85 results about "Sulfide production" patented technology

A method for producing polyphenylene sulfide (PPS) polymer, including polymerizing reactants in a reaction mixture in a vessel to form PPS polymer in the vessel, measuring values of operating variables of the vessel and / or PPS process, and determining the amount of quench fluid to add to the vessel based on the values of the operating variables. The technique may rely on the vapor liquid equilibrium (VLE) of the mixture to calculate the concentration of water existing in the reactor prior to quench, and accounts for the effectiveness of the upstream dehydration process and in the amount of water produced during the polymerization. The technique is a striking improvement over the trial-and-error estimation of the amount of quench water based on human operating experience, and avoids direct measurements of the existing water concentration in the reactor. The result is improved control of PPS particle size and other properties.

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.

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.

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 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.

The invention discloses a recovering method of a by-product sodium chloride in polyphenylene sulfide production. The method comprises the steps that: (1) impurities are removed by absorption, wherein a water solution containing sodium chloride is added into a collection tank and is stirred and mixed, a temperature is controlled at 55-65 DEG C, active carbon is added, the mixture is well mixed by stirring, and absorption is carried out for 25-35min; (2) solid-liquid separation is carried out, wherein the mixed liquid obtained in the step (1) is filtered, and active carbon and sodium chloride aqueous solution are obtained by separation; and (3) concentration and crystallization are carried out, wherein the sodium chloride aqueous solution obtained in the step (2) is injected into a multi-effect distillation system for concentration, solid-liquid separation is carried out after sodium chloride is precipitated, and sodium chloride crystals are obtained. In the above method, the active carbon used for absorption can be recovered and repeatedly used, such that resource is not wasted. Multi-effect distillation is adopted, such that energy consumption can be greatly reduced. The appearance and content of the recovered sodium chloride satisfy industrial sodium chloride standards, and provide a certain economic benefits. Further, adverse influences of sodium chloride to the environment can be avoided.