Systems, devices and methods for submarine CO.sub.2 scrubbing are disclosed. The system may comprise an assembly including a sorbent, a scrubbing inlet configured to receive a first airflow during an adsorption mode. The first airflow may comprise air received from a cabin of a submarine. The assembly may be configured to flow the first airflow over and/or through the sorbent during the adsorption mode such that the sorbent removes a portion of CO.sub.2 entrained in the first airflow. The system may also include a scrubbing outlet configured to expel the scrubbed first airflow from the assembly into the cabin. The system may include an outside air inlet configured to receive a second airflow comprising outside air during a regeneration mode. The system may include a regeneration air outlet in configured to expel the second airflow after the second airflow has flowed over and/or through the sorbent during the regeneration mode.

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.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers. Alternatively, the pre-purification systems and methods employ a hopcalite catalyst layer and a noble metal catalyst layer separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layer.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers. Alternatively, the pre-purification systems and methods employ a hopcalite catalyst layer and a noble metal catalyst layer separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layer.

An air separation unit for an OBOGS includes a housing having an inlet for receiving a wet inlet air and an outlet for outputting a dry product gas. The housing includes an outer side wall and annular walls defining a series of concentric annular chambers. A first annular chamber is coupled to the inlet and includes a desiccant material to receive the wet inlet air and output a dried air. An unfilled second annular chamber is coupled to the first annular chamber. A third annular chamber is coupled to the second annular chamber at a first end and the outlet at a second end. The third annular chamber receives air separation material to selectively remove unwanted constituents from the dried air and output the dry product gas. A tap may be coupled to the second annular chamber so that dried air may be removed from the housing.

An exhaust-gas aftertreatment device for an internal combustion engine, for use in a motor vehicle, includes an exhaust tract with at least one exhaust pipe and at least one exhaust-gas aftertreatment element. The exhaust-pipe internal wall and/or the at least one exhaust-gas aftertreatment element have/has a vapor-sorbing material forming at least one exhaust-tract-side sorption element.

Adsorbent materials are disclosed, along with filter elements containing the adsorbent materials methods of using adsorbents to remove siloxane contaminants from a gas stream. The method includes providing an adsorbent material that has been washed with an acid and passing a gas through the adsorbent material so as to reduce siloxane levels in the gas. A filter element for reducing siloxane levels in a gas includes a first adsorbent material, the first adsorbent material comprising an acid-washed adsorbent; and a second adsorbent material, the second adsorbent material comprising an acid-impregnated adsorbent.

Solar thermal units and methods of operating solar thermal units for the conversion of solar insolation to thermal energy are provided. In some examples, solar thermal units have an inlet, and a split flow of heat absorbing fluid to either side of the solar thermal unit, along a first fluid flow path and a second fluid flow path. Optionally, one or more photovoltaic panels can be provided as part of the solar thermal unit, which may convert solar insolation to electric power that may be used by a system connected to the solar thermal unit.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers.