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氟改性納米HZSM-5分子篩催化生物乙醇制丙烯的研究

時間:2019-04-30 21:38來源:畢業論文
采用浸漬法制備了一系列的氟改性納米HZSM-5分子篩催化劑。并對樣品進行了XRD、BET、NH3-TPD等表征,并在常壓、反應溫度為500 ℃和乙醇空速(WHSV)為1.58h-1的反應條件下

摘要:采用浸漬法制備了一系列的氟改性納米HZSM-5分子篩催化劑。并對樣品進行了XRD、BET、NH3-TPD等表征,并在常壓、反應溫度為500 ℃和乙醇空速(WHSV)為1.58h-1的反應條件下,在連續流動固定床微型反應器上考察了其催化乙醇制丙烯的性能。研究結果表明,對納米HZSM-5分子篩進行氟改性后,分子篩的結構未被破壞,仍保持良好的MFI構型。但對孔結構及酸性質影響較大。隨著氟含量的不斷增加,介孔逐漸增多,強酸位的數量減少,弱酸位的數量增加。并且弱酸位對應的脫附峰向低溫偏移,表明處理后的分子篩酸強度減弱。其中氟含量為15%的改性分子篩,由于其適當的酸性質,使得其丙烯選擇性較之前有所提高,且穩定性由未改性時的51h顯著延長至102h,而且氟改性后,催化劑在乙醇制丙烯反應中的積碳量和積碳速率明顯降低。35039
畢業論文關鍵詞: 納米HZSM-5分子篩;氟化銨;丙烯;生物乙醇;乙醇制丙烯;氟含量。
 Study on peparation of propylene by bio ethanol on the fluorinated nanosized HZSM-5 zeolites
Abstract:A series of fluorinated modified nano HZSM-5 zeolite catalysts were prepared by impregnation method. And the samples were bet, XRD, NH3-TPD, and at atmospheric pressure, reaction temperature to 500℃ and ethanol airspeed (WHSV) 1.58h-1 reaction conditions of the, in a continuous flow fixed bed micro reactor was investigated the performance of the catalytic ethanol propylene. The results show that the structure of the molecular sieve is not destroyed after the modification of the nano HZSM-5 zeolite, and the structure of the MFI is maintained. However, the structure and acid properties of the hole are relatively large. With the increase of fluorine content, mesoporous gradually increased, reducing the number of strong acid sites, the increase in the number of sites. And the weak acid sites corresponding to the desorption peak to low temperature, indicating that the molecular sieve acid strength after treatment. Which fluorine content is 15% of the modified molecular sieve, due to its proper acid properties, making the propene selectivity increased compared to before and stability by the unmodified 51h significantly extended to 102H and fluorine modified, catalyst in ethanol propylene reaction product carbon content and carbon deposition rate decreased significantly. 源`自*六)維[論*文'網www.aftnzs.live
KeyWords:Nano HZSM-5 zeolite;Ammonium fluoride;Propylene;Bio ethanol;Preparation of propylene by ethanol;Fluoride content.
 目錄
1    前言    1
1.1    丙烯的主要用途及丙烯的生產技術    1
1.1.1    丙烯的主要用途及市場需求    1
1.1.2    丙烯的生產技術    2
1.2    生物乙醇的發展現狀及乙醇制丙烯技術的發展    4
1.2.1    生物乙醇    4
1.2.2    乙醇制丙烯技術的發展    5
1.3    HZSM-5分子篩及其改性的研究    6
1.3.1    HZSM-5分子篩    6
1.3.2    HZSM-5分子篩的改性研究    7
1.4    研究目的及研究內容    9
1.4.1    研究目的    9
1.4.2    研究內容    9
2    實驗部分    10
2.1    試劑與儀器    10
2.2    分子篩改性    11
2.2.1    測定吸水量    11
2.2.2    配置氟化銨溶液    11
2.2.3    等體積浸漬    11
2.2.4    烘干    12 氟改性納米HZSM-5分子篩催化生物乙醇制丙烯的研究:http://www.aftnzs.live/huaxue/20190430/32800.html
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