Mixing Reactor and Related Process

Abstract

A mixing reactor ( 10 ) for precipitating nanoparticles by mixing a precursor fluid with a second fluid at a higher temperature than the precursor fluid. The reactor comprises: a first fluid conduit ( 1 ) with an inlet region ( 3 ) configured to receive a flow of the precursor fluid, and an outlet region ( 4 ) configured to output a mixed flow; and a second fluid conduit ( 2 ) configured to receive a flow of the second fluid. The second fluid conduit ( 2 ) extends into the first fluid conduit ( 1 ) in a direction substantially perpendicular to the flow within the first fluid conduit, and has an opening ( 5 ) for introducing the second fluid into the first fluid conduit. Related processes for producing nanoparticles are disclosed.

1 . A mixing reactor for precipitating nanoparticles by mixing a precursor fluid with a second fluid at a higher temperature than the precursor fluid, wherein the reactor comprises: a first fluid conduit with an inlet region configured to receive a flow of the precursor fluid, and an outlet region configured to output a mixed flow; and a second fluid conduit configured to receive a flow of the second fluid, the second fluid conduit extending into the first fluid conduit in a direction substantially perpendicular to the flow within the first fluid conduit, and having an opening for introducing the second fluid into the first fluid conduit. 
     
     
         2 . The mixing reactor according to  claim 1 , wherein the inlet region is substantially co-axial with the outlet region 
     
     
         3 . The mixing reactor according to  claim 1 , configured such that flow in both the inlet region and outlet region is in an upward, substantially vertical direction. 
     
     
         4 . The mixing reactor according to  claim 1 , wherein the inlet region has a single inlet port for receiving the precursor fluid. 
     
     
         5 . The mixing reactor according to any preceding  claim 1 , wherein the opening faces with the direction of flow through the first conduit. 
     
     
         6 . The mixing reactor according to  claim 1 , wherein the opening faces against the direction of flow through the first conduit. 
     
     
         7 . The mixing reactor according to  claim 1 , wherein the opening faces substantially perpendicular to the direction of flow through the first conduit. 
     
     
         8 . The mixing reactor according to  claim 1 , wherein the first conduit has a substantially uniform cross section. 
     
     
         9 . The mixing reactor according to  claim 8 , wherein the first conduit comprises a former adapted to fill a recess in the first conduit, the former thereby at least partially defining the uniform cross section. 
     
     
         10 . The mixing reactor according to  claim 1 , wherein the second fluid conduit extends across the full width of the first fluid conduit. 
     
     
         11 . The mixing reactor according to  claim 10 , wherein the second fluid conduit extends through the first fluid conduit and is configured to flow the second fluid towards the opening from two opposite directions. 
     
     
         12 . The mixing reactor of  claim 1 , wherein the opening introduces the second fluid directly into a central flow region of the first fluid conduit. 
     
     
         13 . The mixing reactor of  claim 12 , wherein the first fluid conduit has a circular cross section, and the second fluid is introduced on a central axis of the first fluid conduit. 
     
     
         14 . The mixing reactor according to  claim 1 , wherein the second fluid is introduced at a plurality of regions in the cross section of the first fluid conduit, said regions being rotationally symmetric about a central axis of the first conduit. 
     
     
         15 . The mixing reactor of  claim 1 , wherein the opening is defined through a sidewall of the second fluid conduit. 
     
     
         16 . The mixing reactor according to  claim 1 , wherein the second fluid conduit comprises a plurality of openings. 
     
     
         17 . The mixing reactor according to  claim 16 , wherein the openings are spaced axially along the second fluid conduit. 
     
     
         18 . The mixing reactor according to  claim 16 , wherein the openings are spaced circumferentially around the fluid conduit. 
     
     
         19 . The mixing reactor according to  claim 1 , wherein the reactor comprises a T-piece with a two opposite ports, and a third side-port, wherein the first fluid conduit comprises a region between the opposite ports, and the second fluid conduit is introduced via the side-port. 
     
     
         20 . The mixing reactor according to  claim 1 , wherein the reactor comprises a cross piece with a first pair of opposite ports and a second pair of opposite ports, the first pair being at 90 degrees to the second pair, wherein the first fluid conduit comprises a region between the first pair of ports, and the second fluid conduit is introduced through the second pair of ports. 
     
     
         21 . The mixing reactor according to  claim 1 , wherein the profile of the second conduit is adapted to improve mixing downstream of the second conduit. 
     
     
         22 . The mixing reactor according to  claim 21 , wherein a profile of the second conduit is adapted by a former attached thereto. 
     
     
         23 . The mixing reactor according to  claim 22 , wherein the former tapers away from the second fluid conduit so that is narrower in an upstream direction. 
     
     
         24 . The mixing reactor according to  claim 21 , wherein the former extends the profile of the second conduit in a direction perpendicular to flow through the first conduit. 
     
     
         25 . The mixing reactor according to  claim 1 , wherein a heater or a cooler is provided around the outlet region to control the temperature of the mixed fluid. 
     
     
         26 . The mixing reactor according to  claim 1 , wherein a heater is provided around the second conduit to provide heat to the second fluid. 
     
     
         27 . The mixing reactor according to  claim 1 , wherein the inlet region comprises a heater or cooler to control the temperature of the precursor fluid. 
     
     
         28 . The mixing reactor according to  claim 1 , further comprising an inlet port in the outlet region for receiving a third fluid. 
     
     
         29 . The mixing reactor according to  claim 28 , wherein the inlet port is configured to receive a quenching fluid. 
     
     
         30 . The mixing reactor according to  claim 1 , wherein the inlet region comprises a mixing device. 
     
     
         31 . The mixing reactor according to  claim 1 , wherein the second fluid comprises superheated water. 
     
     
         32 . The mixing reactor according to  claim 1 , wherein the precursor fluid comprises an aqueous solution of a metal salt. 
     
     
         33 . (canceled) 
     
     
         34 . A method for preparing nanoparticles by flowing a precursor fluid into a mixing reactor through a first fluid conduit, introducing a second fluid to the first fluid to the first fluid conduit via a second fluid conduit which extends into the first fluid conduit in a direction substantially perpendicular to the direction of flow in the first fluid conduit. 
     
     
         35 . (canceled) 
     
     
         36 . The method according to  claim 34 , wherein the nanoparticles comprise metal and/or metal oxide. 
     
     
         37 . (canceled) 
     
     
         38 . A process of producing nanoparticles comprising: flowing a precursor fluid upwards in a cylindrical precursor fluid pipe and introducing a flow of supercritical fluid into the flow of precursor fluid through a supercritical fluid pipe substantially perpendicular to the precursor fluid flow, at a point on the central axis of the flow of the precursor fluid, or at point disposed around the central axis of flow with rotational symmetry, the supercritical fluid being introduced in a co-current flow, at right angles to the direction of flow of the precursor, or in a direction that has a co-current component; allowing the precursor and supercritical fluid flows to mix and react to produce nanoparticles. 
     
     
         39 . The process of  claim 38 , wherein the second pipe extends completely across a direction of the precursor pipe. 
     
     
         40 . The process of  claim 38 , wherein a flow controller is provided associated with the supercritical fluid pipe and upstream of the central axis of the supercritical pipe, controlling fluid flow of precursor around the supercritical fluid pipe so as to achieve more uniform mixing than if no fluid controller were present. 
     
     
         41 . Nanoparticles produced by the method or process of  claim 38 .