Technical operation, installation and repair of the hydrotreatment reactor

Contents

INTRODUCTION

Section 1. DESCRIPTIVE PART

1.1 Reactor equipment. Classification

1.2 Brief description of the production facility

1.3 Characteristics of the plant process equipment

1.4 Purpose of hydrotreating reactor, its technical characteristics, designation and decryption

1.5 Characteristics of feedstock, materials

1.6 Structure and operating principle of LG-24 unit reactor

Section 2. PROCESS PART

2.1 Installation of reactor

2.1.1 General issues of equipment installation

2.1.2 Technical documentation of installation works

2.1.3 Supply and acceptance of equipment for installation

2.1.4 Requirements for foundations and construction structures

2.1.5 Installation Methods

2.1.6 Installation quality control

2.2 Operation of the reactor

2.2.1 General information on operation

2.2.2 General requirements for preparation, start-up and setting to mode

2.2.3 Preparation of reactor unit for start-up

2.2.4 Catalyst loading into reactor

2.2.5 Leak test

2.2.6 Replacement of inert gas with hydrogen-containing gas

2.2.7 Catalyst drying

2.2.8 Setting of the unit to the mode

2.2.9 Start of the plant in case of emergency situations

2.2.10 Normal operation of reactor unit

2.2.11 Normal stop of the unit

2.2.12 Catalyst Regeneration

2.2.13 Special control and emergency situations

2.3 Reactor Repair

2.3.1 Characteristics of faults and methods of their rectification

2.3.2 Preparation of reactor for repair

2.3.3 Types of works during reactor repair

2.3.4 Tools, accessories used during repair

2.3.5 Repair Documentation

Section 3. DESIGN PART

3.1 Calculation of main reactor characteristics

3.1.1 Calculation of reactor geometrical dimensions

3.2 Calculation of parts, assemblies, quantity of fasteners for reactor

3.2.1 Calculation of vessel body and bottom thickness

3.2.2 Calculation and selection of connectors

3.2.3 Calculation of traction force during equipment transportation and selection of vehicles

3.2.4 Selection of lifting method and calculation of rigging

Section 4. ECONOMIC PART

4.1 Organizational Structure

4.2 Work time balance and headcount

4.3 Calculation of the value of fixed assets

4.4 Calculation of annual costs

4.4.1 Calculation of the annual staff salary fund

4.4.2 Calculation of social insurance contributions

4.4.3 Definition of Depreciation

4.4.4 Calculation of maintenance and operation costs

4.4.5 Calculation of material costs

4.5 Product Cost Calculation [23, 24]

4.6 Main technical and economic indicators of the plant

Section 5. SAFETY PRECAUTIONS

5.1 Safety measures during installation

5.2 Safety precautions during operation

CONCLUSION

Literature

Introduction

The topic of the thesis is technical operation, installation and repair of the hydrotreating reactor.

As a production facility, the unit for hydrotreating diesel, kerosene fractions and raw materials of the Parex process was chosen (hereinafter the unit LG24/7).

The purpose of the diploma is to study the material related to technical operation, installation and repair of reactor equipment of the first unit (flow I) of LG24/7 unit hydrotreatment.

The oil refining industry is one of the leading industries of our industry, which greatly contributes to technical progress in the national economy. One of the most common oil refining processes is hydrotreating motor fuels, as it improves the quality of gasoline, kerosene, diesel fuels.

The need to improve the quality of motor fuels is caused by the increased need for new quality oil products and stringent environmental requirements.

The hardware design and fundamental features of the equipment are typical for almost all types of hydrotreating plants for motor fuels.

In many manufacturing processes, it is required to separate the feedstock into constituent components, heat and cool the products, and mechanically separate the different phases of the system. At the same time, the same physical processes can be used at different stages of the technological process, ensuring the production of the required quality and properties.

The process diagrams of these processes include reactors, columns, gas circulation compressors, and in some cases fresh hydrogen or hydrogen-containing gas (HPG) booster compressors, pumps, heat exchangers, coolers, various tanks, and furnaces.

The equipment used may differ in dimensions, interior parts, type of trays or nozzles, elements of baffles, material design, etc.

The main and most responsible apparatus of the reactor unit is the reactor, since its successful operation depends on the cost-effectiveness of the process and the quality of the resulting products. In the reactor, the process of hydrotreating the diesel fraction is carried out.

Experience of operation of diesel fuel hydrotreatment plants indicates the feasibility of the process in the reactor with axial feed injection in the fixed catalyst bed [6]. This type of reactor is selected in this project.

The project contains: 106 pages of typewritten text, 15 tables, 18 drawings, 16 literary sources. The graphic part is represented by 2 sheets of A1 format.

Brief description of the production facility

The LG24/7 plant has a design capacity of 1.2 million tons/year.

The plant is designed to remove sulfur, nitrogen and oxygen compounds from straight-run diesel and kerosene fractions by catalytic hydrogenation. The process scheme LG24/7 of two in-line, consists of two independently operating units of 600 thousand tons/year each and provides for the possibility of simultaneous processing of one or two types of raw materials to obtain the corresponding hydrotreated products [5].

Each unit has two reactors and two heating furnaces.

The following products are available on the LG24/7 unit [5]:

1. Wasps fraction 200360 hydrocleaned (DTL) - is used as a component of the commodity diesel fuel (DF).

2. Wasps fraction 140240 hydrocleaned (TC1) - is used as a component of commodity fuel for jet engines of TC1 brand, a component of commodity diesel fuel.

3. The fraction hydrocleaned 180240 wasps - is used as a component of commodity fuel A-1 Jet.

4. Wasps fraction 200320 hydrocleaned - is used as raw materials for installations of Parex 1.2.

5. Hydrotreating spur - sent for H2S cleaning to L2410/2000 unit.

6. Hydrogen sulfide gas. It is used as a raw material for plants for the production of elemental sulfur and sulfuric acid.

The unit includes:

- Unit No. 1. Hydrotreating Reactor Unit (Stream I)

- Unit No. 2. Hydrotreating reactor unit (II stream)

- Unit No. 3. Stabilization Column Unit (Stream I)

- Unit No. 4. Stabilization Column Unit (II Stream)

- Unit No. 5. Hydrocarbon gas purification unit.

- Unit No. 6. MDEA regeneration unit.

- Unit No. 7. Fuel preparation unit.

- Unit No. 8. Industrial fleet of the plant.

The plant was commissioned in July 1971.

In 2007, the hydrotreatment unit was put into operation after reconstruction under the project of Lengiproneftekhim LLC "Replacement of LG24/71200 unit flow I equipment with the transfer of the entire unit to an automated process control system (APCS) and the replacement of field instrumentation and automation equipment (instrumentation and A)."

Characteristics of the plant process equipment

Each diesel fuel hydrotreating unit consists of a number of units having certain equipment and purpose.

The reactor unit of the plant is the main one. In it there is hydrodesulfurization of diesel fuel in reaction apparatus and separation of gas-product mixture in separators into liquid reaction products, hydrocarbon gas and circulating hydrogen-containing gas [1].

It includes heat exchangers for heating the gas-oil mixture, a heating furnace, a reactor itself or two reactors, separators and circulating gas with compressors.

