CN113479843A

CN113479843A - Carbon monoxide segmented heat transfer semi-reaction conversion process with adjustable water-gas ratio for oxo synthesis

Info

Publication number: CN113479843A
Application number: CN202110763351.8A
Authority: CN
Inventors: 王同宝; 傅亮; 韩振飞; 詹媛媛; 施晓鲁; 亢万忠; 冯亮杰; 王立成
Original assignee: Sinopec Engineering Group Co Ltd; Sinopec Ningbo Engineering Co Ltd; Sinopec Ningbo Technology Research Institute
Current assignee: Sinopec Engineering Group Co Ltd; Sinopec Ningbo Engineering Co Ltd; Sinopec Ningbo Technology Research Institute
Priority date: 2021-07-06
Filing date: 2021-07-06
Publication date: 2021-10-08
Anticipated expiration: 2041-07-06
Also published as: CN113479843B

Abstract

The invention relates to a carbon monoxide sectional heat transfer semi-reaction conversion process for oxo synthesis with adjustable water-gas ratio, which is equivalent to the loading of two sections of adiabatic process catalysts, but can avoid the problems of over-temperature of the I section of a converter and methanation reaction caused by low load or water-gas ratio change by a method of bypass adjustment and conversion catalyst dynamics control; before the raw synthesis gas enters the low-pressure steam generator, water of the high-pressure boiler is sprayed, so that the supersaturated raw synthesis gas can discharge a large amount of water during subsequent condensation, and more ash and impurities are carried away, therefore, the setting of a detoxification groove can be cancelled, and the process is simplified; the I section of the shift converter adopts dynamic control, the reaction condition is mild, and the service life of the catalyst is prolonged; the temperature of the conversion gas at the outlet of the I section of the shift converter can be effectively adjusted through the bypass at the outlet of the gas-liquid separator, so that the superheat degree of the conversion gas entering the medium-high pressure steam superheater is ensured, and stable superheated medium-high pressure steam is obtained.

Description

Carbon monoxide segmented heat transfer semi-reaction conversion process with adjustable water-gas ratio for oxo synthesis

Technical Field

The invention relates to a high-concentration carbon monoxide sectional heat transfer half-reaction conversion process for oxo synthesis with adjustable water-gas ratio.

Background

The carbon monoxide shift device has a very important position in a synthesis gas production device, and the raw synthesis gas from an upstream gasification device is totally or partially reacted to generate hydrogen under the action of a catalyst according to the requirement of a downstream product on the hydrogen-carbon ratio. Different product requirements have a greater impact on the set up of the conversion process flow. For plants producing hydrogen, synthetic ammonia, it is generally necessary to convert as completely as possible the carbon monoxide into hydrogen; for plants producing oxo-synthesis gas, such as methanol, ethylene glycol, synthetic oil, natural gas, etc., the shift reaction depth is shallow and the ratio of carbon monoxide to hydrogen in the synthesis gas needs to be adjusted according to product requirements. The novel continuous pressurized coal gasification technology is mainly divided into coal water slurry gasification technology (such as GE, multi-nozzle, multi-element slurry and the like) and pulverized coal gasification technology (shell, oriental furnace, space furnace, GSP and the like). The concentration of the crude synthesis gas produced by the gasification of the pulverized coal is usually 10-20% higher than that of the coal water slurry, and particularly, the crude synthesis gas produced by the gasification of the chilling type pulverized coal has high carbon monoxide concentration and high water-gas ratio of 0.7-1.0, and the conversion reaction driving force is large, so that the overtemperature of the first conversion furnace is easily caused, and certain difficulty is brought to the process setting of the conversion reaction.

The adiabatic shift process for producing oxo-gas by chilling type powdered coal gasification is usually as follows:

(1) high water-gas ratio conversion process. The steam is added into the inlet of the conversion device in a large amount at one time, so that the steam-gas ratio is increased to be more than 1.6 or even higher. The process has the advantages that the overtemperature of the first shift converter can be avoided, and the operation is safe and stable. However, as the amount of steam input increases, a great waste of energy is caused, and the added steam is separated in a condensate manner in the downstream low-grade heat recovery stage, so that the equipment investment and the operation cost are increased. The service life of the shift catalyst is short, usually 1-2 years, the catalyst has high requirements on the content of coal sulfur, and if the content of hydrogen sulfide in the crude synthesis gas is low, the catalyst is easy to cause reverse vulcanization.

(2) A low water-gas ratio shift process. The low-pressure steam generator is arranged before the first shift converter, so that part of water brought by the crude synthesis gas can be separated, the water-gas ratio is reduced to about 0.25, the shift reaction driving force of the first shift converter is greatly reduced under the condition of no change of load, the purpose of controlling shift overtemperature is achieved, and high-grade steam can be produced as a byproduct. However, because the content of carbon monoxide in the raw synthesis gas entering the first shift converter is still very high (60% -65%), when the operation of the gasification device is unstable or the operation of the pre-low-pressure steam generator is unstable, the water-gas ratio is not reduced, and the methanation reaction of the first shift converter is likely to occur under the working condition of low water-gas ratio, so that the temperature is over-high.

