Acetylene, method for producing acetylene, and acetylene derivative

Abstract

[Problem] To provide acetylene and acetylene derivatives safely usable as raw materials for various plastics while reducing an environmental load, and to provide a method for efficiently producing the acetylene. [Solution] One aspect of the present invention provides acetylene containing carbon atoms derived from waste, the acetylene containing hydrogen phosphide and / or hydrogen sulfide, the volume fraction of hydrogen phosphide being 0.1% or less, the volume fraction of hydrogen sulfide being 0.2% or less.

Description

Acetylene, method for producing acetylene, and acetylene derivatives

[0001] This invention relates to acetylene, a method for producing acetylene, and acetylene derivatives.

[0002] For example, polyethylene and polyvinyl chloride, representative petrochemical products, are consumed in large quantities and then discarded. These waste products are a major contributor to environmental pollution. Furthermore, the mass production of petrochemical products leads to a global environmental problem: an increase in carbon dioxide in the atmosphere. To solve this problem, if waste that was previously discarded can be converted into chemical products, it will be possible to realize a resource-recycling society that does not rely on petroleum resources. From this perspective, a technology has been disclosed for producing synthesis gas from waste and then producing organic substances from that synthesis gas using a fermentation method (see Patent Document 1). Currently, there is a demand for the development of compounds that can be safely used as raw materials for a wider variety of plastics.

[0003] Special Publication No. 2024-531893

[0004] In view of the above circumstances, the present invention aims to provide acetylene and acetylene derivatives that can be safely used as raw materials for various plastics while reducing the burden on the environment, as well as a method for efficiently producing such acetylene.

[0005] According to one aspect of the present invention, acetylene containing carbon atoms derived from waste is provided, which contains at least one of phosphine and hydrogen sulfide, wherein the volume fraction of phosphine is 0.1% or less and the volume fraction of hydrogen sulfide is 0.2% or less.

[0006] According to this embodiment, acetylene that can be safely used as a raw material for various plastics can be supplied while reducing the burden on the environment.

[0007] The following describes embodiments of acetylene, methods for producing acetylene, and acetylene derivatives. The various features shown in the embodiments below can be combined with each other. In this specification, the content of Y in X means the proportion of Y in the total X. In this specification, "waste" may include any material to be reused or processed. That is, waste is used as a concept that includes used material, unused material, virgin material, and recycled material. Furthermore, in this specification, "combustion" includes a process in which waste is reacted in the presence of oxygen, but does not necessarily mean complete combustion, and is a concept that includes incomplete combustion or partial oxidation reactions carried out under conditions where the oxygen supply or reaction conditions are limited. The combustion residue obtained by such a process may include solid residue containing fixed carbon. That is, combustion residue is used as a concept that includes residue obtained by a process including carbonization or thermal decomposition.

[0008] <Acetylene and Acetylene Derivatives> The acetylene in this embodiment contains carbon atoms derived from waste. Using such acetylene makes it possible to manufacture various types of plastics while reducing the burden on the environment. Therefore, it can contribute to the realization of a carbon-recycling society. In particular, it is preferable that the carbon atoms are derived from the combustion residue of waste. Acetylene containing carbon atoms derived from the combustion residue of waste makes it easier to reduce the amount of impurities. Furthermore, the acetylene derivative in this embodiment is a modified version of the above-mentioned acetylene. Here, modification refers to changing a part of the molecule of a certain compound by a chemical reaction, or combining multiple molecules of a certain compound (for example, dimerization, etc.). Even when using such acetylene derivatives, it is possible to manufacture various types of plastics while reducing the burden on the environment.

[0009] Specifically, acetylene can be used to produce ethylene by hydrogenation, acrylonitrile by reacting it with hydrogen cyanide, vinyl chloride by reacting it with hydrogen chloride, acrylic acid by reacting it with carbon monoxide and water, monovinylacetylene by dimerization, chloroprene monomer (2-chloro-1,3-butadiene) by reacting it with hydrogen chloride after dimerization, vinyl acetate by reacting it with acetic acid, polyacetylene by polymerization, and acetaldehyde by reacting it with water. Acrylic acid can also be reacted with alcohol to produce acrylic acid esters. In particular, it is preferable that the acetylene derivative is at least one selected from the group consisting of ethylene, acrylonitrile, vinyl chloride, acrylic acid, acrylic acid esters, and monovinylacetylene. Acetylene black can also be produced by the thermal decomposition of acetylene.

