Method for Suspending and Introducing Solid Matter in a High-Pressure Process

Abstract

The invention relates to a method for suspending and introducing solid matter in a high-pressure process, for example colorant pigments in a high-pressure process, in which a supercritical fluid is used as the process medium and a pressure in excess of 150 bar prevails. According to the invention, the suspension of the solid matter takes place at a low-pressure in a completely separate suspension method. In the latter, the solid matter is suspended or partially dissolved in a non-critical, liquid gas. The pressure in said suspension method is less than 90% of the critical pressure of the liquid gas. The suspension is introduced into the high-pressure process by means of a pump.

1 - 11 . (canceled)  
   
   
       12 . A process for solids suspension and dosing of a granular, grain or powder type of solid material in a high-pressure process, using essentially a supercritical fluid as process fluid, said process being a suspension step which is part of a high-pressure process and consisting of a suspension vessel and a device for circulation of the liquid as well as for feed and discharge operations, 
 solid material and a fluid being fed to the suspension vessel and the said fluid being a liquefied gas,    the solid material becoming suspended in the fluid with the aid of the device for agitating the liquid, thus keeping the solids in suspension,    wherein    the pressure applied in the suspension step is <90% of the critical pressure of the process fluid, a gaseous phase blanketing the liquid phase in the suspension vessel,    and in a last step the suspension is conveyed by pump into the high-pressure process.    
   
   
       13 . A process according to  claim 12 , wherein the pressure in the suspension vessel is essentially stabilized during the feed cycle to the high-pressure process by admitting solids free gas.  
   
   
       14 . A process according to  claim 12 , wherein the device for circulation of the fluid in the vessel comprises an agitator mounted in the vessel.  
   
   
       15 . A process according to  claim 12 , wherein the device for agitating the liquid comprises a pump connected to the suspension vessel via an intake and delivery line and part of the suspension inventory is constantly circulated in a cycle.  
   
   
       16 . A process according to  claim 12 , wherein the fluid in the suspension vessel is essentially identical chemically with the high-pressure process fluid.  
   
   
       17 . A process according to  claim 12 , wherein that further non-solid feedstock is added to the fluid.  
   
   
       18 . A process according to  claim 12 , wherein the pressure applied in the suspension tank during the feed cycle to the high pressure process is maintained constant by adding gas in the gaseous state.  
   
   
       19 . A process according to  claim 12 , wherein the suspension is permanently stabilized during the suspension feed cycle to the high-pressure process by means of the liquid agitating device.  
   
   
       20 . A process according to  claim 12 , wherein the input solid material is a fluid to be dissolved in the high-pressure process.  
   
   
       21 . A process according to  claim 12 , wherein the suspension feed operation to the high-pressure process is run in a continuous mode during the vessel discharge cycle, the volume feed rate being either even or variable so that the concentration in the suspension vessel is essentially kept constant.  
   
   
       22 . A process according to  claim 12 , wherein the suspension stream is adjusted at the admixture to the high-pressure process in such a manner that the ratio of the volumetric streams of suspension and high-pressure fluid is 1:50.  
   
   
       23 . A process according to  claim 12 , wherein the pressure applied in the suspension step is <60 bars.  
   
   
       24 . A process according to  claim 17 , wherein the further non-solid fee stock comprises: H 2 O or cyclic and acyclic short-chain hydrocarbons or short-chain alcohols, aldehydes or ketones as well as mixtures thereof.  
   
   
       25 . A process according to  claim 20 , wherein the input solid material comprises: color pigments, bonding agents, bleaching agents, aromatic fluids, scent extracts or mixtures thereof.  
   
   
       26 . A process according to  claim 22 , wherein the ratio of the volumetric streams of suspension and high pressure fluid is ≦1:100.