(3) And (4) controlling the catalyst dynamics. The method is characterized in that the temperature of a bed layer is controlled within a controllable range by reducing the catalyst loading of a first shift converter without adding steam and by a method of far reaching reaction balance, boiler water is gradually added for subsequent shift reactions according to the requirement of reaction depth, and steam is basically not required to be added. However, the method also has certain limitations, and due to the dual functions of high carbon monoxide content and high water-gas ratio, the reaction driving force is large, the equilibrium temperature distance is large, and the dosage of the catalyst must be accurately calculated. If the catalyst loading exceeds the range, the reaction depth is increased, and the overtemperature is caused; for the stage with lower start-up load, the raw synthesis gas amount is usually only half of the normal amount or even lower, and for the same catalyst loading, the over-temperature is easily caused. However, since the catalyst loading of the first shift converter is constant, it is difficult to have a control means when the excess temperature occurs.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art, and provides a carbon monoxide segmental heat transfer semi-reaction conversion process for carbonyl synthesis, which can be used for coping with different water-gas ratios and crude synthesis gas load working conditions, has the advantages of simple process flow, simple operation, flexible control and low investment, and can adjust the water-gas ratio.

The technical scheme adopted by the invention for solving the technical problems is as follows: a carbon monoxide segmental heat removal semi-reactive shift process for oxo synthesis with adjustable water-gas ratio is characterized by comprising the following steps:

the method comprises the following steps that firstly, crude synthesis gas from the upstream is subjected to primary liquid separation through a gas-liquid separator and then is divided into two parts, one part is sprayed with a small amount of mist high-pressure boiler water through a spray head in a mixer to enable the crude synthesis gas to form a supersaturated state, then the crude synthesis gas enters a low-pressure steam generator to produce low-pressure saturated steam as a byproduct, meanwhile, the temperature of the crude synthesis gas is reduced to form condensate, the condensate enters the upper part of a high-pressure condensate separation part, and impurities in the gas are also settled along with the condensate; the other strand enters the lower part of the high-pressure condensate separation tower through the flow control valve, and the high-pressure condensate separation tower is of a two-layer structure for adjusting the water-gas ratio, wherein the uppermost layer is a solid partition plate with a liquid seal structure, and the lower layer is a plurality of layers of tower plates;

the crude synthesis gas from an upstream low-pressure steam generator becomes low-water-gas-ratio crude synthesis gas after condensate is separated from the upper layer, and the low-water-gas-ratio crude synthesis gas is discharged from the top, enters the crude synthesis gas for heating and enters a section I of a sectional heat transfer type shift converter; the upper layer condensate flows into a lower layer tower plate through a liquid seal, another strand of crude synthesis gas from the lower layer is washed, the washed crude synthesis gas with medium-high water-gas ratio is extracted from the middle part of the high-pressure condensate separation tower and is taken as the non-converted gas to pass through a bypass to the downstream, and the condensate in the high-pressure process at the bottom is further processed by other devices; the I section of the sectional heat transfer type shift converter is subjected to dynamic control, the loading amount of a catalyst is small, the shift reaction is far from reaching balance, and the temperature of an outlet shift gas is controlled to be 300-500 ℃; the converted gas at the outlet of the section I of the sectional heat transfer type shift converter sequentially passes through a medium-high pressure steam superheater I (used for superheating the byproduct saturated steam of the medium-high pressure steam generator), a medium-high pressure steam generator I (used for byproduct saturated steam) and a crude synthesis gas heater (used for preheating the crude synthesis gas), and then enters a section II of the sectional heat transfer type shift converter after high-pressure boiler water required by the shift reaction is supplemented;

the section II of the sectional heat transfer type shift converter adopts thermodynamic equilibrium control, the shift gas reaches reaction equilibrium, and the temperature of the shift gas at an outlet is controlled to be 300-500 ℃; the outlet of the section II of the heat transfer type shift converter is provided with temperature range control, and the temperature of the shift gas at the inlet of the section II of the heat transfer type shift converter is adjusted by adjusting the bypass gas volume (namely adjusting the heat taking quantity of the shift gas at the section I) and the water supplement quantity of the high-pressure boiler at the inlet and the outlet of the medium-pressure steam generator II, so that the shift gas outlet of the section II of the heat transfer type shift converter is not over-temperature or over-low under different working conditions (including low load of crude synthesis gas, working conditions of the initial stage and the final stage of a catalyst and the like), and the heat taking quantity and the steam yield of the medium-pressure boiler water preheater and the medium-pressure steam generator II are ensured; the shifted gas at the outlet of the section II of the sectional heat transfer type shift converter sequentially passes through a medium-high pressure steam generator II and a medium-pressure boiler water preheater, is mixed with the bypass crude synthetic gas from the outlet of the gas-liquid separator, and then enters a section III of the sectional heat transfer type shift converter for reaction;

the converted gas at the outlet of the section III of the sectional heat transfer type conversion furnace passes through a medium-pressure steam generator to produce a byproduct of saturated medium-pressure steam, and then is mixed with the converted gas at the inlet of the section II of the sectional heat transfer type conversion furnace from the bypass and sent to a downstream waste heat recovery device for further treatment.

Preferably, a crude synthesis gas bypass is arranged between the outlet of the gas-liquid separator and the outlet of the medium-pressure boiler water preheater, part of the crude synthesis gas passes through the bypass to cross the I section and the II section of the sectional heat transfer type shift converter, and the crude synthesis gas enters the III section shift converter of the sectional heat transfer type shift converter after being mixed with the converted gas at the outlet of the medium-pressure boiler water preheater and the II section of the sectional heat transfer type shift converter.