[0010] Ethylene is used, for example, as a raw material for polyethylene, ethylene vinyl acetate copolymer (EVA), and ethylene propylene rubber (EPR). Acrylonitrile is used, for example, as a raw material for polyacrylonitrile, ABS resin, AS resin, acrylamide, and nitrile rubber. Vinyl chloride is used, for example, as a raw material for polyvinyl chloride. Acrylic acid is used, for example, as a raw material for polyacrylic acid (PAA) and polyacrylamide. Acrylic acid esters are used, for example, as raw materials for polymethyl acrylate (PMA), polyethyl acrylate (PEA), polybutyl acrylate (PBA), and polyethylhexyl acrylate (PEHA). Monovinyl acetylene is used, for example, as a raw material for polyvinyl acetylene. Chloroprene monomer is used, for example, as a raw material for polychloroprene.

[0011] Such acetylene contains at least one of phosphine and hydrogen sulfide. The volume fraction of phosphine in the acetylene is approximately 0.1% or less, and the volume fraction of hydrogen sulfide is approximately 0.2% or less. Acetylene with such low phosphine and hydrogen sulfide content is highly safe for the human body and can be safely used as a raw material for various plastics. The volume fraction of phosphine is preferably approximately 0.06% or less, more preferably approximately 0.03% or less, and even more preferably approximately 0.01% or less. On the other hand, the volume fraction of hydrogen sulfide is preferably approximately 0.1% or less, more preferably approximately 0.05% or less, and even more preferably approximately 0.02% or less. By setting the volume fractions of phosphine and hydrogen sulfide within these ranges, the above effects can be further improved.

[0012] From a safety standpoint, it is preferable that the content of phosphine and hydrogen sulfide in acetylene be as low as possible. However, by leaving a small amount of phosphine and hydrogen sulfide in the acetylene, the oxygen that would have otherwise been mixed with the acetylene is consumed by reacting with the phosphine and hydrogen sulfide, thereby suppressing the mixing of acetylene and oxygen, and thus the safety of the acetylene is not easily compromised. In addition, because the oxygen content in the acetylene is low, a decrease in the yield of monomer compounds obtained from acetylene, and consequently the yield of polymers, can be prevented or suppressed. Furthermore, acetylene containing phosphine and hydrogen sulfide will have a slight odor, so even if acetylene leaks, it can be detected, which also contributes to its high safety from this standpoint.

[0013] In this case, the volume fraction of phosphine is preferably about 0.1 ppm or more, more preferably about 0.5 ppm or more, even more preferably about 1 ppm or more, and particularly preferably about 1 ppm or more. For example, the volume fraction of phosphine can be about 0.1 ppm or more and 5 ppm or less. On the other hand, the volume fraction of hydrogen sulfide is preferably about 0.1 ppm or more, more preferably about 0.5 ppm or more, even more preferably about 1 ppm or more, and particularly preferably about 1 ppm or more and 1.5 ppm or more. For example, the volume fraction of hydrogen sulfide can be about 0.1 ppm or more and 5 ppm or less. By setting the volume fractions of phosphine and hydrogen sulfide within these ranges, the above effects can be further improved.

[0014] <Method for producing acetylene> The acetylene described above can be produced, for example, by the following method for producing acetylene. The method for producing acetylene in this embodiment includes a preparation step of preparing a fixed carbon source containing combustion residue of waste and a metal source, a heating step of heating the fixed carbon source and the metal source in a heating furnace to obtain metal carbide, and a reaction step of reacting the metal carbide with water to obtain acetylene. Each step will be described below. Examples of heating furnaces include electric furnaces such as resistance furnaces, induction furnaces, and arc furnaces, gas combustion furnaces, heavy oil combustion furnaces, rotary kilns, shaft furnaces, and muffle furnaces.

[0015] <<Preparation Process>> First, a fixed carbon source containing combustion residue from waste and a metal source are prepared. After pre-treatment of the waste, such as crushing and drying, a carbonization treatment corresponding to the combustion residue in this specification is obtained by using a rotary kiln, fluidized bed furnace, or high-temperature vacuum atmosphere furnace to perform a carbonization treatment for about one hour at a temperature of about 400°C to 1000°C, under a low-oxygen atmosphere (oxygen concentration of about 10% by volume or less), or under an inert gas atmosphere such as nitrogen or argon. In such treatment under low-oxygen conditions, some components in the waste undergo an oxidation reaction, while a considerable portion of the carbon component remains unoxidized as a solid. Here, it is preferable that the waste contains at least one of waste plastics, waste rubber, and waste carbon fibers. By utilizing such waste, which is a major cause of environmental pollution, it is easier to realize a resource recycling society that does not rely on petroleum resources.

