JPS62195087A - High-pressure storage of coke oven gas - Google Patents

Abstract

PURPOSE:To enable high-pressure storage of coke oven gas at low initial cost and operation cost, by compressing coke oven gas refined under a low pressure, cooling the compressed gas, removing impurities with a pressure-swinging adsorption column, desulfurizing the gas and feeding the refined gas to a high-pressure gas holder. CONSTITUTION:Coke oven gas refined under a low pressure is compressed, cooled and introduced into a pressure-swinging adsorption column 6 to remove impurities in the low-pressure refined gas (e.g. corrosive component such as sulfur, clogging component such as benzene, toluene, xylene, naphthalene, styrene, etc.). The refined gas is desulfurized in a desulfurization column 7 and supplied to a high-pressure gas holder 8.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a method for storing coke oven gas generated in a steelworks, and more particularly to a method for storing coke oven gas at high pressure with low equipment and operating costs.

Conventional technology and its problems Steelworks rely on by-product gases, namely blast furnace gas (BFG), coke oven gas (COG), and converter gas (LDG), for most of the fuel they require, but it is difficult to absorb fluctuations in supply and demand. One or two low-pressure gas holders are installed for each gas for safety purposes and for safety in the event of a factory abnormality.

Low-pressure gas holders are used to store each gas because blast furnace gas and converter gas are used to store dust, and coke oven gas is used to store clogging components (benzene, toluene, xylene, naphthalene, styrene, etc.) and corrosive components (sulfur content). ), and considering the processing costs, it is economical to clean it under low atmospheric pressure.

Among the by-product gases, coke oven gas, which has a high unit calorific value, is stored in large quantities because it is used not only as a fuel gas but also as a gas for chemical raw materials. However, as described above, low-pressure storage of coke oven gas requires a gas holder with a very large capacity since it is stored at approximately atmospheric pressure, and requires a large amount of land and equipment costs. For this reason, a method of storing coke oven gas under high pressure has recently been adopted.

As shown in Fig. 2, the conventional coke oven gas high-pressure storage method is to fill the coke oven low-pressure refined gas (2) with a compressor (to) and cool it to a predetermined temperature in a cooler 04, and then store it in a desulfurization tower 06. Corrosive components (hydrogen sulfide, organic sulfur) are removed in a cryogenic separator αQ, and clogging components are removed in a cryogenic separator αQ, followed by storage in a high-pressure gas holder. (to) is a heater. However, the conventional high-pressure storage method, as shown in Figure 2,
At least two desulfurization towers α to remove corrosive components (sulfur content)
In addition, it requires complex equipment such as a cryogenic separator αQ, which requires a refrigerator αη to obtain a low temperature source to remove clogging components (benzene, naphthalene, etc.), resulting in high equipment costs and The drawback was that operating costs were high.

Purpose of the Invention This invention was made in order to eliminate the above-mentioned drawbacks of the conventional technology, and by adopting a pressure swing adsorption method (PSA method) for pretreatment of coke oven gas, equipment costs and operating costs can be significantly reduced. The purpose of this project is to propose a high-pressure storage method that can efficiently reduce and remove impurities (corrosive components, clogging components) from coke oven low-pressure purified gas.

Structure of the Invention In the high-pressure storage method for coke oven gas according to the present invention, coke oven low-pressure purified gas is compressed and cooled and introduced into a pressure fluctuation type adsorption tower, and the corrosive components in the low-pressure purified gas are removed by the adsorption tower. After removing the clogging components, residual corrosive components are removed in a desulfurization tower and then supplied to a high-pressure holder.

The method of this invention will be explained in detail below with reference to FIG.

FIG. 1 is a schematic diagram showing an example of equipment for carrying out the method of this invention.

That is, (1) is an oil-cooled screw compressor used in consideration of the influence of impurities in coke oven gas, (2) is an oil separator installed by using the oil-cooled screw compressor, (
3] is an oil cooler that cools the oil separated by the oil separator, (4) is a hydraulic pump, and (5) is a gas cooler that cools the gas compressed by the compressor (1) to a predetermined temperature. be.