The reactor is a vertical cylindrical apparatus, the diameter and height of which depends on the capacity of the process unit and the process diagram and can be within the range: diameter 14004000 mm, height 600024000 mm.

Currently, reactors for hydrotreating motor fuels as devices with a moderate process temperature (up to 450 0C) are designed and manufactured with a 12CM type double-layer steel case without an internal lining with a torcret coating of heat-resistant concrete are calculated for strength by a pressure source. Therefore, safety valves are not installed. To strengthen the shotcretbeton, the latter is applied to the walls through a layer of a shell mesh.

These reactors are free from the disadvantages of lined reactors and, although they are 22.5 times more expensive than lined reactors, the initial capital cost of fabrication is paid off by the reliability of their operation.

During the reconstruction of the first reactor unit of the LG24/7 plant, hydrotreating reactors were installed with an increase in the total volume of catalyst to 100.26 m3 (80.645 tons), while before the reconstruction 32.5 m3 catalysts were loaded (total in two old reactors), which allowed to reduce the volumetric feed rate from 3.4 to 1.1 part 1, while maintaining the maximum productivity at 110 m3/h [1].

Purpose of hydrotreating reactor, its technical characteristics, designation and decryption

Currently, the first reactor unit of the LG24/7 unit is equipped with two reactors (P101, P-102) and is used for cleaning diesel fuel.

In reactors P101, P-102 at temperature 330390 ° C and pressure 3.435.39 MPa, hydrogenation of sulfur, nitrogen and oxygen-containing compounds is carried out, and metal impurities are deposited on the catalyst.

The P101 and P102 reactor are cylindrical devices with a radial stream of raw materials and material execution of brand 12XM + 08X18H10T.

Interpretation of the grade of two-layer steel 12XM+08X18H10T:

12XM - steel heat resisting low-alloyed;

08X18H10T - the stainless steel alloyed, corrosion-resistant, heat-resistant. Interpretation of steel 08X18H10T allows to define what elements are a part. Steel 08X18H10T contains carbon no more than 0.08%, X18 - specifies chrome content in steel about 18%. As a rule, a high concentration of chromium leads to a significant increase in corrosion resistance. H10 indicates a nickel content of about 10% in steel, the letter T at the end of the brand means that about 1% of titanium is contained in steel.

Technical characteristics of P101 reactor (P102):

1. Overall dimensions of the reactor:

- reactor height 11520 mm;

- internal diameter 3000 mm.

2. Design pressure in apparatus P = 5.88 MPa.

3. Operating pressure in apparatus P = 3.145.39 MPa.

4. Design temperature is 480 0С.

5. Operating temperature 3303900С.

6. Characteristics of the environment:

- 3 hazard class of harmful substances as per GOST 12.1.00776;

- IICT1, IIA-T3 categories of explosive mixture according to GOST P51330.5 and GOST P51330.11;

- GG (combustible gases), LVW (easily flammable liquids) fire hazard as per GOST 12.1.00491.

7. Capacity - 64 m3.

8. The estimated service life is 12 years.

Section 2. PROCESS PART

2.1 Installation of reactor

2.1.1 General issues of equipment installation

Installation of equipment means a set of works related to bringing it into working condition. For this purpose, the installed equipment must be fully assembled, installed in the design position and incorporated into a single process system using the appropriate communications.

The variety of equipment and communications has led to the specialization of installation - the basis for improving the quality of work and labor productivity. From the general work on the installation of technological equipment, special installation works are distinguished - electrical and thermal installation, installation of a system of instrumentation and automation of production, work on corrosion protection, lining, insulation of equipment surfaces, and so on.

Installation of equipment at oil refineries is carried out during the construction of new facilities, as well as during the reconstruction and repair of existing ones. In the last two cases, the installation is preceded by dismantling, which is usually carried out in reverse sequence.

2.1.2 Technical documentation of installation works

All installation works are performed on the basis of technical documentation. The primary, as-built (intermediate) and work delivery documentation are distinguished.

Primary documentation. Any construction or reconstruction is carried out in accordance with a previously drawn up and approved project .

Large facilities are designed by design institutions specializing in the design of objects in this industry. They issue to the customer - the company under construction - all the necessary design documentation. Small construction facilities can be designed by the design departments of the enterprise itself.

Based on the design task issued by the customer, the design organization performs design in one or two stages depending on the cost of the object, its study, the presence of typical projects or proven solutions.

In single-stage design, the customer is given a so-called techno-working project. Large objects are designed in two stages - technical design (first stage) and working drawings (second stage). The technical design contains detailed developments and specific solutions to all issues, detailed drawings are drawn up on the basis of the updated and approved technical design.

For the installation of equipment of such large and critical facilities as chemical and oil refineries, it is mandatory to have a special installation project. The project is carried out by a specialized project organization or project bureaus at installation associations and trusts. The erection project contains: calculation schedules; data on the scope and methods of the upcoming installation works; Layout plan for installation tooling, billets and pre-assembly of equipment, steel structures and individual assemblies on the construction site; location plan of warehouses and temporary facilities; description of technology and order of all installation works on elements and units; calculation of mounting equipment; information on the need for workers of different qualifications; drawings of mounting devices of non-standard manufacture in relation to these installation conditions; information on safety measures during work at all sites and permanent workplaces, etc.

The installation project is a development, differentiation of the construction organization project developed as part of the main project. The construction organization project contains: estimated element-by-element and consolidated schedule plans for the construction of the facility; data on the distribution of logistical and labour resources; construction site master plan; design of roads and access roads to the construction site; description of the source of water, compressed air and electricity; information on the procedure and special conditions of work, etc.

The plot plan shows the location of the facilities of the plant under construction, the places of installation of equipment, the main ground and underground communications, and the sequence of installation. This data allows you to organize the installation so as not to disturb communications and, in addition, use them for installation purposes. On the erection plot plan there are sites for warehousing, pre-assembly, as well as roads necessary for the start of work and their implementation. The plot plan indicates the location and size of the foundations for the mounted equipment, as well as, if necessary, the location of the foundations for cranes and rigging, places of supply of electricity or compressed air, methods of lighting the site and the location of lighting fixtures or searchlights, a hazardous area, places and structures of protective structures, fences for passages and crossings.

In the design, mechanization schemes are developed, which indicate the places of installation of cranes, their areas of action, the maximum possible departure of hooks depending on the location of equipment and cranes, the location of mast lifts with all lifting equipment. At the same time, the schemes are designed so that the movement of cranes, mast lifts and equipment is minimal when installing simple types of various equipment or simple types of the same type of equipment on one site.

The section "Mechanization of works" shall contain the list of equipment required for installation.

On the basis of the above mentioned works, a schedule for the performance of work and the movement of labor by profession is developed.

As-built documentation. As-built documentation includes acts on performance of hidden works (preparation of foundations, trenches, hidden parts of structures includes preparation of surfaces of devices, etc.) and diagrams to them; certificates of foundation acceptance for equipment; acts of testing of materials, welds and assembled equipment as a whole; as-built drawings and diagrams reflecting all design and system changes made during installation; certificate for installation of equipment, as well as deviations from the design, indicating the reasons for such deviations.

Work delivery documentation. Completion of construction of the facility is executed by the corresponding documentation, which includes the initial design documentation and documents drawn up at the stage of performance of all construction and installation works. Acts drawn up by the working commission shall be submitted to the State Commission hosting the facility for operation.

