A method for operating a fuel cell system is provided. The method includes controlling a provision of fuel to the fuel cell system operating in a steady-state mode. The catalyst sensor is operated by providing a portion of the fuel and anode exhaust generated by the system to the catalyst sensor. Further, a change in an outlet temperature of the catalyst sensor is detected. Thereafter, it is determined whether a reformation catalyst of the catalyst sensor is poisoned by contaminants in the fuel based on the detected change in the outlet temperature.

A method of purifying gaseous mixtures, for example ternary or quaternary gaseous mixtures, using a sorbent media comprising two or more sorbent materials. The method involves obtaining a target gas from a gaseous composition comprising the target gas, a first gas and a second gas, and optionally further gases by contacting the gaseous composition with the sorbent media to remove at least some of the first gas and at least some of the second gas from the gaseous composition. The sorbent media comprises at least a first sorbent material and a second sorbent material; wherein the first sorbent material has a higher adsorption selectivity for the first gas than for the target gas; and wherein the second sorbent material has a higher adsorption selectivity for the second gas than for target gas. The method may be particularly useful for the separation of pure ethylene, methane or propylene from such gaseous mixtures. A sorbent media and an apparatus for obtaining a target gas from such a gaseous composition are also disclosed.

The invention relates to a VOC reduction apparatus (1) comprising first and a second rotor elements (2, 3) configured to separate VOC (9) from air by adsorption and desorption; a first adsorption zone (16) configured to guide a process airflow (8) through the first rotor element (2); a first desorption zone (13) configured to guide a first regenerating airflow (18) through the first rotor element (2); a converter (36) configured to convert the VOC (9) to residual products (37). The second rotor element (3) is configured to receive the first regenerating airflow (18), after passing through the first rotor element (2), at a second adsorption zone (38). A second desorption zone (34) is configured to guide a second regenerating airflow (32) through the second rotor element (3). The converter (36) is configured to receive the second regenerating airflow (32) after the second regenerating airflow (32) has passed the second rotor element (3).

The present disclosure relates to systems and methods useful for power production. In particular, a power production cycle utilizing CO.sub.2 as a working fluid may be configured for simultaneous hydrogen production. Beneficially, substantially all carbon arising from combustion in power production and hydrogen production is captured in the form of carbon dioxide. Further, produced hydrogen (optionally mixed with nitrogen received from an air separation unit) can be input as fuel in a gas turbine combined cycle unit for additional power production therein without any atmospheric CO.sub.2 discharge.

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.

Described are methods, devices, and systems useful for removing gaseous ammonia from a gas mixture at a pressure in an ambient pressure range by allowing the ammonia to adsorb onto a solid adsorbent, as well as related systems and methods.

Provided is a system for adsorbing a gaseous component comprising nitrogen from a pressurized flow of air containing the gaseous component. The system comprises a first adsorption bed, and a second adsorption bed. Each of the adsorption beds are suitable for selectively adsorbing the gaseous component from the flow of air to produce a product gas having a higher oxygen concentration than that of the air. The system includes an adjustable feed gas supply which alternately supplies the first adsorption bed and the second adsorption bed with the air. The first adsorption bed is supplied with air during a first half cycle of operation of the system, and the second adsorption bed is then supplied with air during a second half cycle of operation of the system. The feed gas supply enables adjustment of at least one parameter relating to the amount or respective amounts of air being supplied to the first adsorption bed in the first half cycle and/or to the second adsorption bed in the second half cycle. A connection and valve assembly is provided between the first and second adsorption beds. The connection and valve assembly diverts a portion of the product gas, produced from the respective absorption bed being supplied with the flow of air during the respective half cycle, to the other adsorption bed. This causes previously adsorbed gaseous component to be released from latter. The released gaseous component then escapes from the system, e.g. to the atmosphere, via a vent. A sensor system determines a measure of the flow rate of waste gas, including the released gaseous component, escaping from the system via the vent. The at least one parameter can be adjusted based on the measure in order to tune the performance of the system. Further provided is a method for operating the system.

The present invention, and embodiments thereof, provide a process to separate ethylene products from impurities such as nitrogen, hydrogen, ethane, propane and isobutane without the need for distillation processes.

The present invention is directed to a method and system of purifying hydrogen supplied from a storage cavern, particularly to removing methane and other hydrocarbons from the hydrogen withdrawn from the cavern by using selective adsorption. The adsorbed impurities can be removed from the adsorbent by increasing the temperature, reducing the pressure, or a combination of both.

Disclosed in the present invention are a pressure equalizing system for air separation purification, and a control method. The system comprises: a first air main pipe; a pressurizing gas pipeline, which is connected to the first air main pipe and used for receiving a pressurizing gas and delivering same to the first air main pipe; and a control valve, located on the pressurizing gas pipeline, and having a degree of opening regulated by the flow regulator, thereby regulating an air intake amount of the pressurizing gas pipeline. The present invention solves the problem of an air separation rectification process being affected when dry nitrogen is used for pressure equalization of an adsorber; in the switching process of entering an adsorption stage from a regeneration stage, pressurizing dry nitrogen used in a pressure equalizing step previously mixes with damp air from a main air compressor before entering the adsorber, such that the gas components flowing towards an air separation cold box remain substantially unchanged, in order to reduce disturbance in conditions of gas entering a rectification column to take part in rectification due to a gas component gradually changing from dry nitrogen to dry air in the prior art, thus stabilizing the process conditions of the air separation cold box.