(6) is a pressure fluctuation type adsorption tower that removes impurities, that is, corrosive components (sulfur content) and clogging components (aromatic components such as benzene and naphthalene) in the coke oven low-pressure purified gas. This adsorption tower is capable of removing 100% of silicage clogging components as an adsorbent. (7) is a dry normal temperature desulfurization tower provided to remove residual corrosive components not removed by the pressure fluctuation type adsorption tower (6).

(8) is a high pressure gas holder.

Note that (9) is a pressure control device (PIC) and QO is a flow rate control device (FIC).

In the above equipment, the coke oven low-pressure refined gas (2) sent from the coke oven gas main α°C is compressed to a predetermined pressure by the oil-cooled screw compressor (1), and then passed through the oil separator (2). The oil in the gas is separated, and the separated oil is cooled in an oil cooler (3) and then pumped into a hydraulic pump (4).
) is supplied to the oil-cooled screw compressor (1).

The coke oven low-pressure refined gas that has passed through the oil separator (2) is
After being cooled to a predetermined temperature in a gas cooler (5), it is introduced into a pressure fluctuation type adsorption tower (6). Here, corrosive components (H, S, C8, CO8, etc.) and clogging components (=4-aromatic components such as naphthalene, toluene, xylene, etc.) in the gas are adsorbed and removed. This pressure fluctuation type adsorption tower (6) repeats the steps of charging, adsorption, and blow purge, and this operation is performed by controlling valves (V,) to (v6).

The coke oven gas leaving the pressure fluctuation type adsorption tower (6) is supplied to the desulfurization tower (7), where the remaining 5 minutes are removed and the gas becomes completely free of impurities and stored in the high pressure gas holder (8). be done.

In addition, although the equipment in which three pressure fluctuation type adsorption towers (6) and three high pressure gas holders (8) were installed was shown here, it goes without saying that it is not limited to this.

Example Using the equipment shown in Figure 1, the impurity concentration at the inlet and outlet of the adsorption tower was determined when coke oven low-pressure refined gas (11000 ON''/1 ()) having the composition shown in Table 1 was processed and stored at high pressure. Shown in Table 2.

The capacities and operating conditions of the oil-cooled screw compressor, oil cooler, gas cooler, pressure fluctuation type adsorption tower, and high-pressure gas holder in this example are shown below.

A. Oil-cooled screw compressor: Compression pressure 25kv/e+
JG constant, power 1800kW B, oil cooler: heat exchange amount 1600X10 kCa
l/HC, gas cooler: heat exchange amount 3500 x 10
8kca//H.

Inlet temperature 100℃ or higher (prevents moisture condensation), outlet temperature 50℃ or higher (prevents naphthalene precipitation) D. Pressure fluctuation type adsorption tower: 100OOON/HX 8
H adsorption.

300ON door/HXBH detachment, Adsorbent: 15% activated carbon.

5t(), 55%.

Altos 30% As is clear from Table 2, the H, S, C8, and C08 components were removed in 5 minutes using the pressure fluctuation type adsorption tower to the extent that some remained, and the aromatic components were completely removed. The 5 minutes that were not removed by the pressure fluctuation adsorption tower were completely removed by the desulfurization tower, yielding coke oven gas containing almost no impurities.

(Leaving space below) Table 1 Table 2 As explained in detail of the invention, according to the method of this invention, corrosive components and clogging components in the coke oven low-pressure purified gas can be removed using a pressure fluctuation type adsorption tower. This method has the effect of significantly reducing equipment costs compared to high-pressure storage methods, and also has the effect of being efficient and low cost since only the electric power for compression is required for operating costs.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of equipment for implementing the method of the present invention, and FIG. 2 is a schematic diagram showing a conventional high-pressure storage method for coke oven gas. 1... Oil-cooled screw compressor, 2... Oil separator,
3...Oil cooler, 4...Hydraulic pump, 5...
・Gas cooler, 6...pressure fluctuation type adsorption tower J7...
Desulfurization tower, 8...high pressure gas holder.

Claims (1)

[Claims] In a method of purifying coke oven gas and storing it under high pressure,
The coke oven low-pressure purified gas is compressed and cooled, introduced into a pressure fluctuation type adsorption tower, impurities in the low-pressure purified gas are removed in the adsorption tower, and then desulfurized in a desulfurization tower and supplied to a high-pressure holder. A method for high-pressure storage of coke oven gas, characterized by: