KR890002856B1 - Preparation method of adsorbent for hydrogen sulfide - Google Patents

Abstract

The method comprises (i) calcining Jarosite at 200-600 deg.C to leach in water, (ii) neutralizing the leached solution with alk. aq. soln. for pptg. and washing the pptn, (iii) mixing pptn. with active material/additive i.e. active carbon, phosphates, gypsum, clay, zeolite, and (iv) molding and drying to have more than 20% of porosity rate.

Description

Process for producing hydrogen sulfide absorbent

1 is a performance test of the absorbent prepared by the method of Example 1.

2 is a performance test of the absorbent prepared by the method of Example 2.

3 is a performance test of the absorbent prepared by the method of Example 3.

4 is a performance test of the absorbent prepared by the method of Example 4.

5 is a performance test of the existing international product (Nissan Girdler).

Currently, domestic sewage and wastewater are not purified. However, according to the Han River Development, the sewage treatment of big rivers and other regions of the whole country is in earnest as comprehensive treatment of daily sewage is performed to prevent river contamination. In this case, the gas generated during the decomposition of solids in the sewage treatment process is mainly composed of methane and carbon dioxide, so the gas can be used as a fuel, but the gas contains 100-500 ppm hydrogen sulfide. Therefore, when the gas generated at this time is used as fuel or incineration, sulfur dioxide is generated and air pollution becomes a big problem, so hydrogen sulfide removal in this gas must be performed. In addition, the same problem occurs for the desulfurization in the city gas, so a desulfurization agent at a low temperature must be used. However, if the high-temperature desulfurization agents used in factories such as oil refining processes are used to remove hydrogen sulfide from gas generated from city gas or sewage treatment plants, the treatment costs are increased and the desulfurization agents are expensive and very ineffective. There is an urgent need to develop suitable and inexpensive hydrogen sulfide absorbers.

The present invention relates to a method for producing iron oxide-based low-temperature hydrogen sulfide absorbent of the above object at low cost using jarosite as a main raw material. The method for producing this product is to calcinate jarosite below 600 ℃, convert it into water-soluble substance, and then leach it with water or acidic solution to neutralize it with alkali such as caustic soda, hydrated lime (or quicklime), ammonia water, or alkaline solution. Neutralize direct leaching. At this time, the resulting precipitate is washed and filtered to mix special additives to enhance the porosity (20% or more) and strength, and is characterized in that the molding and drying in the required form, such as spherical or cylindrical. In addition, in order to enhance the performance of the hydrogen sulfide absorber made of jarosite, the solution obtained by leaching a solution of iron chloride or iron sulfate and iron oxide with acid or alkali treatment under high temperature and high pressure is recovered and mixed with an appropriate amount. . In this case, as a mixing method, the main raw material, the sub raw material, and the additives are mixed in a slurry state or mixed in a solid state to be molded and dried. The low-temperature hydrogen sulfide absorbent production method of the present invention has a low production cost than the conventional production method, and has the advantage of excellent absorption capacity of hydrogen sulfide. In addition, there is an advantage of using the chief resource as an available resource by using the jarosite produced as a by-product in the zinc smelter as the main raw material.

In the present invention, the performance test for the developed absorbent of hydrogen sulfide was carried out by diluting with a nitrogen gas so that the concentration of hydrogen sulfide was about 1% in a state in which the glass tube having a diameter of 38 mm was used as a desulfurization tube and nitrogen gas was blown to make the tube completely inert atmosphere. The desulfurization performance was tested while maintaining the flow rate at 3 cm / sec in the desulfurization tube.

Example 1

1 part of the calcined product obtained by calcining jarosite for 4 hours at 350 ° C. was leached with 9 parts of water for 2 hours, and then neutralized the leached solution to pH 8.5 with caustic soda to precipitate iron compounds including iron hydroxide. The precipitate is washed, filtered and molded into a columnar shape such that the porosity is 20% or more to prepare the hydrogen sulfide absorbent of the present invention.

[Performance Test]

100 g of hydrogen sulfide absorbent prepared above was put into a 38 mm diameter glass tube, and nitrogen gas was blown to dilute with nitrogen gas so that the concentration of sulfide water was 1% while the inside of the tube was completely inert, and the flow rate in the glass tube was 3 cm / sec. The hydrogen sulfide absorption rate with time was as shown in FIG. That is, as shown in FIG. 1, while passing through a gas containing 1% hydrogen sulfide to 100 g of the hydrogen sulfide absorbent prepared in Example 1, about 98% of hydrogen sulfide was absorbed up to about 4 hours, and after about 70 hours after 5 hours and 30 minutes % Hydrogen sulfide is absorbed.