Erection works during the construction of large facilities are carried out by specialized erection enterprises. Other specialized organizations also work at the facility, which carry out construction, plumbing and electrical installation, chemical protection of equipment, installation of instrumentation and automation equipment, etc.

The actions of all organizations involved in the construction of the facility are coordinated by one of them, called the general contractor. Previously, the construction organization (construction department or construction trust) begins work on the site, so it is usually the general contractor with whom the customer enters into an agreement for the entire scope of work provided for by the estimated financial calculation. Other organizations involved in the construction of the facility are called subcontractors; they enter into a contract with the general contractor for the corresponding scope of work.

Each installation organization distributes the entire scope of work to be performed among its production divisions, some of which are located on the territory of the constructed facility. Production units perform rigging works (loading, unloading, moving and installation of equipment to the design position); assembly and assembly works (assembly of equipment, mainly technological devices); mechanical works (installation and adjustment of pumps, compressors, centrifuges, fans, mills, etc.); installation of steel structures (assembly of stairs, platforms, load-bearing frames, etc.) welding, piping and some other works.

At oil refineries with well-equipped repair and mechanical bases, a certain amount of work on the construction of individual facilities (usually of a reconstruction nature) is carried out in-house - the so-called economic method.

2.1.6 Installation quality control

Quality control of performed works shall be carried out systematically at all stages of installation. Work that cannot be detected after subsequent work is completed should be monitored especially carefully. By the time of implementation, control is divided into input (at equipment acceptance), intermediate (post-operation), carried out in the process of work, and final, carried out after installation.

There are many quality control methods that can be divided into two main groups.

Direct control methods directly determining the quality of controlled works.

Indirect control methods determining quality of controlled works on samples

Production quality control of construction and installation works shall include control of working documentation, structures, products, materials and equipment, operational control of individual construction processes or production operations and acceptance control of construction and installation works.

During incoming control of detailed documentation, its completeness and reliability of technical information contained in it for performance of works shall be checked.

During the incoming inspection of building structures, products, materials and equipment, it is necessary to inspect their compliance with the requirements of standards or other regulatory documents and working documents, as well as the availability and content of passports, certificates and other accompanying documents.

Operational control should be carried out during construction processes or production operations and ensure timely detection of defects and taking measures to eliminate and prevent them. During operational control, it is necessary to check compliance with the technology of construction and installation processes; compliance of performed works with working drawings, construction codes, rules and standards. Before the blocks are docked, check the geometry of each block, visually inspect the edges of the docked blocks, make sure that the preparations are correct, according to the requirements for this device. Observe required clearances when connecting each unit. Perform visual inspection of the weld frame, inspect visible defects at the end of welding.

Upon completion of welding works on assembly of the device, perform work on inspection of welds: gammalouch transmission, magnetic and ultrasonic flaw detection. These control methods allow to detect hidden defects of joints without their destruction and to accurately determine the nature and location of the defects

The main documents for operational control are regulatory documents, task lists and their composition of the operational quality control scheme.

During acceptance inspection, it is necessary to check and evaluate the quality of construction and installation works performed, as well as critical structures. The certificate of examination of hidden works shall be prepared for the completed process performed by an independent subdivision of the contractor. Hidden works are subject to inspection with the preparation of acts. Responsible structures, as soon as they are ready, shall be accepted during construction (with the participation of a representative of the design organization or author's supervision) with the preparation of an act of intermediate acceptance of these structures. At all stages of construction in order to check the effectiveness of the previously performed production control, inspection control should be selectively carried out.

Inspection control is carried out by special services, if they are part of a construction organization, or specially created commissions for this purpose.

During the installation of the reactor, all the above listed methods and control methods are used.

The installation equipment is a hydrocracking reactor for diesel fuel.

2.2 Operation of the reactor

2.2.1 General information on operation

The reactors are operated in accordance with the manufacturer's instructions and other regulatory and technical documentation.

In such a process as hydrotreating reactor equipment, as well as others included in the plant, the devices and devices are a single system, the operation of which is sharply affected by problems even in one unit, so in such cases they talk about the reactor unit.

To ensure normal operation of diesel fuel hydrotreating plants, strict compliance with the regulated process conditions is required, which guarantees the planned mileage of any hydrotreating plant.

During reactor operation it is necessary to monitor:

- the level of catalyst and pressure, preventing their sharp fluctuation;

- due to the presence of pressure drops at the control valves under the reactor.

2.2.2 General requirements for preparation, start-up and setting to mode

The preparation of the plant for start-up consists in checking the completion of all repair works, closing all devices with hatches and covers, testing the equipment for tightness, assembling the process diagram, receiving energy carriers, ensuring the connection of the plant with the general plant, instructing the plant personnel on all changes made during the repair period.

All operations for preparation, start-up and setting of the plant to the mode are carried out after issuing the appropriate order for the enterprise and a written order of the shop manager. Preparation, start-up and setting of the plant to normal mode is performed by written order of the plant manager and under the supervision of the shop management.

2.2.3 Preparation of reactor unit for start-up

During preparation it is necessary to perform the following measures to ensure emergency-free startup of the unit:

- clean the plant area from foreign objects, close the process trays and wells, fill the pit covers with sand;

- place registration plates on the devices;

- provide maintenance personnel with personal protective equipment and workwear;

- complete the installation with all necessary documentation (regulations, production instructions, STP, shift reception and delivery log, submarine, etc.) according to the list of NTD;

- provide installation with primary fire extinguishing equipment, first aid kit;

- check fire extinguishing, steam extinguishing, column water sprinkling systems;

- check serviceability of communication and fire alarm systems;

- provide the installation with the necessary materials: lubricating oil, locksmith tools, packing, rags, portable lamps, hoses in the required quantity;

- check the technical condition of the sewage system, pay attention to correct operation of hydraulic locks in sewage wells;

- check the installation of safety valves on the devices and pipelines in accordance with the list and set pressures;

- check packing of gland seals on all shut-off valves, lubrication of friction parts;

- check the freedom of rotation of the moving parts of pumps and fans, valves;

- start supply and exhaust ventilation;

- during inspection of flange connections pay special attention to total number of studs, bolts, gaskets, tightening of connections, presence of blankings on drains of devices;

- check condition of electrical equipment, condition of thermal insulation, grounding circuits of pipelines and devices, availability of systems of protection against static electricity, serviceability of emergency lighting;

- prepare instrumentation for actuation;

As the individual plant systems are ready and in agreement with the plant, the following are accepted for the plant: steam, electric power, instrument air and A, water, inert gas (nitrogen), reagents.

Raw materials to the park are accepted by agreement with the plant dispatcher and the MCC service of workshop No. 14. Raw materials are accepted directly for installation before start-up.

The catalyst is supplied to the plant once, for the entire volume of reactor loading, at the request of workshop No. 8 from the equipment base of workshop No. 38. The catalyst is packed in metal barrels of 200 liters each or in Bigbegi (innovative packaging, bag for packing and transportation) weighing up to 1 ton. Loading is carried out mechanically in dry weather, excluding moisture ingress on the catalyst.

VSG comes from catalytic reforming units LCh3511/1000, L-35-11/600 and L3511/300 via high pressure VSG line No. 381.

