CN103305296A - Method for filtering and separating coal-to-liquid coal-based catalyst coal-water suspension - Google Patents

Abstract

The invention discloses a method for filtering and separating a coal-to-liquid coal-based catalyst coal-water suspension. According to the method, by employing a filter press, solid-liquid separation of a coal-based catalyst, washing and pre-drying are finished. The problems that an existing plate frame type filter press is high in labor intensity and discontinuous in discharging, the subsequent process is influenced, the discharging product quality is instable and the like are solved. The method has the advantages of continuous system operation, high operability, less equipment, low equipment failure rate, small occupied area of a device and low investment.

Description

Coal-to-oil coal-based catalyst coal-water suspension filtration and separation method

technical field

The invention relates to a method for filtering and separating the coal-water suspension of a coal-based catalyst for coal-to-oil, to be precise, a method for separating the coal-water suspension through "filtering, washing and pre-drying".

Background technique

The coal-water suspension of the coal-to-oil coal-based catalyst in the Shenhua direct coal liquefaction unit is separated by a plate and frame filter. This separation process has the following disadvantages:

①Intermittent operation of equipment is labor-intensive

The main equipment of coal-water separation in the coal-to-liquids catalyst preparation process is a plate-and-frame filter that operates intermittently, and its labor load is large and labor-intensive.

② Discontinuous discharge, affecting the subsequent process

In the coal-to-oil catalyst preparation process, the main equipment of coal-water separation, the plate-and-frame filter, discharges the material intermittently and in batches at regular intervals, and the discharge cannot be continuous, which will easily cause the catalyst to block in the subsequent buffer bin. Moreover, in order to ensure the continuous and stable operation of subsequent equipment, the buffer bin must have sufficient volume.

③ The quality of the output product is unstable

In the coal-to-oil catalyst preparation process, the coal-water separation process is an intermittent switching operation of two plate and frame filters. The performance of the two equipment cannot be completely consistent, resulting in inconsistent performance of the catalyst filtered out in each batch and affecting the quality of subsequent products. Moreover, even if the same equipment is operated intermittently, the change of feed conditions and operation each time will easily lead to inconsistent performance of the catalyst filtered out in each batch and affect the quality of subsequent products.

Contents of the invention

Aiming at the deficiencies of the prior art, the object of the present invention is to provide a method for filtering and separating the coal-water suspension of the coal-based catalyst for coal-to-oil. This method adopts an integrated equipment-pressure filter, which replaces the traditional "plate and frame filter press method", so that the process of "filtering, washing and pre-drying" of coal-based catalyst coal-water suspension in coal-to-oil can be completed in one device .

The purpose of the present invention is achieved through the following technical solutions:

A method for filtering and separating a coal-water suspension of a coal-based catalyst for coal-to-oil, the steps of which are:

a. The coal-based catalyst coal-water suspension in the slurry tank is pressurized by the slurry pump and then enters the filter unit of the pressure filter. The pressure filter rotates centripetally by frequency conversion to suspend the coal-based catalyst coal water. The coal-based catalyst in the liquid is continuously separated from the liquid. After separation, the coal-based catalyst accumulates in the filter unit room and is transported to the subsequent washing (ion exchange) unit room for washing with the rotation of the drum; the separated filtrate is passed through The filtrate pipe connecting the filter unit chamber and the control head is discharged;

b. When the filter unit chamber of the pressure filter is completely filled with the coal-based catalyst, the rotation of the drum will transport the coal-based catalyst filter cake to the washing unit chamber, and at the same time, the water stored in the washing liquid tank will be pressurized by the washing liquid pump Enter the washing unit chamber of the pressure filter to wash the coal-based catalyst filter cake;

c. Use compressed nitrogen or air to squeeze and purge the coal-based catalyst filter cake into the drying unit chamber of the pressure filter, and dry the trace liquid contained in the coal-based catalyst filter cake;

d. The coal-based catalyst filter cake entering the discharge unit chamber of the pressure filter is in the non-pressure zone, and is discharged under the double action of back-blowing nitrogen or air.

The drying medium in the drying area of the pressure filter can be nitrogen, air or other inert gases at a temperature of 20°C to 150°C.

Advantages of the present invention:

(1) The pressure filter used in the present invention is a patented product (Patent No. 2009 2 0144208.5) obtained by Tianhua Chemical Machinery and Automation Research and Design Institute named "a continuous pressure filter integrating filtration, washing and drying". ). This equipment is used in the process technology of the solid-liquid separation and washing unit of the coal-based catalyst device for coal-to-oil, and completes the solid-liquid separation, washing and pre-drying of the coal-based catalyst." The system is simple and highly operable.

(2) Compared with the traditional technology, the present invention replaces the traditional "plate and frame filter press filter", adopts a pressure filter, and the equipment is continuously fed and discharged continuously, which solves the problem of the large labor intensity of the plate and frame filter press , Discontinuous discharge, affecting the follow-up process, unstable product quality and other issues.

(3) pressure filter has integrated press filter and washing unit among the present invention, adopts a pressure filter to replace two plate-and-frame type filter presses with respect to existing process route, in process system, without increasing equipment At the same time, a washing unit that can improve product quality is added, with less equipment and low equipment failure rate.

(4) process equipment quantity is few among the present invention, except pressure filter, other equipment adopts conventional or standard equipment. The device occupies a small area and requires less investment.