[0016] The waste plastic is preferably at least one selected from the group consisting of, for example, polyethylene, polystyrene, polypropylene, polyvinyl chloride, phenolic resin, polyacetal, polycarbonate, polyamide, modified polyphenylene ether, polyetherether ketone, polyethersulfone, polyetherimide, polyphenylene sulfide, polysulfone, liquid crystal polymer, polyethylene terephthalate, and polybutylene terephthalate.

[0017] The waste rubber is preferably at least one selected from the group consisting of, for example, natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, butyl rubber, acrylonitrile-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, acrylic rubber, fluororubber, silicone rubber, urethane rubber, and epichlorohydrin rubber. The waste may further include at least one of glass and silica sand.

[0018] Furthermore, if the combustion residue contains metal, it is preferable to separate the metal from the combustion residue by crushing, sieving, or magnetic force. Also, if polyvinyl chloride, chloroprene rubber, etc., are used as waste, the combustion residue may contain unwanted components such as chlorine. In this case, it is preferable to remove the chlorine from the combustion residue by washing the waste with water before and / or after the carbonization treatment. In addition, if necessary, the powdered combustion residue may be granulated to a certain size before use.

[0019] The fixed carbon source may contain carbon atoms derived from the combustion residue of waste, as well as at least one of phosphorus atoms and sulfur atoms. In this case, it is preferable that the phosphorus atom content is about 1% by mass or less, and the sulfur atom content is about 5% by mass or less. By reducing the phosphorus atom content and sulfur atom content in this way, the amount of phosphine and hydrogen sulfide generated when producing organic substances (acetylene, acetylene derivatives, polymers, etc.) can be reduced. In particular, reducing the sulfur atom content can reduce the amount of sulfur oxide (SOx) generated, which can prevent corrosion of components constituting the organic substance production system and adverse effects on the synthesis catalyst of organic substances (monomer compounds and polymers).

[0020] Here, phosphorus-based substances containing phosphorus atoms in a fixed carbon source include, for example, elemental phosphorus, phosphine, phosphorus oxides, phosphorus-based plasticizers, phosphorus-based flame retardants, and phosphorus pentoxide (P ２ O ５Examples include the following. Furthermore, sulfur-based substances containing sulfur atoms in the fixed carbon source include, for example, elemental sulfur, hydrogen sulfide, sulfur oxides, factis, polysulfurized rubber, naphthenic oil, sulfur-modified chloroprene rubber, and various additives such as vulcanization accelerators containing sulfur atoms in their structure. The phosphorus atom content is preferably about 0.1% by mass or less, more preferably about 0.05% by mass or less, and even more preferably about 0.01% by mass or less. On the other hand, the sulfur atom content is preferably about 0.5% by mass or less, more preferably about 0.05% by mass or less, and even more preferably about 0.005% by mass or less. By setting the phosphorus atom content and sulfur atom content within these ranges, the above effects can be further improved.

[0021] From a safety standpoint, it is preferable that the phosphorus and sulfur atom content in the fixed carbon source be as low as possible. However, by leaving a small amount of phosphorus atoms (phosphorus-based substances) and sulfur atoms (sulfur-based substances) in the fixed carbon source, phosphine and hydrogen sulfide will remain in the acetylene obtained using the fixed carbon source in the above-mentioned amounts after oxygen consumption. Since the mixing of such acetylene with oxygen is sufficiently suppressed, the effects described above can be suitably exhibited.

[0022] In this case, the phosphorus atom content is preferably about 0.1 ppm (0.00001 mass%) or more, more preferably about 1 ppm (0.0001 mass%) or more, and even more preferably about 10 ppm (0.001 mass%) or more. For example, the phosphorus atom content can be about 0.1 ppm to 1 mass%. On the other hand, the sulfur atom content is preferably about 0.1 ppm (0.00001 mass%) or more, more preferably about 1 ppm (0.0001 mass%) or more, and even more preferably about 10 ppm (0.001 mass%) or more. For example, the sulfur atom content can be about 0.1 ppm to 5 mass%. By setting the phosphorus atom content and sulfur atom content within these ranges, the above effects can be further improved.

