Methods of making a poly(propylenimine) (PPI) sorbent, a PPI sorbent, structures including the PPI sorbent, methods of separating CO.sub.2 using the PPI sorbent, and the like, are disclosed.

A membrane including a polymer substrate having pore channels and a metal-organic framework disposed on the polymer substrate. Methods of producing the membrane are described. Methods of separating gases using the membrane are also provided.

A dehydration method is a dehydration method for selectively separating water from a mixture that contains water, using a zeolite membrane having an AFX structure, and the method includes a step of supplying the mixture to a supply side space of the zeolite membrane having an AFX structure, and a step of making a pressure difference between the supply side space and a permeation side space of the zeolite membrane having an AFX structure.

A ceramic filter is provided with a porous substrate 3 “made of ceramic and having partition walls 1 separating and forming a plurality of cells 2 extending from one end face 11 to the other end face 12”, a separation membrane 21 “made of ceramic and disposed on wall surfaces of the cells 2”, and glass seals 31 disposed on the one end face 11 and on the other end face 12 “so as not to cover openings of the cells 2”. Ceramic particles having a thermal expansion coefficient of 90 to 110% of that of glass contained in the glass seals 31 are dispersed in the glass seals 31. There is provided a ceramic filter usable for a long period of time in high temperature conditions.

Carbon dioxide gas in a high-pressure gas to be treated is stably separated using a separation membrane. Upon separating carbon dioxide gas in a high-pressure gas to be treated using a separation membrane module including a separation membrane, a preliminary boosted gas is supplied to the separation membrane module before the supply of natural gas is started to boost a pressure on a primary side of the separation membrane to a preliminary pressure between a stand-by pressure and an operating pressure. Thus, when the supply of a high-pressure gas to be treated is started to increase the pressure of the separation membrane module to an operating pressure, an abrupt decrease in temperature of the gas to be treated can be suppressed.

A separation membrane structure comprises a porous support, a first separation membrane formed on the porous support, and a second separation membrane formed on the first separation membrane. The first separation membrane has an average pore diameter of greater than or equal to 0.32 nm and less than or equal to 0.44 nm. The second separation membrane includes addition of at least one of a metal cation or a metal complex that tends to adsorb nitrogen in comparison to methane.

A separation membrane structure comprises a porous suppor, and a separation membrane formed on the porous support. The separation membrane has an average pore diameter of greater than or equal to 0.32 nm and less than or equal to 0.44 nm. The separation membrane includes addition of at least one of a metal cation or a metal complex that tends to adsorb nitrogen in comparison to methane.

A separation membrane structure comprises a porous support body, a zeolite membrane formed on the porous support body and comprising pores having a major diameter and a minor diameter. The ratio of a major diameter to a minor diameter is greater than 1.0. The minor diameter is greater than or equal to 0.30 nm and less than or equal to 0.35 nm.

The invention provides mixed matrix membranes (MMMs) for olefin/paraffin separation and methodes of making and using the same. The MMMs comprise a continuous polymer matrix with metal doped zeolite nano-particles. A separation technology based upon the composite membranes is effective for propylene and other olefin separation from olefin/paraffin mixtures, and the separation is more energy-efficient than the conventional cryogenic technique.

The present invention provides a method for fabricating an oriented zeolite film including preparing a metal substrate and zeolite crystal with an aspect ratio of at least 2; laying the zeolite crystal on the metal substrate to obtain a first metal substrate; applying a precursor solution containing a first structure directing agent and a solvent on the first metal substrate to obtain a second metal substrate; placing the second metal substrate in a sealed container containing a predetermined amount of the solvent; and heating the sealed container at 100-550° C. for at least 15 minutes. Thus, a continuous oriented zeolite film is formed with uniform thickness and improved anti-corrosion ability.