Disclosed is an electrocatalytic degradation device for organic wastewater, which includes an electrocatalytic oxidation reactor, a spray tower and a drying tower. The electrocatalytic oxidation reactor is provided with a hydroxyl generator, a catalyst filler and a box body. The box body of the electrocatalytic oxidation reactor is provided with a gas gathering device connected with the spray tower. An upper gas outlet of the spray tower is connected with the drying tower. The disclosure combines the electrooxidation reaction with the catalytic reaction to improve the electrooxidation efficiency of the electrocatalytic oxidation reactor and efficiently degrade the high salt high organic wastewater. The decomposed by-products are effectively utilized. The generated hydrogen is collected by the gas gathering device and enters the spray tower. The CO.sub.2 gas is absorbed after treatment. The CO.sub.2-removed gas passes through the drying tower to absorb moisture to obtain pure hydrogen.

An H.sub.2-rich fuel gas production plant comprising a syngas production unit can be advantageously integrated with an olefins production plant comprising a steam cracker in at least one of the following: (i) fuel gas supply and consumption; (ii) feed supply and consumption; and (iii) steam supply and consumption, to achieve considerable savings in capital and operational costs, enhanced energy efficiency, and reduced CO.sub.2 emissions, compared to operating the plants separately.

A volume of natural gas including a volume of methane and a volume of other alkanes may be cleaned of the other alkanes using a steam reformer system to create synthesis gas.

What is described is an integrated steel mill and a bioreactor configured to produce useful products from the waste stream of the steel mill. A waste gas stack which is connected to the steel mill is connected to a heat exchanger to cool the waste gas from the steel mill. The cooled gas is pressurized using a pressurization apparatus connected to the heat exchanger. The pressurized gas is sent to an oxygen removal apparatus connected to the pressurization apparatus. An oxygen depleted waste stream from the oxygen removal apparatus is passed to a bioreactor (connected to the oxygen removal apparatus) where microorganisms ferment the waste stream to products. Optional apparatus such as scrubbers, valves, buffers, are also disclosed. The products of the fermentation in the bioreactor can be ethanol and or acetate.

A process for producing syngas that uses the syngas product from an oxygen-fired reformer to provide all necessary heating duties, which eliminates the need for a fired heater. Without the flue gas stream leaving a fired heater, all of the carbon dioxide produced by the reforming process is concentrated in the high-pressure syngas stream, allowing essentially complete carbon dioxide capture.

A process for producing syngas that uses the syngas product from a partial oxidation reactor to provide all necessary heating duties, which eliminates the need for a fired heater. Soot is removed from the syngas using a dry filter to avoid a wet scrubber quenching the syngas stream and wasting the high-quality heat. Without the flue gas stream leaving a fired heater, all of the carbon dioxide produced by the reforming process is concentrated in the high-pressure syngas stream, allowing essentially complete carbon dioxide capture.

An H.sub.2-rich fuel gas stream can be advantageously produced by reforming a hydrocarbon/steam mixture in to produce a reformed stream, followed by cooling the reformed stream in a waste-heat recovery unit to produce a high-pressure steam stream, shifting the cooled reformed stream a first shifted stream, cooling the first shifted stream, shifting the cooled first shifted stream to produce a second shifted stream, cooling the second shifted stream, abating water from the cooled second shifted stream to obtain a crude gas mixture stream comprising H.sub.2 and CO.sub.2, and recovering a CO.sub.2 stream from the crude gas mixture stream. The H.sub.2-rich stream can be advantageously combusted to provide thermal energy needed for residential, office, and/or industrial applications including in the H.sub.2-rich fuel gas production process. The H.sub.2-rich fuel gas production process can be advantageously integrated with an olefins production plant comprising a steam cracker.

Methods and systems for reducing greenhouse gas emissions, including producing a waste gas stream comprising form greater than 0 vol % to less than 20 vol %, inclusive, carbon dioxide, pre-concentrating the waste gas stream to increase a concentration of carbon dioxide, producing a concentrated byproduct stream comprising more than 40 vol %, dissolving carbon dioxide contained in the concentrated byproduct stream in water, producing a dissolved byproduct stream and an undissolved byproduct stream, injecting the dissolved byproduct stream or a portion thereof into a reservoir containing mafic rock, and allowing components of the dissolved byproduct stream to react in situ with components of the mafic rock to precipitate and store components of the byproduct stream in the reservoir.

In a hydrocarbon-fed steam methane reformer hydrogen-production process and system, carbon dioxide is recovered in a pre-combustion context, and optionally additional amounts of carbon dioxide are recovered in a post-combustion carbon dioxide removal, to provide the improved carbon dioxide recovery or capture disclosed herein.

An integrated process for the production of a useful liquid hydrocarbon product comprises: feeding a gasification zone with an oxygen-containing feed and a first carbonaceous feedstock comprising waste materials and/or biomass, gasifying the first carbonaceous feedstock in the gasification zone to produce first synthesis gas, partially oxidising the first synthesis gas in a partial oxidation zone to generate partially oxidised synthesis gas, combining at least a portion of the first synthesis gas and/or the partially oxidised synthesis gas and at least a portion of electrolysis hydrogen obtained from an electrolyser in an amount to achieve the desired hydrogen to carbon monoxide molar ratio of from about 1.5:1 to about 2.5:1, and to generate a blended synthesis gas, wherein the electrolyser operates using green electricity; and subjecting at least a portion of the blended synthesis gas to a conversion process effective to produce the liquid hydrocarbon product.