Reimagining petroleum refining

doi:10.1126/science.abd1307

GSTDTAP > 气候变化

DOI	10.1126/science.abd1307
	Reimagining petroleum refining
	Joan F. Brennecke; Benny Freeman
	2020-07-17
发表期刊	Science
出版年	2020
英文摘要	Chemical separations involve often-complex mixtures of molecules into individual components or mixtures of components with similar properties. Such separations are integral to a variety of technologies, such as the production of liquid fuels and chemicals for transportation as well as everything from plastic bags to sterile medical equipment. On page 310 of this issue, Thompson et al. ([ 1 ][1]) describe the preparation and characterization of new polymeric membranes for crude oil fractionation, an extremely complex hydrocarbon separation process that is vital to the production of modern fuels and chemicals. The traditional technique for separating crude oil into various fractions involves distillation, a process known since antiquity to separate more volatile from less volatile liquids. However, distillation is extremely energy intensive, relying on repeated evaporation and condensation cycles to achieve separation. Distillation dominates industrial chemical separations and consumes more than a quadrillion British thermal units (Btus) each year in the United States (∼1% of total U.S. energy use). Thus, the U.S. National Academies of Sciences, Engineering, and Medicine (NASEM) pinpointed lower-energy alternatives to distillation as a critical need ([ 2 ][2]). The use of membranes for separation of organic liquid mixtures is an attractive alternative because membranes do not rely on energy-intensive phase changes (such as boiling or condensation) to separate mixtures. The key to the development of new polymeric membranes by Thompson et al. was the synthesis of rigid spirobifluorene aryl diamine polymers (SADP). These polymers are endowed with intrinsic microporosity, which permits high rates of molecule transport. Furthermore, the rigidity enables separation of molecules on the basis of size, shape, and affinity for the membrane material while helping to control swelling of the polymers when in contact with chemically challenging environments. Traditionally, polymers are constructed from organic building blocks, so they absorb these components and swell when in contact with organic mixtures (such as those found in crude oil). Swelling can be highly deleterious to a membrane's ability to separate molecules of similar shape and size. Therefore, although polymeric membranes are widely used for water purification (desalination) and gas separation (air separation, natural gas purification, and hydrogen recovery), they have not been commercialized for large-scale separations of complex organics, such as crude oil ([ 3 ][3]). Early-stage experiments use dense, thick films and simple binary mixtures of organic liquids to acquire preliminary membrane separation data. This step is important for two reasons: developing structure-property relations to guide future membrane choices and elucidating fundamental details of penetrant transport mechanisms in such materials. However, to be of practical relevance, any interesting membrane material must also be manufactured as a thin-film asymmetric or thin-film composite membrane and be able to separate mixtures of interest. Whereas the former studies are quite common in the membrane literature, the latter thin-film studies are exceptionally rare. Thompson et al. report both types of data, including the successful preparation of thin-film (∼0.2 µm) composite membranes by dip-coating the polymer onto a porous support. The success of these studies demonstrated the practical feasibility of the new approach. In addition to showing excellent selectivity when challenged with model mixtures (for example, separation of 80% of 1,3,5-triisopropylbenzene from toluene), t he thin-film membrane developed by Thompson et al. also demonstrated very good separation results for an actual sample of (extremely) light crude oil. The previously mentioned NASEM report also highlighted the lack of separation materials that can handle complex mixtures as a major gap in materials science ([ 2 ][2]). Crude oil is a quintessential example of a complex mixture of great commercial interest. Challenging the new membrane materials with real crude oil and demonstrating its successful separation into two streams (one comprising mostly higher boiling compounds and the other comprising lower boiling compounds) suggest that the membranes have practical promise. Thus, the new study moved all the way from rational molecular tailoring of new materials with attractive separation properties to the practical realization of a promising new thin separation membrane, a rare and extraordinary feat of great value to the field. Another exciting aspect of the Thompson et al. study is its focus on one of the largest-scale chemical-separation challenges on the planet: the fractionation of crude oil into components needed for fuels and chemicals. Membranes are already being used for other important separation processes at scales comparable with that needed for crude