) to Amine Regenerator PROCESS STREAMS
TAIL GAS TREATMENT SECTION– PROCESS FLOW DIAGRAM • TGT Heater is designed to • heat the tail gas coming from • both Claus trains and preheated • in the gas/gas exchanger. • Hydrogenation Reactor • filled with special catalyst, • capable to convert all sulphur • compounds in the Claus tail gas • to H2S, under slight H2 excess. • Hydrogenation Reactor • Inlet/Outlet temperature = 280 °C/310 °C at SOR • For turndown capacities, the Recycle Gas Blower is used to maintain in recirculation to ensure the min. flow of gas for the Hydr. Reactor and the TGT Absorber (also at start-up/SD).
TAIL GAS TREATMENT SECTION– PROCESS FLOW DIAGRAM • Quench Tower • Gas from Quench Tower temperature = 38 °C • H2 content @ Quench Tower outlet = 3% vol. • TGT Absorber • MDEA solution = 50% wt. • Lean MDEA inlet temp. = 40°C • Tail Gas outlet temp. = 42°C • The Quench circuit is completed by the Quench Water Cooler, by the Sour Water Filter, and by the draw-off line (excess of condensed water).
AMINE REGENERATION SECTION • To regenerate the rich amine containing H2S and CO2 from TGT Absorber. • To recycle the acid gas back to the Claus. PURPOSE • The process streams involved in the Amine Regeneration Section are: • FEEDS • Rich Amine (MDEA) from TGT Absorber • PRODUCTS • Lean Amine (MDEA) to TGT Absorber • Acid Gas Recycled to Claus PROCESSSTREAMS
AMINE REGENERATION SECTION– PROCESS FLOW DIAGRAM • AMINE REGENERATION • Rich Amine to Regen. = 100 °C • Recycle Gas temperature = 50°C • Regenerator Reflux Drum pressure = 0.9 kg/cm2 g • AMINE ABSORPTION • Lean Amine to TGT Absorber temperature = 40 °C • Lean Amine to filtration system about 50% of total amine flow • Amine type: MDEA
AMINE REGENERATION SECTION– PROCESS FLOW DIAGRAM • AMINE FACILITES • Steam Condensate make up is fed to Reflux Drum to maintain 50%wt. • Amine Drain Drum is provided to collect amine drains and is equipped with Amine Drain Pump. Blanketing medium to protect amine from degradation. • Amine Filters are designed to remove particles (mechanical filters) and to absorb entrained impurities (active carbon filter).
INCINERATOR SECTION • To perform the incineration (=oxidation at high temperature) of residual H2S and all sulphur compounds to SO2, in presence of excess air. • To discharge the flue gas to the atmosphere via a stack in safe conditions (dispersing the resulting product at altitude). PURPOSE • The process streams, involved in the Thermal Incinerator, are the followings: • FEEDS • - Tail Gas from TGT Absorber • Sweep Air from Sulphur Pit • Thermal Incinerator is sized to accomplish the combustion of tail gas coming directly from Claus train, in the event of TGT section shutdown (TGT by-pass). • PRODUCTS • Flue Gas from Stack PROCESS STREAMS
INCINERATOR SECTION– PROCESS FLOW DIAGRAM • Incinerator • Oper. temp.= 650°C • Natural draught type • Flue Gas O2 content = 2% vol. minimum on wet basis • O2 analyzer at the Stack Due to low heating value of tail gas, it is necessary to sustain the combustion using the fuel gas. The fuel gas flow to the burner is adjusted by temperature control in the thermal incinerator.
AMINE REGENERATION SECTION (ARU) – Process Streams • To regenerate the rich amine containing H2S from Hydrocracking Section (HCU). • To produce Amine Acid Gas that shall be treated in the Claus Trains. PURPOSE The process streams involved in the ARU Section are: FEED - Rich Amine (DEA 25%wt.) from HCU PRODUCTS - Amine Acid Gas to Claus Trains - Lean Amine (DEA 25%wt.) to HCU PROCESS STREAMS
ARU SECTION – PROCESS FLOW DIAGRAM • AMINE REGENERATION • Rich Amine to Regen. = 93 °C • Acid Gas temperature = 55°C • Regenerator Reflux Drum pressure = 0.9 kg/cm2 g • Lean Amine to HCU temperature = 55 °C • Lean Amine to filtration system = 15% of total amine flow • Amine type: DEA
ARU SECTION – PROCESS FLOW DIAGRAM • AMINE FACILITES • Demi-water make up is fed to Regenerator Reflux Drum to maintain 25%wt. • Rich Amine Flash Drum is provided to collect rich amine from HCU Sectionand is equipped with Rich Amine Pump and Slop Oil Pump. • Amine Filters are designed to remove particles (mechanical filters) and to absorb entrained impurities (active carbon filter). • Amine Sump Drum is provided to collect amine drains from HCU Section and is equipped with Amine Sump Pump. Blanketing medium to protect amine from degradation.
SOUR WATER STRIPPING SECTION – Process Streams • To remove Hydrogen Sulphide and Ammonia from Sour Water Streams. • To produce Sour Water Stripper Acid Gas that shall be treated in the Claus Trains. PURPOSE The process streams involved in the ARU Section are: FEED - Sour Water from SRU - Sour Water from TGT - Sour Water from HCU - Sour Water from DHT PRODUCTS - Sour Water Stripper Acid Gas to Claus Trains - Stripped Water to HCU/DHT PROCESS STREAMS
SWS SECTION– PROCESS FLOW DIAGRAM • Sour Water Stripping • Sour Water to Stripper = 84 °C • SWS Acid Gas temperature = 85°C • Stripper pressure = 0.9 kg/cm2g • Stripped water to HCU/DHT temperature = 90°C • SWS FACILITES • Sour Water Feed Surge Drum is provided to collect sour water streams and is equipped with Stripper Feed Pump and Slop Oil Pump. • Sour Water Stripper is also equipped with pumping/pumparound cooling system
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