Description of drawings

Fig. 1. is process flow chart of the present invention.

In the figure: 1-pressure filter 2-slurry tank 3-slurry pump 4-washing liquid recovery tank 5-washing liquid pump 6-washing liquid tank

Detailed ways

Below, in conjunction with accompanying drawing 1 technical scheme of the present invention is further described again:

Step 1: The coal-based catalyst suspension in the slurry tank 2 is pressurized to 0.3MPa(G) by the slurry pump 3 and then enters the filter unit room of the pressure filter 1, and the pressure filter 1 is centripetally rotate. The annular area between the drum and the shell is sealed with a specially designed packing, and is divided into different airtight cavities by the separator, and the compressed air of the separation unit of 0.5MPa(G) is passed into the airtight cavity to make the pressure filter 1 under pressure. The surface of the drum is composed of a filter unit chamber connected to the control head through a filtrate pipe. Under pressure, the catalyst in the coal-based catalyst slurry is continuously separated from the solution. After separation, the coal-based catalyst accumulates in the filter unit chamber. And with the rotation of the drum, it is transported to the subsequent washing unit; the separated separation liquid is discharged through the filtrate pipe connected to the control head in the separation liquid filtration unit chamber.

Step 2: When the filter unit chamber is completely filled with the separated coal-based catalyst, it is transported to the washing unit chamber with the rotation of the drum, and the toluene washing liquid stored in the washing liquid tank 6 is pressurized by the washing liquid pump 5 at the same time After reaching 0.3MPa (G), enter the washing unit chamber of the pressure filter 1 to wash the coal-based catalyst filter cake; the coal-based catalyst filter cake is washed (the number of times of washing can be increased by arranging the unit chamber); The rotating coal-based catalyst filter cake on the drum is transported to the drying unit chamber.

Step 3: The coal-based catalyst filter cake entering the drying unit chamber contains a small amount of liquid, and the coal-based catalyst needs to be pre-dried to reduce the moisture content of the coal-based catalyst material. The pre-drying is carried out with 0.3MPa(G) compressed nitrogen at a temperature of 120°C. The coal-based catalyst entering the drying unit chamber is squeezed and purged to dry and remove the residual liquid in the filter cake of the coal-based catalyst. After the pre-drying is completed, the coal-based catalyst filter cake is transported to the unloading unit chamber with the rotation of the drum, and the extruded washing liquid and compressed nitrogen are discharged through the washing liquid connected to the control head in the washing unit chamber of the pressure filter 1 The condensate in the wet gas is demisted and collected through the demister, the purified compressed nitrogen is emptied, and the separated liquid collected by demisting is discharged into the washing liquid recovery tank 4 for collection.

Step 4: The coal-based catalyst filter cake entering the unloading unit chamber is in the non-pressure zone, and the mechanical force of the movable scraper at the discharge port of the pressure filter 1 and the 0.5MPa (G) pressure connected from the control head to the unloading unit chamber Unloading is carried out under the double action of backflushing nitrogen, and the unloaded coal-based catalyst filter cake is sent to the drying unit. After the unloading is completed, there will be a small amount of coal-based catalyst filter cake remaining in the active unit chamber, so before entering the next cycle, it is necessary to pass 0.3MPa(G) washing liquid and 0.5MPa(G) nitrogen to the active unit chamber respectively. The filter screen is cleaned and backflushed, and the filter screen washing liquid entrained with a small amount of coal-based catalyst filter material enters the coal-based catalyst slurry tank 2 through the collection pipe, and is pressurized by the slurry pump 2 along with the next batch of coal-based catalyst mother liquor into the next cycle.

Claims (2)

1. A method for coal-based catalyst coal-water suspension filtration and separation of coal-to-oil, its steps are: a. The coal-based catalyst suspension in the slurry tank enters the filter unit chamber of the pressure filter (1) after being pressurized by the slurry pump (3), and the pressure filter (1) rotates centripetally in the mode of frequency conversion speed regulation, The suspension in the coal-based catalyst suspension is continuously separated from the water. After separation, the coal-based catalyst accumulates in the filter unit room and is transported to the subsequent washing unit room for washing with the rotation of the drum; the separated water passes through The filtrate pipe connected between the coal-based catalyst filter unit chamber and the control head is discharged into the washing liquid recovery tank (4) for collection; b. When the filter unit chamber of the pressure filter (1) is completely filled with the separated coal-based catalyst suspension, the rotation of the drum will transport the coal-based catalyst filter cake to the washing unit chamber and store it in the washing liquid tank (6) at the same time The washing liquid inside enters the washing unit chamber of the pressure filter (1) after being pressurized by the washing liquid pump (5) to wash the coal-based catalyst filter cake; c. Squeeze and purge the coal-based catalyst filter cake entering the pressure filter (1) drying unit chamber with compressed nitrogen, and dry the trace liquid contained in the coal-based catalyst suspended filter cake; d. Enter the discharge unit chamber of the pressure filter (1), the coal-based catalyst filter cake is in the non-pressure zone, and the discharge is carried out under the dual action of backflushing nitrogen. 2. the method for a kind of coal-to-oil coal-based catalyst coal-water suspension filtration and separation as claimed in claim 1 is characterized in that the drying medium in the drying zone of the pressure filter (1) can adopt nitrogen, or air, or other inert gases , at a temperature of 20°C to 150°C.

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