KR20160021216A - A process for the removal of metal contaminants from fluids - Google Patents

Abstract

The present invention provides a process for removing metal contaminants from a contaminated fluid stream comprising contacting the fluid stream with macroporous alpha alumina to obtain a fluid stream containing less than 50 ppm metal. The fluid stream may be selected from the group consisting of a stream of inorganic acid (s) and a stream of alkylene (s), and the metal contaminants may be at least one of a natural metal and a metal oxide. The process also includes obtaining pulmonary macroporous alpha alumina and converting the pulmonary macroporous alpha alumina into at least one pure stream selected from the group consisting of a stream of inorganic acid (s) and a stream of alkylene (s) And washing and recovering active macroporous alpha-alumina therefrom.

Description

FIELD OF THE INVENTION The present invention relates to a process for removing metal contaminants from a fluid,

The present invention relates to a process for removing metal contaminants from a fluid.

Chlorinated polymers are widely used in roofing membranes and geomembranes, in coated fabrics, in cable insulation, as impact modifiers and as base polymers. Their excellent physical and mechanical properties, such as resistance to chemicals and oils, flame tolerance, tensile strength and abrasion resistance, have resulted in huge industrial popularity and applicability.

Chlorinated polymers are generally prepared by reacting a chlorine-free polymer and / or a copolymer with a chlorinating agent at predetermined temperature and pressure conditions. Ethylene and hydrochloric acid are commonly used raw materials in this polymerization process. However, various corrosive effects of the reaction vessel and the pipeline are observed, especially due to the strong corrosiveness of the chemical in the presence of water. Furthermore, the corrosive surfaces emit metallic particulate matter that enters the polymerization reaction through the raw material. The presence of metal contaminants in the reaction causes a pressure drop in the system with the production of hot spots in the downstream catalyst bed, thus reducing the catalyst's shelf life. Furthermore, the attachment of the catalyst occurs, which leads to the production of undesirable products in the reaction, which reduces overall yield.

Angled methods for removing metal contaminants from raw materials have been developed. EP 0618170 proposes a strong basic anion exchange resin for the removal of iron impurities from hydrochloric acid. EP 0725759 proposes filtration and ion exchange techniques to remove coloring substances such as iron or halogen from hydrochloric acid. The process recited in EP 0725759 further comprises the step of removing the coloring material and then adding the reducing agent in hydrochloric acid. US 3411879 proposes a process for removing fluoride ions in aqueous hydrochloric acid by treating aqueous hydrochloric acid with a treating agent such as activated alumina or silica gel. US 5330735 proposes a contaminated hydrochloric acid treatment process for removing silicon-containing materials that can act as impurities such as silanes and silanol, siloxane. The process quoted in US 5330735 uses hydrophobic polystyrene resins. Techniques for removing metal contaminants from raw materials have improved considerably, but conventional methods are still unable to remove metal contaminants below a certain size and are accompanied by disadvantages such as the use of expensive reagents and substrates. US 8298311 and EP 0630677 propose ceramic products for the purpose of filtering and removing impurities such as dust. However, the prior art methods do not mention the use of ceramic materials to remove metal contaminants.

The inventors of the present invention have anticipated a simple and economical process to remove metal contaminants from the raw materials of the polymerization process.

Some objects of the present invention in which at least one embodiment is satisfied are as follows:

It is an object of the present invention to provide a process for removing metal contaminants from a fluid stream.

It is a further object of the present invention to provide a simple and cost effective process for removing metal contaminants from a fluid stream.

It is yet another object of the present invention to provide an environmentally friendly process for removing metal contaminants from a fluid stream.

It is a further object of the present invention to attenuate one or more of the problems of the prior art or to provide at least a useful alternative.

Other objects and advantages of the present invention will become more apparent from the following description, which is not intended to limit the scope of the invention.

The present invention provides a process for removing metal contaminants from a contaminated fluid stream comprising contacting the fluid stream having macroporous alpha alumina to obtain a fluid stream containing less than 50 ppm metal .

The fluid stream may be selected from the group consisting of a stream of inorganic acid (s) and a stream of alkylene. The metal contaminants can be at least one of a natural metal and a metal oxide.

The process comprises obtaining macroporous alpha alumina and washing the macroporous alpha alumina with at least one pure stream selected from the group consisting of a stream of inorganic acid (s) and a stream of alkylene Further comprising the step of regenerating active macroporous alpha alumina.

The inorganic acid may be at least one corrosive acid selected from the group consisting of hydrochloric acid and hydrofluoric acid, hydrobromic acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, and perchloric acid.

In one embodiment, the fluid stream is a hydrochloric acid stream.

The alkylene may be at least one selected from the group consisting of ethylene, methylene and propylene.

In one embodiment, the fluid stream is an ethylene stream.

