The invention relates to a method for regulating a unit for separating a gas stream, having P adsorbers, where P≥2, each following a PSA-type adsorption cycle with a phase time shift, the method involving the steps of operating the unit according to the nominal cycle when the required flow rate is equal to a nominal flow rate or optionally when the required flow rate is higher than the nominal flow rate, and operating the unit according to the reduced cycle when the required flow rate is lower than or equal to a predetermined flow rate, the predetermined flow rate being lower than the nominal flow rate.

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.

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.

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.

A gas separation and recovery method is provided. Based on the fact that a gas adsorbent has differing adsorption and desorption characteristics depending on the affinities and pressures of gas species, and gases of different species are desorbed at different timings, a target gas component is separated and recovered from a source gas by a pressure swing adsorption process in such a manner that a desorption step is divided into, for example, two time periods and desorbed gases are recovered separately in the respective time periods. In this manner, when gas 1 and gas 2 having different desorption timings are adsorbed to an adsorbent, a gas rich in gas 1, and a gas rich in gas 2 may be recovered separately from each other. Thus, it becomes possible to separate and recover selectively a target gas component with high concentration.

A pressure swing adsorption gas production device that enables performing a desorption process in adsorption towers is provided. The device includes an off gas discharge route connected to the adsorption towers, a membrane separation unit with a separation membrane allowing miscellaneous gas in the off gas discharge route to pass faster than purification target gas, an off gas tank, and a pressure boosting unit that raises the pressure of and supplies the off gas to the membrane separation unit. The off gas tank and the pressure boosting unit are upstream of the membrane separation unit. The device includes a recycle gas return route via which some recycle gas is returned to the source gas supply route. The operation control unit adjusts the off gas adjustment unit so the off gas discharge flow rate is a flow rate where the amount of off gas discharged from one adsorption tower during the desorption process is equivalent to the amount of off gas discharged from the off gas tank when the one adsorption tower starts the desorption process until another starts the desorption process.

A gas separation and recovery method is provided. Based on the fact that a gas adsorbent has differing adsorption and desorption characteristics depending on the affinities and pressures of gas species, and gases of different species are desorbed at different timings, a target gas component is separated and recovered from a source gas by a pressure swing adsorption process in such a manner that a desorption step is divided into, for example, two time periods and desorbed gases are recovered separately in the respective time periods. In this manner, when gas 1 and gas 2 having different desorption timings are adsorbed to an adsorbent, a gas rich in gas 1, and a gas rich in gas 2 may be recovered separately from each other. Thus, it becomes possible to separate and recover selectively a target gas component with high concentration.

The present disclosure provides a method for a mobile pressure swing adsorption oxygen production device, comprising a first PSA section, a second PSA section and a third PSA section which are operated in series; the first PSA section adsorbs oxygen in raw air by a velocity-selective adsorbent; the second PSA section adsorbs nitrogen etc. in desorption gas of the first PSA section by a nitrogen balance-selective adsorbent; the third PSA section removes nitrogen from oxygen-rich gas flowing out of the second PSA section; the first PSA section sequentially undergoes at least adsorption A and vacuumizing VC in one cycle; the second PSA section sequentially undergoes at least adsorption A, pressure-equalizing drop ED, backward discharge BD and pressure-equalizing rise ER; and the third PSA section sequentially undergoes at least adsorption A, pressure-equalizing drop ED, backward discharge BD and pressure-equalizing rise ER.

A pressure swing adsorption gas production device that enables performing a desorption process in adsorption towers is provided. The device includes an off gas discharge route connected to the adsorption towers, a membrane separation unit with a separation membrane allowing miscellaneous gas in the off gas discharge route to pass faster than purification target gas, an off gas tank, and a pressure boosting unit that raises the pressure of and supplies the off gas to the membrane separation unit. The off gas tank and the pressure boosting unit are upstream of the membrane separation unit. The device includes a recycle gas return route via which some recycle gas is returned to the source gas supply route. The operation control unit adjusts the off gas adjustment unit so the off gas discharge flow rate is a flow rate where the amount of off gas discharged from one adsorption tower during the desorption process is equivalent to the amount of off gas discharged from the off gas tank when the one adsorption tower starts the desorption process until another starts the desorption process.

A staged complementary pressure swing adsorption system and method for low energy fractionation of a mixed fluid. Two beds in a four-column PSA system are selective for component A, and another two columns are selective for component B. The cycle creates an intermittent A and B product, using the purge effluent from the complementary product fed at an intermediate pressure. This intermittent product is used as purge gas for low-pressure purged elsewhere in the cycle using appropriate storage tanks. The use of an intermediate pressure in this cycle enables continuous production of purified component A and B without the use of compressors. Columns may also be configured to enable pressure to equalize between complementary columns.