Method and apparatus for removing vinyl monomers from a gas stream

Abstract

An apparatus for removing vinyl monomers from a gas stream includes a tube, a shading casing and a light emitting unit. The tube includes a first section having a connecting port with an opening, a second section, and a third section having an outlet. The three sections sequentially link together, with the second section connecting between the first section and the third section. A photoactive-inorganic medium is arranged inside the second section. The shading casing surrounds and seals the second section and an inner surface of the shading casing defines a reflecting face. The light emitting unit is mounted to the shading casing to irradiate and activate the photoactive-inorganic medium in the second section. Accordingly, the photoactive-inorganic medium can be activated by the light emitting unit to photocatalyze vinyl monomers in a gas stream to polymerize on surfaces of the photoactive-inorganic medium, such that vinyl monomers are removed.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a method and an apparatus for the treatment of exhaust gas and, more particularly, to a method and an apparatus for removing vinyl monomers from a gas stream.[0003]2. Description of the Related Art[0004]Generally, there are three chemical reactors in chemical engineering, which are continuous stirred-tank reactor (CSTR), plug flow reactor (PFR) and pack-bed reactor (PBR). According to aspects of chemical engineering applications, these reactors are packed with catalysts and are often equipped with different units, such as a thermostat. Hence, a diversity of chemical reactors is designed. Key process variables for the design of a chemical reactor include flow rate, temperature, concentrations of chemical species, pressure and so on. Furthermore, the following are advantages and disadvantages of different kinds of chemical reactors.[0005]First, the CSTR is most used in industry and can be ...

AI Technical Summary

Benefits of technology

[0012]The primary objective of the present invention is to provide a new pollution treatment for a gas stream, which solves the problems of the prior art described above to allow vinyl monomer recovery by polymerization and reduction of consumption of energy by photocatalytic reaction.

[0013]To accomplish the above objective, the present invention provides a method for removing vinyl monomers from a gas stream. The method for removing vinyl monomers from a gas stream according to the preferred teachings of the present invention includes the steps of: irradiating a photoactive-inorganic medium by a light emitting unit to activate the photoactive-inorganic medium; and pumping a gas stream including vinyl monomers to contact with the activated photoactive-inorganic medium to make the vinyl monomers in the gas stream to polymerize on the photoactive-inorganic medium and jointly form a polymeric nano-composite. Accordingly, recovery of vinyl monomers is achieved and vinyl monomers can be reused in the future.

[0014]The present invention further provides an apparatus for removing vinyl monomers from a gas stream. The apparatus according to the preferred teachings of the present invention includes a tube, a shading casing and a light emitting unit. The tube includes a first section that has a connecting port with an opening, a second section, and a third section having an outlet. The three sections sequentially link together, with the second section connecting between the first section and the third section. A photoactive-inorganic medium is arranged inside the second section. The shading casing surrounds and seals the second section and an inner surface of the shading casing defines a reflecting face. The light emitting unit is mounted to the shading casing to irradiate and activate the photoactive-inorganic medium in the second section. Accordingly, the photoactive-inorganic medium can be activated to photocatalyze vinyl monomers in a gas stream to polymerize, such that cost of treating gas pollution can be reduced.

Problems solved by technology

However, in all kinds of continuous flowing reactors, CSTR has a lowest volumetric unit of conversion and that leads to the necessity of a reaction tank with large volume to enhance volumetric unit conversion.

Disadvantages of plug flow reactors are that temperatures are hard to control due to exothermic reactions and can result in undesirable temperature gradients.

However, it is also hard to control temperature of the PBR and to replace material of a catalyst packed in the PBR.

Nevertheless, said conventional apparatus for treating exhaust has several drawbacks.

Thus, saturated activated carbon should be disposed in landfill or incinerated without recovery of the organic compounds, so that using activated carbon costs much and the organic compounds can not be reused.

Besides, when the activated carbon is saturated, the adsorbing processes will be stopped for replacing absorbent, such that the treatment is not continuous.

If some usable compounds, such as vinyl monomer, exist in the organic waste air, their degradation also occurs.

Furthermore, amount of free radicals for decomposition of organic pollutants and generated from the catalyst of TiO2 is decreased to low efficiency of degradation of the organic pollutants, while TiO2 is exposed to light outside the first UV oxidation reactor.

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