2.2.4 Catalyst loading into reactor

Catalyst loading is performed with the appropriate quality certificate. Before loading, it is necessary to remove dust and fine particles from the catalyst by screening. For a catalyst in use, this operation is mandatory. Loading must be carried out continuously and in an orderly manner, loading the catalyst around the entire perimeter of the reactor using special hoses. Before loading the catalyst into the bottom of the reactor, a layer of porcelain balls is filled onto a special grid-table. At the same time, maintenance personnel must work in austriators or gas masks.

After loading the catalyst, layers of porcelain balls of different diameters are filled over it, with larger diameter balls being laid in the upper layer. Further, the catalyst bed is purged from dust with dried air through the broken flanges at the reactor outlet. After blowing the reactor with air, it is completely sealed.

The leak test of the system shall be performed by nitrogen so that the oxygen content of the system does not exceed 0.5% vol.

2.2.5 Leak test

Leak check of the plant equipment is performed by nitrogen (inert gas) supplied from CVC1 or CVC2 with oxygen content not more than 0.5% of volume fraction and includes the following operations:

- blow-down of devices and pipelines;

- separation of plant systems by process pressures;

- blowing of pipelines and devices in order to check for permeability;

- preliminary leak check of the systems;

- leak check of the systems for density and strength;

- elimination of defects;

- If additional pneumatic tests are required, a nitrogen or air leak test shall be carried out with the system set for time exposure.

Blow-down of devices and pipelines is carried out in order to clean them from foreign objects, to free them from water, scale, dirt, to detect patency and loopholes of the system after completion of repair works, as well as to free the systems from oxygen and carbon oxides after catalyst regeneration.

Pressure gauges and safety valves shall be installed on the apparatus, piping and pump compressor equipment prior to purging.

The products are discharged into the atmosphere through vents, drains or broken flanges to avoid the transfer of dirt and scale from one device to another.

At the same time as blowing of the main components of the system, all auxiliary pipelines, bridges and drains are blown. Blowing is performed by bypass of control valves.

Upon completion of blowdown and assembly of all flange connections, systems are tested for density for operating pressure (it is necessary to take into account the presence of devices with operating pressure less than 40 kgf/cm2 S-101, K-3 in the high pressure system).

Pressure rise shall be performed smoothly:

- up to 1 kgf/cm2 (0.1 MPa) - 15-20 min.;

- up to 10 kgf/cm2 (1 MPa) - 60-90 min .;

- up to 40 kgf/cm2 (4.0 MPa) - 2.53.0 h.

All primary instrumentation and A instruments, flowmeters, pressure meters, gas analyzers, control valves associated with the tested system are connected during the density check.

The leak test of the high pressure system shall be performed at the operating pressure. The test is carried out by an inert high pressure gas by stepwise pressure rise:

- 1 stage - 16 kgf/cm2;

- II stage - 25 kgf/cm2;

- III stage - 40 kgf/cm2

When the installed pressure for each stage is reached, the flange joints, gland seals and welds are washed to detect possible passes.

Detected defects are eliminated after pressure is reduced to atmospheric pressure. After testing the reactor unit, the inert gas contained therein can be used to purge and leak test the stabilization units and the gas purification unit.

Tightness check of process systems for density and strength, in accordance with process pressures, is performed according to separate diagrams in accordance with their operating pressures. Leak check shall be carried out by written order of the plant manager. After elimination of defects, the systems are put for holding under pressure.

Scheme of expulsion and test for tightness of the reactor block: the nitrogen pipeline → the T-connector of mixture of the I block → interpipe space of T101/1.2 T-102/1.2 T103/1.2 p-101 P101, R-102 → pipe space of T103/1.2 → T102/1.2 → T101/1.2 → BX101 → X1 → S-101 → K3s105 → F-101, F101A → TsK101svecha in the atmosphere.

The leak test shall be performed at a working pressure of 30 kg/cm2 (g).

2.2.6 Replacement of inert gas with hydrogen-containing gas

After checking the system for tightness, nitrogen pressure is released at a rate of 4? 5 kg/cm2 per hour (no more than) to 0.3? 0.8 kg/cm2. Before replacement by VSG of inert gas (nitrogen) to check an otglusheniye of drainages, vozdushnik, to select nitrogen on verification of the contents in it of oxygen then to start reception of VSG according to the scheme: the line of fresh VSG on ustanovkuS105F101, F-101atsk-101troynik mixtures the I blokamezhtrubny space of T101/1, 2 T102/1, 2T-103/1, 2p101r101, R-102trubnoye T103/1 space, 2T-102/1, 2T101/1, 2BX-101X-1C-101K-3→щит an otduva.

Raise the pressure in the system to 1015 kgf/cm2, select HSV for analysis. If H2 concentration is less than 75%, release the pressure and refill the HSV system. At concentration of H2 more than 75% to turn on the TsK101 compressor on circulation through X105. Check normal operation of the compressor and smoothly switch the operation of CC101 to the system.

Shock the P101 furnace and start raising the temperature in P101, R-102 at the rate of 1015 ° С/h and pressure up to 30 kg/cm2 at the rate of 5 kg/cm2 per hour.

2.2.7 Catalyst drying

Drying of the catalyst is recommended in a circulating inert gas or hydrogen-containing gas at a total pressure of 1015 kg/cm2. Catalyst drying with inert gas is carried out using PC3 compressor of L2410/2000 unit or PC4,105 compressors of L3511/600 unit. The temperature of the circulating gas upstream of the C101 separators is kept at the lowest possible level for maximum water release in all catalyst drying and sulfidation stages.

When the catalyst is dried, the temperature in the reactors increases at the beginning to 110 ° C at a rate of 15 ° C per hour and is maintained at this level for at least 2 hours when determining the amount of water entering the separator (5070 l/h).

Draining of separator into industrial storm sewer is performed every hour. If, at the specified temperature, water does not enter, is released in a small amount or its supply after 2 hours practically stops, the temperature in the reactor is increased at a rate of 15 ° C (with holding for 2 hours at each temperature increase) to a level at which a steady release of water in an amount of 5070 l/h is ensured.

After the water supply to the C101 separator is stopped, the temperature in the catalyst bed rises to 160 ° C at a rate of 15 ° C per hour.

When water is recovered in the separator in the amount of 5070 l/h, the temperature rise in the catalyst bed is stopped and it is maintained at an available level until water release is stopped.

At a temperature of 160 wasps the endurance becomes not less than 2-3 hours. Drying ends after water supply to C101 separator is stopped. Using an inert gas to dry the catalyst, the temperature in the reactor is reduced to 100 ° C and replaced with a hydrogen-containing gas.

2.2.8 Setting of the unit to the mode

Before drying the catalyst and feeding the raw material to the mixing tee, put the stabilization unit into normal process mode.

All start-up measures for pressure set, injection of column levels, separators and vessels, as well as flow temperature control shall be carried out only after complete adjustment of instrumentation by the instrumentation service of control instruments, actuation of control valves and installation of all sensors.

The raw material pump TsN1, 2, in addition to the reactor unit, pumps the raw material into the K-1 column.

Due to the large pressure difference at the discharge of the raw pumps (60 kgf/cm2) and in the separator S-3 (4.5 kgf/cm2), care must be taken when the circuit is put into operation. Open shut-off valves smoothly, constantly monitoring the pressure in the separator by instruments and A and pressure gauge on the separator. If the level appears in C3, send excess to column K-1.

