本文選題：氮化硼　切入點：三聚氰胺　出處：《江蘇大學》2017年碩士論文

【摘要】：燃油中的含硫化合物經(jīng)燃燒后產(chǎn)生的SOx,NOx等有毒有害氣體對空氣、水等人類生存環(huán)境造成了嚴重的威脅。抑制或者減少硫的排放量成為當前的一個熱點話題。工業(yè)上傳統(tǒng)的加氫脫硫(HDS)技術雖然能夠?qū)⑷加椭械牧蛎�、硫醇、噻吩化合物輕易地除去,然而對于像含有大量二苯并噻吩(DBT)及其衍生物的柴油,運用HDS技術需要更高的溫度和壓力,消耗更多的氫氣,同時在如此苛刻的條件下,油品的損失也會增加,這大大提高了生產(chǎn)成本。與HDS技術相比,吸附脫硫(ADS)技術具有耗能低、操作條件溫和等優(yōu)點而被認為是極具應用前景的技術之一。本論文設計合成了一系列氰胺化合物衍生的氮化硼(BN)吸附劑并用于燃油吸附脫硫研究。在該工作中,以三聚氰胺(C3H6N6)、二聚氰胺(C2H4N4)、單氰胺(CH2N2)為氮源用于改變BN的納米結(jié)構(gòu)。其中,以C3H6N6為氮源合成得到的BN是一種多孔納米片堆集而成的類棒狀結(jié)構(gòu),且具有很高的吸附脫硫性能。這種結(jié)構(gòu)的BN能夠暴露更多的邊緣且在其表面形成孔結(jié)構(gòu),從而有大量的低配位原子存在,提供更多的吸附位點,大大提升了BN的吸附性能。該吸附劑對硫含量為500 ppm的模擬油的吸附容量達到了40.2 mgS·g-1 adsorbent。此外,對極難脫除的4,6-DMDBT,該吸附劑依然展現(xiàn)了極佳的吸附性能。鑒于前面的工作基礎,通過引入電負性更高的雜原子可以提升B原子的正電性,從而增強BN與硫化物之間的相互作用。為了進一步提高BN的吸附性能,以硼酸和三聚氰胺為原料、P123為模板劑,成功合成了一種氧原子摻雜的介孔BN納米線。通過多種表征手段研究了合成的BN的結(jié)構(gòu)、形貌、表面性質(zhì)以及電子結(jié)構(gòu)。所得的介孔BN納米線首次被用于燃油吸附脫硫考察,對模擬油中DBT具有極佳的吸附性能,根據(jù)Langmuir吸附曲線擬合得到理論最大吸附容量為65.4 mgS·g-1 adsorbent。與商品級BN和類石墨烯BN相比,其吸附性能大幅度提升,這主要是由于氧原子的引入增強了吸附劑與硫化物之間的相互作用。此外,介孔BN納米線具有很好的穩(wěn)定性,而且對4,6-DMDBT的吸附容量達到了33.2 mgS·g-1 adsorbent。盡管摻雜氧原子能夠增強BN與硫化物之間的相互作用,但是氧原子摻雜的BN吸附劑的吸附性能并不能滿足當前的國Ⅴ標準需求。因此,針對目前燃油的國Ⅴ標準,本工作進一步通過模板法在較低溫度下合成了一系列的BN吸附劑。旨在通過調(diào)節(jié)模板劑的種類、用量、合成溫度,優(yōu)化BN的吸附脫硫性能。經(jīng)過優(yōu)化之后的活性BN-P123吸附劑具有較大的比表面積,其比表面積達到了1185m2·g-1,對初始硫含量為500 ppm的模擬油中DBT的吸附容量達到了45.7 mgS·g-1adsorbent。此外,合成得到的活性BN-P123吸附劑能夠?qū)崿F(xiàn)燃油的深度脫硫,達到目前所需要的燃油標準(10 ppm)。該活性BN-P123吸附劑具有無毒、無金屬、高吸附脫硫性能,有望在工業(yè)上得到應用。
[Abstract]:So _ xN _ x and other toxic and harmful gases produced by burning sulfur compounds in fuel oil pose a serious threat to the living environment of human beings such as air, water and so on.Restraining or reducing sulfur emissions has become a hot topic.Although the traditional industrial hydrodesulfurization (HDS) technology can easily remove thioether, mercaptan and thiophene compounds from fuel oil, however, for diesel oil such as diesel containing a large amount of dibenzothiophene (DBT) and its derivatives,Using HDS technology requires higher temperature and pressure to consume more hydrogen. At the same time, the loss of oil will increase under such harsh conditions, which greatly increases the production cost.Compared with HDS technology, adsorption desulfurization (HDS) technology has the advantages of low energy consumption and mild operating conditions, so it is considered to be one of the most promising technologies.A series of boron nitride (BN) adsorbents derived from cyanamide compounds were designed and synthesized in this paper.In this work, melamine C _ 3H _ 6N _ 6C _ 3H _ 6N _ 6, C _ 2H _ 4N _ 4N _ 4 and Ch _ 2N _ 2) were used as nitrogen sources to change the nanostructure of BN.The BN synthesized with C3H6N6 as nitrogen source is a kind of rod-like structure stacked by porous nanochips and has high adsorption and desulfurization performance.The BN with this structure can expose more edges and form pore structures on its surface, thus there are a large number of low coordination atoms, providing more adsorption sites, which greatly improves the adsorption performance of BN.The adsorption capacity of the adsorbent for the simulated oil with sulfur content of 500 ppm was 40.2 mgS g ~ (-1) adsorbent.In addition, the adsorbent showed excellent adsorption properties for 4H 6 DMDBT, which is very difficult to be removed.In view of the previous work, the interaction between BN and sulfides can be enhanced by introducing higher electronegativity heteroatoms to enhance the positive charge of B atoms.In order to further improve the adsorption properties of BN, a mesoporous BN nanowire doped with oxygen atom was successfully synthesized with boric acid and melamine as template.The structure, morphology, surface properties and electronic structure of the synthesized BN were studied by various characterization methods.The mesoporous BN nanowires have been used for the first time to investigate the desulfurization of fuel oil. The mesoporous BN nanowires have excellent adsorption performance for DBT in simulated oil. The theoretical maximum adsorption capacity is 65.4 mgS g-1 adsorbent. according to Langmuir adsorption curve fitting.Compared with commodity grade BN and graphene like BN, the adsorption properties of the adsorbents were greatly improved, which was mainly due to the introduction of oxygen atoms to enhance the interaction between adsorbents and sulfides.In addition, the mesoporous BN nanowires have good stability, and the adsorption capacity of 4-DMDBT reaches 33.2 mgS g-1 adsorbent.Although doping oxygen atoms can enhance the interaction between BN and sulfides, the adsorption properties of oxygen atom doped BN adsorbents can not meet the needs of current state 鈪，

本文編號：1721454