JP3655002B2 - Adsorbent and method for producing adsorbent - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to adsorbents, especially for environmental protection, or to prevent the contaminants are released into the environment, also suitable adsorbents for use contaminants to or removed from the environment and The present invention relates to a method for producing an adsorbent .
[0002]
[Prior art]
In today's industrial society, a wide variety of pollutants are released into the environment and remain possible. Therefore, in order to maintain a limited global environment, it is possible to effectively prevent the release of pollutants into the environment, and the pollutants released to the environment, depending on the characteristics and generation mode of the pollutants. It is an urgent issue to establish a technology for effectively removing the odor from the environment.
[0003]
[Problems to be solved by the invention]
The present invention can effectively use wood resources such as adsorbents, particularly thinned wood, which are used to treat pollutants by adsorption as one of the technologies that meet the above-mentioned problems, and can be manufactured at a relatively low cost. It is an object of the present invention to provide an adsorbent that can be used and a method for producing the adsorbent .
[0004]
[Means for Solving the Problems]
The adsorbent according to the present invention is obtained by thermally converting wood. More preferably, wood is once converted into charcoal under generally used charcoal firing conditions, and then this charcoal is again thermally converted. Specifically, first, wood is fired at, for example, 600 to 700 ° C. to obtain charcoal. Then, the charcoal is reheated at 800 to 2000 ° C. for 2 to 5 hours, for example, by heating nitrogen gas or the like in an inert gas atmosphere. The reason why wood is once used as charcoal is to facilitate management of heating conditions for heat conversion. In other words, once the wood is made into charcoal, runaway self-combustion that may occur when wood is directly converted to heat can be eliminated, and the heating conditions for heat conversion can be easily managed. Become. And it can be set as the adsorbent which was more excellent by stability of adsorption capacity by managing heating conditions more strictly.
[0005]
The adsorbent obtained in this way has the inherent porosity of wood that is specifically heat-converted under the specific heating conditions as described above. For example, isopropyl is widely used as a cleaning agent. High adsorption capacity for alcohols such as alcohol, methyl alcohol and ethyl alcohol. Although its adsorption capacity is inferior to activated carbon, in comparison with ordinary charcoal, for example, taking isopropyl alcohol as an example, the heating temperature is most preferably 800 to 1000 ° C., and the initial concentration is 10,000 ppm. The adsorption concentration of ordinary charcoal is about 4000 ppm, and is about 8000 to 9000 ppm, which is twice or more, and can sufficiently satisfy the practically required adsorption capacity.
[0006]
Such characteristics can be efficiently exhibited under the above heating conditions. That is, when the heating temperature is 800 ° C. or less or the heating time is 2 hours or less, there is almost no difference from the adsorption ability in normal charcoal, but heating is performed for 2 hours or more under a heating temperature condition of 800 ° C. or more. As a result, the adsorption ability that is specifically exhibited for various contaminants as described later can be rapidly increased. On the other hand, even if the heating temperature is set to 2000 ° C. or higher, or the heating time is set to 5 hours or longer, substantially no improvement in adsorption capacity is observed. Therefore, by using the heating conditions as described above, it is possible to obtain an adsorbent that sufficiently satisfies the practical adsorption ability at a lower cost than activated carbon or the like.
[0007]
Contaminants that can be treated with the adsorbent according to the present invention are subject to release into the air, such as alcohols widely used as industrial cleaners, NOx contained in exhaust gas, Examples of SOx and substances that cause release into water are heavy metals that are harmful to living organisms, and persistent organic polymers contained in agricultural chemicals and detergents.
[0008]
Embodiment
In order to implement the present invention in a preferred form, black coal obtained by firing wood at 600 to 700 ° C. is used as a raw material. The black charcoal is heated for a predetermined time while maintaining a predetermined temperature while slowly descending, for example, in a cylindrical heating furnace. In this heating, an inert gas such as nitrogen gas is supplied to the heating furnace.
[0009]
【Example】
In one example, cedar black charcoal was used as a raw material, and the heating temperatures were 800 ° C., 900 ° C., and 1000 ° C., and each was heated for 3 hours. The adsorption capacity of the adsorbent thus obtained for isopropyl alcohol is about 8000 ppm for an adsorbent with a heating temperature of 800 ° C. and about 8500 ppm for an adsorbent with a heating temperature of 900 ° C. For an adsorbent with a heating temperature of 1000 ° C., it was about 9000 ppm.

Claims (5)

  An adsorbent obtained by heating wood at 800 to 2000 ° C. for 2 to 5 hours. An adsorbent obtained by sintering wood at 600 to 700 ° C. to obtain charcoal, and heating the wood at 800 to 2000 ° C. for 2 to 5 hours. The adsorbent according to claim 1 or 2, wherein the adsorption ability for alcohols exemplified by isopropyl alcohol has an ability to adsorb 8000 to 9000 ppm with respect to an initial concentration of 10,000 ppm. The manufacturing method of the adsorption agent which heats wood at 800-2000 degreeC for 2 to 5 hours. A method for producing an adsorbent in which wood is sintered at 600 to 700 ° C to obtain charcoal, and then heated at 800 to 2000 ° C for 2 to 5 hours.