A method of obtaining purified hydrogen and purified carbon monoxide from crude synthesis gas. A first crude synthesis gas stream is passed through a first separation zone to separate a hydrogen stream from a stream comprising carbon monoxide and methane. The carbon monoxide and methane are subjected to thermal reforming to produce a second crude synthesis gas, which is passed through a second separation zone to separate carbon monoxide from the second crude synthesis gas stream.

Provided is a method for reusing an adsorbent which can stably exhibit purification ability by regenerating a used absorbent, in order to keep the composition of a purified syngas constant.

The present invention concerns a method for regenerating a zeolite adsorbent which adsorbs a carbon dioxide gas from a syngas comprising the carbon dioxide gas and reduces the concentration of the carbon dioxide gas in the syngas, comprising: a step of recovering a used zeolite adsorbent; a step of calcining the used zeolite adsorbent at a temperature of 300° C. to 600° C. in an oxygen atmosphere to produce a regenerated zeolite adsorbent; and a step of reusing the regenerated zeolite adsorbent.

A method for adjusting a gas stream separation unit having N adsorbers, where N≥2, 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.

A method for producing a carbon-monoxide-rich gas product, in which method at least carbon dioxide is subjected to electrolysis, so as to obtain an untreated gas comprising at least carbon monoxide and carbon dioxide, and in which method the untreated gas is subjected to a separation process, which comprises an adsorption and membrane separation, so as to obtain a recycling stream, which comprises the major part of the carbon dioxide contained in the untreated gas, a residual gas, and the carbon-monoxide-rich gas product. A plant for carrying out such a method is also proposed.

A process for separating two gaseous streams, including purifying a first gaseous stream in a first acid gas removal absorber, purifying in a first temperature swing adsorption unit, and then separating at a cryogenic temperature in a separation unit to produce a stream of fluid enriched in carbon monoxide and a stream of fluid enriched in hydrogen, sending a second gaseous stream containing at least carbon monoxide, hydrogen and at least one acid gas to a shift reaction unit, the shifted second stream is purified in a second acid gas removal absorber to remove carbon dioxide and the purified second stream is sent as a feed stream to a pressure swing adsorption unit to produce a hydrogen enriched stream, and sending at least part of the stream enriched in hydrogen from the separation unit as a feed stream to the pressure swing adsorption unit to produce the hydrogen-enriched stream.

The invention relates to a process and plant for purifying a raw synthesis gas containing hydrogen and carbon monoxide as target components and carbon dioxide and sulfur components as disruptive components by gas scrubbing with a physically acting, liquid scrubbing medium selective for carbon dioxide and sulfur components. The process/the plant comprise an absorption apparatus, a hot regeneration apparatus, a preferably multistage flash regeneration apparatus and a reabsorber column supplied with the first portion of a stripping gas. According to the invention the flash regeneration apparatus is supplied with the second portion of the stripping gas

The invention present provides a method (and suitable apparatus) to convert biomass to ethanol, comprising gasifying the biomass to produce raw syngas; feeding the raw syngas to an acid-gas removal unit to remove at least some CO.sub.2 and produce a conditioned syngas stream; feeding the conditioned syngas stream to a fermentor to biologically convert the syngas to ethanol; capturing a tail gas from an exit of the fermentor, wherein the tail gas comprises at least CO.sub.2 and unconverted CO or H.sub.2; and recycling a first portion of the tail gas to the fermentor and/or a second portion of the tail gas to the acid-gas removal unit. This invention allows for increased syngas conversion to ethanol, improved process efficiency, and better overall biorefinery economics for conversion of biomass to ethanol.

The invention relates to a process and a plant for removing thiols from synthesis gas. Thiols and optionally thiophene and carbon disulfide are absorbed in a dedicated absorption stage with methanol as physical absorption medium. Methanol laden with at least thiols is freed of thiols in a stripping stage with methanol vapours as stripping gas and the methanol vapours-containing thiols are freed of methanol in a scrubbing stage. The process according to the invention minimizes methanol losses and the amounts of coolant required for the process.

A hydrogen production system including a steam reformer unit, a steam addition line arranged to add steam upstream the steam reformer unit, a hydrogen membrane unit comprising a hydrogen permeable membrane and being arranged to allow at least a part of a reformed stream and a hydrocarbon feed stream to pass on different sides of a hydrogen permeable membrane, so that hydrogen passes from the reformed stream into the hydrocarbon feed stream, thereby forming said hydrogen enriched hydrocarbon stream, and a separation unit downstream the first side of the hydrogen membrane unit, where the separation unit is arranged to separating the reformed stream exiting the first side of the hydrogen membrane unit into a hydrogen product gas and an off-gas.

Disclosed herein is a gas separation membrane comprising a furan-based polymer, an apparatus comprising the gas separation membrane, and a process for separating a mixture of gases using said gas separation membrane. The process comprises contacting one side of a gas separation membrane comprising a furan-based polymer with a mixture of gases having different gas permeances, whereby at least one gas from the mixture of gases permeates preferentially across the gas separation membrane, thereby separating the at least one gas from the mixture of gases.