摘要:
The present invention involves the use of a novel membrane system for natural gas upgrading. This membrane system includes a first-stage membrane such as a membrane prepared from the polymer of intrinsic microporosity (PIM) to selectively remove hydrocarbons from C3 to C35 to control the dew point of natural gas, and a second-stage membrane such as a polybenzoxazole (PBO) or crosslinked PBO membrane to selectively remove CO2 from natural gas. The new membrane system described in the current invention eliminates the use of high cost and high footprint membrane pretreatment. Therefore, the membrane system can significantly reduce the footprint and cost for natural gas upgrading compared to the current commercially available membrane systems that include a non-membrane-related pretreatment system.
摘要:
The present invention involves the use of a multi-stage membrane system for gas, vapor, and liquid separations. In this multi-stage membrane system, high selectivity and high permeance or at least high selectivity polybenzoxazole membranes or cross-linked polybenzoxazole membranes are applied for a pre-membrane or both the pre-membrane and the secondary membrane. A primary membrane can be from conventional glassy polymers. This multi-stage membrane system can reduce inter-stage compression cost, increase product recovery and product purity for gas, vapor, and liquid separations. It can also save the cost compared to the system using all the high cost polybenzoxazole membranes or cross-linked polybenzoxazole membranes.
摘要:
Processes for olefin/paraffin separation utilizing porous, hydrophobic poly(ether ether ketone) (PEEK) membranes are provided. In accordance with an exemplary embodiment, a process for olefin/paraffin separation comprises providing a porous membrane formed of PEEK polymer functionalized with hydrophobic groups, the porous membrane having a first surface and a second surface. The first surface of the porous membrane is contacted with a feed comprising an olefin and a paraffin and a permeate is caused to flow from the second surface of the porous membrane. The permeate has a concentration of the paraffin that is higher than a concentration of the paraffin of the feed.
摘要:
The present invention discloses blend polymer membranes comprising thermally rearranged polymers derived from aromatic polyimides containing ortho-positioned functional groups and methods for making and using these blend polymer membranes. The blend polymer membranes described in the current invention are prepared by heat treatment of blend polymer membranes comprising aromatic polyimides containing ortho-positioned functional groups such as —OH or —SH groups. In some instances, an additional crosslinking step is performed to improve the selectivity of the membrane. These blend polymer membranes have improved flexibility, reduced cost, improved processability, and enhanced selectivity and/or permeability compared to the comparable polymer membranes that comprise a single polymer.
摘要:
The present invention discloses a new process of treating natural gas using high gas permeability polybenzoxazole polymer membranes operated at high temperatures that can provide sufficient dew point margin for the product gas. The high gas permeability polybenzoxazole polymer membranes can be used for a single stage membrane system or for the first stage membrane in a two stage membrane system for natural gas upgrading. Simulation study has demonstrated that a costly membrane pretreatment system such as a MemGuard™ system will not be required in the present new process. The new process can achieve significant capital cost saving and reduce the existing membrane footprint greater than 50%.
摘要:
A gas separation membrane comprises a blend of polyethersulfone (PES) and aromatic polyimide polymers that may comprise a plurality of first repeating units of formula (I), wherein X1, X 2 and X3 are herein defined.
摘要:
The present invention discloses a blends of an aromatic polyimide polymer and a polymer containing aromatic sulfonic acid groups that can be converted into polybenzoxazole (PBO) membranes for gas, vapor, and liquid separations. The PBO membranes that were prepared by thermal treating aromatic polyimide membranes containing between 0.05 and 20 wt-% of a poly(styrene sulfonic acid) polymer. These polymers showed up to 95% improvement in selectivity for CO2/CH4 and H2/CH4 separations compared to PBO membranes prepared from corresponding aromatic polyimide membranes without a poly(styrene sulfonic acid) polymer.
摘要:
In the present invention high performance cross-linked polybenzoxazole and polybenzothiazole polymer membranes and methods for making and using these membranes have been developed. The cross-linked polybenzoxazole and polybenzothiazole polymer membranes are prepared by: 1) first synthesizing polyimide polymers comprising pendent functional groups (e.g., —OH or —SH) ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone; 2) fabricating polyimide membranes from these polymers; 3) converting the polyimide membranes to polybenzoxazole or polybenzothiazole membranes by heating under inert atmosphere such as nitrogen or vacuum; and 4) finally converting the membranes to high performance cross-linked polybenzoxazole or polybenzothiazole membranes by a crosslinking treatment, preferably UV radiation. The membranes can be fabricated into any convenient geometry. The high performance cross-linked polybenzoxazole and polybenzothiazole polymer membranes of the present invention are suitable for a variety of liquid, gas, and vapor separations.
摘要:
A thin film composite membrane comprises a core layer and a sheath UV-crosslinked polymer layer. The thin film composite membrane is produced by the co-extrusion of two polymer solutions. The core layer and the sheath layer can be separately optimized. The sheath layer may be UV-crosslinked to provide stability and selectivity at the desired operating temperature of the composite membrane.
摘要:
The present invention discloses a novel method to improve the selectivities of polybenzoxazole (PBO) membranes prepared from aromatic polyimide membranes for gas, vapor, and liquid separations. The PBO membranes that were prepared by thermal treating aromatic polyimide membranes containing between 0.05 and 20 wt-% of a poly(styrene sulfonic acid) polymer. These polymers showed up to 95% improvement in selectivity for CO2/CH4 and H2/CH4 separations compared to PBO membranes prepared from corresponding aromatic polyimide membranes without a poly(styrene sulfonic acid) polymer.