Preferably, the medium-pressure boiler water preheater is communicated with the medium-pressure steam generator II through a bypass II, a bypass III is connected between the input end of the medium-pressure boiler water preheater and the bypass II, and the bypass III is provided with a regulating valve which is linked with a temperature control structure of the sectional heat transfer type shift converter entering the III section shift gas to control the heat taking amount of the medium-pressure boiler water preheater so as to prevent the temperature of the shift gas entering the III section heat transfer type shift converter from being too low.

Preferably, a hydrolysis tank is arranged between the downstream of the medium-pressure steam generator and the outlet of the II section of the sectional heat transfer type shift converter and is used for removing trace toxic components in the mixed shift gas.

Preferably, an adjusting valve is arranged at the inlet of the hydrolysis tank, and the adjusting valve is linked with a hydrogen-carbon ratio control structure arranged on an output pipeline of the section III of the heat transfer type shift converter at the downstream of the outlet of the hydrolysis tank, so that the gas flow entering the hydrolysis tank is controlled according to the hydrogen-carbon ratio requirement of the final shift gas.

Preferably, the volume content of carbon monoxide dry basis in the raw synthesis gas from upstream is 30-90%, the volume ratio of water to absolute dry gas is 0.1-1.6, and the pressure range is 1.0-9.0 MPaG.

Preferably, the byproduct saturated steam pressure of the low-pressure steam generator ranges from 0.1 MPaG to 4.0 MPaG; the byproduct saturated steam pressure ranges of the medium-high pressure steam generator and the medium-high pressure steam generator are 2.5-8.0 MPaG.

Preferably, the outlet temperature of the raw synthesis gas heater is 150-350 ℃; the temperature of the transformed gas outlet of the stage I of the sectional heat transfer type transforming furnace is more than 350 ℃, and the temperature of the transformed gas outlet of the stage II of the sectional heat transfer type transforming furnace is more than 300 ℃.

The sectional heat transfer type conversion furnace consists of a section I, a section II and a section III, wherein the inner layer of the section I is a semi-isothermal zone I, the outer layer of the section I is an adiabatic zone I, the inner layer of the section II is a semi-isothermal zone II, the outer layer of the section II is an adiabatic zone II, and the section III is an adiabatic zone III.

Specifically, an inner upper cylinder, a central pipe, a boiler water inlet cavity, a steam collecting cavity and a boiler water array pipe are arranged in the section I/II of the sectional heat transfer type conversion furnace, the inner upper cylinder is provided with an inner cavity for filling a heat insulation conversion reaction catalyst, an air inlet annular space is formed between the outer peripheral wall of the inner upper cylinder and the inner peripheral wall of a furnace body of the sectional heat transfer type conversion furnace, and a plurality of first air inlets which are arranged at intervals are formed in the outer peripheral wall of the inner upper cylinder; the central tube is arranged at the central part of the inner upper tube body, the upper end of the central tube is closed, the lower end of the central tube is provided with a lower port, and the peripheral wall of the central tube is provided with a plurality of air vents for allowing the gas in the inner upper tube body to enter the central tube; the boiler water inlet cavity is arranged at the bottom of the section I/II of the boiler body; the steam collecting cavity is arranged above the inner upper cylinder and is used for collecting steam generated by heating boiler water; the boiler water tubes are arranged in the inner upper cylinder body, the lower end of each boiler water tube is connected with the boiler water inlet cavity, the upper end of each boiler water tube is connected with the steam collecting cavity, and each boiler water tube is arranged on the periphery of the central tube in a surrounding mode close to the central tube, so that a semi-isothermal area I/semi-isothermal area II is formed in the area, in which the boiler water tubes are arranged, in the inner upper cylinder body, and an adiabatic area I/adiabatic area II is formed in the area, in the periphery of the semi-isothermal area I/semi-isothermal area II, where the boiler water tubes are not arranged. The section III adopts an axial-radial or axial converter structure, and the specific structure is mature technology in the field and is not described herein.

The semi-isothermal regions are formed in the section I and the section II by combining the controllable steam generation system, the temperature of a conversion gas outlet can be effectively adjusted by controlling the bypass air inflow and the boiler water flow according to the load of crude synthesis gas or the water-steam ratio and the working condition of the initial and final stages of the conversion catalyst, and the stability of a downstream heat exchange system is ensured; the temperature of the transformed gas outlet can be flexibly controlled by controlling the working condition of the semi-isothermal zone, high-pressure saturated steam is superheated, an external superheater is not required to be arranged or is in thermal combination with other devices, the flow of the existing transformation process is shortened, and the investment and operation difficulty are reduced.

Preferably, the waste heat recovery device is formed by combining equipment such as a gas-liquid separator, a heat exchanger and a washing tower, and is used for recycling, cooling, washing and purifying the waste heat of the conversion gas so as to meet the feeding requirement of a downstream acid gas removal device. The mixer has one or several stage nozzles for atomizing high pressure boiler water and mixing with the coarse synthetic gas to form supersaturated state. The top of the catalyst bed layer of the I section and the III section of the shift converter is also provided with a layer of detoxifying agent for removing trace mercury, arsenic and other components which can poison the catalyst in the crude synthesis gas or the shift converter gas. The medium-pressure steam generator and the medium-pressure and high-pressure steam superheater can adopt a combined type with directly connected pipe orifices, so that the occupied land is saved, and the complexity of the flow path is reduced.

