JPH0421537B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a desulfurization agent useful for removing hydrogen sulfide from hydrogen sulfide-containing gas such as coal gas. <Conventional technology> Conventionally, desulfurization agents for removing hydrogen sulfide from hydrogen sulfide-containing gases such as coal gas have mainly contained iron hydroxide, and sawdust has been used to improve gas passage and increase the contact surface. A mixture of these is used. As the iron component, dagger powder (cast iron shavings) is mainly used because it is easy to obtain, is not in a fine powder form, and has good gas permeability, but other materials include Lux Masse, a by-product of the aluminum industry, or iron powder. Swamp iron ore and loess, which have a high content, are also used. <Problems to be solved by the invention> The conventional method using the above-mentioned dry powder requires a long curing period to convert the iron component into iron hydroxide, and the desulfurization agent after use also has problems such as cement solidification. Requires complicated post-processing. Furthermore, when using loess, the particle size is very small, so even if it is used in combination with sawdust, the gas pressure loss is large, and it can only be used at low concentrations. <Means and effects for solving the problem> The present inventors have found that among the substances conventionally used as the iron component of desulfurization agents, loess containing iron in the form of iron hydroxide suitable for desulfurization agents. We focused on this and considered its use. In conventional methods, sawdust was used as a carrier material to improve gas passage and contact with the desulfurizing agent component. However, unlike Dalai powder, loess has small particles, so the gas pressure drop is large, so the proportion of use has to be reduced, and this cannot be solved by methods such as increasing the particle size of sawdust. As a result of various studies on desulfurization agents with a high content of loess, the present inventors discovered that rice husk has particularly excellent performance as a carrier material when used in combination with loess, and completed the present invention. That is, the desulfurization solution of the present invention has loess as a main component, and contains 35 to 65 parts by weight of sawdust per 100 parts by weight of loess.
This desulfurizing agent for hydrogen sulfide-containing gas is characterized in that it contains 25 to 25 parts by weight of rice husks and, if necessary, 3 to 15 parts by weight of an alkali component. The principle of desulfurization is to collect hydrogen sulfide in the form of hydrous iron sulfide, but since this composite is stable in the presence of an alkali, it is preferable to add an alkaline component such as sodium carbonate. The blending ratio of loess, sawdust, rice husk, etc. may be appropriately determined within the above range depending on the amount of hydrogen sulfide in the gas to be treated, the pressure of the gas, the period of refilling the desulfurizing agent, etc. Too much loess will increase pressure loss, while too little will reduce desulfurization performance, which is not preferable. It is preferable to adjust the particle size of the sawdust so that 80% is 1 mm or less and 20% is 1 to 3 mm. Rice husks can be used in the form in which they are normally available. The desulfurization agent of the present invention has a moisture content of 20 to 65% by adding water.
Adjust and use. After use, the desulfurization agent can be heated and incinerated to recover the sulfur content and then disposed of as normal industrial waste, but unlike when using dust powder, no lumps of iron remain, and it can also be used as a raw material for cement. <Effects of the Invention> The desulfurization agent of the present invention is easy to manufacture and post-process, has good desulfurization performance, and is useful for removing hydrogen sulfide from hydrogen sulfide-containing gases such as coal gas, especially for gases containing relatively low concentrations of hydrogen sulfide. Effective for fixed bed desulfurization. <Reference example> Loess excluding lumps and 80% less than 1 mm, 1 to 3
Sawdust whose particle size was adjusted so that mm was 20% was mixed at a weight ratio of 1:1 and mixed well to obtain desulfurizing agent A. On the other hand, the particle size was adjusted so that 80% was 1 mm or less and 20% was 1 to 3 mm. Mix the powder and sawdust in a weight ratio of 1:1, add water to make the moisture content about 40%, and then Desulfurization agent B was obtained after curing for 40 days while appropriately supplementing water. These desulfurization agents A and B were adjusted to the moisture content shown in Table 1, and charged into a fixed bed desulfurization equipment, and hydrogen sulfide was removed.
Coke oven gas (COG) containing 4.0±0.5g/ ^Nm3
was passed through the gas at a flow rate of 0.52 m ³ /Hr and a flow rate of 1.1 m/min, and the time until hydrogen sulfide was detected at the gas outlet was compared.

【table】

[Table] From the results shown in Table 2, desulfurization agent A using loess is better than desulfurization agent B using lime powder.
It has a high H ₂ S adsorption capacity per weight of desulfurization agent and iron content, demonstrating excellent performance as a desulfurization agent. <Examples, Comparative Examples> 50 parts by weight of loess, 25 parts by weight of sawdust, 20 parts by weight of rice husk
parts by weight and 5 parts by weight of Na ₂ CO ₃ and mix well.
A desulfurization agent (desulfurization agent C) whose moisture content was adjusted to 40% and the same amount of sawdust added instead of rice husks and a desulfurization agent (desulfurization agent D) adjusted in the same manner were charged into a fixed bed desulfurization equipment, and H ₂ S inlet concentration 0.15±0.05g/ ^Nm3 ,
Pass through COG at a COG flow rate of 0.3 m/min,
The results of measuring the H ₂ S concentration and pressure drop at the outlet are shown in Figures 1 and 2. Desulfurization agent D using only sawdust has a large pressure loss and low desulfurization performance, whereas desulfurization agent C of the present invention, which uses rice husk in combination, has low pressure loss and extremely excellent desulfurization performance.

[Brief explanation of drawings]

Figures 1 and 2 are graphs showing experimental examples comparing the performance of the desulfurizing agent C of the present invention and _the comparative desulfurizing agent D, respectively.
Figure 2 shows the pressure drop situation.

Claims (1)

[Claims] 1. Hydrogen sulfide, which contains loess as a main component and is made by mixing 100 parts by weight of loess with 35 to 65 parts by weight of sawdust, 25 to 55 parts by weight of rice husk, and 3 to 15 parts by weight of an alkali component if necessary. Desulfurizing agent for containing gas.