[0023] Furthermore, the fixed carbon source may contain carbon atoms derived from the combustion residue of waste and silicon atoms. Examples of silicon-based materials containing silicon atoms in the fixed carbon source include silicon oxide (silica). As will be described later, when metal carbide is produced by heating the fixed carbon source and the metal source in a heating furnace, the silicon oxide is reduced in the heating furnace as the reaction progresses to elemental silicon (Si). This elemental silicon consumes the fixed carbon source, which reacts with carbon to produce silicon carbide (SiC), thus reducing the yield of metal carbide. On the other hand, silicon oxide acts as a solvent in the melting of the metal source. Therefore, it can be expected to contribute to lowering the viscosity of the molten metal source and promoting the formation of metal carbide in the heating furnace.

[0024] For these reasons, there is a suitable range for the silicon atom content in the fixed carbon source. Specifically, the silicon atom content in the fixed carbon source is preferably about 10% by mass or less, more preferably 0.1 ppm to 10% by mass, even more preferably 0.5 ppm to 5% by mass, even more preferably 1 ppm to 1% by mass, particularly preferably 5 ppm to 0.5% by mass, and most preferably 10 ppm to 0.1% by mass. In this case, the efficiency of metal carbide production can be increased while also increasing the yield of metal carbide.

[0025] Furthermore, the nitrogen atom content in the fixed carbon source is preferably about 20% by mass or less, more preferably about 10% by mass or less, and even more preferably about 5% by mass or less. By reducing the nitrogen atom content, the amount of nitrogen oxides generated can be reduced, and corrosion of components constituting the organic substance manufacturing system and adverse effects on the organic substance synthesis catalyst can be prevented. The phosphorus, sulfur, and nitrogen atom content in the fixed carbon source can be measured in accordance with JIS M 8813:2004. In addition, the content of various atoms in the fixed carbon source can be determined, for example, by selecting the type of waste, setting its combination and mixing ratio, and by using phosphorus-based plasticizers, phosphorus-based flame retardants, and phosphorus pentoxide (P). ２ O５ ), can be adjusted by adding additives containing sulfur atoms in the structure, or additives containing nitrogen atoms in the structure. In other words, the various atoms may be present in the waste or added later.

[0026] Furthermore, it is preferable that the fixed carbon source does not contain ash, or if it does contain ash, the amount is small. Here, as ash, for example, silicon dioxide (SiO₂) ２ ), rare earth oxides (R ２ O ３ ), calcium oxide (CaO), magnesium oxide (MgO), sulfur oxide (SO ３ Examples include the following. These ashes are reduced in the heating furnace during acetylene production, reducing the efficiency and quality of acetylene production. Specifically, when magnesium oxide is reduced in the heating furnace, it becomes elemental magnesium, which volatilizes and rises to the top of the furnace, oxidizes back to magnesium oxide upon contact with air, descends to the bottom of the furnace, and is reduced again. This repeated oxidation and reduction process results in unnecessary consumption of electricity. Furthermore, carbon is wasted during the reduction of magnesium oxide.

[0027] Similarly, silicon dioxide wastes electricity when reduced, as the elemental silicon produced volatilizes and oxidizes. Furthermore, some silicon dioxide reacts with carbon to produce silicon carbide. Silicon carbide is a crystalline form known as carborundum, which has a high melting point and is extremely hard. Therefore, if silicon carbide accumulates in the heating furnace, it can eventually clog the furnace and render it inoperable. To avoid this, the ash content in the fixed carbon source is preferably around 30% by mass or less, more preferably around 20% by mass or less, and even more preferably around 7% by mass or less. The ash content in the fixed carbon source can be measured according to JIS M 8812:2006. The ash content in the fixed carbon source can also be adjusted, for example, by selecting the type of waste, setting its combination and mixing ratio, or by using additives containing one or more of the following atoms in their structure: silicon, rare earth, calcium, magnesium, or sulfur. In other words, ash may be present in the waste or added later.

[0028] The fixed carbon source is preferably such that the crushing strength of a sample formed from it to a size of 35 mm × 35 mm × 10 mm is 10 kgf or more, more preferably 20 kgf or more, even more preferably 30 kgf or more, and particularly preferably 40 kgf or more, as measured according to JIS Z 8841:1993. The upper limit of the crushing strength of the sample is not particularly limited, but is approximately 60 kgf. The crushing strength of the sample can be, for example, between 10 kgf and 60 kgf. By using a fixed carbon source capable of forming a sample with such crushing strength, collapse during the preparation and heating furnace when manufacturing metal carbide can be effectively prevented.

