84 results about "Sulfide production" patented technology

Applicants have created a method and system of deep sea mining comprising mining SMS deposits from the sea floor with a subsea miner, pumping the solids from the subsea miner through a jumper and pumping the solids from the jumper up a riser to a surface vessel. Further, applicants have created a method of deploying a deep sea mining system, comprising stacking a riser hangoff structure on top of a subsea pump module forming an assembly; picking up the assembly by a hanging mechanism, hanging the assembly on a moon pool, attaching a first riser joint; disconnecting the riser hangoff structure from the assembly; and attaching at least one second riser joint to form the riser.

The invention relates to a separation and recovery method for n-methylpyrrolidone (NMP) and a lithium chloride catalyst during polyphenylene sulfide producing. The method is characterized by: directly carrying out vacuum distillation for a polyphenylene sulfide polycondensation mother liquid until the polyphenylene sulfide polycondensation mother liquid is dried to recover a solvent of the NMP, wherein the NMP can be used in the next recycling production; adding water to the distilled residues, then heating to a temperature of 40 DEG C, carrying out stirring and completely dissolving the distilled residues, carrying out filtering and washing the filter residues, mixing the resulting filtrate and the washing solution, and analyzing lithium content in the mixed solution; adding the mixed solution to a phosphoric acid solution or a sodium aluminate solution, wherein the phosphoric acid solution or the sodium aluminate solution has a lithium reaction equivalent of 105-115%, then completely stirring to enable lithium phosphate or lithium aluminate to be precipitated completely, then carrying out steps of filtering, washing, drying for the lithium phosphate or the lithium aluminate to recover the lithium salt having a purity more than 97%. According to the present invention, the operation of the method is simple; the cost is low; the recovered NMP and the recovered lithium salt havehigh purities.

Biogenic sulfide production is synergistically inhibited by treating sulfate-reducing bacteria (SRB) with a biocide and a metabolic inhibitor. The biocide directly kills a first portion of the SRB. The metabolic inhibitor inhibits sulfate-reducing growth of a second portion of the SRB without directly killing the second portion of the SRB. The treatment of SRB with both a biocide and a metabolic inhibitor provides effective biogenic sulfide inhibition at significantly lower concentrations than would be required if the biocide or metabolic inhibitor was used alone.

The invention discloses a novel continuous recycling method of an NMP (N-methyl pyrrolidone) solvent for a polyphenylene sulfide production device. The polyphenylene sulfide production device comprises three vacuum rectifying towers, a heat exchanger, a centrifuge machine, a storage tank, a pump and relevant pipelines. In an existing polyphenylene sulfide solvent recycling process, pipelines are easily blocked by salt crystals in a dehydration process, so that the halt maintenance needs to be frequently carried out, the rate of equipment utilization is low, and the solvent loss is high. According to the novel continuous recycling method of the NMP (N-methyl pyrrolidone) solvent for the polyphenylene sulfide production device, a novel technological process device is developed; by virtue of forced circulation of high-concentration salt fraction at the tower bottoms, solid salt formed after water and the solvent are removed can be adequately stirred and circulated, and the blockage, caused by the salt crystals, of valves of the pipelines is avoided, so that the heating efficiency of the column bottoms is increased, the yield of NMP is improved, the quality of an recycled NMP product can reach 99.5% or above, recycling requirements of a system are met, and meanwhile, the long-period, stable and efficient operation of the device are guaranteed.

The invention discloses a method for continuously washing products generated in the process of production of polyphenylene sulfide, which can improve the production efficiency, reduce the energy consumption and provide a stable material flow for subsequent technologies. The method comprises the following steps: firstly, a mixture required to be washed after polymerization is sent into a horizontal helical discharging sedimentation centrifuge for filtration, and separated solid substances, namely coarse products of polyphenylene sulfide resin, are directly sent into a disposable washing kettle; secondly, the coarse products of the polyphenylene sulfide resin are mixed with washing water in the disposable washing kettle, and fully stirred, and enters into a second horizontal helical discharging sedimentation centrifuge for filtration and separation, and separated solid substances are sent into a second washing kettle for secondary washing; and thirdly, washing and centrifugal separation are continuously performed until the purity of the polyphenylene sulfide resin meets the standards, wherein washing and centrifugal separation each time is a washing period.