The metal may be at least one selected from the group consisting of iron and nickel, copper, chromium, lead, zinc, manganese, and oxides thereof.

In one embodiment, the metal contaminant is iron oxide.

The contacting step can be carried out at a temperature of 20 ° C to 200 ° C.

The contacting step can be carried out at a pressure of from 1 kg / cm ² to 10 kg / cm ² .

The contacting step may be carried out at a space velocity (GHSV) of 20,000 gaseous hourly per 10,000-hour.

The shape of the macroporous alpha-alumina may be selected from the group consisting of a bead type and a disc type.

The present invention provides a process for obtaining a fluid stream that is substantially free of metal contaminants, which can be used as a raw material in the process of making the chlorinated polymer. The polymerization process results in a cost effective and environmentally friendly high yield process using the pure feed stream provided by the process of the present invention. The fluid stream is substantially free of metal contaminants and characterized by the metal content of the stream being less than 50 ppm.

The process of obtaining a fluid stream substantially free of metal contaminants comprises an initial step of providing a fluid stream contaminated with at least one metal contaminant. The fluid stream may be selected from the group consisting of a stream of inorganic acid (s) and a stream of alkylene (s). The inorganic acid used in the present invention is at least one corrosive acid selected from the group consisting of hydrochloric acid and hydrofluoric acid, hydrobromic acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, perchloric acid and the like. The alkylene used in the present invention includes, but is not limited to, ethylene and methylene and propylene. The metal contaminants contained in the fluid stream include, but are not limited to, natural metal (s) and metal oxide (s). The metal contaminants of the present invention may be selected from the group consisting of iron and nickel, copper, chromium, lead, zinc, manganese, and oxides thereof.

The next step is accompanied by a process of contacting the above described fluid stream with macroporous alpha alumina for capturing the metal contaminants described above. Macroporous alpha-alumina typically endures in long-term highly acidic and corrosive environments. Therefore, its use as a molecular sieve is highly effective in the process of the present invention. Macroporous alpha alumina, which is characterized and characterized in one embodiment, is obtained when the precursor gamma alumina is heat treated at a temperature of 1500 [deg.] C - 1700 [deg.] C. The form of macroporous alpha alumina is selected from the group of form consisting of bead type and disc type. The contacting step is carried out at a temperature of 20 ° C to 200 ° C at a pressure of 1 kg / cm ² - 10 kg / cm < ^{2 &} gt ;. The gas hourly space velocity (GHSV) of the fluid stream is 10,000 to 10,000 hours per hour.

The process of the present invention removes metal contaminants by form selection. This feature is characteristic of the process of the present invention. The contacting step provides a fluid stream without metal contaminants and pulmonary macroporous alpha alumina. The macroporous alpha alumina of the present invention may also be regenerated by washing with at least one pure stream selected from the group consisting of a stream of inorganic acid (s) and a stream of alkylene (es). The inorganic acid of the present invention is at least one corrosive acid including, but not limited to, hydrochloric acid and hydrofluoric acid, hydrobromic acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, perchloric acid and the alkylene is at least one selected from the group consisting of ethylene, methylene and propylene .

In one embodiment of the present invention, the hydrochloric acid vapor substantially free of iron oxide pollutants is obtained by passing a dry hydrochloric acid vapor containing iron oxide pollutants through a fixed bed containing macroporous alpha alumina.

In another embodiment of the present invention, the ethylene stream substantially free of iron oxide pollutants is obtained by passing a dry hydrochloric acid vapor containing iron oxide pollutants through a fixed bed containing macroporous alpha alumina.

The invention is illustrated by the following non-limiting examples:

Example  One: HCl Stream in  Removal of metal contaminants

300 g of porous alpha alumina was loaded into an adsorptive column trap containing SS316 and activated at 200 < 0 > C for 4 hours in air flow. The dried hydrochloric acid stream was passed through a column at a flow rate of 1 liter per minute at 160 < 0 > C. The exit stream from the bed was analyzed for Fe content at the end of 24 hours. The presence of Fe in the outlet stream was analyzed by washing the stream in deionized water. After washing, the deionized water turned pale yellow. The outlet stream-wash deionized water was analyzed by inductively coupled plasma emission spectrometry (ICP-OES) and showed the presence of 38 ppm Fe in the liberated HCl.

Determination of Fe content: The dry HCl obtained at the vinyl chloride monomer (VCM) plant at 160 ° C was analyzed for Fe contaminants. The stream was washed in deionized water for about 15 minutes to analyze the discharged hydrochloric acid stream. The cleaner was made by filling 50 ml of double distilled water in a glass trap. After washing, the deionized water was pale yellow and analyzed by ICP-OES. ICP analysis showed that 38 ppm iron was present in the effluent stream versus 600 ppm iron present in a stream not subjected to porous alpha alumina adsorption.

