A gas block (10) for the removal of multiple contaminants from a gaseous stream from an electrolyser (1). The gas block (10) comprises at least one inlet (13), the at least one inlet being configured to receive a gaseous stream from an electrolyser, and at least two outlets (12, 14), wherein the first outlet (12) is configured for the removal of contaminant liquid from the gas block, and the second outlet (14) is configured for the release of the gaseous stream from the gas block. A first removal chamber (15) is situated along a flow path of the gaseous stream between the at least one inlet and the first outlet, the first removal chamber being for removal of liquid and/or vapour from the gaseous stream. A second removal chamber (16) is situated along a flow path of the gaseous stream between the first removal chamber and the second outlet, the second removal chamber being for removal of a further contaminant from the gaseous stream. The gas block is primarily for use in the purification of a hydrogen stream from an electrolyser.

An air dryer includes a first flow path through the air dryer and a second flow path through the air dryer in parallel with the first flow path. A diverter valve has a first position that provides fluid communication to the first flow path and a second position that provides fluid communication to the second flow path. A system parameter signal is reflective of fluid flow through the air dryer, and a controller receives the system parameter signal and produces a first control signal based on the system parameter signal. The first control signal controls the position of the diverter valve.

A method for providing upgraded biogas includes feeding a stream of biogas into a biogas upgrading system in order to remove carbon dioxide from the stream of biogas. The biogas upgrading system, which may be based on absorption, adsorption, membrane permeation, and/or cryogenics, provides a stream of upgraded biogas and a tail gas stream. The tail gas stream, which may be CO.sub.2-rich, is enriched with natural gas so that it is combustible in medium-BTU equipment. The upgraded biogas is used for transportation use and/or the generation of fuel credits. Accordingly, both the tail gas and the upgraded biogas are used effectively and at lower cost.

An apparatus, method and system remove contaminants from a vapor. In an embodiment, a contaminant removal apparatus includes a vacuum box. The vacuum box is a vessel. The apparatus also includes a demister pad disposed in the vacuum box. A vapor is introduced to the vacuum box on an opposing side of the demister pad from a vapor exit from the vacuum box.

Wastewater treatment and conveyance; and other chemical processes result in emission of a wide variety of odorous compounds. Contaminated exhaust air is typically a byproduct emitted from sludge in tanks and wells that are part of a wastewater treatment, conveyance, or chemical process. Said contaminated air has to be treated to capture or reduce odorous compounds or pollutants below human smell recognition threshold levels before the exhaust is discharged to the atmosphere. The present invention is a carbon scrubber used to treat and filter contaminated exhaust air produced in wastewater treatment and conveyance; and other chemical processes.

A method for providing upgraded biogas includes feeding a stream of biogas into a biogas upgrading system in order to remove carbon dioxide from the stream of biogas. The biogas upgrading system, which may be based on absorption, adsorption, membrane permeation, and/or cryogenics, provides a stream of upgraded biogas and a tail gas stream. The tail gas stream, which may be CO.sub.2-rich, is enriched with natural gas so that it is combustible in medium-BTU equipment. The upgraded biogas is used for transportation use and/or the generation of fuel credits. Accordingly, both the tail gas and the upgraded biogas are used effectively and at lower cost.

An on-board aircraft inert gas system includes a source of hydrocarbon, a source of gas comprising oxygen, and a first fluid flow path between the source of gas comprising oxygen and an inert gas output. A reactor is disposed along the first fluid flow path that reacts oxygen and hydrocarbon from the fuel tank gas space to produce an oxygen-depleted gas. A heat exchanger condenser removes some water from the oxygen-depleted gas. A water-permeable gas membrane separator receives the oxygen-depleted gas from the heat exchanger and outputs dried oxygen-depleted gas.

A method for providing upgraded biogas includes feeding a stream of biogas into a biogas upgrading system in order to remove carbon dioxide from the stream of biogas. The biogas upgrading system, which may be based on absorption, adsorption, membrane permeation, and/or cryogenics, provides a stream of upgraded biogas and a tail gas stream. The tail gas stream, which may be CO.sub.2-rich, is enriched with natural gas so that it is combustible in medium-BTU equipment. The upgraded biogas is used for transportation use and/or the generation of fuel credits. Accordingly, both the tail gas and the upgraded biogas are used effectively and at lower cost.

A refrigerator includes a storage compartment having a front opening and an air sanitation device mounted on a top wall of the storage compartment. The air sanitation device includes: a housing, an air channel located in the housing, a fan, and an air detection device and/or an air purification device located in the air channel. The housing includes a front wall facing the front opening, a rear wall, an upper wall, a lower wall, and a pair of side walls. The air channel includes an air inlet and an air outlet. The fan is configured to force air to enter the air channel from the air inlet, and then be discharged out from the air outlet. The air inlet is located on at least one of the side walls, and the air outlet is located on the rear wall.

A refrigerator has an air sanitation device. The air sanitation device includes: a housing; an air channel located in the housing and having an air inlet and an air outlet; a fan located in the air channel, to force air to enter the air channel from the air inlet, and then be discharged out of the air channel from the air outlet; and an air detection device and/or an air purification device located between the air inlet and an inlet of the fan.