If level appears in column K-1, start the circulating pump TsN4, TsN-4A, send part of the flow through the control valve, pos. FV6430, 6431 to the P103 furnace, another stream through heat exchangers T12-9, water cooler X-7 through the circulation line to the injection line of the K1 column: TsN-1, 2→S3→T9÷12→K1.

After the set of the operating level in the K-1 column and the normal circulation scheme by the stabilization unit, stop the feed pump TsN1, 2, close the valve pos. UV1511.

Disassemble the injection diagram.

Ignite furnace P103, start temperature rise at outlet of furnace P103 at the rate of 20 ° С per hour pos. TIRCSA6032A. When the bottom temperature is reached, pos. TIRA1014 in column K-1 90 ° C to hold for 1 hour. Further increase the temperature at the rate of 510 ° C per hour to 130 ° C. To avoid discharge of TsN4, TsN-4A pumps, open the compensating line at reception. After passing of "critical" temperatures of a bottom of a column to increase the speed of temperature rise to 20 wasps an hour.

In normal mode of circulation of hydrogen-containing gas on reactor unit, hot circulation on stabilization unit it is possible to come to supply raw material to reactor unit system.

Feed is supplied to the mixing tee when the total pressure in the reactor reaches not less than 25 kg/cm2 and the temperature is 150 ° С over the catalyst beds.

In order to avoid hydraulic shocks and catalyst failure, feed to the hydrogen-containing gas stream shall be carried out smoothly starting from a minimum of 40 m3/h. The increase in feed load shall not be accompanied by abrupt temperature fluctuations in the reactor and furnace and abrupt pressure surges in the system.

At emergence of level in C101, a product to send to S-3. If level appears in C3, send excess to stabilization unit.

When pressure rises in C3, pay attention to operation of pressure regulator (pos. PV1206. At increase of level in K-1 column to transfer a stream via T12÷9 heat exchangers, the water H-7 fridge and the air BX19 fridge through circulation to reservoir E263 park.

Raise K-1 bottom temperature to operating temperature. If the level appears in the C107 separator, start the CP7 reflux pumps and pump out to L24/6 or, if there is water, grind to E20. Gas from S-3 is sent to the K-5 column and fuel network, and S107 through S10 to K6, S-19 to the furnaces or to the flare.

In advance, before the gas flows are sent for purification, CP10 is switched on and reflux is adjusted for columns K5, K-6 with MDEA solution with a concentration of 2545%.

After obtaining a high-quality stable hydrotreated diesel fuel, bring it to the tank farm.

The MDEA concentration should be maintained at the level of 25-45% by pumping fresh solution to E10 by CP16 pump.

2.2.9 Start of the plant in case of emergency situations

The reactor unit can be started without lowering the reactor inlet temperature in two cases:

In case of compressor shutdown or HSV flow decrease below the blocking value according to SS and ESD logic, the feed pump stops and the reactor unit furnace nozzles goes OFF.

After that, you must:

- find out the cause of compressor shutdown. After its elimination, start the compressor in the reactor unit system;

- In order to avoid possible catalyst reduction, stop the supply of MDEA solution for the irrigation of absorber K-3 (K-4);

- after stabilization of HSV circulation in the reactor unit supply the raw material to the mixing tee with minimum flow rate;

-Circulate the reactor unit furnace and start the temperature rise at the reactor inlet to the operating value.

During equipment shutdown, control the temperature in the catalyst beds. If it is not possible to start the compressor and the temperature in the catalyst beds rises dramatically, start depressurizing the system and supplying inert gas to the reactors.

In case of shutdown of the feed pump or decrease of the raw material flow rate below the blocking value according to SS and ESD logic, the reactor unit furnace nozzles go out. The circulation compressor is in operation.

After that, you must:

- find out the cause of pump shutdown. After its elimination, start the pump and shut down the furnace of the reactor unit.

If the feed pump was not started within 20 minutes after the feed to the mixing tee was stopped, it is necessary to:

- to avoid possible catalyst reduction stop supply of MDEA solution for K3 absorber irrigation, control hydrogen sulfide content in circulating HSG.

- start reducing the reactor inlet temperature to 300 0С at a rate of 2030 0С per hour.

If the concentration of H2S in the circulating HSG decreases below 0.1% of the volume fraction, it is necessary to reduce the reactor inlet temperatures to 180 0C at a rate of 2030 0C per hour.

If it is ready to supply the raw material to the mixing tee in the amount of 50% of the design load, shock the furnace of the reactor unit and start the temperature rise at the reactor inlet to the operating values ​ ​ with an increase in the load.

2.2.10 Normal operation of reactor unit

During normal operation of the unit during the process it is necessary to observe the following requirements:

- withstand values of all process parameters within the limits of process regulations;

- regularly monitor the condition of equipment, utilities, pump-compressor equipment, ventilation, furnaces, tanks and other equipment;

- prevent violations of the current safety and fire safety instructions;

- periodically check correctness of instrumentation and A instruments operation, perform checks of operating instruments, measure parameters with reference instruments;

- maintain cleanliness at workplaces and plant premises;

- timely recording in the regime sheets and watch logs of the regime indicators, reflect the quality of raw materials and manufactured products, as well as all changes made by the personnel of the process team for maintaining the regime during the watch;

- prevent leaks of oil products, timely eliminate all passes to flange joints, end seals of pumping equipment, carefully and economically consume energy resources, reagents, fuel and other consumables;

The main conditions ensuring normal operation of the equipment are:

- the temperature at the outlet of the furnaces for each flow should be the same and constant, avoid sharp temperature fluctuations for furnaces, columns and other equipment;

- the load on the burners and nozzles of the furnaces must be uniform, the flame is light straw in color and do not touch the coils pipes. The temperature of flue gases at the furnace passes shall not exceed the standard values, combustion in the chambers shall be complete, without smoke;

- it is necessary to regularly monitor the surface condition of coil tubes. The appearance of dark spots may indicate the beginning of coking of the product in the coil;

- control the load of air cooling refrigerators and change the supply of cooling water to refrigerators to withstand the temperatures of circulation reflux and waste products within the limits of the technological regulations.

2.2.11 Normal stop of the unit

Normal shutdown of the plant is carried out if it is necessary to carry out major repairs and inspection of the equipment, for catalyst regeneration, in the absence of raw materials.

If it is necessary to perform catalyst regeneration, it is recommended to wash the catalyst with a lighter raw material with respect to the processed one. For diesel summer fuel - fraction 200320 ° C or kerosene. This reduces the burning time of the coke by 1020% and avoids a sharp rise in temperatures during the initial regeneration period.

Before starting the catalyst flushing, it is necessary to stop the steam condensate supply to the low-temperature duct of the reactor unit.

Reduce the capacity of each unit to 60 m3/h at a rate of 20 m3/h.

It is necessary to stop the supply of MDEA solution for K-3 irrigation in order to increase the H2S content in the circulating HSG. Circulating HSV flow rate should be maintained at maximum level. Stop or minimize SHF discharge via the blow-off line to GRP.

The catalyst is washed for 4-6 hours.

