Partial oxidation process and burner with porous tip

A burner for simultaneously introducing a stream of free-oxygen containing gas and a pumpable fuel stream downward into the reaction zone of a free-flow partial oxidation gas generator comprising:

• a coaxial central cylindrically shaped conduit;
• an unobstructed converging exit nozzle that develops into a straight cylindrical portion with a circular exit orifice at the downstream end of the said central conduit;
• inlet means in fluid communication with the upstream end of said central conduit for introducing a gaseous feedstream comprising free-oxygen containing gas optionally in admixture with a temperature moderator such as H.sub.2 O, or a hydrocarbon gas or a portion of recycle product gas optionally in admixture with a temperature moderator such as H.sub.2 O;
• a second conduit coaxial and concentric with said central conduit along its length and forming therebetween a first annular passage;
• a converging exit nozzle that develops into a straight cylindrical portion with a circular exit orifice at the downstream end of said second conduit;
• inlet means in fluid communication with the upstream end of said second conduit for introducing a feedstream comprising a liquid hydrocarbon fuel optionally in admixture with a temperature moderator or a pumpable slurry of solid carbonaceous fuel;
• an outer conduit with a downstream circular exit orifice, said outer conduit being coaxial and concentric with said second conduit along its length and forming therebetween a second annular passage;
• inlet means in fluid communication with the upstream end of said outer conduit for introducing a feedstream of free-oxygen containing gas optionally in admixture with a temperature moderator into said second annular passage;
• wherein said central, second, and outer conduits and said first and second annular passages are closed at their upstream ends and open at their downstream ends;
• a porous ceramic or porous metal cooling means attached to the downstream tip of said burner and forming a hollow annular-shaped liquid coolant chamber;
• liquid coolant supply and removal means in fluid communication with said porous cooling means;
• wherein said porous cooling means is cup-shaped or is shaped like a flat annular disc and has a wall thickness in the range of about 0.1 to 3 cm and comprises a porous material of uniform composition, wall thickness and porosity including porous inside and outside surfaces and a porous core with the various pores interconnecting;
• wherein said liquid coolant is liquid water or liquid carbon dioxide;
• said porous cooling means is a porous ceramic material selected from the group consisting of alpha alumina, gamma alumina, zirconia, silica, titania, and mixtures thereof;
• or said porous cooling means is a porous metal selected from the group consisting of porous stainless steel, nickel alloy selected from Inconel and Incoloy, and cobalt alloy selected from Haynes 188 and UMCO 50;
• wherein the flow rate of said liquid coolant through said porous tip cooling means is controllable, and said porous tip cooling means contains a central discharge hole for the freeflow of said feedstreams;
• wherein at least a portion of said liquid coolant under pressure passes successively through the porous inside surface, porous core, and porous outside surface of said porous cooling means and vaporizes thereby cooling the tip of said burner;
• wherein the downstream ends of said central and second conduits may be retracted upstream from the outer conduit exit orifice, or may terminate in the same plane with the outer conduit exit orifice perpendicular to the longitudinal axis of the burner;
• and wherein a cylindrical shaped slurry stream with a gaseous core passes through the front portion of the burner and is impacted by a high velocity stream of free-oxygen containing gas optionally in admixture with a temperature moderator and said impact takes place prior to, at, or downstream from the tip of the burner to provide atomization and intimate mixing of the slurry feed with free-oxygen containing gas.

A burner for simultaneously introducing a stream of free-oxygen containing gas and a pumpable fuel stream downward into the reaction zone of a free-flow partial oxidation gas generator comprising:

• a coaxial central cylindrically shaped conduit;
• an unobstructed converging exit nozzle that develops into a straight cylindrical portion with a circular exit orifice at the downstream end of said central conduit;
• a first inlet means in fluid communication with the upstream end of said central conduit for introducing a reactant feedstream (1) comprising free-oxygen containing gas optionally in admixture with a temperature moderating gas, or alternatively, a reactant feedstream (2) comprising a liquid hydrocarbonaceous fuel optionally in admixture with a temperature moderator of an aqueous slurry of solid carbonaceous fuel;
• an outer conduit coaxial and concentric with said central conduit along its length and forming therebetween a first annular passage;
• a converging exit nozzle that develops into a frusto-conical section with a circular exit orifice at the downstream end of said outer conduit;
• a second inlet means in fluid communication with the upstream end of the outer conduit for introducing whichever feedstream (1) or (2) that is not introduced through said first inlet means;
• a porous ceramic or porous metal cooling means which controls the flow rate of a portion of liquid coolant through said porous cooling means, and which contains a central hole for the free passage of said reactant feedstreams and which is provided with porous inside and porous outside surfaces and a porous core, wherein said porous cooling means comprises a porous material of uniform composition, wall thickness, and porosity with the various pores interconnecting;
• and wherein said porous cooling means is cup-shaped or is shaped like a flat annular disc and has a wall thickness in the range of about 0.1 to 3 cm and is attached to the downstream tip of said burner and forming a hollow annular-shaped liquid coolant chamber;
• liquid coolant supply and removal means in fluid communication with said porous cooling means whereby said porous cooling means is contacted with at least a portion of said liquid coolant on its inside porous surface and said portion of liquid coolant passes through the inside porous surface, porous core, and outside porous surface of said porous cooling means and vaporizes, thereby cooling the tip of said burner;
• wherein said liquid coolant is liquid water or liquid carbon dioxide;
• said porous cooling means is a porous ceramic material selected from the group consisting of alpha alumina, gamma alumina, zirconia, silica, titania, and mixtures thereof;
• or said porous cooling means is a porous metal selected from the group consisting of porous stainless steel, nickel alloy selected from Inconel and Incoloy, and cobalt alloy selected from Haynes 188 and UMCO 50;
• wherein the downstream end of said central conduit may be retracted upstream from the outer conduit exit orifice, or may terminate with the outer conduit exit orifice in the same plane perpendicular to the longitudinal axis of the burner;
• and wherein said reactant feedstreams impact together prior to, at, or downstream from the tip of the burner to provide an atomized and intimately mixed fuel.