[0029] Further, the fixed carbon source preferably has a volatile content of 5% by mass or less, more preferably about 4% by mass or less, and even more preferably about 3% by mass or less, measured in accordance with JIS M 8812:2006. The lower limit of the volatile content of the fixed carbon source is not particularly limited, but is about 0.01% by mass. The volatile content of the fixed carbon source can be, for example, about 0.01% by mass or more and 5% by mass or less. Thereby, it is possible to suitably prevent the fixed carbon source from burning during storage or the like.

[0030] The fixed carbon source preferably has a carbon atom content derived from the combustion residue of the waste of about 70% by mass or more, more preferably about 80% by mass or more, even more preferably about 90% by mass or more, particularly preferably about 95% by mass or more, and may be substantially 100% by mass. By using a fixed carbon source having a high content of carbon atoms derived from the combustion residue of the waste in this way, it is easy to produce highly pure organic substances (for example, acetylene, etc.). Further, by setting the content of carbon atoms derived from the combustion residue of the waste in the fixed carbon source within the above range, it is easy to realize a resource recycling society that does not depend on petroleum resources. The fixed carbon source containing the combustion residue of the waste can be obtained as a carbide by the carbonization treatment of the waste as described above, and in addition to the content of phosphorus atoms and sulfur atoms, its properties (crushing strength, volatile content, etc.) can be easily adjusted to the desired range.

[0031] On the other hand, examples of the metal source include oxides of alkaline earth metals, carbonates of alkaline earth metals, hydroxides of alkaline earth metals, sulfates of alkaline earth metals, chlorides of alkaline earth metals, and the like. These metal sources may be used alone or in combination of two or more. The metal source preferably contains an oxide or carbonate of an alkaline earth metal (for example, calcium oxide, barium oxide, or barium carbonate), and more preferably contains calcium oxide. Calcium oxide (CaO) is, for example, calcium carbonate (CaCO ３It is an unstable substance obtained by thermal decomposition of ) at approximately 900°C. For this reason, calcium oxide is suitable as a metal source due to its high reactivity. Suitable metal carbides include calcium carbide, barium carbide, and magnesium carbide.

[0032] <<Heating Process>> Next, the mixture of the fixed carbon source and the metal source is placed in a heating furnace and heated. This causes the fixed carbon source and the metal source to react to obtain metal carbide. The heating temperature is not particularly limited, but is preferably between 1700°C and 2200°C, and more preferably between 1900°C and 2100°C. The heating time is also not particularly limited, but when the above heating temperatures are used, it is preferably between 2 minutes and 3 hours, and more preferably between 30 minutes and 1.5 hours. By heating under these conditions, the reaction between the fixed carbon source and the metal source can be sufficiently carried out.

[0033] The heating atmosphere is preferably an inert gas atmosphere such as an argon gas atmosphere. This prevents the rapid combustion (consumption) of the fixed carbon source and the unwanted combustion of carbon monoxide and hydrogen generated during the reaction between the fixed carbon source and the metal source. The amount of the fixed carbon source is preferably 30 to 400 parts by mass, more preferably 50 to 300 parts by mass, and even more preferably 70 to 200 parts by mass, per 100 parts by mass of the metal source. By reacting in such a ratio, the yield of metal carbide can be sufficiently increased. The fixed carbon source and the metal source are preferably in particulate form. This increases the contact area between the fixed carbon source and the metal source, thereby improving their reaction efficiency.

[0034] The average particle diameter of the fixed carbon source is not particularly limited, but is preferably about 8 mm to 50 mm, more preferably about 8 mm to 30 mm, and even more preferably about 8 mm to 10 mm. Similarly, the average particle diameter of the metal source is not particularly limited, but is preferably about 8 mm to 50 mm, more preferably about 8 mm to 30 mm, and even more preferably about 8 mm to 10 mm. In this specification, the average particle diameter refers to the particle diameter (D50) when the cumulative value in the volume-based cumulative particle size distribution obtained by laser diffraction scattering reaches 50%. The laser diffraction scattering method is measured in accordance with the method described in JIS Z 8825:2013 "Particle size analysis - Laser diffraction and scattering method".

[0035] Prior to the main heating described above, preheating may be performed by heating the mixture at a temperature lower than the main heating temperature. By performing such preheating, the amount of fixed carbon source consumed during the main heating can be reduced, and the yield of metal carbide can be further increased. Examples of fuel for preheating include the gas emitted during the main heating (a mixture of carbon monoxide and hydrogen). By using this gas as fuel for preheating, energy can be effectively utilized while effectively preventing air pollution.

