The invention relates to a method to start up a Fischer-Tropsch process. A catalyst with a latent activity is used. The catalyst comprises titania, cobalt, promoter, and chlorine. The catalyst comprises more than 0.7 and less than 4 weight percent of the element chlorine, calculated on the total weight of the catalyst.

The present invention provides a process for preparing 2,3,3,3-tetrafluoropropene from 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane, comprising the following steps: (a) catalytic reaction of 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane with HF into a reaction mixture comprising HCl, 2-chloro-3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, unreacted HF, and optionally 1,1,1,2,2-pentafluoropropane; (b) separating the reaction mixture into a first stream comprising HCl and 2,3,3,3-tetrafluoropropene and a second stream comprising HF, 2-chloro-3,3,3-trifluoropropene and optionally 1,1,1,2,2-pentafluoropropane; (c) catalytic reaction of the second stream into a reaction mixture comprising 2,3,3,3-tetrafluoropropene, HCl, unreacted 2-chloro-3,3,3-trifluoropropene, unreacted HF and optionally 1,1,1,2,2-pentafluoropropane and (d) feeding the reaction mixture of step (c) directly without separation to step (a).

The present invention provides a process for preparing 2,3,3,3-tetrafluoropropene from 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane, comprising the following steps: (a) catalytic reaction of 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane with HF into a reaction mixture comprising HCl, 2-chloro-3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, unreacted HF, and optionally 1,1,1,2,2-pentafluoropropane; (b) separating the reaction mixture into a first stream comprising HCl and 2,3,3,3-tetrafluoropropene and a second stream comprising HF, 2-chloro-3,3,3-trifluoropropene and optionally 1,1,1,2,2-pentafluoropropane; (c) catalytic reaction of the second stream into a reaction mixture comprising 2,3,3,3-tetrafluoropropene, HCl, unreacted 2-chloro-3,3,3-trifluoropropene, unreacted HF and optionally 1,1,1,2,2-pentafluoropropane and (d) feeding the reaction mixture of step (c) directly without separation to step (a).

Methods for regenerating a sulfur-contaminated catalyst are disclosed. Such methods may employ a step of washing the sulfur-contaminated catalyst with an aqueous solution containing an alkali metal, followed by contacting the washed catalyst with a halogen solution containing chlorine and fluorine.

Methods for regenerating a sulfur-contaminated catalyst are disclosed. Such methods may employ a step of washing the sulfur-contaminated catalyst with an aqueous solution containing an alkali metal, followed by contacting the washed catalyst with a halogen solution containing chlorine and fluorine.

The present invention provides a process for preparing 2,3,3,3-tetrafluoropropene from 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane, comprising the following steps: (a) catalytic reaction of 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane with HF into a reaction mixture comprising HCl, 2-chloro-3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, unreacted HF, and optionally 1,1,1,2,2-pentafluoropropane; (b) separating the reaction mixture into a first stream comprising HCl and 2,3,3,3-tetrafluoropropene and a second stream comprising HF, 2-chloro-3,3,3-trifluoropropene and optionally 1,1,1,2,2-pentafluoropropane; (c) catalytic reaction of the second stream into a reaction mixture comprising 2,3,3,3-tetrafluoropropene, HCl, unreacted 2-chloro-3,3,3-trifluoropropene, unreacted HF and optionally 1,1,1,2,2-pentafluoropropane and (d) feeding the reaction mixture of step (c) directly without separation to step (a).

The present invention provides a process for preparing 2,3,3,3-tetrafluoropropene from 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane, comprising the following steps: (a) catalytic reaction of 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane with HF into a reaction mixture comprising HCl, 2-chloro-3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, unreacted HF, and optionally 1,1,1,2,2-pentafluoropropane; (b) separating the reaction mixture into a first stream comprising HCl and 2,3,3,3-tetrafluoropropene and a second stream comprising HF, 2-chloro-3,3,3-trifluoropropene and optionally 1,1,1,2,2-pentafluoropropane; (c) catalytic reaction of the second stream into a reaction mixture comprising 2,3,3,3-tetrafluoropropene, HCl, unreacted 2-chloro-3,3,3-trifluoropropene, unreacted HF and optionally 1,1,1,2,2-pentafluoropropane and (d) feeding the reaction mixture of step (c) directly without separation to step (a).

The invention concerns a process for preparing a chlorine comprising catalyst using one or more metal salts of chloride, hydrochloric acid (HCl), one or more organic chloride compounds, or a combination thereof. The prepared catalyst preferably comprises 0.13-3 weight percent of the element chlorine. The invention further relates to the prepared catalyst and its use.

The invention concerns a process for preparing a chlorine comprising catalyst using one or more metal salts of chloride, hydrochloric acid (HCl), one or more organic chloride compounds, or a combination thereof. The prepared catalyst preferably comprises 0.13-3 weight percent of the element chlorine. The invention further relates to the prepared catalyst and its use.

A method of producing an organoselenium-based nanocomposite includes acid-treating a mixture containing multi-walled carbon nanotubes (MWCNT) and palm waste with phosphoric acid to form an acid-treated mixture; carbonizing the acid-treated mixture to form a MWCNT/biochar; mixing the MWCNT-biochar with TiO.sub.2 nanoparticles to form a TiO.sub.2-MWCNT/biochar; chlorinating acyl groups present on the TiO.sub.2-MWCNT/biochar to form a chlorinated TiO.sub.2-MWCNT/biochar; reacting the chlorinated TiO.sub.2-MWCNT/biochar with an organoselenium compound to form a SeTiO.sub.2-MWCNT/biochar.