In the above scheme, according to the difference between the upstream raw synthesis gas components and the ratio of ash to water (if the ratio of water to gas of the raw synthesis gas is low, the amount of condensed liquid of the raw synthesis gas in the low-pressure steam generator is small, and the effect of removing ash is limited), a detoxification groove is optionally added at the outlet of the gas-liquid separator to ensure complete removal of ash and toxic components in the raw synthesis gas.

Compared with the prior art, the invention has the advantages that: the invention has short process flow, less equipment quantity, simple control and low investment and operation cost; compared with the conventional flow, the method also has the following advantages:

(1) the filling amount of the catalyst is equivalent to that of the two sections of adiabatic flow, but the problems of excess temperature and methanation reaction of the I section of the shift converter caused by low load or water-gas ratio change can be avoided by a method of bypass adjustment and shift catalyst dynamics control;

(2) before the raw synthesis gas enters the low-pressure steam generator, water of the high-pressure boiler is sprayed, so that the supersaturated raw synthesis gas can discharge a large amount of water during subsequent condensation, and more ash and impurities are carried away, therefore, the setting of a detoxification groove can be cancelled, and the process is simplified;

(3) the I section of the shift converter adopts dynamic control, the reaction condition is mild, and the service life of the catalyst is prolonged;

(4) the temperature of the conversion gas at the outlet of the I section of the shift converter can be effectively adjusted through the bypass at the outlet of the gas-liquid separator, so that the superheat degree of the conversion gas entering the medium-high pressure steam superheater is ensured, and stable superheated medium-high pressure steam is obtained;

(5) the temperature of the shift gas at the outlet of the II section of the shift converter can be effectively adjusted through the bypass of the medium-high pressure steam generator, so that the superheat degree of the shift gas entering the medium-high pressure steam generator is ensured, and the yield of medium-high pressure steam is ensured;

(6) the bypass is arranged in front of the crude synthesis gas heater, the gas flow entering the crude synthesis gas heater is reduced, the size of equipment is reduced, and the temperature of the gas at the outlet of the crude synthesis gas heater can be raised to a higher temperature, so that the temperature raising adjustment of the gas at the inlet of the shift converter at the final stage of the catalyst is facilitated;

(7) the process of the invention is flexible to adjust and simple to control, can cope with different working conditions and different loads, maintains the stability of a heat exchange network, and can ensure that the temperature of the conversion gas at the outlet of the section I and the section II of the shift converter is not reduced by reducing the bypass gas quantity at the outlet of the raw material gas liquid separation tank under the working conditions of low load and temperature increase at the final stage of the catalyst; the inlet temperature of the section II can be adjusted by increasing the bypass gas quantity of the medium-high pressure steam generator, so that the superheat degree of the outlet converted gas is ensured;

(8) by arranging the hydrolysis tank, components such as organic sulfur and the like can be effectively reduced or removed;

(9) a layer of detoxifying agent is laid on the catalyst bed layer of the shift converter, so that the catalyst can be protected, and the service life is prolonged.

Drawings

FIG. 1 is a flowchart of example 2 of the present invention;

FIG. 2 is a schematic structural view of a section I/II of a shift converter according to embodiments 1 and 2 of the present invention;

FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 2;

FIG. 4 is a flowchart of embodiment 1 of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

Example 1:

as shown in fig. 4, the carbon monoxide staged heat transfer semi-reaction shift conversion process for oxo synthesis with adjustable water-gas ratio of the embodiment adopts the reaction system as shown in fig. 4, which comprises a gas-liquid separator 1, a mixer 2, a washing boiler water control valve 3, a low-pressure steam generator 4, a staged heat transfer type shift converter 5, a raw synthesis gas bypass control valve 6, a high-pressure condensate separation tower 7, a non-shift gas bypass regulating valve 8, a raw synthesis gas heater 9, a medium-high pressure steam superheater 10, a medium-high pressure steam generator bypass control valve 11 in the stage I, a medium-high pressure steam generator I12, a stage II inlet high-pressure boiler water control valve 13, a medium-high pressure steam generator II14, a medium-high pressure boiler water preheater 15, a medium-high pressure boiler water preheater 16, a stage III bypass control valve 17, a medium-pressure steam generator 18, a hydrolysis tank 19 and a waste heat recovery device 20, the specific connection and matching relationship of each device are consistent with those in fig. 1, and will not be described in detail herein.

Taking an example of a device for producing methanol by gasifying pulverized coal in a chilling process, the carbon monoxide staged heat transfer semi-reaction conversion process for oxo synthesis with adjustable water-gas ratio in the embodiment comprises the following steps:

the raw synthesis gas from the upstream gasification unit, temperature 206 ℃, pressure 3.84MPaG, carbon monoxide dry basis content 70%, water to gas ratio 0.9. Firstly, the raw materials enter a gas-liquid separator 1 for primary liquid separation, and then are divided into two parts: a 60% crude synthesis gas is sprayed into a small amount of boiler water from a washing boiler water control valve 3 through a mixer, enters a low-pressure steam generator 4 to produce 0.8MPaG low-pressure saturated steam as a byproduct, and enters the upper layer of a high-pressure condensate separation tower 7; the other 40% of the raw synthesis gas enters the lower layer of the high-pressure condensate separator tower 7 through a raw synthesis gas bypass control valve 6. The raw synthesis gas coming out from the top of the high-pressure condensate separator tower 7 is heated to 210 ℃ by a raw synthesis gas heater 9, and then enters a section I of a sectional heat transfer type shift converter 5A; the crude synthesis gas with the water-gas ratio of 0.9 is discharged from the upper part of the uppermost tower plate of the high-pressure condensate separator tower 7 and enters a downstream flow through a non-conversion gas bypass regulating valve 8; the bottom of the high-pressure condensate separator tower 7 is high-pressure process condensate which is finally sent to other devices for further treatment. Wherein, the temperature control is arranged on one path of the coarse synthesis gas with the medium-high water-gas ratio and is used for adjusting the gas quantity of the coarse synthesis gas bypass control valve 6.