[0036] Furthermore, the heating process may include a recovery step for a gas containing at least carbon monoxide and hydrogen generated in the heating furnace. That is, the acetylene production method may further include a recovery step for recovering a gas containing at least one of carbon monoxide and hydrogen. The recovered carbon monoxide and hydrogen may be used, for example, as an energy source when converting calcium carbonate to calcium oxide, or as an energy source when converting metal carbide to acetylene, and may be used to convert carbon compounds. In the latter case, the acetylene production method may further include a reaction step for reacting at least carbon monoxide and hydrogen to obtain a carbon compound. This makes it possible to effectively utilize the gas generated in the metal carbide production process. Examples of such carbon compounds include acrylic acid, olefins (jet fuel), and acetylene black.

[0037] <<Reaction Step>> Next, the metal carbide is reacted with water. This yields acetylene. The amount of water added is preferably 2 moles to 10 moles per mole of metal carbide, and more preferably 2.5 moles to 5 moles. This allows the reaction between the metal carbide and water to proceed sufficiently. The holding temperature during the reaction between the metal carbide and water is preferably 80°C to 200°C, and more preferably 100°C to 180°C. By maintaining the reaction temperature within this range, the vaporization of water is effectively prevented, and the reaction with the metal carbide can proceed sufficiently.

[0038] The metal carbide may be in block form, but it is preferable that it be in particulate form. By using particulate metal carbide, the contact area with water can be increased. As a result, the reaction between the metal carbide and water can proceed without excess or deficiency. In this case, the average particle size of the metal carbide is not particularly limited, but it is preferably between 1 mm and 150 mm, and more preferably between 5 mm and 120 mm. In this case, the above effect can be further improved.

[0039] Further, for water, for example, tap water, distilled water, ion-exchanged water, pure water, ultrapure water, RO water, etc. can be used. Since the reaction between the above metal carbide and water is an exothermic reaction, the generated heat may be recovered and used for the reaction between the fixed carbon source and the metal source as described above. Further, slaked lime (calcium hydroxide) produced when calcium carbide is used as the metal carbide can be suitably used, for example, as a cement admixture. By going through the above steps, acetylene with a sufficiently low content of hydrogen phosphide and a sufficiently low content of hydrogen sulfide as described above can be obtained. Further, it may be provided in each of the aspects described below.

[0040] (1) Acetylene containing carbon atoms derived from waste, containing at least one of hydrogen phosphide and hydrogen sulfide, wherein the content of hydrogen phosphide is 5 ppm or less and the content of hydrogen sulfide is 5 ppm or less.

[0041] (2) The acetylene according to (1) above, wherein the content of hydrogen phosphide is 0.1 ppm or more and the content of hydrogen sulfide is 0.1 ppm or more.

[0042] (3) The acetylene according to (1) or (2) above, wherein the waste contains at least one of waste plastic, waste rubber, and waste carbon fiber.

[0043] (4) The acetylene according to (3) above, wherein the waste plastic is at least one selected from the group consisting of polyethylene, polystyrene, polypropylene, polyvinyl chloride, phenol resin, polyacetal, polycarbonate, polyamide, modified polyphenylene ether, polyether ether ketone, polyether sulfone, polyether imide, polyphenylene sulfide, polysulfone, liquid crystal polymer, polyethylene terephthalate, and polybutylene terephthalate.

[0044] (5) Acetylene according to (3) or (4) above, wherein the waste rubber is at least one selected from the group consisting of natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, butyl rubber, acrylonitrile-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, acrylic rubber, fluororubber, silicone rubber, urethane rubber, and epichlorohydrin rubber.

[0045] (6) Acetylene according to any one of (3) to (5) above, wherein the waste further comprises at least one of glass and silica sand.

[0046] (7) A method for producing acetylene, comprising: a preparation step of preparing a fixed carbon source containing combustion residue of waste and a metal source; a heating step of heating the fixed carbon source and the metal source in a heating furnace to obtain metal carbide; and a reaction step of reacting the metal carbide with water to obtain acetylene.

[0047] (8) A method for producing acetylene as described in (7) above, wherein the metal source includes an oxide or carbonate of an alkaline earth metal.

[0048] (9) A method for producing acetylene according to (7) or (8) above, further comprising a recovery step of recovering a gas containing at least one of carbon monoxide and hydrogen.

[0049] (10) A method for producing acetylene as described in (9) above, further comprising a reaction step of reacting at least the carbon monoxide with the hydrogen to obtain a carbon compound.