Upon termination of washing to reduce the performance of each block of installation to 50 m3/h, to reduce temperature on catalyst layers to 200 wasps, with a speed no more than 30 wasps/h. When the catalyst bed temperature reaches 200 ° C, stop CP1.2 feed pumps. After the raw material circulation is stopped, a short-term temperature increase in the reactors is possible.

Continue HSV circulation from compressors CC101 (gas circulation mode). Duration of gas circulation is up to 24 hours at a temperature of 200225 wasps. The gas circulation temperature shall not exceed 200 ° C if the concentration of H2S in the circulating HSG is less than 0.01% vol.

During the entire period of gas circulation, C101 separators are cleaned from oil products by bypassing it to C-3 low-pressure separators and further to K-1. During the bypass from S101 to S-3 and from S-3 to K-1, monitor the pressure in S-3 and K1 devices, which should not exceed the maximum permissible parameters of the devices .

Gas circulation is carried out according to the scheme: → liters. circus. VSG → C105 (106) → F101, F-101A (F102, F-102A) → TsK101 (102) → mixture T-connector → interpipe space of T101/1.2 → T102/1.2 → T103/1.2 (3A,3.4/1.2) → P101 (102) → P101.102 (3.4) trubny space T103/1.2t102/1.2t101/1.2 (4/1,2,3,3A) → BX101 (102) → H-1 (2) → C101 (2) → K-3 (4) → C105 (106).

At the outlet temperature of P102 200 ° C, the nozzles on the P101 furnace are extinguished, HSV intake to the plant is stopped, after which the circulation compressors are stopped.

Pressure is released from the system up to 3 kg/cm2. Inert gas at the inlet to the plant is checked for O2 content - not more than 0.5% of volume fraction, CO - not more than 0.4% of volume fraction and the entire system of reactor units is blown by inert gas .

The system is considered washed if the content of combustible gases is not more than 0.5% vol.

When specifying the conditions of the shutdown process of the II reactor unit, the recommendations of the Catalyst Supplier shall be taken into account.

2.2.12 Catalyst Regeneration

The hydrotreating catalyst undergoes gas-air regeneration in the following cases:

- temperature rise at the reactor inlet does not allow to obtain the product of the required quality;

the temperature in the reactor reached a maximum;

- increase of pressure drop across reactors (more than 4 kgf/cm2 by any of reactors I of reactor unit and more than 6 kgf/cm2 II of reactor unit ).

Recovery of catalyst activity is achieved by burning coke in a mixture of nitrogen and air.

Oxidative regeneration of the catalyst is carried out by a gas-air mixture at a pressure in the reactors of up to 20 kgf/cm2 and a temperature of up to 455 ° C.

The reactor pressure is controlled by the valve pos. PV1205B located on regeneration gas discharge line to spark plug.

Before regeneration, the reactor unit of the plant is normally stopped, purged with nitrogen to a fuel content of not more than 0.5% vol.

After expulsion the system is filled with nitrogen (inert gas) up to the pressure of 1516 kgfs/cm2 on reception of the compressor, and circulation according to the scheme returns to normal: PK4 (PK105) L3511/600, PK-3 installation L2410 installation → T101/1.2 → T102/1.2 → T103/1.2 p-101 → P101 → P102 → T103/1.2 → T102/1.2 → T101/1.2 VH-101 → H1s101 → K-3 of a s-9 (L3511/600 installation) → PK4, (PK105 )

Then the furnace P101 is ignited and the temperature in the reactor P101, P-102 rises to 250 ° C at a rate of not more than 15 ° C/h. These conditions are maintained until the temperature in the entire catalyst bed reaches 250 ° C, the temperature difference between the reactor inlet temperature and the temperature in any zone of the catalyst bed shall not exceed 30 ° C.

At the same time, the C101 separator for 60% is filled with steam condensate (according to the scheme from the pumps H101, 101A on BX101 entrance). Circulation of steam condensate for washing of the air BX101 fridge returns to normal.

At achievement of temperature of 250 °C (in a catalyst layer) alkali solution circulation according to the scheme joins: E102 → H102 (H-102A) → BX101 → H-1 (on a bypass) → C101 → H102 (H-102A)

The flow rate of the circulating aqueous alkali solution is controlled by the circuit pos. FIRC1411 with valve installed on common pipeline for supply of caustic aqueous solution to pipeline upstream of VX101, BX-102.

If the pH of the circulating alkali solution decreases less than 7.0, fresh 2-5% aqueous alkali solution is supplied by pumps H106,106A from vessel E102 in the amount necessary to maintain pH within the range of 7.08.5. The spent aqueous caustic solution is withdrawn from the unit to the carbonation unit .

When the temperature is reached throughout the catalyst bed up to 250 ° C, air is supplied to the inert gas stream, the concentration of oxygen increases stepwise to a concentration of 0.5% vol. During the oxygen concentration set, the temperature rise in the reactor is monitored.

In the absence of ∆T (by ∆T means the difference between the temperature at the inlet of the reactor and the maximum temperature at any point of the reactor), the temperature at the inlet of the reactor rises at a rate not higher than 25 ° C/h. First, the temperature of the reactor rises, then the concentration of O2, until the ∆T reaches 55 ° C. The reactor inlet temperature shall not exceed 345 ° C and the oxygen concentration at the reactor inlet shall not exceed 0.5 vol%. The ∆T drop is maintained at 55 ° C (at oxygen concentration not more than 0.5 vol%) until oxygen slips through the reactor. With oxygen slipping, the flow rate of the supplied air is reduced so that the oxygen content at the inlet to the reactor is at the level of 0.3 vol% but not more than 0.5 vol %.

At a reactor inlet temperature of 345 ° C and a reduction of ∆T to zero, the following regeneration step is started: the temperature at the inlet of the reactor rises to 400 ° C (at a rate of not more than 25 ° C/h), after which it is necessary to increase the concentration of oxygen until one of two moments occurs: ∆T = 30 ° C or O2 content = 0.5 vol%

The ∆T drop is maintained at a maximum level of 30 ° C, increasing oxygen consumption if necessary. When the oxygen content at the inlet of the reactor reaches 0.5 vol%, after the completion of burning of the coke at this stage, the temperature difference will gradually begin to decrease and become zero. Under these conditions, oxygen slipping is possible, so it is necessary to adjust the oxygen supply so that the maximum concentration of 0.5 vol% is maintained at the reactor inlet at all times.

After the temperature difference is zero, the reactor inlet temperature gradually rises to 425 ° C at a rate of 25 ° C/h and the oxygen concentration is maintained at 0.5 vol%. After reaching this temperature, the oxygen concentration in the recycle gas at the reactor inlet gradually increases until the temperature difference is 30 ° C or the O2 content reaches 0.5 vol%, which will occur sooner. When ∆T begins to decline, the concentration of O2 gradually rises to 0.5% (if this concentration is not reached); when the concentration is 0.5%, monitor the gradual reduction of the temperature difference to zero. The oxygen concentration shall not exceed 0.5 vol%, especially after the O2 slip at the outlet of the last reactor.

When the temperature difference becomes zero, the O2 content at the reactor inlet gradually increases to 1 vol%; if the ∆T exceeds 30 ° C, the concentration increase stops. After the oxygen content reaches 1 vol%, these conditions are maintained for 8 hours or until the temperature difference is zero (which will occur later).

