A catalytic flameless combustion apparatus has a fuel inlet, a combustion-supporting gas inlet, a gas premixer, a combustion plate, an igniter, a gas deflector, a flameless combustion cavity, a catalyst filled in the flameless combustion cavity, a gas collection chamber and an exhaust port. The method for starting the catalytic flameless combustion apparatus includes initially combusting and heating the flameless combustion cavity and the catalyst filled therein with low power flame; and then increasing flow velocity and switching to high power flame for conducting catalytic flameless combustion. The catalytic flameless combustion apparatus can be used for various non-solid fuel combustion and heat extraction processes.

A catalytic flameless combustion apparatus has a fuel inlet, a combustion-supporting gas inlet, a gas premixer, a combustion plate, an igniter, a gas deflector, a flameless combustion cavity, a catalyst filled in the flameless combustion cavity, a gas collection chamber and an exhaust port. The method for starting the catalytic flameless combustion apparatus includes initially combusting and heating the flameless combustion cavity and the catalyst filled therein with low power flame; and then increasing flow velocity and switching to high power flame for conducting catalytic flameless combustion. The catalytic flameless combustion apparatus can be used for various non-solid fuel combustion and heat extraction processes.

A furnace for performing an endothermic process, comprising tubes containing a catalyst for converting a gaseous feed, wherein tubes are positioned in rows inside the furnace, wherein burners are mounted between the tubes and between the tubes and the furnace walls parallel to the tubes rows, and wherein the burners rows and the tubes rows are ended by end walls and are divided into sections with, on each row of tubes, the distance from a wall end tube to the end wall being T2W, the distance between two adjacent inner tubes in a section being T2T, and the distance between two symmetry end tubes of two adjacent sections being T2S, wherein the tubes in the rows are arranged in such a way that the ratios T2T/T2W and T2T/T2S are greater than 0.5 and smaller than 2 thus limiting the differences in the heat transfer to the outer tubes (wall end tubes and symmetry end tubes) with respect to the inner tubes and reducing the temperature difference between outer tubes and inner tubes.

A furnace for performing an endothermic process, comprising tubes containing a catalyst for converting a gaseous feed, wherein tubes are positioned in rows inside the furnace, wherein burners are mounted between the tubes and between the tubes and the furnace walls parallel to the tubes rows, and wherein the burners rows and the tubes rows are ended by end walls and are divided into sections with, on each row of tubes, the distance from a wall end tube to the end wall being T2W, the distance between two adjacent inner tubes in a section being T2T, and the distance between two symmetry end tubes of two adjacent sections being T2S, wherein the tubes in the rows are arranged in such a way that the ratios T2T/T2W and T2T/T2S are greater than 0.5 and smaller than 2 thus limiting the differences in the heat transfer to the outer tubes (wall end tubes and symmetry end tubes) with respect to the inner tubes and reducing the temperature difference between outer tubes and inner tubes.

A steam generating system includes a furnace, a nozzle tip assembly for pulverized coal and primary air as well as means for conveying secondary air in the furnace. The nozzle according to the invention comprises a nozzle body (3) and several channels (5) being connected with the nozzle body, the channels are diverging from each other. At the exit faces (17) of the channels obstructions (13) are disposed to induce huge turbulences of the primary air when entering the furnace. Due to these turbulences the primary air and the entrained coal are mixed very well before being combusted in the furnace. This results in a better more effective combustion with reduced NOx- emissions.

An afterburner system and method for reducing the CO.sub.2 and other pollutants produced by the combustion of a fuel in a combustion chamber while maintaining or increasing the efficiency of said combustion includes feeding a catalyst, preferably lithium and/or boron to the afterburner, or a preconditioning afterburner, along with the exhaust from the combustion chamber. The presence of the catalyst in the after burner results in further reduction of pollutants generated by the combustion in the combustion chamber.

An afterburner system and method for reducing the CO.sub.2 and other pollutants produced by the combustion of a fuel in a combustion chamber while maintaining or increasing the efficiency of said combustion includes feeding a catalyst, preferably lithium and/or boron to the afterburner, or a preconditioning afterburner, along with the exhaust from the combustion chamber. The presence of the catalyst in the after burner results in further reduction of pollutants generated by the combustion in the combustion chamber.

A furnace for performing an endothermic process comprising tubes containing a catalyst for converting a gaseous feed, wherein tubes are positioned in rows inside the furnace, wherein burners are mounted between the tubes and between the tubes and the furnace walls parallel to the tubes row and wherein the burners rows and the tubes rows are ended by end walls and are divided into sections with the distance from the end burner to the end wall being B2W, the distance between two adjacent burners in the section being B2B, and half the distance in-between two sections being B2S, wherein the burners in the rows are arranged in such a way that the ratios B2B/B2W and B2B/B2S are greater than 1.3 thus limiting the occurrence of the flame merging phenomenon and reducing significantly the quadratic mean of the tube temperature profile.

A furnace for performing an endothermic process comprising tubes containing a catalyst for converting a gaseous feed, wherein tubes are positioned in rows inside the furnace, wherein burners are mounted between the tubes and between the tubes and the furnace walls parallel to the tubes row and wherein the burners rows and the tubes rows are ended by end walls and are divided into sections with the distance from the end burner to the end wall being B2W, the distance between two adjacent burners in the section being B2B, and half the distance in-between two sections being B2S, wherein the burners in the rows are arranged in such a way that the ratios B2B/B2W and B2B/B2S are greater than 1.3 thus limiting the occurrence of the flame merging phenomenon and reducing significantly the quadratic mean of the tube temperature profile.

A reactor for a mixture of fluids that can react with each other exothermically, the reactor combining the properties of heat transfer and porosity, and having a first chamber wherein reacted fluids are maintained above the reaction temperature threshold, a second chamber disposed adjacent to the first chamber, wherein unreacted fluids enter the second chamber at a temperature that is below a reaction temperature threshold that is necessary for reaction of the fluids to occur, the fluids flowing in a second direction, opposite the first direction and a porous wall disposed between the first chamber and a second chamber, allowing portions of the unreacted fluids from the second chamber to seep into the reacted fluids of the first chamber, thereby heating the seeped fluids, causing the seeped fluids to react, the reaction increasing the temperature of the reacted fluid.