Systems and methods are provided for performing hydrocarbon reforming within a reverse flow reactor environment (or another reactor environment with flows in opposing directions) while improving management of CO.sub.2 generated during operation of the reactor. The improved management of CO.sub.2 is achieved by making one or more changes to the operation of the reverse flow reactor. The changes can include using an air separation unit to provide an oxygen source with a reduced or minimized content of nitrogen and/or operating the reactor at elevated pressure during the regeneration stage. By operating the regeneration at elevated pressure, a regeneration flue gas can be generated that is enriched in CO.sub.2 at elevated pressure. The CO.sub.2-enriched stream can include primarily water as a contaminant, which can be removed by cooling while substantially maintaining the pressure of the stream. This can facilitate subsequent recovery and use of the CO.sub.2.

Systems and methods are provided for using a high heat capacity gas as at least a portion of the diluent during the regeneration step of a reverse flow reactor process. Instead of using nitrogen or air as the primary diluent gas, CO.sub.2 and/or H.sub.2O can be added as diluent gas for the regeneration step in the reaction cycle. Increasing the heat capacity of the diluent gas provides a reduction in the peak temperature within the reactor relative to the amount of fuel combusted during regeneration. This can allow for a reduction in the volume of diluent used during regeneration and/or an increase in the amount of fuel used. Reducing the volume of diluent can reduce the pressure drop during regeneration, which can provide a corresponding reduction in the amount of compression required for recycle of the diluent. Increasing the amount of fuel can allow for a corresponding increase in the amount of endothermic reaction performed during the reaction step.

A hydrogen producing apparatus includes a reforming unit, a feed unit, and a heating unit. The reforming unit includes a casing defining a receiving space and having gas intake and outlet ports, a plurality of reformers disposed in the receiving space, at least one gas pipe winding around one of the reformers, and a connecting pipe in fluidic communication with the gas pipe. The feed unit is in fluidic communication with the reformers and the connecting pipe such that air delivered from the gas intake port through the gas pipe and the connecting pipe is mixed with a fuel in the feed unit to form a reactant mixture to be fed to the reformers for hydrogen production. The heating unit includes a heater connected to the casing.

A hydrogen producing apparatus includes a reforming unit, a feed unit, and a heating unit. The reforming unit includes a casing defining a receiving space and having gas intake and outlet ports, a plurality of reformers disposed in the receiving space, at least one gas pipe winding around one of the reformers, and a connecting pipe in fluidic communication with the gas pipe. The feed unit is in fluidic communication with the reformers and the connecting pipe such that air delivered from the gas intake port through the gas pipe and the connecting pipe is mixed with a fuel in the feed unit to form a reactant mixture to be fed to the reformers for hydrogen production. The heating unit includes a heater connected to the casing.

A distributed Biogas Combined Heat and Power (CHP) Generator can provide automatically hot water and electricity for local applications. Since biogas is produced by an anaerobic digester from human, animal, kitchen and agriculture's wastes, it is a short term recycled product from the photosynthesis of CO.sub.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.sub.2S by the hydrogen produced from the biogas over Pt group metal catalysts; (2). adsorbing the H.sub.2S 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, which can be connected to a downstream IC engine/gas turbine, and/or a steam turbine to drive electric generators for generating electricity. The hot reformate and the exhaust gases can be cooled in heat exchangers to produce hot water/hot air.

A distributed Biogas Combined Heat and Power (CHP) Generator can provide automatically hot water and electricity for local applications. Since biogas is produced by an anaerobic digester from human, animal, kitchen and agriculture's wastes, it is a short term recycled product from the photosynthesis of CO.sub.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.sub.2S by the hydrogen produced from the biogas over Pt group metal catalysts; (2). adsorbing the H.sub.2S 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, which can be connected to a downstream 1C engine/gas turbine, and/or a steam turbine to drive electric generators for generating electricity. The hot reformate and the exhaust gases can be cooled in heat exchangers to produce hot water/hot air.

A reforming catalyst with improved surface area is provided by using high surface area alumina doped with a stabilizer metal as a catalyst support. The surface area of the catalyst can be higher than a typical reforming catalyst, and the surface area can also be maintained under high temperature operation. This can allow use of the catalyst for reforming in a higher temperature environment while maintaining a higher surface area, which can allow for improved dispersion and/or activity of an active metal such as rhodium on the catalyst support. The catalyst can be suitable for production of syngas from natural gas or other hydrocarbon-containing feeds.

Ceramic compositions with catalytic activity are provided, along with methods for using such catalytic ceramic compositions. The ceramic compositions correspond to compositions that can acquire increased catalytic activity by cyclic exposure of the ceramic composition to reducing and oxidizing environments at a sufficiently elevated temperature. The ceramic compositions can be beneficial for use as catalysts in reaction environments involving swings of temperature and/or pressure conditions, such as a reverse flow reaction environment. Based on cyclic exposure to oxidizing and reducing conditions, the surface of the ceramic composition can be converted from a substantially fully oxidized state to various states including at least some dopant metal particles supported on a structural oxide surface.

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, it is a short term recycled product from the photosynthesis of CO.sub.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.sub.2S by the hydrogen produced from the biogas over Pt group metal catalysts; (2) adsorbing the H.sub.2S 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.

A meshed catalyst based high-yield preparation and regeneration method for carbon nanotubes and hydrogen includes the following steps: step one, adding waste plastic into a low-temperature pyrolysis section, conducting slow heating, and continuously introducing nitrogen; step two, using a multilayer stainless steel mesh obtained through laminated pressing and vacuum sintering as a catalyst, introducing the volatiles into a high-temperature catalytic section, conducting a catalytic reaction under the action of a meshed stainless steel catalyst obtained through acid etching and calcination pretreatment, generating the carbon nanotubes on a surface of the catalyst, and meanwhile generating high-purity hydrogen; and step three, after temperature drop, conducting ultrasonic treatment on a stainless steel mesh after the reaction, achieving physical stripping of the carbon nanotubes from the stainless steel mesh, then placing the stainless steel mesh subjected to secondary calcination in a system for recycling, and regenerating the carbon nanotubes and the hydrogen.