A stirrer includes a magnetic bar and a microwave absorbing layer around the magnetic bar. The stirrer absorbs a microwave and converts the microwave to thermal energy to heat the mixed solution reactant.

The present invention relates to the reduction of materials at low temperatures (<600° C.) by means of microwave radiation without needing to use chemical reducing agents or electrical contacts. It relates more specifically to a method for reducing a material, which comprises the following steps: applying microwave radiation to a material disposed in a microwave application cavity; and separating simultaneously the fluid oxidation products generated from the reduced material,
such that the method is carried out without chemical reducing agents or electrical contacts.

Synthesizing upconverting nanoparticles includes heating a precursor solution comprising one or more rare earth salts, an alkali metal salt or alkaline earth salt, and a solvent comprising a plasticizer in a microwave reactor to yield a product mixture, and cooling the product mixture to yield the upconverting nanoparticles. Core-shell upconverting nanoparticles are synthesized by combining the upconverting nanoparticles with a precursor solution comprising one or more rare earth salts, an alkali metal salt or alkaline earth salt, and a solvent comprising a plasticizer to yield a nanoparticle mixture, heating the nanoparticle mixture in a microwave reactor to yield a product mixture, and cooling the product mixture to yield the core-shell upconverting nanoparticles.

A large capacity natural material composition conversion apparatus using a microwave with a preset pressure function includes a chamber including a sealed reaction space accommodating a material, an radiator configured to heat the material by radiating a microwave into the reaction space, a pressure regulator configured to regulate a pressure of the reaction space by supplying a gas into the reaction space, and a controller configured to control the pressure regulator and the radiator, and preliminarily increase a pressure of the reaction space by controlling the pressure regulator before heating the material.

A system for processing rubber material pre-heats the material and then applies microwave energy to process the system The system comprising a rubber material receiver for accepting the rubber material which passes the material to a pre-heating unit adapted for the rubber material passing through comprising a plurality of heating elements that heat the rubber material to between about 100 to about 350 C in an oxygen depleted atmosphere. Once pre-heated, the material is conveyed to a microwave unit adapted for receiving the pre-heated rubber material comprising microwave magnetrons, which radiate the pre-heated rubber material and external heat sources in an oxygen depleted environment until the pre-heated rubber is substantially reduced to a carbonaceous material having a volatile content of below 5% and more preferably below 2%. After being processed by microwave energy, the processed material exits on a cooling conveyor that receives processed rubber material from the microwave unit and cools the material in an oxygen depleted environment. One or more conveyors are used to transport the rubber material from the rubber material receiver into and through the pre-heating unit and into and through the microwave unit to the cooling conveyor.

This invention provides an innovative method to manufacture graphene layers or quantities and graphene oxide layers or quantities from graphite, coal slags, asphalt, and other carbon-rich sold materials in nature. The present invention uses controllable microwave irradiation to heat the mixtures of basic material, graphite, or coal slags, or asphalt, or their combinations with ionic liquids and surfactant plus environmentally friendly oxidation agents. This invention can generate the said-products of graphene layers and graphene oxides in a short time period of one second to 300 seconds. The present invention does not involve any concentrated sulfuric acid, nitric acid, nor huge water quantities needed for the purification, unlike the prior art. The as-produced graphene-based materials can be used for preparing conductive films for touch screens, producing graphene carbon fibers and three-dimensional porous graphene nanomaterials, and preparing graphene-based other intelligent nanocomposites for super-light-weight machines and vehicles.

There is described a microwave pyrolysis process for the depolymerization of plastic for the production of monomers, waxes and heavy oils including the steps of: a) steam purge of the plastic from about 0.5% to about 50% w/w of a catalyst, in a media; b) pyrolysis of the plastic and the catalyst in the media with a microwave (MW) for a time sufficient to allow generation of heat providing a thermal treatment between 300° C. and 650° C. through absorption of microwaves by the catalyst and the media. The catalyst includes a compound having a high dielectric loss at the frequency of the MW to absorb microwaves, transfer heat to the plastic and initiate a pyrolysis reaction.

The present invention provides a microwave pyrolysis reactor (1) comprising an inner pipe element (2) and a housing (4), wherein the inner pipe element (2) is made of a microwave transparent material and is arranged within the housing and comprises a first open end (5) and a second open end (6); the housing (4) comprises a first inner surface, enclosing an annular space (7,44) around the inner pipe element (2), a waste inlet (10), a solids outlet (11), a gas outlet (12), and a port (13) for a microwave waveguide (14), the waste inlet and the solids outlet are in communication with the first open end and the second open end of the inner pipe element, respectively, and the port for a microwave waveguide is in communication with the annular space; the inner pipe element, the waste inlet and the solids outlet of the housing form parts of a conduit not in fluid communication with the annular space around the inner pipe element and wherein the inner pipe element is clamped within the housing via a cylinder-shaped resilient assembly (54) arranged at at least one of the first open end (5) and the second open end of the inner pipe element, the resilient assembly is adapted to allow longitudinal expansion of the inner pipe element (2) and comprises a central through-going passage (57) having a centerline in line with a centerline (C) of the inner pipe element.

Apparatus for plasma synthesis of carbon nanotubes, comprising: a plasma nozzle coupled to a reaction tube or chamber; means for supplying a process gas to the plasma nozzle, the process gas comprising a carbon-containing species; means for supplying radio frequency radiation to the process gas within the plasma nozzle, so as to sustain a plasma within the nozzle in use, and thereby cause cracking of the carbon-containing species; and means for providing a catalyst; wherein the plasma nozzle is arranged such that an afterglow of the plasma extends into the reaction tube/chamber, the cracked carbon-containing species also pass into the reaction tube/chamber, and the cracked carbon-containing species recombine within the afterglow, so as to form carbon nanotubes in the presence of the catalyst. A method of plasma-synthesising carbon nanotubes is also provided.

This invention describes large microwave/radiofrequency (RF/MW) heating equipments scalable to any size heated with RF/MW heating systems employing multiple magnetrons independent of its wave characteristics arranged in a particular fashion to avoid wave interferences and concentrated heating without turn tables. The invention also explains the various embodiments of the invention like solvent dehydration and solvent recovery using the above mentioned invention.