The I section 5A of the sectional heat transfer type shift converter adopts dynamic control, and the temperature of the outlet shift gas is 460 ℃. The shifted gas at the outlet sequentially passes through a medium-high pressure steam superheater 10, a medium-high pressure steam generator I12 and a crude synthesis gas heater 9, and then high-pressure boiler water required by the reaction is supplemented through a high-pressure boiler water control valve 13 at the inlet of the section II, the temperature is 245 ℃, and the shifted gas enters a section II 5B of the sectional heat transfer type shift converter.

And the section II adopts thermodynamic equilibrium control, the shift gas reaches reaction equilibrium, and the outlet temperature is 420 ℃. And the outlet of the section II is provided with temperature range control, and the temperature of the transformed gas outlet of the section II is controlled to be stabilized at a set value of 420 ℃ by adjusting a bypass control valve 11 of the high-pressure steam generator in the section I and a water control valve 13 of the high-pressure boiler at the inlet of the section II. The shift gas at the outlet of the section II sequentially passes through the medium-high pressure steam generator 1II4 and the medium-pressure boiler water preheater 16, is mixed with the bypass crude synthesis gas from the outlet of the high-pressure condensate separator tower 7, and then enters the section III of the sectional heat transfer type shift converter 5C again for reaction. Wherein the medium-high pressure boiler water preheater 16 is provided with a bypass, and the inlet temperature of the III section is kept to be stable at 210 ℃ by adjusting the medium-high pressure boiler water preheater bypass control valve 13.

The shifted gas at the outlet of the stage III passes through a medium pressure steam generator 18 to produce a byproduct of saturated medium pressure steam. The shift gas from the bypass control valve 17 at the section III passes through the hydrolysis tank 19, is mixed with the shift gas at the outlet of the section III to 250 ℃, and is sent to a downstream waste heat recovery device 20 for further treatment.

For the middle and final stages of the catalyst, the reaction depth of the crude synthesis gas is reduced, the outlet temperature of the I section 5A of the sectional heat transfer type shift converter is reduced to 450 ℃, and the inlet crude synthesis gas quantity of the II section 5A of the sectional heat transfer type shift converter can be increased by reducing the opening degree of the non-shift gas bypass regulating valve 8, so that the II section is ensured to be stabilized at 460 ℃; the temperature of the outlet of the 5B section of the sectional heat transfer type shift converter II is reduced to 410 ℃, at the moment, the opening degree of a bypass control valve 10 of a medium-high pressure steam generator in the I section is increased, the shift gas quantity passing through the medium-high pressure steam generator I12 is reduced, the temperature of the inlet of the 5B section of the sectional heat transfer type shift converter II is improved from 245 ℃ to 255 ℃, and the temperature of the outlet of the shift gas in the II section is ensured to be stabilized at 420 ℃; and for the final working condition of the catalyst, the reaction depth of the crude synthesis gas is further reduced, and under the condition that the opening of the high-pressure steam generator bypass control valve 10 in the section I is increased, the opening of the water control valve 13 of the high-pressure boiler at the inlet of the section II can be increased, and the boiler water supplement amount is increased to ensure that the temperature of the shift gas outlet of the section II is stabilized at 420 ℃.

When the load of the crude synthesis gas of the conversion unit is reduced, the opening degree of the non-conversion gas bypass regulating valve 8 is increased, so that the quantity of the crude synthesis gas entering the section II of the sectional heat transfer type conversion furnace 5A is ensured to be unchanged, and the temperature of the conversion gas at the outlet of the section I of the sectional heat transfer type conversion furnace 5A is kept unchanged.

In this embodiment, the sectional heat-transfer type shift converter 5 is composed of a section I, a section II and a section III, wherein the inner layer of the section I is a semi-isothermal zone I, the outer layer is an adiabatic zone I, the inner layer of the section II is a semi-isothermal zone II, the outer layer is an adiabatic zone II, and the section III is an adiabatic zone III. Wherein, the section III adopts an axial-radial or axial converter structure, and the specific structure is mature technology in the field and is not described herein; in the present embodiment, the structure of the stage I/II of the staged heat transfer type shift converter is described as follows:

as shown in FIGS. 2 and 3, an inner upper barrel 2a ', a central pipe 21', a boiler water inlet cavity 26 ', a steam collecting cavity 5', a boiler water tube 10 'and a steam pocket 2' are arranged in the I section/II section of the sectional heat transfer type conversion furnace.

Specifically, the top of the furnace body 19 'is provided with a raw synthesis gas inlet 4', the furnace body 19 'is provided with a partition plate 1c which can divide the inner cavity into an upper part, a middle part and a lower part which are relatively independent, and the side part of the furnace body 19' can also be provided with an output port for outputting gas after the reaction of the section I and the section II.