The present invention provides a production method and a production apparatus for a polyarylene sulfide (PAS), thus the formation of a floating polymer and the leakage of the floating polymer to the outside of the vessel in a washing step are prevented, to achieve steady production of the polymer with high quality, to improve the yield of the polymer and to reduce environmental load, wherein the floating polymer refers to a particles of the polymer which are floating on the surface of a washing solution, in the upper part of the inside of a washing vessel, as a result of the adhesion of a gas onto the surface of the particles of the polymer.

The present invention provides a production method for a PAS comprising step (I), performing polymerization, step (II), separating and collecting a polymer, step (III), washing a slurry, and step (IV), collecting the polymer after washing, wherein an aqueous medium is sprayed onto a PAS floating on the surface of the aqueous washing solution in the upper part of the inside of the washing vessel in step (III) (step (IIIa), washing a slurry using a counter current, and/or step (IIIb), treating a slurry with acid using a counter current, or the like); and a production apparatus for a PAS comprising a washing device (counter current washing device and/or a counter current contact/acid treatment device or the like) having an aqueous medium spray means.

A polyarylene sulfide containing reactive functional groups with a narrow dispersity and low amount of generated gas is produced by heating a cyclic polyarylene sulfide composition in the presence, with respect to 1 mole of arylene sulfide structural units, of 0.1 mole% to 25 mole% of a sulfide compound having reactive functional groups selected from amino groups, carboxyl groups, hydroxyl groups, acid anhydride groups, isocyanate groups, epoxy groups, silanol groups and alkoxysilane groups.

The invention discloses a lithium salt recovery method which comprises the following steps of: firstly, carrying out a sulfohydrogenation reaction between a hydrosulfide and a lithium salt existing in an N-methylpyrrolidinone system in an inert gas environment, thereby converting the lithium salt into lithium hydrosulfide, and then performing solid-liquid separation; after solid-liquid separation, heating a N-methylpyrrolidinone solution containing the lithium hydrosulfide in the inert gas environment and decomposing and converting the lithium hydrosulfide into lithium sulfide precipitate, and collecting the lithium sulfide precipitate after solid-liquid separation. The method has the advantages that the production process is safer and more convenient because no high-risk hydrogen sulfide gas is utilized, and the recovery process is short, the investment is saved, the efficiency is high and the recovery rate of the lithium salt is higher than 99%. As the solvent NMP does not need to be evaporated at a high temperature, high-temperature decomposition of the solvent is also avoided. For polyarylene sulfide production, the lithium salt recovery method is suitable for different preparation processes/routes; and the recovered lithium sulfide can be recycled directly for polyarylene sulfide preparation.

The present invention is a production method for producing polyarylene sulfide, wherein an unreacted dihalo aromatic compound is recovered and reused.

The present invention is a production method for producing polyarylene sulfide, the method include: (a) a polymerization step; (b) a separation step; and (c) a recovery step of recovering an unreacted dihalo aromatic compound from a water-containing mixture in the form of a water-containing liquid mixture containing the separated liquid by steam distillation entailing adjusting the reflux ratio of water in the steam distillation column without adding water other than the refluxed water. Alternatively, the present invention is a production method for producing polyarylene sulfide, the method include: (a) a polymerization step; (d) a dehydration step; and (c) a recovery step of recovering an unreacted dihalo aromatic compound from a water-containing mixture in the form of a water-containing liquid mixture and/or a water-containing steam mixture containing a raw material mixture and/or a polymerization reaction solution by steam distillation entailing adjusting the reflux ratio of water in the steam distillation column without adding water other than the refluxed water in the dehydration step.