Regeneration is considered complete when three conditions are met:

- oxygen consumption stops;

- C02 generation is stopped;

- Temperature rise in the catalyst bed stops.

Alkaline washing continues all the time until SO2 is detected in the exhaust gases and an additional 8 hours after the SO2 content drops to zero.

After that, the supply of an aqueous alkali solution is stopped. Steam condensate of pump N101, N-101A is supplied to remove the residual alkali solution from the regeneration circuit and circulation circuit, while the reactor inlet temperature is maintained at 425 ° C.

The end of system flushing is determined by pH and visual assessment of drainage water.

In order to dry the system (after stopping the water supply), the reactor inlet temperature is maintained at 425 ° C, while the temperature at the outlet of the refrigerators should be kept at the minimum possible level with the drainage of water from all cold points. The duration of this operation is about 4 hours, but not more than 6 hours.

The reactor inlet temperature is then lowered from 25 ° C/h to 70 ° C. During cooling, the temperature difference between the reactor inlet temperature and the temperature of any point in the catalytic bed shall not exceed 30 ° C.

After cooling of the catalyst the PK4 (PK105) compressor ustanovkil3511/600 stops, PK-3 of L2410/2000 installation, dumps pressure in a contour and expulsion of a system is made by quality nitrogen.

2.2.13 Special control and emergency situations

Before catalyst regeneration, it is necessary to isolate the reactor unit on which the catalyst regeneration is carried out from adjacent units by installing plugs. Nitrogen and air pipelines for regeneration on a unit where catalyst regeneration is not performed shall be dehumidified or cut off by double shut-off valves with an open witness between them.

During catalyst regeneration, it is necessary to control the pH of spent caustic solution (caustic): if the pH is too low, there is a risk of acid corrosion, and if the pH is too high, alkaline corrosion and excessive caustic consumption are possible.

Emergency situations:

1. In case of a sharp increase in ∆T, it is necessary to close the air supply to the system, reduce the temperature in the reactors, and, if necessary, accept the maximum possible amount of nitrogen into the system with the regeneration gas blow-off to the plug.

2. If the fresh alkali solution is stopped, it is possible to continue regeneration until the pH is 6.5, after which it is necessary to stop the air supply. If the fresh alkali solution is not supplied again within an hour, stop the furnace and cool the reaction section.

3. In case of shutdown of the recycle gas compressor, it is necessary to stop the air supply, accept fresh nitrogen from the MCC in the exhaust pipeline of the compressor with gas blow-off to the "spark plug" of PK4 reception, extinguish the furnace and continue circulation of alkali solution during

15 minutes and supply the water used for washing for 30 minutes.

4. In case of pressure drop in the line between the inlet of the product air cooler and the inlet of the separator, it is necessary to stop the air supply and supply the water used for washing with maximum flow rate.

2.3 Reactor Repair

2.3.1 Characteristics of faults and methods of their rectification

Disruption of reaction equipment can occur as a result of corrosion wear (chemical or electrochemical effects of aggressive medium on material), erosion wear (abrasion of material by friction forces and impact from liquid or solid-particulate working medium)thermal wear of housings and internal devices (reduction of strength and violation of density of elements and joints as a result of high temperatures, high temperature stresses, creep, relaxation and deterioration of steel structure), mechanical wear (plastic deformations and violation of integrity of details) and also as a result of pollution of working surfaces deposits [16].

Equipment failure, in most cases, is due to high rates of metal corrosion and accumulation of corrosion-salt deposits in process paths. Equipment of hydrotreating plants is subject to chemical, electrochemical and hydrogen corrosion.

Problems associated with equipment corrosion, formation and accumulation of salt deposits in the process streams of hydrotreating units are due to the processing of raw materials with an increased content of organochlorine compounds.

Salt deposits lead to an increase in pressure drop in process paths, which entails a decrease in productivity, to unscheduled and sometimes emergency shutdowns of plants. Increased corrosion of equipment and accumulation of corrosion-salt deposits in process paths are related to the fact that chlorine, nitrogen and oxygen-containing organic substances are present in oil refining products along with organic compounds containing sulfur [1].

Hydrogen corrosion is affected by reaction apparatus operating at high pressures and temperatures in the presence of hydrogen-containing gas. Diffusion of hydrogen into the metal leads to the destruction of cementite and an increase in the internal pressure in the metal, which is accompanied by the formation of cracks.

Methods of equipment corrosion protection [1]:

- application along with low-alloyed and high-alloyed chromium and chromomolybdenum alloys;

- reactor torcreting;

- fabrication of equipment from double-layer steel (carbon base with internal cladding from stainless steel);

- application of corrosion inhibitors and neutralizers in equipment units operating under conditions of vapour condensation at temperature up to 200 0С.

Materials for manufacturing the housing and internal devices are selected depending on the operating conditions in the apparatus (temperature, pressure, aggressiveness of the medium). Apparatus housings are made of steel BC.S. (wall temperature t ≤ 425 0C, pressure less than or equal to 5 MPa), 12CM (reaction equipment, t ≤ 560 0C) and other materials.

In the presence of corrosive media, the casing of the equipment column is made of bimetal with a protective layer of 12X18N10T steel (hydrochloric corrosion) and other materials [16].

Erosion wear occurs as a result of liquid or gas flow.

Mechanical wear of the housing and internal devices is manifested in the form of their plastic deformations, as well as the formation of cracks in the metal when the apparatus exceeds design pressures and temperatures or high temperature stresses.

To protect the reactor wall from overheating, the shell of reaction equipment operating at high temperatures is usually covered from the inside with a layer of heat-resistant torcretbetone, which provides a decrease in the temperature of the shell wall and protects it from corrosion and erosion by the medium. Material of internal devices - steel 12X18H10T, 08X18H10T, 08X13.

The thickness of the shotcret concrete coating is taken from 100 to 200 mm depending on the process temperature so that the wall temperature of the housing is not more than 150200 0C.

In the absence of internal torkret-concrete isolation and high temperature of process of the case of the reactionary equipment carry out from heat resisting staly 12XM, 12X18H10T or from bimetal 12XM+08X18H10T, 12XM +08X13 and cover with external thermal insulation.

The service life of the hydrotreating catalyst depends on the intensity of coke formation, so during operation of the reaction equipment it is necessary to control the activity of the catalyst, which over time decreases due to the deposition of sulfur and coke on its surface.

To suppress the process of coke formation, a certain partial pressure of hydrogen, a certain molar ratio of hydrogen to raw material, a certain fractional composition of the raw material must be maintained.

Coke formation is enhanced in the case of:

- abrupt violation of the specified process mode (reduction of circulation of hydrogen-containing gas, pressure drop, abrupt temperature increase in the reactor);

- ingress of various kinds of oils, lubricants on the catalyst;

- weighting of fractional composition of processed raw materials (ingress of high-boiling fractions );

- presence of oxygen dissolved in the feedstock, olefins;

If catalyst activity drops below permissible one performs its regeneration process consisting in burning of deposited coke and sulfur.

Oxidative regeneration of the catalyst is carried out by a gas-air mixture at a pressure in the reactors of up to 20 kgf/cm2 and a temperature of up to 455 ° C.