The inner upper cylinder 2a ' is provided with an inner cavity for filling the adiabatic shift reaction catalyst 20 ', an air inlet annular space 9 ' is formed between the outer peripheral wall of the inner upper cylinder 2a ' and the inner peripheral wall of the furnace body 19 ', and a plurality of first air inlets 22 ' arranged at intervals are formed on the outer peripheral wall of the inner upper cylinder 2a '.

The central tube 21 ' is disposed at the central portion of the upper inner cylinder 2a ', the upper end of the central tube is closed, the lower end of the central tube has a lower port communicated with the lower portion of the partition board 1c ', and the peripheral wall of the central tube 21 ' is provided with a plurality of vent holes 211 ' for allowing the gas in the upper inner cylinder 2a ' to enter the central tube 21 '.

The boiler water inlet chamber 26 ' is arranged at the lower part of the I section/II section of the boiler body 19 ' and is close to the corresponding partition plate 1c '.

The steam collecting cavity 5 'is arranged at the upper part of the section I/II and is positioned above the corresponding inner upper cylinder body 2 a' and is used for collecting steam generated by heating boiler water.

The boiler water tubes 10 'are provided with a plurality of boiler water tubes 10', the lower ends of the boiler water tubes 10 'are connected with the boiler water inlet cavity 26', the upper ends of the boiler water tubes are connected with the steam collecting cavity 5 ', each boiler water tube 10' is arranged around the central tube 21 'close to the central tube 21', so that a semi-isothermal area I/II8 'is formed in the area of the inner upper cylinder 2 a' where the boiler water tubes 10 'are arranged, and an adiabatic area I/II 6' is formed in the area of the outer periphery of the semi-isothermal area I/II8 'where the boiler water tubes 10' are not arranged.

The steam drum 2 ' is arranged above the furnace body 19 ', the top of the steam drum 2 ' is provided with a steam outlet 1 ', the steam drum 2 ' is communicated with a boiler water inlet cavity 26 ' through a boiler water descending pipe 3 ' and is communicated with a steam collecting cavity 5 ' through a steam ascending pipe 15 ', and the steam drum 2 ' and the boiler water descending pipe 3 ', the boiler water inlet cavity 26 ', the boiler water array pipe 10 ', the steam collecting cavity 5 ' and the steam ascending pipe 15 ' jointly form a controllable saturated steam generating system.

The two boiler water down-comer pipes 3 'are symmetrically arranged at two sides of the boiler water inlet cavity 26', and one boiler water down-comer pipe 3 'is provided with an adjusting valve 16' which can control the flow of fluid. The natural circulation ratio of water and gas in the system is controlled by adjusting the opening of the adjusting valve 16', so that the aims of adjusting the temperature of the conversion gas and the yield of saturated steam in the semi-isothermal reaction zone are fulfilled. The number, the arrangement range and the density of the boiler water tubes in the semi-isothermal zone can be adjusted according to the water-gas ratio of the crude synthesis gas, the load range and the temperature requirement of the transformed gas outlet, so that the heat of partial transformed gas reaction in the semi-isothermal zone is transferred away through the boiler water, and the transformed reaction in the zone is between adiabatic reaction and isothermal reaction.

When the raw synthesis gas passes through the I section/II section of the sectional heat transfer type shift converter, raw gas at a raw synthesis gas inlet 4 'enters an air inlet annular gap 9' through an upper end enclosure of the shift converter, passes through an adiabatic shift reaction catalyst 20 'from the axial direction through a first air inlet 22', firstly enters an adiabatic region I/II 6 'for adiabatic shift reaction, and then enters a semi-isothermal region I/II 8'; the conversion gas is subjected to semi-isothermal conversion reaction in a semi-isothermal zone I/II8 ', the temperature is kept unchanged, redundant heat is absorbed by boiler water in a semi-isothermal zone boiler water tube 10 ' to generate saturated steam, and the converted gas after reaction is collected through a central tube 21 ' and conveyed downwards; in the above process, the operation flow of the controllable saturated steam generation system is as follows: the low-temperature boiler water from the boiler water downcomer 3 ' firstly enters a boiler water inlet cavity 26 ' to be collected, then enters a boiler water tube array 10 ' of a semi-isothermal zone, the low-temperature boiler water is changed into a water-vapor mixture after absorbing heat of reaction of the semi-isothermal zone I/II8 ', saturated steam rises to a steam collecting cavity 5 ' along the boiler water tube array 10 ' to be subjected to primary liquid separation, then continuously enters a steam pocket 2 ' along a steam riser 15 ', condensed water is separated again, and then the saturated steam is produced from a steam outlet 1 ' and is sent out of the system.

Example 2:

this example differs from example 1 in that: as shown in fig. 1, the flow can also be simplified and the hydrolysis tank eliminated when the downstream requirement for organic sulfur content is not particularly high.

