Systems and methods are provided for combined cycle power generation while reducing or mitigating emissions during power generation. Recycled exhaust gas from a molten carbonate fuel cell power generation reaction can be separated by using a swing adsorption process so as to generate a high purity CO.sub.2 stream while reducing or minimizing the energy required for the separation and without having to reduce the temperature of the exhaust gas. A high temperature adsorption reactor adsorbs the CO.sub.2 and recovers H.sub.2 from an exhaust gas of a first molten carbonate fuel cell at a high temperature and at a low pressure. The reactor passes along the adsorbed CO.sub.2 to a cathode and the recovered H.sub.2 to an anode of a second molten carbonate fuel cell for further power generation. This can allow for improved energy recovery while also generating high purity streams of CO.sub.2 and H.sub.2.

A carbon capture system can include a plurality of CO.sub.2 thermal swing adsorption (TSA) beds. The plurality of CO.sub.2 TSA beds can include at least a first TSA bed, a second TSA bed, and a third TSA bed configured to capture CO.sub.2 within a capture temperature range and to regenerate the captured CO.sub.2 at a regeneration temperature range above the capture temperature range. The carbon capture system can include a plurality of valves and associated flow paths configured to allow switching operational modes of each of the first, second, and third TSA beds.

A method for removing a target impurity substance from a main process flow by a regenerate material and associated systems are provided. In some embodiments, the method includes (1), directing an input flow from the main process flow to a parallel structure of components; (2) introducing the regenerate material, by the parallel structure, to the input flow to generate an impurity laden regenerate flow; (3) cooling the impurity laden regenerate flow to generate a cooled regenerate flow; (4) cleaning up the cooled regenerate flow to generate a clean regenerate flow.

A pressure swing adsorption (PSA) system and a PSA process including a PSA cycle schedule are disclosed. The PSA cycle schedule includes an unlimited number of equalization steps, no idle steps, no dead time and a minimum number of three PSA adsorbent beds assisted with two or more equalization tanks. The PSA system, process and cycle schedule include the following sequence of cycle steps: a feed step, two or more down equalization steps either between beds or between a bed and a tank, an optional forced cocurrent depressurization step coupled with a forced intermediary light end pressurization step, a countercurrent depressurization step, a light reflux step, two or more up equalization steps between beds or between a bed and a tank, an optional forced intermediary light end pressurization step coupled with the forced cocurrent depressurization step, and a light product pressurization step.

A method for preparing hydrogen gas includes a decomposition step, a first adsorption step, a second adsorption step, a first regeneration step, a third heat-exchange step, and a second regeneration step.

A pressure swing adsorption (PSA) system for purifying a feed gas is provided. The PSA system may have a first adsorber bed and a second adsorber bed, each having a feed port, a product port, and adsorbent material designed to adsorb one or more impurities from the feed gas to produce a product gas. The PSA system may also have a network of piping configured to direct the feed gas to the feed ports of the adsorber beds and direct the product gas to and from the product ports of the adsorber beds. The network of piping may also be configured to transfer gas between the first adsorber bed and the second adsorber bed during a pressure equalization step and a purge step. The PSA system may also have a first valve configured to direct flows of the feed gas and the product gas through the network of piping. The PSA system may further have a first orifice configured to regulate a flow rate of gas between the first adsorber bed and the second adsorber bed during at least one of the pressure equalization step and the purge step.

A fuel vapor processing apparatus may include a first adsorption chamber, a second adsorption chamber and a third adsorption chamber that are arranged in series with respect to a flow of gas. A ratio of a length to a diameter of the second adsorption chamber may be larger than a ratio of a length to a diameter of the first adsorption chamber. A filling ratio of an adsorbent within the second adsorption chamber may be smaller than a filling ratio of an adsorbent within the first adsorption chamber.

A fuel vapor processing apparatus may include a first adsorption chamber, a second adsorption chamber and a third adsorption chamber that are connected in series with respect to a flow of gas. A ratio of a length to a diameter of the second adsorption chamber may be larger than that of the first adsorption chamber. A cross sectional area of each of the second and third adsorption chambers may be smaller than a cross sectional area of the first adsorption chamber.

A method for adjusting a gas stream separation unit having N adsorbers, where N2, each following a PSA, VSA or VPSA adsorption cycle, with a time lag of a phase time, said adjustment method including continuously measuring a physical parameter associated with the gas stream entering and/or leaving the adsorber; for at least one step of the adsorption cycle, determining at least one characteristic value of the step chosen in step a) which is selected from the values of the physical parameter measured in step a) or a function of those values; comparing this characteristic value with a target value; and modifying the flow of the gas stream in order to obtain the target value, in the event of a variation between the value of this (these) difference(s) and the target values.

Disclosed are a system and method for purifying hydrogen, and a system for producing hydrogen by water electrolysis. The system for purifying hydrogen includes three dryers, and the three dryers share one regeneration cycle module. This significantly reduces a quantity of regeneration cycle modules, and therefore, manufacturing cost of the system is relatively low. In addition, a first gas-gas heat exchanger (4) is arranged in a regeneration cycle system, so that heat exchange can be performed between low-temperature regeneration hydrogen before regeneration and high-temperature regeneration tail gas after regeneration. In this way, residual heat of the high-temperature regeneration tail gas can be fully utilized, and power consumption of a subsequent heater and regeneration cooler can be significantly reduced. Therefore, energy consumption of the system is relatively low.