[0050] (11) A method for producing acetylene according to any one of (7) to (10) above, wherein the crush strength of a sample of the fixed carbon source molded to a size of 35 mm × 35 mm × 10 mm is 10 kgf or more, as measured according to JIS Z 8841:1993.

[0051] (12) A method for producing acetylene according to any one of (7) to (11) above, wherein the fixed carbon source has a volatile content of 5% by mass or less as measured in accordance with JIS M 8812:2006.

[0052] (13) A method for producing acetylene according to any one of (7) to (12) above, wherein the fixed carbon source contains carbon atoms derived from the combustion residue of waste and silicon atoms, and the content of silicon atoms is 10% by mass or less.

[0053] (14) A method for producing acetylene as described in (13) above, wherein the fixed carbon source has a silicon atom content of 0.1 ppm or more.

[0054] (15) An acetylene derivative which is a modified acetylene according to any one of (1) to (6) above.

[0055] (16) The acetylene derivative described in (15) above, wherein the acetylene derivative is at least one selected from the group consisting of ethylene, acrylonitrile, vinyl chloride, acrylic acid, acrylic acid ester, and monovinylacetylene. Of course, this is not limited to this.

[0056] Finally, while various embodiments relating to this disclosure have been described, these are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0057] The following describes acetylene and methods for producing acetylene in more detail using the following examples and comparative examples, but these are not limited to the following examples.

[0058] 1. Preparation of raw materials <Stable carbon sources> <<Stable carbon sources A to O>> First, 1 kg of waste (see Table 1 below) containing at least one of waste plastic, waste rubber, and waste carbon fiber, and in a specified example, glass, was crushed and then dried as a pretreatment. After that, carbonization treatment was carried out at approximately 1000°C under a nitrogen atmosphere for 1 hour using a high-temperature vacuum atmosphere furnace (Hirochiku Co., Ltd., "CVF-2030"). This yielded stable carbon sources A to O containing the combustion residue of the waste. Stable carbon sources A to O were then crushed and separated using a sieve so that the average particle size was approximately 10 mm before use.

[0059] <<Steady Carbon Sources P-R>> First, 1 kg of waste plastic (see Table 1 below) was melted and poured into a 10 cm x 10 cm x 10 cm mold, followed by cooling and drying as a pretreatment. Then, sitting carbon sources P-R were obtained by carbonization treatment similar to that of sitting carbon sources A-O. Sifty carbon sources P-R were crushed and separated using a sieve so that the average particle size was approximately 10 mm.

[0060] <<Steady Carbon Source S>> Coke was prepared as the sitdy carbon source S. This coke was crushed and separated using a sieve so that the average particle size was about 10 mm. <Calcium Source (Metal Source)> Calcium oxide (manufactured by Denka Co., Ltd.) with an average particle size of 10 mm was prepared.

[0061] 2. Production of Calcium Carbide (Metal Carbide) and Acetylene (Example 1) First, a mixture was obtained by mixing 100 parts by mass of a fixed carbon source A with 195 parts by mass of calcium oxide as a calcium source. Next, this mixture was placed in a high-temperature vacuum atmosphere furnace (Hirochiku Co., Ltd., "CVF-2030") and heated at 2000°C for 30 minutes while flowing argon at a rate of 7 L / hr. This obtained calcium carbide. The average particle size of the obtained calcium carbide was 10 mm. Subsequently, acetylene was produced by adding 2.5 moles of distilled water per mole of calcium carbide. At this time, the reaction temperature was maintained at 120°C.

[0062] (Examples 2-18) Calcium carbide and acetylene were obtained in the same manner as in Example 1, except that fixed carbon sources B-R were used instead of fixed carbon source A. (Reference Example) Calcium carbide and acetylene were obtained in the same manner as in Example 1, except that fixed carbon source S was used instead of fixed carbon source A.

[0063] 3. Measurement and Evaluation 3-1. Measurement of phosphorus and sulfur atom content in fixed carbon source The phosphorus and sulfur atom content in the fixed carbon source was measured in accordance with JIS M 8813:2004. 3-2. Measurement of carbon atom content in fixed carbon source The carbon atom content in the fixed carbon source was measured in accordance with JIS M 8812:2006.

[0064] 3-3. Measurement of crushing strength A fixed carbon source was molded to a size of 35 mm × 35 mm × 10 mm to obtain a sample. The crushing strength of this sample was measured according to JIS Z 8841:1993.

