News News
Contact us
  • Customer service number:64321087
  • Commercial service telephone:13918059423
  • Technical service telephone:13918059423
  • Contact person: Mr. Cui 
  • Service email:shxtb@163.com
  • Address: room 107, building 8, no. 100, guilin road, xuhui district, Shanghai

Fine-tuned hydrocarbon separation at low energy cost

The date of: 2021-09-23
viewed: 0

source:EurekAlert

An electrochemical approach developed at KAUST produces molecular-sieving membranes that could enable a cheap energy-efficient separation of light hydrocarbons, such as olefins and paraffins. This separation, critical for the petrochemical industry, usually relies on extremely energy-intensive processes, such as distillation.

Membrane-based strategies have emerged as promising alternatives to heat-driven separation approaches. Existing polymer-based membranes are not selective enough for hydrocarbon separation and also undergo plasticization, a structural change that alters their pores, at high pressure. On the other hand, highly porous crystalline materials, called face-centered cubic metal-organic frameworks (MOFs), exhibit modular pores with precisely tunable triangular apertures.  This means they can be modified to separate light hydrocarbon mixtures. Moreover, the selected MOFs are impervious to plasticization.

Conventional MOF manufacturing methods, such as solvothermal synthesis, involve reacting organic linkers of appropriate length and bulk with a metal source to yield an extended crystalline solid with desired pore geometry. However, these methods require relatively high temperatures, high pressures and long reaction times, which are not easy to scale up.

“Our approach enables the synthesis of continuous MOF films at room temperature and ambient pressure in a short time,” says Mohamed Eddaoudi, who led the study.

The researchers chose preassembled rare-earth and zirconium hexanuclear clusters as building blocks, which reacted with linkers capable of deprotonation on demand to form tiny interconnected crystallites with exposed triangular windows.

Instead of using a base, the electrochemical approach uses external electrons to deprotonate the linkers, which makes it adaptable and easier to control by adjusting the current density and linker concentration. “The protonated linkers are first added and then deprotonated in a controlled manner for immediate consumption, affording the desired crystalline materials,” says Ph.D. student Sheng Zhou.

The resulting nanoporous membranes selectively separated propylene/propane and butane/isobutane mixtures. They also performed well under high pressure, high humidity and highly corrosive conditions similar to industrial hard streams.

The team, explained senior research scientist Osama Shekhah, chose their MOF platform for its proven chemical stability. “If we translate this MOF series into continuous membranes, it will fully meet the industrial requirements and desired robustness under practical industrial extreme conditions,” he adds. “The remaining challenge is to scale up these membranes to the requisite industrial scale.”

The team collaborated with KAUST catalysis scientists to perform simulations that suggested that the zirconium-based membranes can substantially save energy and utility costs if implemented in hybrid membrane–distillation systems producing high-purity propylene.

The team is now trying to scale up the manufacturing process to generate more compact membrane modules and assess their performance under industrial conditions. 



Hot News / Related to recommend
  • 2022 - 06 - 24
    Click on the number of times: 0
    source:azomFerroelectric materials are known as substances that exhibit spontaneous electrical polarization. Polarization implies the isolation of the negative and positive charges present inside a ma...
  • 2022 - 06 - 23
    Click on the number of times: 0
    source:bismarcktribuneNorth Dakota can’t be accused of not trying when dealing with its resources. Among other efforts, it has focused on renewable energy, has set lofty goals for carbon capture and h...
  • 2022 - 06 - 21
    Click on the number of times: 1
    source:nanowerk(Nanowerk News) Erbium-doped fiber amplifiers (EDFAs) are devices that can provide gain to the optical signal power in optical fibers, often used in long-distance communication fiber op...
  • 2022 - 06 - 20
    Click on the number of times: 1
    source:eurekalertmechanoluminescent materials are subjected to external mechanical stress, they emit visible or invisible light. Such excitation can occur due to bending or gentle pressure, for exampl...
  • Copyright ©Copyright 2018 2020 Shanghai rare earth association All Rights Reserved Shanghai ICP NO.2020034223
    the host:Shanghai Association of Rare Earth the guide:Shanghai Development and Application Office of Rare Earth the organizer:Shanghai rare earth industry promotion center
    犀牛云提供云计算服务