Abstract:
A reactor vessel is provided with a solvent in a supercritical PVT state for use in depositing films on a deposition substrate. A metal organic precursor is dissolved in the supercritical solvent, as is a reaction agent. A chemical reaction deposits a film, such as a metal film on a semiconducting wafer, and reaction byproducts including a ligand ensue from the chemical reaction. Effluent from the reactor vessel is submitted to a precursor-forming agent that reacts with the ligand to rejuvenate the precursor. Alternatively, the precursor-forming agent can be used for point-of-use formation of the precursor with or without recycle of reaction byproducts.
Abstract:
The invention provides a method for forming particles of a target substance (26), involving: (a) preparing a solution or suspension of the substance in a vehicle (21) which is or includes either a near-critical fluid (21) or a first supercritical fluid; (b) introducing the solution or suspension into a particle formation vessel (32); and (c) contacting the solution or suspension, in the particle formation vessel, with a second super-critical fluid, under conditions which allow the second supercritical fluid to cause precipitation of particles of the target substance from the solution or suspension; wherein the second supercritical fluid is miscible or substantially miscible with the vehicle and is a fluid in which the target substance is insoluble or substantially insoluble. Also provided is apparatus for use in carrying out an embodiment of the method, including a particle formation vessel and means for controlling the temperature and pressure inside it; a fluid mixing vessel and means for controlling the temperature and pressure inside it; first fluid inlet means for introducing into the fluid mixing vessel a vehicle and a solution of a target substance in a primary solvent, so as to form in the fluid mixing vessel a solution of the substance and the primary solvent in the vehicle; and second fluid inlet means for introducing the solution thus formed, preferably together with a second supercritical fluid, into the particle formation vessel. The invention also provides a particulate product formed using the method.
Abstract:
A system and method for performing hydrothermal treatment includes reactor vessel formed with a pressure bearing wall surrounding a reactor chamber. A liner protects the wall from exposure to temperature extremes, corrosives and salt deposits. The liner is formed with three layers: a non-porous, corrosion resistant primary layer; a porous layer; and a non-porous, secondary layer. The porous layer is sealed between the primary layer and the secondary layer. The liner is positioned in the reactor chamber with the secondary layer facing the pressure bearing wall of the reactor chamber and the primary layer facing the reactor chamber. Connectors extend through the wall of the reactor vessel and the secondary layer to allow a fluid to be pumped through the porous layer to maintain the temperature of the liner. The connectors also allow for sampling of the fluid within the porous layer to detect leaks in the primary layer.
Abstract:
Improved methods for conducting solid acid-catalyzed, near- or supercritical heterogeneous chemical reactions (e.g., alkylation reactions) are provided which give enhanced product yields and permit longer processing runs. The preferred reactions of the invention are carried out in the presence of a solid macroporous catalyst having a surface area of from about 50-400 m2/g and a pore size of from about 70-150 null. Product selectivity is enhanced by pressure-tuning of the reaction to promote production and separation of desired reaction products. In continuous processing, the chemical reaction may be interrupted before significant catalyst deactivation, followed by increasing reactor pressure and/or reducing reactor temperature to remove the accumulating coke; when the catalyst is regenerated, the original reaction conditions and reactant introduction may be resumed.
Abstract:
A method and apparatus for fabricating and drying wafers, including micro-electro-mechanical system (MEMS) structures, in a second, supercritical processing fluid environment. The apparatus utilizes an inverted pressure vessel connected to a supercritical processing fluid supply and recover system, with an internal heat exchanger connected to external heating and cooling sources, which is closed with a vertically movable base plate. A wafer cassette configured for supporting multiple wafers is submerged in a first processing fluid within a container, which is installed on the base plate for insertion into the pressure vessel. Vessel inlet and outlet tubes extend vertically downward from the ceiling of the pressure vessel to nearly the base plate. Container inlet and outlet tubes extend vertically downward from the ceiling of the pressure vessel to inside the container and nearly to the bottom of the container. The tubes provide for displacement of the first processing fluid with the second processing fluid still in a liquid state, from which it is raised to supercritical state.
Abstract:
An inverted pressure vessel system for conducting automated industrial processes requiring elevated pressure and temperatures has a vertically movable pedestal for opening and closing the underside loading port, with pedestal drive system and locking mechanism located below the pedestal top and isolated from the chamber opening. The chamber is connectible to a pressure control and process fluid supply system, and has heat exchangers connected to an external source for temperature control. Process fluids are distributed across a central process cavity through divergent inflow and convergent outflow process fluid channels.
Abstract:
For conversion of harmful compound in contaminated liquid into harmless compound by use of reactant, a plurality of agitators are arranged in a vertical superposition within a closed agitation chamber and, after the contaminated liquid is charged into the agitation chamber, the agitators are driven for rotation at a high speed in a rage from 10,000 to 18,000 rpm in order to create a field of super critical conditions in which free radicals are liberated from the harmful compound and coupled by the reactant. Neither high temperature heating nor high level pressurization is needed for processing of the contaminated liquid.
Abstract:
A reaction product is formed and transferred from an autoclave to a receiving vessel at a laminar flow rate, using a self-adjusting transfer mechanism. A specific amount of water in the receiving vessel is heated and vaporized prior to the reaction product transfer to raise the pressure in the receiving vessel to saturation pressure. A flow passage between the autoclave and the receiving vessel is now opened, and a resulting pressure differential between the autoclave and the receiving vessel initiates the transfer process. A heat exchanger cools the reaction product flowing from the autoclave to the receiving vessel, where the amount of cooling is dependent upon the transfer rate of the reaction product. An increased transfer rate will cause the hotter reaction product entering the receiving vessel to increase the pressure inside the receiving vessel, thereby reducing, or self-adjusting, the transfer rate. The heat exchanger may also generate steam which is fed into the receiving vessel to adjust the pressure in the receiving vessel and thus adjust the transfer rate of the reaction product.
Abstract:
A system (10) and method for hydrothermal treatment of a feed material (11) includes a reaction chamber (14) in a reactor (12). Importantly, an additive (16) is added with the feed material (11) to the reaction chamber (14). The additive (16) causes a reaction medium (18) in the reaction chamber (14) to include phosphate compounds. The phosphate compounds allow precipitating salts to be transported through the reactor (12) without plugging and inhibiting the build-up of precipitating salts in the reaction chamber (14).
Abstract:
A system for pressurizing a propylene polymerization reactor includes: a pressurization vessel including an internal heat exchanger; a pressure sensor for monitoring the pressure in the vessel, the pressure sensor providing a signal indicative of the pressure in the vessel; a control valve for supplying heated gas to a first region of the vessel in response to signals from the pressure sensor, the first region of the vessel being maintained above the critical temperature and pressure of propylene; a temperature sensor for monitoring the temperature in a second region of the pressurization vessel, the temperature sensor providing a signal indicative of the temperature in the second region of the vessel; and a control valve for supplying a cooling medium to the internal heat exchanger to cool propylene in the second region below the critical temperature of propylene at the pressure in the pressurization vessel.