Catalytic Biogas Combined Heat and Power Generator

Abstract

An apparatus and method to desulfurize a biogas containing sulfur. Since biogas is produced by an anaerobic digester from human, animal, kitchen and agriculture's wastes, Itis a short term recycled product from the photosynthesis of CO 2 , and has a net zero carbon emission. The sulfur compounds in the biogas can be removed by the following steps: (1) converting all sulfur compounds into H 2 S by the hydrogen produced from the biogas over Pt group metal catalysts; (2) adsorbing the H 2 S at high temperature by the regenerable Pt group metal catalyst and adsorbents. The desulfurized biogas is further converted by an ATR/CPO reformer or a steam generating reformer to produce various reformates.

1 - 20 . (canceled) 
     
     
         21 . An apparatus to produce a reformate containing a given H 2 /CH 4  ratio from one or more of a biogas or hydrocarbon gas, comprising:
 (A) a gas storage tank configured to hold the biogas or hydrocarbon gas;   (B) a catalytic H 2  reformer selected from one or more of a flex-fuel catalytic ATR, a catalytic steam generating reformer or a CPO reformer to produce a reformate gas containing the given H 2 /CH 4  ratio from the biogas or hydrocarbon gas over a Pt metal group catalyst;   (C) a reformate storage tank and/or a manifold configured to store the reformate; and   (D) an automatic control system including one or more devices selected from a programmable logic controller, a microprocessor, a valve, a flow controller, a thermocouple, a sensor and a pump, wherein the automatic control system is configured to provide an inlet fuel mixture to the catalytic H 2  reformer, the inlet fuel mixture having at least one of 1) an O 2 /CH 4  ratio, 2) a H 2 O/CH 4  ratio, and 3) a (H 2 O+CO 2 )/CH 4  ratio.   
     
     
         22 . The apparatus of  claim 21 , comprising an optional water electrolysis device for producing H 2  and O 2  from water. 
     
     
         23 . The apparatus of  claim 21 , wherein the Pt metal group catalyst contains at least one or more metals selected from the group consisting of a Platinum, a Palladium, a Rhodium, an Iridium and a Ruthenium metal supported on an Al 2 O 3  powder at 0.01 to 10.0% metal content. 
     
     
         24 . The apparatus of  claim 23 , wherein the Al 2 O 3  powder contains a high temperature oxide stabilizer to provide a stabilized Al 2 O 3 , and wherein the high temperature oxide stabilizer includes one or more oxides selected from the group consisting of lanthanum, cerium, praseodymium, rhenium, zinc, tin, calcium, potassium, zirconium, an yttrium, barium, strontium, neodymium and magnesium. 
     
     
         25 . The apparatus of  claim 24 , wherein the Pt metal group catalyst supported on the stabilized Al 2 O 3  includes one or more oxides selected from the group consisting of Zn, Ni, Ce, Ce/Zr, Fe, Co, Mo, Cu, Cu/Zn, zeolite, Mn, La, Ba, Sr, Al and Si as a H 2 S adsorbent. 
     
     
         26 . The apparatus of  claim 23 , wherein the Pt metal group catalyst is further coated on the surface of a high temperature inert carrier at 0.1 to 2500 g/ft 3 , and the inert carrier is selected from the group consisting of a ceramic monolith, a metallic monolith, a pellet, a wire mesh, a screen, a foam, a plate, a gauze, a silicon carbide, a static mixer and a heat exchanger. 
     
     
         27 . The apparatus of  claim 21 , wherein the inlet fuel mixture contains pure oxygen, water, and one or more fuels selected from the group consisting of a natural gas, a hydrocarbon and a bio-fuel for the purpose of increasing the % (hydrogen and CO) concentration in the reformate. 
     
     
         28 . The apparatus of  claim 21 , comprising a downstream IC engine/gas turbine, wherein the produced reformate from the catalytic H 2  reformer, with a given H 2 /CH 4  ratio, is used as the fuel to perform hydrogen assisted combustion by the downstream IC engine/gas turbine producing an exhaust gas. 
     
     
         29 . The apparatus of  claim 28 , wherein the engine/gas turbine is connected to an electric generator to produce power as a distributed power station. 
     
     
         30 . The apparatus of  claim 29 , wherein the heat in the exhaust gas is recovered as hot air and/or hot water, so that the apparatus becomes a distributed combined heat and power generator. 
     
     
         31 . The apparatus of  claim 28 , wherein the biogas or hydrocarbon gas is a vaporized gas of one or more fuels selected from the group consisting of a bio-fuel, a natural gas, a LPG, a CNG, a bio-ethanol, a methanol, a gasoline, a diesel, and a bio-diesel, and wherein the produced reformate is used as the sole fuel or part of the fuel mixture for the engine/gas turbine to perform hydrogen assisted combustion. 
     
     
         32 . The apparatus of  claim 28 , wherein the catalytic steam generating reformer is operably connected to at least one of the gas turbine and IC steam engine and is configured to produce high pressure steam to at least one of the gas turbine and IC steam engine, and wherein the inlet fuel mixture of the steam generating reformer operates at an O 2 /CH 4  ratio greater than 1.0, and a H 2 O/CH 4  ratio greater than 3.0, and at a temperature below 1000° C., and a pressure between 5 to 50 atmospheres. 
     
     
         33 . The apparatus of  claim 28 , wherein the CPO reformer is configured to adjust a reformate H 2 /CH 4  ratio as a fuel for at least one of the gas turbine and IC steam engine, and wherein the O 2 /CH 4  ratio of the inlet fuel mixture is less than 0.80, and a (CO 2 +H 2 O)/CH 4  ratio is less than 5.0. 
     
     
         34 . The apparatus of  claim 21 , wherein the O 2 /CH 4  ratio of the inlet reformer's fuel mixture is used to control a reaction path, and wherein the produced reformate is used as the fuel for one of a reformate IC engine, a gas turbine, a steam turbine and a fuel cell device to generate electricity.