Process and agents to remove metals from high-boiling hydrocarbon fractions

Abstract

The object of the invention is a process and agents to remove metal contaminants from hydrocarbon fractions like those obtained as a product from the Fischer-Tropsch synthesis involving the use of suspended catalyst. As per the present invention, the feed hydrocarbon fraction is treated with a demetallizing agent, comprising at least one sulfur source and at least one basic compound, under anhydrous conditions. The metals to be removed are obtained in the form of precipitate that can be easily separated by means of a mechanical separation process such as filtration, for example.

1 - 10 . (canceled) 
     
     
         11 . A process for the production of a hydrocarbon fraction with low metal content, wherein metals contained in the hydrocarbon fraction are chemically bonded or dispersed in the hydrocarbon fraction in a colloidal or finely-dispersed form, wherein a demetallizing agent is added to the liquid hydrocarbon fraction comprising:
 (a) at least one sulfur source that is at least partially soluble in the hydrocarbon fraction,   (b) at least one basic compound that is at least partially soluble in the hydrocarbon fraction,   wherein after addition of the demetallizing agent, the metals are precipitated in the form of a precipitate and separated by means of a mechanical separation process.   
     
     
         12 . A demetallizing agent for hydrocarbon fractions, in particular for use in a process according to  claim 11 , comprising
 (a) at least one sulfur source that is at least partially soluble in hydrocarbon fractions,   (b) at least one basic compound that is at least partially soluble in hydrocarbon fractions.   
     
     
         13 . The demetallizing agent according to  claim 12 , wherein at least one of the compounds below is selected as a sulfur source: thiourea, thiocarbonates, dithiocarbonates, thiocarbamates, dithiocarbamates, mercaptanes, organic disulfides, organic polysulfides, thioacid amides; hydrogen sulfide, ammonium sulfide, inorganic monosulfides, inorganic disulfides, inorganic polysulfides or elementary sulfur. 
     
     
         14 . The demetallizing agent according to  claim 12 , wherein at least one of the compounds below is selected as a basic compound: ammonia, amines, alkanol amines, preferably triethanol amine; pyridines, ammonium compounds, phosphonium compounds, sulfonium compounds. 
     
     
         15 . The demetallizing agent according to  claim 13 , wherein elementary sulfur or hydrogen sulfide is used as a sulfur source. 
     
     
         16 . The demetallizing agent according to  claim 13 , wherein sulfur-impregnated activated carbon is used as a sulfur source. 
     
     
         17 . The process according to  claim 11 , wherein filtration, sedimentation, decantation or centrifugation or combinations thereof are used as mechanical separation processes. 
     
     
         18 . The process according to  claim 11 , wherein sulfur-impregnated activated carbon is used as a sulfur source and that, after addition of the base, the hydrocarbon fraction to be treated is added to a bed of demetallizing agent in a fixed bed reactor whereby a metal-depleted hydrocarbon fraction is withdrawn as a product from the fixed bed reactor. 
     
     
         19 . The demetallizing agent according to  claim 12 , wherein mercaptanes, preferably trimercapto-s-triazine, are used as a sulfur source.