In oxidative regeneration, sulfurous iron sinters with the upper catalyst bed, which causes a significant increase in hydraulic resistance and a deterioration in catalyst operating conditions.

The presence of water in the feed leads to a decrease in the mechanical strength of the catalyst and a decrease in its specific surface area.

Therefore, catalyst overload is required after regeneration.

Gradually, due to recrystallization and changes in surface structure, as well as due to adsorption of organometallic and other substances on the surface of the catalyst, the catalyst "ages."

In case of a decrease in catalytic activity irretrievably, the catalyst is replaced with fresh one.

2.3.2 Preparation of reactor for repair

Preparation for repair is especially important in oil refineries, where explosion and fire hazard are very significant factors. Therefore, the sequence and contents of the preparation for repair operations are specified in the unit Job Instruction or in the Operating Instructions for specific equipment. When compiling the map, the properties of the medium filling the equipment (or the system into which it is included), the dimensions of the equipment, as well as the accepted method of repair [12] are taken into account.

Equipment shutdown and preparation for repair is carried out by process personnel (operators, equipment). Abrupt changes in temperature, pressure, loads during shutdown can cause serious damage to the equipment, therefore, the shutdown of large equipment or technological facility is led by the head of the plant (workshop).

Further preparation of the equipment depends on its design features, specific conditions and the nature of the required repairs. It can include washing and steaming, alternating a certain number of times, the use of special reagents, etc. The process service shall issue an official certificate guaranteeing the equipment preparation to the repair executors. During the overhaul of the plant, an act is drawn up in a certain form, which confirms the readiness of the equipment and communications for repair and specifies special precautions during the work.

General responsibility for preparation and timely delivery of equipment for repair is assigned to the head of the production shop. Equipment delivery for repair is carried out in accordance with the requirements of GOST 27.20174. According to the approved form, written permission is drawn up for welding and other fire work carried out on the equipment itself or on the plant (unit) territory. Such a permit is signed by the shop manager, signed by a representative of the fire department, who, before the start of work and during work, checks strict compliance with all measures specified in the issued permit and in the general safety rules of the organization.

When preparing the reactor for repair, it is necessary to:

- stop the feed to the reactor and continue the catalyst circulation until the coke is completely burned. After burning the coke, stop the catalyst circulation;

- release the reactor from the catalyst into the spare hopper;

- disconnect the reactor with gate valves from pipelines and other devices;

- depressurize the flare. Release residual pressure into the atmosphere by opening the gate valve on the plug. The pressure must be monitored by a serviceable pressure gauge installed on the device and the pressure device on the panel;

- steam and blow with air;

- dehumidify the reactor unit system from other devices and pipelines with standard blankings;

- take analysis for hydrocarbon gases and oxygen content from the reactor. Before firing works, in addition to the specified analyses, perform air analysis for the content of fire and explosion hazardous substances.

2.3.5 Repair Documentation

Repair documents for individual equipment are compiled by the developer.

Repair documents are developed on the basis of design, operation and process documentation, as well as operating experience. These documents shall reflect repair methods, tools and instruments required for repair, technical requirements for repaired equipment, consumption rates of spare parts and materials [12].

Repair drawings. For organized repairs, it is of great importance to have quality repair drawings compiled in accordance with GOST 2.60468 (for repair of assembly units, assembly and control of repaired parts).

Repair dimensions are the dimensions established for the manufacture of a new part instead of a worn one. They can be categorical (final) and racing (designed to fit the part in place). Repair drawings shall indicate only those dimensions, limit deviations, clearances and other data that are checked during repair. At the same time, the accuracy class and fit provided in the working drawings must be preserved.

Repair schedules. The main starting documents when drawing up the general repair plan are annual plans and schedules for repairs of process units or individual equipment. Plans and schedules are drawn up based on the production plan and current standards for one repair. At the same time, real capabilities, forces and means of repair service, and in some cases seasonality, are also taken into account.

The structure of the overhaul cycle, the overhaul period and the duration of equipment outage during repair must comply with the repair standards.

The annual schedules specify the months during which this process unit (equipment) must be repaired. Based on the annual schedules, monthly repair schedules in them indicate the calendar days of idle of each object in the repair of the type provided for by the annual plan. According to the monthly schedule, the object is stopped for repair at a strictly assigned time.

The design of the overhaul schedule is previously agreed with all organizations that take part in the repair work.

Repair schedules. The list of repair works details all works performed in accordance with this scheduled repair. They should contain information sufficient to correctly determine the required labor, necessary materials and spare parts, as well as the cost of all repairs and individual elements of it.

In addition to repair works, they may reflect work due to production requirements aimed at improving working conditions (nomenclature safety work), as well as work on partial modernization of the technological unit or complete modernization of specific equipment (replacement of old equipment).

The list is made up of the managers of the operation of the site, the head and mechanic of the site, the senior mechanic and the head of the workshop. The statement is agreed with the chief mechanic and approved by the chief engineer of the enterprise.

Based on the lists of repair works (lists of defects), consolidated requests are made for the materials and spare parts necessary for repair, which must be prepared for the appointed repair period by the supply services of the enterprise or the contractor.

Taking into account consumable materials and spare parts, the lists provide an estimate for repairs, which determines the element and total cost of all repairs. The guidelines for the preparation of estimates are approved price tags or, if they are not available, appropriately prepared calculations.

The revised list, which reflects the list and scope of actual works performed, is called as-built and together with the preliminary list serves as a reporting document when issuing the object delivery after repair. Discrepancies between preliminary and as-built statements should be explained in detail in the Notes column or in a special act.

Conclusion

The main and most responsible apparatus of many refinery plants is the reactor, since its successful operation depends on the cost-effectiveness of the process and the quality of the resulting products.

During the chemical-technological process in the reactor, various substances with various physicochemical properties are subjected to chemical conversion.

The essence of the effect on the degree of conversion (conversion) and selectivity (selectivity) of the process is determined by a certain relationship of physical and chemical factors necessary for successful chemical reactions. The design of the apparatus is only a means of influencing this relationship by changing the speed of individual physical and chemical stages of the process.

The diploma work considered the reactor, in which the process of hydrotreating the diesel fraction at the LG24/7 unit is carried out.

Most of the hydrotreating reactors currently in operation were designed and built in the mid-1970s. As product yields and quality have changed, many refiners have been able to benefit from advances in catalyst development and avoid major investment in their plants. However, in order to realize the full potential of the reactor system economically, a detailed evaluation of the performance and design of the existing reactor systems is needed, combined with a careful consideration of the available reactor modernization options.

In the technological section of the diploma project, the basic information on the installation of reactor equipment was considered and the main features of their implementation were disclosed. Much attention was paid to the issues related to the main features and requirements for the operation and repair of reactor equipment. In addition, the main faults arising during the operation of the reaction equipment and methods for their elimination are described in detail.

The design section contains data on the material balance of the reactor unit, the main geometric dimensions of the hydrotreating reactor are calculated, mechanical calculation is carried out.

The economic part shows the balance of working time, the number of personnel and the calculation of annual costs, the annual salary fund of personnel, the cost of production and the main technical and economic indicators.

The Safety Precautions Section considers the measures for labor protection and the safest use of reactors of the hydrotreatment unit in the performance of works related to installation, operation and repair.

Реактор монтаж (Чертеж 2).cdw