Example  2: Ethylene In the stream  Removal of metal contaminants

Experiment 1 was repeated, but instead of the hydrochloric acid stream, the ethylene stream from the VCM plant was passed through an adsorption column containing 86 g of porous alpha-alumina at a flow rate of 500 ml / min. The iron content of the effluent stream was 46 ppm relative to 394 ppm Fe present when the effluent stream did not undergo adsorption after alumina adsorption.

The manner of carrying out the invention and various features and advantages thereof are set forth with reference to the non-limiting embodiments of the description. The descriptions of known components and process techniques are omitted so as not to unnecessarily obscure the embodiments of the present invention. The embodiments of the present invention are intended to facilitate an understanding of the manner in which the embodiments of the invention are carried out and to enable those skilled in the art to practice the methods of the present invention. Accordingly, the examples should not be construed as limiting the scope of embodiments of the invention.

The above description of particular implementations will be representative of the general characteristics of the embodiments and therefore those skilled in the art will readily appreciate that many modifications may be made to adapt a particular embodiment without departing from the generic concept and / Accordingly, such adaptations and modifications are to be understood as being within the same meaning and scope as the disclosed embodiments. The predicates or terms employed herein are for purposes of illustration and are not intended to be limiting. Thus, while embodiments of the present disclosure have been described in terms of a preferred embodiment, those skilled in the art will recognize that the embodiments of the present disclosure may be practiced with modification within the spirit and scope of the embodiments described herein.

Technical Advantages

The present invention relating to a process for removing metal contaminants from a fluid stream has the following technical advantages.

The process of the present invention eliminates catalyst poisoning during the production of chlorinated polymers.

The process of the present invention can also remove small sized iron oxide contaminants that can not be removed by known methods.

The word " comprises, " or variations such as " comprising " or " comprising " are intended to indicate that an element, integer or step, And does not denote the exclusion of any other element, integer or step, or group of elements, integers, or steps.

The terms " at least " or " at least one " refer to the use of one or more elements or ingredients or quantities utilized in the practice of the invention to achieve one or more desired purposes or results.

The numerical values mentioned for physical parameters, sizes or quantities are approximations only and values greater or smaller than these numerical values assigned to parameters, sizes or quantities are not intended to be < RTI ID = 0.0 > Of the total population.

While specific embodiments of the invention have been described, these embodiments are provided by way of example only and are not intended to limit the scope of the invention. It will be appreciated by those skilled in the art from consideration of the present invention that modifications and variations in the process or compounds or formulas or combinations thereof of the invention may be practiced within the scope of the invention. Such changes and modifications are not to be taken in a spirit of the present invention clearly. The appended claims and their equivalents are intended to cover such forms or modifications as fall within the scope and spirit of the invention.

Claims (14)

A process for removing metal contaminants from a contaminated fluid stream, the process comprising contacting the fluid stream with macroporous alpha alumina to obtain a fluid stream containing less than 50 ppm metal . 2. The process of claim 1, wherein the fluid stream is selected from the group consisting of a stream of inorganic acid (s) and a stream of alkylene (s). The process according to claim 1, wherein the metal contaminants are at least one of natural metals and metal oxides. The process according to claim 1, wherein macroporous alpha alumina is obtained and the macroporous alpha alumina is reacted with at least one pure (alpha) alumina selected from the group consisting of a stream of inorganic acid Stream and recovering active macroporous alpha-alumina therefrom. ≪ RTI ID = 0.0 > 11. < / RTI > The process according to claim 2 or 4, wherein the inorganic acid is at least one corrosive acid selected from the group consisting of hydrochloric acid and hydrofluoric acid, hydrobromic acid, nitric acid, phosphoric acid, sulfuric acid, boric acid and perchloric acid. 2. The process of claim 1, wherein the fluid stream is a hydrochloric acid stream. The process according to Claim 2 or Claim 4, wherein the alkylene is at least one selected from the group consisting of ethylene and methylene and propylene. 2. The process of claim 1, wherein the fluid stream is an ethylene stream. The process according to claim 1, wherein the metal contaminant is at least one metal selected from the group consisting of iron and nickel, copper, chromium, lead, zinc, manganese, and oxides thereof. 2. The process of claim 1, wherein the fluid metal contaminant is iron oxide. The process according to claim 1, wherein the contacting step is carried out at a temperature of 20 ° C to 200 ° C. The process according to claim 1, wherein the contacting step is carried out at a pressure of 1 kg / cm ² to 10 kg / cm ² . 2. The process of claim 1, wherein the contacting step is performed at a space velocity (GHSV) of between 10, 000 and 20. 000 hours per hour. The process according to claim 1, wherein the form of the macroporous alpha-alumina is selected from the group consisting of a bead type and a disc type.