Example 3:

as shown in FIG. 1, the embodiment is applied to a device for producing methanol by chilling process pulverized coal gasification. The raw synthesis gas from the upstream gasification unit, temperature 206 ℃, pressure 3.84MPaG, carbon monoxide dry basis content 70%, water to gas ratio 0.9. Firstly, the raw material enters a raw material gas separator 1 for primary liquid separation, and then the raw material gas is divided into two parts: a 60% crude synthesis gas is sprayed into a small amount of boiler water from a washing boiler water control valve 3 through a mixer, enters a low-pressure steam generator 4 to produce 0.8MPaG low-pressure saturated steam as a byproduct, and enters the upper layer of a high-pressure condensate separation tower 7; the other 40% of the raw synthesis gas enters the lower layer of the high-pressure condensate separator tower 7 through a raw synthesis gas bypass control valve 6. The raw synthesis gas coming out from the top of the high-pressure condensate separator tower 7 is heated to 210 ℃ by a raw synthesis gas heater 9, and then enters a section I of a sectional heat transfer type shift converter 5A; the crude synthesis gas with the water-gas ratio of 0.9 is discharged from the upper part of the uppermost tower plate of the high-pressure condensate separator tower 7 and enters a downstream flow through a non-conversion gas bypass regulating valve 8; the bottom of the high-pressure condensate separator tower 7 is high-pressure process condensate which is finally sent to other devices for further treatment. Wherein, the temperature control is arranged on one path of the coarse synthesis gas with the medium-high water-gas ratio and is used for adjusting the gas quantity of the coarse synthesis gas bypass control valve 6.

The I section 5A of the sectional heat transfer type shift converter adopts dynamic control, and the temperature of the outlet shift gas is 460 ℃. The shifted gas at the outlet sequentially passes through a medium-high pressure steam superheater 10, a medium-high pressure steam generator 12 in the section I and a crude synthesis gas heater 9, and then high-pressure boiler water required by the reaction is supplemented through a high-pressure boiler water control valve 13 at the inlet of the section II, the temperature is 245 ℃, and the shifted gas enters a section II 5B of the sectional heat transfer type shifting furnace.

And the section II adopts thermodynamic equilibrium control, the shift gas reaches reaction equilibrium, and the outlet temperature is 420 ℃. And the outlet of the section II is provided with temperature range control, and the temperature of the transformed gas outlet of the section II is controlled to be stabilized at a set value of 420 ℃ by adjusting a bypass control valve 11 of the high-pressure steam generator in the section I and a water control valve 13 of the high-pressure boiler at the inlet of the section II. The shift gas at the outlet of the section II sequentially passes through a medium-high pressure steam generator 14 and a medium-pressure boiler water preheater 16 at the section II, is mixed with the bypass crude synthesis gas from the outlet of the high-pressure condensate separator tower 7, and then enters the section III of the sectional heat transfer type shift converter 5C again for reaction. Wherein the medium-high pressure boiler water preheater 16 is provided with a bypass, and the inlet temperature of the III section is kept to be stable at 210 ℃ by adjusting the medium-high pressure boiler water preheater bypass control valve 13.

The shifted gas at the outlet of the stage III passes through a medium pressure steam generator 18 to produce a byproduct of saturated medium pressure steam. The converted gas from the section III bypass control valve 17 and the section III outlet converted gas are mixed to 250 ℃ and sent to a downstream waste heat recovery device 19 for further treatment.

For the activity reduction of the catalyst at the middle and final stages, the reaction depth of the crude synthesis gas is reduced; the temperature of the outlet of the 5B section of the sectional heat transfer type shift converter II is reduced to 450 ℃, at the moment, the opening degree of a bypass control valve 10 of a medium-high pressure steam generator in the I section is increased, the converted gas quantity passing through the medium-high pressure steam generator 7 is reduced, the temperature of the inlet of the 5B section of the sectional heat transfer type shift converter II is improved from 245 ℃ to 255 ℃, and the temperature of the outlet of the converted gas in the II section is ensured to be stabilized at 460 ℃; and for the final working condition of the catalyst, the reaction depth of the crude synthesis gas is further reduced, and under the condition that the opening of the bypass control valve 10 of the high-pressure steam generator in the section I is increased, the opening of the water control valve of the high-pressure boiler at the inlet of the section II can be increased, and the boiler water supplement amount is increased to ensure that the temperature of the shift gas outlet of the section II is stabilized at 400 ℃.

When the load of the raw synthesis gas of the shift unit is reduced, the opening degree of the non-shift gas bypass regulating valve 6 is increased to regulate the temperature of the shift gas at the outlet of the stage I5A of the staged heat transfer type shift converter.

Wherein, the I section and the III section of the sectional heat transfer type shift converter adopt one form of figure 2 or figure 3. Wherein, the catalyst bed comprises a 51A-detoxication agent bed layer, a 52A-axial shift catalyst bed layer and a 53A-axial radial shift catalyst bed layer.

Example 3 has the following advantages compared to example 2:

the regulation is flexible, the control is simple, different working conditions and different loads can be met, the stability of a heat exchange network is maintained, the temperature of the I section outlet conversion gas has no specific requirements, and the controllable range is wide. For the low-load working condition, the temperature of the conversion gas at the outlets of the I section and the II section of the shift converter can be ensured not to be reduced by reducing the bypass gas amount at the outlet of the raw material gas liquid separation tank; for the working condition that the temperature needs to be raised in the final stage of the catalyst, the inlet temperature of the section II is adjusted by increasing the bypass gas quantity of the medium-high pressure steam generator, so that the temperature of the converted gas at the outlet of the section II is ensured.

(8) All the raw synthesis gas is subjected to shift reaction through the shift reaction furnace, toxic components such as COS and the like in the raw synthesis gas are subjected to full reaction, so that a hydrolysis tank is not required to be arranged between the section II and the section III for removal, and the complexity of the process is reduced.

