Provided herein are gas permeable membranes comprising an amine-containing selective layer on top of a gas permeable polymer support as well as methods of making and using thereof. The membranes are useful for the separation of CO.sub.2 from N.sub.2-containing gases.

A fossil fuel fired power plant exhaust gas clean-up system is provided to remove detrimental compounds/elements from the exhaust gas emitting from the power plant to protect the environment. This is accomplished primarily by directing the exhaust gas from a fossil fuel fired power plant through both a reaction chamber containing a chemically produced compound and a catalytic converter. The final exhaust gas can now be safely exhausted to the atmosphere and only contains nitrogen gas, oxygen, water and a trace amount of carbon dioxide.

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.

A transfer line between the outlet of a steam cracker and the inlet for the quench system has metallic or ceramic inserts having a pore size from about 0.001 to about 0.5 microns inside the line forming a gas tight barrier with the inner surface of the line and having a vent for the resulting gas tight pocket are used to separate H.sub.2, CH.sub.4, CO and CO.sub.2 from cracked gases reducing the load on the down-stream separation train of the steam cracker.

The present invention provides for a pressure swing adsorption (PSA) process for the substantial removal of H.sub.2O and CO.sub.2 from a synthesis gas to obtain a multicomponent product gas substantially free of H.sub.2O and CO.sub.2 with high recovery of the product gas. Further, the present invention provides an integrated process that achieves sufficiently high H.sub.2 and CO recoveries such that compression and recycling of the syngas purification PSA tailgas is not necessary to be economically advantageous compared to the conventional processes.

Generation of bubbles in an organic-substance production apparatus is suppressed. A gas treatment method including: an adsorption step of passing a source gas containing at least carbon dioxide and nitrogen through an adsorption unit housing an adsorbent for adsorbing carbon dioxide to reduce a carbon dioxide concentration in the source gas; a supply step of supplying the source gas whose carbon dioxide concentration has been reduced by the adsorption step to an organic-substance production apparatus that produces an organic substance; and a monitoring step of monitoring a carbon dioxide concentration and a nitrogen concentration in the source gas before passing through the adsorption unit, a carbon dioxide concentration and a nitrogen concentration in the source gas after having passed through the adsorption unit, or a carbon dioxide concentration and a nitrogen concentration in the source gas having been supplied to the organic-substance production apparatus; wherein the adsorption step has an ability regulation step of enhancing an ability of the adsorption unit to reduce a carbon dioxide concentration in the source gas, when a total concentration of the carbon dioxide concentration and the nitrogen concentration monitored in the monitoring step exceeds a threshold value.

The process of the present invention provides high recovery and low capital cost giving it an economic advantage over previously known purification processes. The present process has particular applicability to the purification of synthesis gases comprising at least hydrogen (H.sub.2), carbon monoxide (CO), methane (CH.sub.4), CO.sub.2, and H.sub.2O to obtain a gas stream including at least H.sub.2, CO, and CH.sub.4, that is substantially free of H.sub.2O and CO.sub.2. The process also has applicability to the purification of natural gases inclusive of at least CH.sub.4, N.sub.2, CO.sub.2, and H.sub.2O to produce a gas stream including at least CH.sub.4 and N.sub.2, but which is substantially free of H.sub.2O and CO.sub.2.

Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membrane can comprise a support layer; and a selective polymer layer disposed (e.g., coated) on the support layer. The selective polymer layer can comprise a polymer matrix (e.g., a hydrophilic polymer, an amine-containing polymer, or a combination thereof), and a guanidine-based mobile carrier dispersed within the polymer matrix. Optionally, the selective polymer later can further include an amine-based mobile carrier, a CO.sub.2-philic ether, a graphene oxide, carbon nanotubes, or a combination thereof, dispersed within the polymer matrix. The membranes can be used to separate carbon dioxide from other gases, such as hydrogen and/or nitrogen. Also provided are methods of separating gas streams using the membranes described herein.

Provided herein are CO.sub.2-selective membranes that can be used to efficiently separate CO.sub.2 and CO. The membranes can be used to produce high-purity CO.sub.2 and CO gas streams from a feed gas stream comprising a mixture of CO.sub.2 and CO (e.g., an exhaust gas stream from a fuel cell, such as a solid oxide fuel cell). In this way, the membranes can be used with a solid oxide fuel cell system to covert CO.sub.2 to CO.

Provision of a gas production apparatus that can stably produce a product gas with carbon monoxide as its main component from a separated gas including carbon dioxide as a main component.

The gas production apparatus 1 consists of the following: a separation and capture section 5, which separates and captures separated gas containing mainly of carbon dioxide from the exhaust gas taken from the line of the exhaust gas equipment; a reaction section 4 including at least a reactor, which is connected to downstream of the separation and capture section 5, contains a reducing agent that generates carbon monoxide through a reduction reaction of carbon dioxide brought into contact with the separated gas, and is capable of separating at least some of oxygen atoms separated from carbon dioxide; a pressure regulating section 7 connected to downstream of the reactor 4 to regulate the pressure of the separated gas supplied to the reactor; and the flow regulating section 6 connected on the upstream of the separation and capture section 5 and regulates the flow rate of the separated gas supplied to the reactor.