oil fractionation. For example, as of 2019, 65.5 × 106 m3/day (17,300 million gallons/day) of water are being desalinated by using reverse osmosis membranes ([ 4 ][4]). For comparison, the amount of global crude oil produced is ∼4200 million gallons/day ([ 5 ][5]). Desalination of Pacific Ocean seawater by using reverse-osmosis membranes requires about 2.5 kWh/m3 to operate the membranes ([ 6 ][6]), with figures varying somewhat depending on location and salinity ([ 7 ][7]). Distillation-based desalination processes such as multieffect evaporation and multistage flash require 5.5 to 9 and 10 to 16 kWh/m3, respectively ([ 8 ][8]). These numbers highlight the large reductions in energy use achievable by transitioning from distillation-based separations to membranes. Even hybrid distillation-membrane systems could yield dramatic energy savings and, in turn, markedly reduce the greenhouse gas production associated with such processes. Challenges remain in the development of polymeric membranes for crude oil refining. The most important advance would be to increase a membrane's flux (t he amount of material that permeates the membrane per unit membrane surface area), which determines the size (or number) of membrane modules required—and thereby the capital cost—to meet a particular refinery capacity. The flux measured by permeance through the less selective, standard polymers of intrinsic microporosity (PIMs) membranes is more than 10 times higher than t hat of the new SADP polymers, demonstrating a trade-off between permeability and selectivity. A reduction in flux over time (fouling) might well be another challenge, especially with heavier crude oils. The new work represents a major step toward a future in which citizens will drive by oil refineries without ever noticing the reduced energy demand, process intensification, and less carbon-intensive nature of this vital industrial process. 1. [↵][9]1. K. A. Thompson et al ., Science 369, 310 (2020). [OpenUrl][10][Abstract/FREE Full Text][11] 2. [↵][12]U.S. NASEM, A Research Agenda for Transforming Separation Science (National Academies Press, 2019). 3. [↵][13]1. R. W. Baker , Membrane Technology and Applications (John Wiley & Sons, ed. 3, 2012), pp. 394–395. 4. [↵][14]1. E. Jones, 2. M. Qadir, 3. M. T. H. van Vliet, 4. V. Smakhtin, 5. S.-M. Kang , Sci. Total Environ. 657, 1343 (2019). [OpenUrl][15] 5. [↵][16]U.S. Energy Information Administration (EIA), Short-term energy outlook (2020); [www.eia.gov/outlooks/steo/report/global_oil.php][17]. 6. [↵][18]1. N. Voutchkov , Desalination 431, 2 (2018). [OpenUrl][19] 7. [↵][20]1. J. Kim, 2. K. Park, 3. D. R. Yang, 4. S. Hong , Appl. Energy 254, 113652 (2019). [OpenUrl][21] 8. [↵][22]1. S. Zhou, 2. L. Gong, 3. X. Liu, 4. S. Shen , Appl. Therm. Eng. 159, 113759 (2019). [OpenUrl][23] Acknowledgments: J.F.B. thanks the Welch Foundation for support (grant F-1945). B.F. thanks the Center for Materials for Water and Energy Systems for support (Award #DE-SC0019272). [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #ref-4 [5]: #ref-5 [6]: #ref-6 [7]: #ref-7 [8]: #ref-8 [9]: #xref-ref-1-1 "View reference 1 in text" [10]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.aulast%253DThompson%26rft.auinit1%253DK.%2BA.%26rft.volume%253D369%26rft.issue%253D6501%26rft.spage%253D310%26rft.epage%253D315%26rft.atitle%253DN-Aryl-linked%2Bspirocyclic%2Bpolymers%2Bfor%2Bmembrane%2Bseparations%2Bof%2Bcomplex%2Bhydrocarbon%2Bmixtures%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.aba9806%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [11]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEyOiIzNjkvNjUwMS8zMTAiO3M6NDoiYXRvbSI7czoyMjoiL3NjaS8zNjkvNjUwMS8yNTQuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9 [12]: #xref-ref-2-1 "View reference 2 in text" [13]: #xref-ref-3-1 "View reference 3 in text" [14]: #xref-ref-4-1 "View reference 4 in text" [15]: {openurl}?query=rft.jtitle%253DSci.%2BTotal%2BEnviron.%26rft.volume%253D657%26rft.spage%253D1343%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [16]: #xref-ref-5-1 "View reference 5 in text" [17]: http://www.eia.gov/outlooks/steo/report/global_oil.php [18]: #xref-ref-6-1 "View reference 6 in text" [19]: {openurl}?query=rft.jtitle%253DDesalination%26rft.volume%253D431%26rft.spage%253D2%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [20]: #xref-ref-7-1 "View reference 7 in text" [21]: {openurl}?query=rft.jtitle%253DAppl.%2BEnergy%26rft.volume%253D254%26rft.spage%253D113652%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [22]: #xref-ref-8-1 "View reference 8 in text" [23]: {openurl}?query=rft.jtitle%253DAppl.%2BTherm.%2BEng.%26rft.volume%253D159%26rft.spage%253D113759%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx
领域	气候变化 ; 资源环境
URL	查看原文
引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/284339
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Joan F. Brennecke,Benny Freeman. Reimagining petroleum refining[J]. Science,2020.
APA	Joan F. Brennecke,&Benny Freeman.(2020).Reimagining petroleum refining.Science.
MLA	Joan F. Brennecke,et al."Reimagining petroleum refining".Science (2020).