Example 2

2 parts of the calcined product obtained by calcination at jarosite 400 ° C. for 3 hours were leached with 8 parts of water for 1 hour and 30 minutes, and then the solution was neutralized to pH 7.5 by calcining circuit to precipitate iron compounds including iron hydroxide. The precipitate was washed and filtered, mixed with 52% of iron hydroxide, 36% of iron hydroxide, active substance and additives (active carbon: phosphate lime, phosphate: gypsum: clay = 1: 1: 10: 10), and then mixed in a blending ratio of 12%, and the porosity was 20% or more. Molding and drying so as to prepare the hydrogen sulfide absorbent of the present invention.

[Performance Test]

The hydrogen sulfide absorbent thus prepared was subjected to the performance test as in Example 1, but using only 250 g of the absorbent, the hydrogen sulfide absorption rate with time was as shown in FIG. 2. That is, hydrogen sulfide was absorbed by 96% or more until 14 hours and 30 minutes, and the absorption rate of hydrogen sulfide gradually decreased as the absorption time elapsed, and about 80% of hydrogen sulfide was absorbed after 20 hours.

Example 3

1.5 parts of the calcined product obtained by calcining jarosite for 3 hours at 450 ° C. were leached with 8.5 parts of water for 1 hour and 30 minutes, and then neutralized the leached solution to pH 7.5 by calcination in which precipitated compounds including iron hydroxide were precipitated. The precipitate was washed and filtered to mix the precipitate with 48% of iron hydroxide and 28% of the active material as in Example 2 and an additive of 24%, followed by molding and drying to have a porosity of 20% or more to prepare the hydrogen sulfide absorbent of the present invention.

[Performance Test]

In the same manner as in the performance test in Example 2, the hydrogen sulfide absorption rate with time was shown in FIG. That is, as compared with the case of Example 2, as a result of reducing the amount of jarosite precipitates and iron hydroxides and increasing the amount of active substances and additives, the absorption capacity of hydrogen sulfide is somewhat decreased, and the time until absorbing more than 95% of hydrogen sulfide is about Nine hours and the time to absorb more than 80% hydrogen sulfide lasted 12 hours.

Example 4

A precipitate was prepared in the same manner as in Example 3, except that it was calcined at jarosite at 240 ° C. and 25% of precipitate 32%, iron hydroxide 20%, activated carbon, phosphate, and zeolite were mixed at 2: 1: 3. The mixture of gypsum and gin dust (1) in 1: 1 is mixed at a mixing ratio of 23%, and then molded and dried to have a porosity of 20% or more to prepare the hydrogen sulfide absorbent of the present invention.

[Performance Test]

In the same manner as in the performance test of Example 2, the hydrogen sulfide absorption rate with time was shown in FIG. 4. That is, in Example 4, the hydrogen sulfide absorption capacity is similar to that of Example 3, as the amount of jarosite precipitate and iron hydroxide is slightly reduced and the active substances and additives are slightly increased compared to Example 3.

[Comparison Performance Test]

Performance of the existing Nissan Girdler, a foreign product in Japan, was carried out as in Example 2, and the hydrogen sulfide absorption rate with time was as shown in FIG.

As can be seen from comparing the performance test of the hydrogen sulfide absorbent prepared according to the present invention of FIGS. 1-4 and FIG. 5, the performance test of the existing foreign product, it can be seen that the present invention has excellent performance in the existing foreign product. It can be seen that the invention is useful for waste gas purification, fuel purification and pollution treatment.

Claims (3)

After calcination of Jarosite to 200-600 ℃, the leaching solution obtained by leaching with water was neutralized with alkaline aqueous solution. The precipitate formed by washing and filtering was mixed with ferrous hydroxide, active substance and additives. Method for producing a hydrogen sulfide adsorbent, characterized in that the molding and drying as possible. The method of claim 1, wherein the active material and the additive are selected from the group consisting of activated carbon, phosphate, gypsum, clay, zeolite, and gin dust. Hydrogen sulfide adsorbent characterized by calcining jarosite to 200-600 ° C. and then leaching with water to neutralize the leaching solution with alkaline aqueous solution to wash and filter the precipitate formed to form a porosity of 20% or more. Manufacturing method.

Images