CN221084690U - Device for coupling coking crude benzene distillation with ammonia distillation waste heat - Google Patents

Abstract

The utility model relates to a device for coupling coking debenzenization with ammonia distillation waste heat, comprising a debenzenization tower, an oil-gas intermediate condenser, an ammonia distillation tower and a reboiler; a closed partition is provided in the middle of the distillation section of the debenzenization tower to divide the distillation section into an upper distillation section and a lower distillation section, an upper section vapor phase inlet and an upper section liquid phase outlet are provided at the bottom of the upper distillation section, a lower section vapor phase outlet, a lower section liquid phase inlet 1 and a lower section liquid phase inlet 2 are provided at the top of the lower distillation section, the lower section vapor phase outlet is connected to the tube side vapor phase inlet of the oil-gas intermediate condenser, the oil-gas intermediate condenser tube side vapor phase outlet is connected to the upper section vapor phase inlet; the oil-gas intermediate condenser tube side liquid phase outlet is connected to the lower section liquid phase inlet 1, the upper section liquid phase outlet is connected to the lower section liquid phase inlet 2, the ammonia distillation tower is connected to the oil-gas intermediate condenser, and the reboiler is connected to the ammonia distillation tower. The utility model can reduce the steam consumption of the ammonia distillation process while also reducing the circulating water consumption of the crude benzene distillation process.

Description

A device for coupling coking crude benzene distillation with ammonia distillation waste heat

Technical Field

The utility model relates to the technical field of coking chemical product recovery, in particular to a device for coupling coking crude benzene distillation with ammonia evaporation waste heat.

Background technique

The crude benzene distillation process and the ammonia evaporation process in the coking process are the two sub-processes that consume the most energy in the coal gas purification device during the coking process.

Coking ammonia evaporation is to use distillation to desorb _NH3 from the coking residual ammonia and other separated wastewater, so as to reduce the ammonia nitrogen content in the wastewater. It is a necessary pretreatment step for the subsequent biochemical treatment of wastewater. At present, the commonly used residual ammonia evaporation processes in the coking industry generally include conventional atmospheric pressure ammonia evaporation process and heat pump ammonia evaporation process; the conventional atmospheric pressure ammonia evaporation process is mature in technology and stable in operation, but this process consumes a large amount of steam. Each ton of residual ammonia water consumed consumes about 170 to 200 kg of low-pressure steam, which consumes a lot of energy and has high operating costs.

At present, the common crude benzene distillation processes in the coking industry are generally divided into the atmospheric superheated steam stripping crude benzene distillation process and the negative pressure superheated steam stripping crude benzene distillation process; the atmospheric superheated steam stripping crude benzene distillation process is mature in technology and stable in operation, but this process consumes a large amount of steam, and about 1500kg/h of 400℃ high-temperature stripping steam is consumed per ton of crude benzene. The negative pressure superheated steam stripping crude benzene distillation uses a vacuum pump to extract the non-condensable gas that is not condensed after the crude benzene condenser cooler to form a negative pressure state of the debenzene system. Compared with the atmospheric superheated steam stripping crude benzene distillation process, this process adds a small amount of investment in vacuum equipment, but can greatly reduce the consumption of superheated steam, and about 750kg/h of 400℃ high-temperature stripping steam is consumed per ton of crude benzene. However, in the above two crude benzene distillation processes, the stripping steam and crude benzene steam in the debenzene tower enter the crude benzene condenser cooler and are directly condensed and cooled by circulating water after coming out of the debenzene tower top. The 120-170℃ rising oil vapor and water vapor in the debenzene tower distillation section need to consume a large amount of circulating water to cool the crude benzene vapor. The energy utilization rate of these high-quality oil-containing steam is low. Improving the utilization rate of waste heat energy between coking processes is an important means to reduce the energy consumption of coking units.

Summary of the invention

The technical problem to be solved by the utility model is to provide a device for coupling the distillation of coking crude benzene with the waste heat of ammonia evaporation, which has small fixed investment and low operating cost.

In order to achieve the above purpose, the utility model adopts the following technical solutions:

A device for coupling coking debenzenization with ammonia distillation waste heat comprises a debenzenization tower, an oil-gas intermediate condenser, an ammonia distillation tower and a reboiler; a closed partition is arranged in the middle of the distillation section of the debenzenization tower to divide the distillation section into an upper distillation section and a lower distillation section, an upper section vapor phase inlet and an upper section liquid phase outlet are arranged at the bottom of the upper distillation section, a lower section vapor phase outlet, a lower section liquid phase inlet 1 and a lower section liquid phase inlet 2 are arranged at the top of the lower distillation section, the lower section vapor phase outlet is connected to the tube side vapor phase inlet of the oil-gas intermediate condenser, and the oil-gas intermediate condenser tube side vapor phase outlet is connected to the upper section vapor phase inlet; the oil-gas intermediate condenser tube side liquid phase outlet is connected to the lower section liquid phase inlet 1, and the upper section liquid phase outlet is connected to the lower section liquid phase inlet 2, the ammonia distillation tower is connected to the oil-gas intermediate condenser, and the reboiler is connected to the ammonia distillation tower.

A device for coupling coking debenzenization and ammonia distillation waste heat, further comprising a wastewater circulation pump, a liquid collecting area at the bottom of an ammonia distillation tower is connected to the wastewater circulation pump, the wastewater circulation pump is connected to the shell side inlet of an oil-gas intermediate condenser; the shell side outlet of the oil-gas intermediate condenser is connected to the vapor phase space at the bottom of the ammonia distillation tower;

The liquid collecting area at the bottom of the ammonia still tower is connected to the inlet of the reboiler, and the outlet of the reboiler is connected to the vapor phase space at the bottom of the ammonia still tower.

Compared with the existing technology, the beneficial effects of the utility model are:

1) Compared with the existing ammonia evaporation and crude benzene distillation devices, the utility model can reduce the steam consumption of the ammonia evaporation process while also reducing the circulating water consumption of the crude benzene distillation process, which greatly reduces the operating costs of the ammonia evaporation process and the crude benzene distillation process in coking.

2) The utility model adds less equipment on the basis of the original ammonia evaporation and crude benzene distillation, and the material requirements of the equipment are reduced. The lower fixed investment and operating cost are suitable for the transformation and upgrading of the existing coking plant;

3) The method for coupling coking crude benzene distillation with ammonia evaporation waste heat is applicable to both normal pressure superheated steam stripping crude benzene distillation process and negative pressure superheated steam stripping crude benzene distillation process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of the utility model.

In the figure: debenzene tower 1, oil vapor intermediate condenser 2, waste water circulation pump 3, ammonia distillation tower 4, reboiler 5, lower section vapor phase outlet A, lower section liquid phase inlet one B, upper section vapor phase inlet C, upper section liquid phase outlet D, lower section liquid phase inlet two E.

Detailed ways

It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means more than two.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

As shown in FIG1 , a device for coupling coking debenzenization with ammonia distillation waste heat comprises a debenzenization tower 1, an oil-gas intermediate condenser 2, a wastewater circulation pump 3, an ammonia distillation tower 4 and a reboiler 5; a closed partition 6 is provided in the middle of the distillation section of the debenzenization tower 1 to divide the distillation section into an upper distillation section and a lower distillation section, an upper section vapor phase inlet C and an upper section liquid phase outlet D are provided at the bottom of the upper section of the distillation section, a lower section vapor phase outlet A, a lower section liquid phase inlet 1B and a lower section liquid phase inlet 2E are provided at the top of the lower section of the distillation section, the lower section vapor phase outlet A is connected to the tube-side vapor phase inlet of the oil-gas intermediate condenser 2, the tube-side vapor phase outlet of the oil-gas intermediate condenser 2 is connected to the upper section vapor phase inlet C; the tube-side liquid phase outlet of the oil-gas intermediate condenser 2 is connected to the lower section liquid phase inlet 1B, and the upper section liquid phase outlet D is connected to the lower section liquid phase inlet 2E.

The bottom liquid collecting area of the ammonia distillation tower 4 is connected to the wastewater circulation pump 3, and the wastewater circulation pump 3 is connected to the shell side inlet of the oil-vapor intermediate condenser 2; the shell side outlet of the oil-vapor intermediate condenser 2 is connected to the vapor phase space at the bottom of the ammonia distillation tower 4; the bottom liquid collecting area of the ammonia distillation tower 4 is connected to the inlet of the reboiler 5, and the outlet of the reboiler 5 is connected to the vapor phase space at the bottom of the ammonia distillation tower 4.

By adopting the method of coupling the coking debenzenization and ammonia evaporation waste heat of the above-mentioned device, the 140℃～175℃ oil-containing vapor at the top of the lower section of the debenzene tower 1 distillation section flows out from the lower section vapor phase outlet A, enters the oil vapor intermediate condenser 2 tube pass for partial condensation; the liquid phase partially condensed by the oil vapor intermediate condenser 2 flows to the debenzene tower 1 by gravity, and returns to the top of the lower section of the distillation section of the debenzene tower 1 from the lower section liquid phase inlet B, and the condensed 120℃～130℃ oil vapor enters the bottom of the upper section of the distillation section of the debenzene tower 1 from the upper section vapor phase inlet C; the debenzene tower 1 distillation section The liquid phase at the bottom of the upper section flows out through the upper section liquid phase outlet D, and flows into the top of the lower section of the distillation section of the debenzene tower 1 through the lower section liquid phase inlet 2E; the ammonia evaporation wastewater at the bottom of the ammonia evaporation tower 4 is pumped out by the wastewater circulation pump 3 and sent to the shell side of the oil-gas intermediate condenser 2, and exchanges heat with the oil-containing steam entering the oil-gas intermediate condenser 2. The ammonia evaporation wastewater of 115℃~120℃ after heat exchange is sent to the bottom of the ammonia evaporation tower 4 for partial flash evaporation, providing part of the rising stripping steam for the ammonia evaporation operation; the other part of the rising stripping steam for the ammonia evaporation operation is provided by the reboiler through heating by a heat source.

The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. In addition, the various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the idea of the present invention, they should also be regarded as the contents disclosed by the present invention.

In order to make the purpose, technical scheme and technical effect of the utility model clearer, the technical scheme in the embodiment of the utility model is now described clearly and completely. However, the embodiment described below is only a part of the embodiment of the utility model, not all of the embodiments. In combination with the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

Example

For example, a coking plant with an annual coke production capacity of 3 million tons, a washing oil circulation volume for benzene removal of 300 m ³ /h, and a residual ammonia water treatment volume of 100 m ³ /h.

A device for coupling coking debenzenization with ammonia distillation waste heat comprises a debenzenization tower 1, an oil-gas intermediate condenser 2, a wastewater circulation pump 3, an ammonia distillation tower 4 and a reboiler 5; a closed partition 6 is arranged in the middle of the distillation section of the debenzenization tower 1 to divide the distillation section into an upper distillation section and a lower distillation section, an upper section vapor phase inlet C and an upper section liquid phase outlet D are arranged at the bottom of the upper section of the distillation section, a lower section vapor phase outlet A, a lower section liquid phase inlet 1B and a lower section liquid phase inlet 2E are arranged at the top of the lower section of the distillation section, the lower section vapor phase outlet A is connected to the tube side vapor phase inlet of the oil-gas intermediate condenser 2, the tube side vapor phase outlet of the oil-gas intermediate condenser 2 is connected to the upper section vapor phase inlet C; the tube side liquid phase outlet of the oil-gas intermediate condenser 2 is connected to the lower section liquid phase inlet 1B, and the upper section liquid phase outlet D is connected to the lower section liquid phase inlet 2E.

The bottom liquid collecting area of the ammonia distillation tower 4 is connected to the wastewater circulation pump 3, and the wastewater circulation pump 3 is connected to the shell side inlet of the oil-vapor intermediate condenser 2; the shell side outlet of the oil-vapor intermediate condenser 2 is connected to the vapor phase space at the bottom of the ammonia distillation tower 4; the bottom liquid collecting area of the ammonia distillation tower 4 is connected to the inlet of the reboiler 5, and the outlet of the reboiler 5 is connected to the vapor phase space at the bottom of the ammonia distillation tower 4.