[0065] 3-4. Measurement of Volatile Content The volatile content of the fixed carbon source was measured in accordance with JIS M 8812:2006. 3-5. Measurement of Oxygen, Phosphine, and Hydrogen Sulfide Content in Acetylene The oxygen content in acetylene was measured by gas chromatography-mass spectrometry using an Agilent 7820A GC system (manufactured by Agilent Technologies, Inc.) employing a TCD detector. In addition, the content (volume fraction) of phosphine and hydrogen sulfide was measured using a UV-1800 (manufactured by Shimadzu Corporation) in accordance with the absorbance spectrophotometric method described in JIS K 1901:2003 5.4.1.

[0066] These results are shown in Tables 1 and 2 below.

[0067]

[0068] The abbreviations in Tables 1 and 2 are as follows: PP: Polypropylene PE: Polyethylene PS: Polystyrene PF: Phenolic resin CR: Chloroprene rubber vulcanized product NBR: Nitrile rubber vulcanized product P-rich: Waste containing a large amount of phosphorus atoms SM-CR: Sulfur-modified chloroprene rubber vulcanized product

[0069] As shown in Tables 1 and 2, the oxygen, phosphine, and hydrogen sulfide content in the acetylene obtained in each example was equivalent to or lower than that of the reference example, confirming that it is possible to produce acetylene that can be safely used.

Claims

1. Acetylene containing carbon atoms derived from waste, comprising at least one of phosphine and hydrogen sulfide, wherein the volume fraction of phosphine is 0.1% or less and the volume fraction of hydrogen sulfide is 0.2% or less.

2. Acetylene according to claim 1, wherein the volume fraction of hydrogen phosphine is 0.1 ppm or more, and the volume fraction of hydrogen sulfide is 0.1 ppm or more.

3. Acetylene according to claim 1, wherein the waste comprises at least one of waste plastics, waste rubber, and waste carbon fibers.

4. Acetylene according to claim 3, wherein the waste plastic is at least one selected from the group consisting of polyethylene, polystyrene, polypropylene, polyvinyl chloride, phenolic resin, polyacetal, polycarbonate, polyamide, modified polyphenylene ether, polyetherether ketone, polyethersulfone, polyetherimide, polyphenylene sulfide, polysulfone, liquid crystal polymer, polyethylene terephthalate, and polybutylene terephthalate.

5. Acetylene according to claim 3, wherein the waste rubber is at least one selected from the group consisting of natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, butyl rubber, acrylonitrile-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, acrylic rubber, fluororubber, silicone rubber, urethane rubber, and epichlorohydrin rubber.

6. The acetylene according to claim 3, wherein the waste further comprises at least one of glass and silica sand.

7. A method for producing acetylene, comprising: a preparation step of preparing a fixed carbon source containing combustion residue of waste and a metal source; a heating step of heating the fixed carbon source and the metal source in a heating furnace to obtain metal carbide; and a reaction step of reacting the metal carbide with water to obtain acetylene.

8. A method for producing acetylene according to claim 7, wherein the metal source comprises an oxide or carbonate of an alkaline earth metal.

9. A method for producing acetylene according to claim 7 or claim 8, further comprising a recovery step of recovering a gas containing at least one of carbon monoxide and hydrogen.

10. A method for producing acetylene according to claim 9, further comprising a reaction step of reacting at least the carbon monoxide with the hydrogen to obtain a carbon compound.

11. A method for producing acetylene according to claim 7 or claim 8, wherein the crushing strength of a sample of the fixed carbon source molded to a size of 35 mm × 35 mm × 10 mm is 10 kgf or more, as measured according to JIS Z 8841:1993.

12. A method for producing acetylene according to claim 7 or claim 8, wherein the fixed carbon source has a volatile content of 5% by mass or less as measured in accordance with JIS M 8812:2006.

13. A method for producing acetylene according to claim 7 or claim 8, wherein the fixed carbon source contains carbon atoms derived from the combustion residue of waste and silicon atoms, and the content of silicon atoms is 10% by mass or less.

14. A method for producing acetylene according to claim 13, wherein the fixed carbon source has a silicon atom content of 0.1 ppm or more.

15. An acetylene derivative, which is a modified acetylene according to any one of claims 1 to 6.

16. The acetylene derivative according to claim 15, wherein the acetylene derivative is at least one selected from the group consisting of ethylene, acrylonitrile, vinyl chloride, acrylic acid, acrylic acid ester, and monovinylacetylene.

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