Claims

1. A carbon monoxide segmental heat removal semi-reactive shift process for oxo synthesis with adjustable water-gas ratio is characterized by comprising the following steps:

2. The adjustable water-to-gas ratio carbon monoxide staged heat removal semi-reactive shift process for oxo synthesis according to claim 1, wherein: and a crude synthesis gas bypass is arranged between the outlet of the gas-liquid separator and the outlet of the water preheater of the medium-pressure boiler, part of the crude synthesis gas passes through the bypass to cross the I section of the sectional heat transfer type shift converter and the II section of the sectional heat transfer type shift converter, and the crude synthesis gas enters the III section shift converter of the sectional heat transfer type shift converter after the outlet of the water preheater of the medium-pressure boiler and the outlet of the II section of the sectional heat transfer type shift converter are mixed.

3. The adjustable water-to-gas ratio carbon monoxide staged heat removal semi-reactive shift process for oxo synthesis according to claim 1, wherein: the medium-pressure boiler water preheater is communicated with the medium-pressure steam generator II through a bypass II, a bypass III is connected between the input end of the medium-pressure boiler water preheater and the bypass II, and a regulating valve which is linked with a temperature control structure of the sectional heat transfer type shift converter entering the III section shift gas to control the heat taking amount of the medium-pressure boiler water preheater is arranged on the bypass III so as to prevent the temperature of the shift gas entering the III section shift type shift converter from being too low.

4. The adjustable water-to-gas ratio carbon monoxide staged heat removal semi-reactive shift process for oxo synthesis according to claim 1, wherein: and a hydrolysis tank is arranged between the downstream of the medium-pressure steam generator and the outlet of the II section of the sectional heat transfer type shift converter and is used for removing trace toxic components in the mixed shift gas.

5. The adjustable water-to-gas ratio carbon monoxide staged heat removal semi-reactive shift process for oxo synthesis according to claim 4, wherein: and the inlet of the hydrolysis tank is provided with an adjusting valve which is linked with a hydrogen-carbon ratio control structure on a segment heat transfer type shift converter III segment output pipeline arranged at the downstream of the outlet of the hydrolysis tank, so that the gas flow entering the hydrolysis tank is controlled according to the hydrogen-carbon ratio requirement of the final shift gas.

6. The adjustable water-to-gas ratio carbon monoxide staged heat removal semi-reactive shift process for oxo synthesis according to claim 1, wherein: the volume content of carbon monoxide dry basis in the crude synthesis gas from upstream is 30-90%, the volume ratio of water to absolute dry gas is 0.1-1.6, and the pressure range is 1.0-9.0 MPaG.

7. The adjustable water-to-gas ratio carbon monoxide staged heat removal semi-reactive shift process for oxo synthesis according to claim 1, wherein: the byproduct saturated steam pressure range of the low-pressure steam generator is 0.1-4.0 MPaG; the byproduct saturated steam pressure ranges of the medium-high pressure steam generator and the medium-high pressure steam generator are 2.5-8.0 MPaG.

8. The adjustable water-to-gas ratio carbon monoxide staged heat removal semi-reactive shift process for oxo synthesis according to claim 1, wherein: the outlet temperature of the crude synthesis gas heater is 150-350 ℃; the temperature of the transformed gas outlet of the stage I of the sectional heat transfer type transforming furnace is more than 400 ℃, and the temperature of the transformed gas outlet of the stage II of the sectional heat transfer type transforming furnace is more than 300 ℃.

9. The adjustable water-to-gas ratio carbon monoxide staged heat removal semi-reactive shift process for oxo synthesis according to claim 1, wherein: the sectional heat transfer type conversion furnace consists of a section I, a section II and a section III, wherein the inner layer of the section I is a semi-isothermal area I, the outer layer of the section I is a heat insulation area I, the inner layer of the section II is a semi-isothermal area II, the outer layer of the section II is a heat insulation area II, and the section III is a heat insulation area III.

10. The adjustable water-to-gas ratio carbon monoxide staged heat removal semi-reactive shift process for oxo synthesis according to claim 9, wherein: an inner upper cylinder, a central pipe, a boiler water inlet cavity, a steam collecting cavity and a boiler water array pipe are arranged in the section I/II of the sectional heat transfer type conversion furnace, the inner upper cylinder is provided with an inner cavity for filling heat insulation conversion reaction catalysts, an air inlet annular gap is formed between the outer peripheral wall of the inner upper cylinder and the inner peripheral wall of a furnace body of the sectional heat transfer type conversion furnace, and a plurality of first air inlets which are arranged at intervals are formed in the outer peripheral wall of the inner upper cylinder; the central tube is arranged at the central part of the inner upper tube body, the upper end of the central tube is closed, the lower end of the central tube is provided with a lower port, and the peripheral wall of the central tube is provided with a plurality of air vents for allowing the gas in the inner upper tube body to enter the central tube; the boiler water inlet cavity is arranged at the bottom of the section I/II of the boiler body; the steam collecting cavity is arranged above the inner upper cylinder and is used for collecting steam generated by heating boiler water; the boiler water tubes are arranged in the inner upper cylinder body, the lower end of each boiler water tube is connected with the boiler water inlet cavity, the upper end of each boiler water tube is connected with the steam collecting cavity, and each boiler water tube is arranged on the periphery of the central tube in a surrounding mode close to the central tube, so that a semi-isothermal area I/semi-isothermal area II is formed in the area, in which the boiler water tubes are arranged, in the inner upper cylinder body, and an adiabatic area I/adiabatic area II is formed in the area, in the periphery of the semi-isothermal area I/semi-isothermal area II, where the boiler water tubes are not arranged.