By adopting the method of coupling the coking debenzenization and ammonia evaporation waste heat of the above-mentioned device, the 140℃～175℃ oil-containing vapor at the top of the lower section of the debenzene tower 1 distillation section flows out from the lower section vapor phase outlet A, enters the oil vapor intermediate condenser 2 tube pass for partial condensation; the liquid phase partially condensed by the oil vapor intermediate condenser 2 flows to the debenzene tower 1 by gravity, and returns to the top of the lower section of the distillation section of the debenzene tower 1 from the lower section liquid phase inlet B, and the condensed 120℃～130℃ oil vapor enters the bottom of the upper section of the distillation section of the debenzene tower 1 from the upper section vapor phase inlet C; the debenzene tower 1 distillation section The liquid phase at the bottom of the upper section flows out through the upper section liquid phase outlet D, and flows into the top of the lower section of the distillation section of the debenzene tower 1 through the lower section liquid phase inlet 2E; the ammonia evaporation wastewater at the bottom of the ammonia evaporation tower 4 is pumped out by the wastewater circulation pump 3 and sent to the shell side of the oil-gas intermediate condenser 2, and exchanges heat with the oil-containing steam entering the oil-gas intermediate condenser 2. The ammonia evaporation wastewater of 115℃~120℃ after heat exchange is sent to the bottom of the ammonia evaporation tower 4 for partial flash evaporation, providing part of the rising stripping steam for the ammonia evaporation operation; the other part of the rising stripping steam for the ammonia evaporation operation is provided by the reboiler through heating by a heat source.

By adopting the above-mentioned device and method, the steam consumption for ammonia evaporation is 105 kg/ton of residual ammonia water, which saves 22.2% of low-pressure steam compared with the low-pressure steam consumption of 135 kg/ton of residual ammonia water in the existing coking ammonia evaporation process; the circulating water consumption for crude benzene distillation is 85 t/ton of crude benzene, which saves 16.6% of circulating water compared with the circulating water consumption of 102 t/ton of crude benzene in the crude benzene distillation process using negative pressure superheated steam stripping.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and basic spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims (3)

1. A device for coupling the distillation of coking crude benzene with the waste heat of ammonia evaporation, characterized in that it comprises a debenzene tower, an oil-gas intermediate condenser, an ammonia evaporation tower and a reboiler; a closed partition is provided in the middle of the rectifying section of the debenzene tower to divide the rectifying section into an upper rectifying section and a lower rectifying section, an upper section vapor phase inlet and an upper section liquid phase outlet are provided at the bottom of the upper rectifying section, a lower section vapor phase outlet, a lower section liquid phase inlet 1 and a lower section liquid phase inlet 2 are provided at the top of the lower rectifying section, the lower section vapor phase outlet is connected to the tube-side vapor phase inlet of the oil-gas intermediate condenser, and the tube-side vapor phase outlet of the oil-gas intermediate condenser is connected to the upper section vapor phase inlet; the tube-side liquid phase outlet of the oil-gas intermediate condenser is connected to the lower section liquid phase inlet 1, the upper section liquid phase outlet is connected to the lower section liquid phase inlet 2, the ammonia evaporation tower is connected to the oil-gas intermediate condenser, and the reboiler is connected to the ammonia evaporation tower. 2. The device for coupling the distillation of coking crude benzene with the waste heat of ammonia evaporation according to claim 1 is characterized in that it also includes a wastewater circulation pump, the liquid collecting area at the bottom of the ammonia evaporation tower is connected to the wastewater circulation pump, the wastewater circulation pump is connected to the shell side inlet of the oil-gas intermediate condenser; the shell side outlet of the oil-gas intermediate condenser is connected to the vapor phase space at the bottom of the ammonia evaporation tower. 3. The device for coupling the distillation of coking crude benzene with the waste heat of ammonia evaporation according to claim 1 is characterized in that the liquid collecting area at the bottom of the ammonia evaporation tower is connected to the inlet of the reboiler, and the outlet of the reboiler is connected to the vapor phase space at the bottom of the ammonia evaporation tower.