The present invention provides a polyarylene sulfide (PAS) production device which suppresses the accumulation of deposits on a baffle (baffle board) or the like disposed inside a reaction vessel via a baffle support for the purpose of enhanced stirring efficiency or the like, thereby contributing to enhanced production efficiency, reduced cost of removing accumulation, and enhanced quality of the PAS product.

The PAS production device of the present invention is a PAS production device provided with a reaction vessel equipped with one or a plurality of baffles; each baffle being supported by one or a plurality of baffle supports provided in a protruding manner on an inside wall of the reaction vessel; and at least one of the baffle supports having one or a plurality of openings preferably passing through the baffle support in the vertical direction.

A method for comprehensive recovery and utilization of lithium containing mixed salts in a polyphenylene sulfide (PPS) production process is disclosed. Na<2>CO3 is added into PPS byproduct slurry, rectification is performed to separate and recover a solvent that is NMP, then obtained lithium containing mixed salts are subjected to dissolution and leaching through an acidic methanol solution, and a wet solid phase and a liquid phase are obtained after pH adjustment and filtration. The wet solid phase is dried, dissolved with water and purified to obtain a refined NaCl solution. The liquid phase is subjected to rectification, ethanol leaching, evaporation, water leaching, purification and evaporative crystallization to obtain a high-purity water-free LiCl product. The method can be used for comprehensive recovery and utilization of the lithium containing mixed salts in the PPS production process. The recovered refined NaCl solution can be directly used for ionic membrane electrolysis to prepare caustic soda, and the LiCl can be directly used as a PPS production auxiliary agent for cyclic use.

The invention discloses a method for recycling NMP (N-Methyl Pyrrolidone) and LiCl in production of polyphenylene sulfide by using a solvent extraction process. The method comprises the following steps: after polyphenylene sulfide production reactions are completed, filtering a reaction mixture through a precise filtering system, adding a certain amount of a solvent into filter residues, performing ultrasonic dissolution, filtering repeatedly, performing distillation on filtrate, respectively recycling the solvent, the NMP and the LiCl, washing the filter residues with a detergent, and respectively collecting a polyphenylene sulfide product and NaCl. Due to adoption of the precise filtering system, cleaning and filtration are implemented for multiple times with the solvent, a polyphenylenesulfide reaction mixed liquid is efficiently separated, the operation is simple, and large-scale industrial application is facilitated.

The invention discloses a recovery and utilization method of highly toxic medium hydrothion waste gas generated in polyphenylene sulfide production. The method includes: adopting waterish sodium sulphide and p-dichlorobenzene as raw materials to be subjected to process steps such as sodium sulphide dehydration and polycondensation to produce polyphenylene sulfide monomers, leading waste gas rich in hydrogen sulfide to be reacted with ammonia water in an alkali liquor absorption tank, leading the reaction product ammonium sulfide to be concentrated to serve as component conditioning agents for polyphenylene sulfide production to be conveyed to a reaction kettle so as to effectively regulate polymerized polyphenylene sulfide resin molecules, wherein the molecular weight distribution coefficient after regulation can keep between 1.91-1.93. After being subjected to ammonium sulfide processing and regulating, content of various metal chloride ions and non-metal chloride ions in the polyphenylene sulfide resin is small, and the total amount of metal ions is 200-300 ppm. By adopting the method, highly toxic medium hydrothion waste gas is treated and good environment protection effect is achieved; and a virtuous closed circle is formed due to the fact that the orginal water gas is converted into production raw materials capable of being reused.

The invention belongs to the field of wastewater treatment, and provides a method for improving bio-availability of sulfur by means of converting the sulfur into polysulfide. The method is characterized in that solid elemental sulfur in an aqueous solution is quickly dissolved and is converted into the polysulfide under normal temperature and normal pressure by means of controlling a pH value and an initial HS<-> concentration, so that the bio-availability of the sulfur is improved. The method disclosed by the invention has the advantages that a synthesis process of dissolved zero-valent sulfur is explained, the biological reduction rate of the elemental sulfur is improved by the dissolved zero-valent sulfur, meanwhile the sulfide production rate is also accelerated, and the synthesis rate of the dissolved zero-valent sulfur is increased with the increasing of the biological reduction rate of the elemental sulfur, therefore a positive feedback reaction among the biological reduction rate of the elemental sulfur, the sulfide production rate and the dissolved zero-valent sulfur is formed under the conditions limited by the method.

A method of producing polyarylene sulfide (PAS) by subjecting a sulfur source and a dihalo aromatic compound (DHA) to polymerization reaction in an organic amide solvent under alkaline conditions, the method suppressing side reactions or the like and yielding PAS having a high degree of polymerization at a high yield is provided; and PAS having a high degree of polymerization are provided.

A method of producing PAS, including: a preparation step of preparing a preparation mixture containing an organic amide solvent, a sulfur source, an alkali metal hydroxide, water, and DHA, and having a pH of 12.5 or higher; a first-stage polymerization step of heating the preparation mixture to 170° C. or higher to initiate a polymerization reaction and continuing the polymerization reaction at 240 to 280° C., thereby forming a prepolymer having a DHA conversion rate of 50% or greater (at this time, a temperature increasing rate from 220° C. to 240° C. is lower than a temperature increasing rate for 240° C. or higher); and a second-stage polymerization step of adding, in the reaction system, an alkali metal hydroxide in an amount of 1 to 20 mol % per 1 mol of the sulfur source in the presence of a phase separation agent to continue the polymerization reaction at 245 to 290° C. PAS having a melt viscosity (310° C.; shear rate: 1216 sec^-1) of 0.1 to 8000 Pa·s produced by the method.

The invention discloses a polyphenylene sulfide production method. The production method comprises the following steps: (1) firstly pumping an NMP solvent and liquid p-dichlorobenzene into a pre-dissolving vessel with a metering pump to carry out pre-dissolving to form a pre-solution, wherein the weight ratio of the NMP solvent to liquid p-dichlorobenzene added to the pre-dissolving vessel is 1 to (1-1.5); (2) then adding the NMP solvent to a reaction kettle with the metering pump, then adding water-containing sodium sulfide and an alkali chloride catalyst to the reaction kettle, then filling nitrogen, raising the temperature to 170-195 DEG C and maintaining the temperature for 20-30 minutes and removing the moisture, wherein the weight ratio of water-containing sodium sulfide to the alkali chloride catalyst to liquid p-dichlorobenzene is 1 to (0.2-0.5) to (1.1-1.3); (3) after dehydration is completed, adding the NMP solvent to the reaction kettle with the metering pump, then heating the materials to 170-195 DEG C and then stopping filling nitrogen; (4) pumping the pre-solution into the reaction kettle with the metering pump; (5) raising the temperature to 280-300 DEG C to carry out condensation polymerization to generate polyphenylene sulfide. The production method has the advantage of quickness and safety in production of polyphenylene sulfide.

The invention discloses a polyphenylene sulfide production wastewater deep treatment method which comprises the following steps: (1) taking polyphenylene sulfide production wastewater, adjusting the pH value to be 7-10, adding PAC and stirring for 30-60 minutes, adding PAM, precipitating, and then taking supernatant liquid; (2) adjusting the pH value of the supernatant liquid to be 4-6, carrying out iron-carbon micro-electrolysis treatment for 2-6 hours, and then taking supernatant liquid; (3) adjusting the pH value of the supernatant liquid to be 7-10, adding PAC and stirring for 30-60 minutes, adding PAM, precipitating, and then taking supernatant liquid; (4) adding active sludge into the supernatant liquid, and then stirring for 6-24 hours, wherein the addition of the active sludge accounts for 20-80% of the weight of the supernatant liquid obtained in the step (3); and (5) carrying out oxygenic aeration for 32-40 hours, and then carrying out centrifugal separation to obtain active sludge and qualified polyphenylene sulfide production wastewater. The polyphenylene sulfide production wastewater deep treatment method has the advantage of treating polyphenylene sulfide production wastewater into qualified industrial wastewater.