化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2014年
11期
4347-4355
,共9页
陈伦刚%刘勇%定明月%张兴华%李宇萍%张琦%王铁军%马隆龙
陳倫剛%劉勇%定明月%張興華%李宇萍%張琦%王鐵軍%馬隆龍
진륜강%류용%정명월%장흥화%리우평%장기%왕철군%마륭룡
催化加氢%费托水%催化剂%羧酸%醇%载体
催化加氫%費託水%催化劑%羧痠%醇%載體
최화가경%비탁수%최화제%최산%순%재체
catalytic hydrogenation%F-T water%catalyst%carboxylic acid%alcohol%support
采用催化加氢技术脱除F-T合成水相中羧酸、醛、醇、酮、酯含氧化合物,考察了Ru/ZrO2、Ru/TiO2、Ru/SiO2和Ru/Al2O34种Ru催化剂的反应性能。相对于酸、醇,水中的醛、酮、酯更易被转化。其中Ru/ZrO2和Ru/TiO2具有良好的加氢脱羰活性,在200℃、9.8 MPa、3.0 h-1空速下,酸、醛、醇、酮、酯均转化为C1~C6的烷烃,总转化率达92%。同条件下,虽然Ru/Al2O3对酸、醛、酮、酯的转化活性较高(>87%),但对醇的转化不到30%,具有选择性转化特点。H2-TPR和NH3-TPD结果表明,Ru/Al2O3催化剂的金属活性位与载体酸性位的协同作用有利于羧酸的加氢反应,能抑制醇的加氢脱羰活性;而金属-载体相互作用较弱和酸度较低的催化剂有利于羧酸、醇发生加氢脱羰反应。Ru/Al2O3催化剂运行500 h后失活,XRD、SEM和N2-物理吸附表明,载体结构物相和织构性质的改变以及活性组分的流失是导致催化剂失活的主要因素。
採用催化加氫技術脫除F-T閤成水相中羧痠、醛、醇、酮、酯含氧化閤物,攷察瞭Ru/ZrO2、Ru/TiO2、Ru/SiO2和Ru/Al2O34種Ru催化劑的反應性能。相對于痠、醇,水中的醛、酮、酯更易被轉化。其中Ru/ZrO2和Ru/TiO2具有良好的加氫脫羰活性,在200℃、9.8 MPa、3.0 h-1空速下,痠、醛、醇、酮、酯均轉化為C1~C6的烷烴,總轉化率達92%。同條件下,雖然Ru/Al2O3對痠、醛、酮、酯的轉化活性較高(>87%),但對醇的轉化不到30%,具有選擇性轉化特點。H2-TPR和NH3-TPD結果錶明,Ru/Al2O3催化劑的金屬活性位與載體痠性位的協同作用有利于羧痠的加氫反應,能抑製醇的加氫脫羰活性;而金屬-載體相互作用較弱和痠度較低的催化劑有利于羧痠、醇髮生加氫脫羰反應。Ru/Al2O3催化劑運行500 h後失活,XRD、SEM和N2-物理吸附錶明,載體結構物相和織構性質的改變以及活性組分的流失是導緻催化劑失活的主要因素。
채용최화가경기술탈제F-T합성수상중최산、철、순、동、지함양화합물,고찰료Ru/ZrO2、Ru/TiO2、Ru/SiO2화Ru/Al2O34충Ru최화제적반응성능。상대우산、순,수중적철、동、지경역피전화。기중Ru/ZrO2화Ru/TiO2구유량호적가경탈탄활성,재200℃、9.8 MPa、3.0 h-1공속하,산、철、순、동、지균전화위C1~C6적완경,총전화솔체92%。동조건하,수연Ru/Al2O3대산、철、동、지적전화활성교고(>87%),단대순적전화불도30%,구유선택성전화특점。H2-TPR화NH3-TPD결과표명,Ru/Al2O3최화제적금속활성위여재체산성위적협동작용유리우최산적가경반응,능억제순적가경탈탄활성;이금속-재체상호작용교약화산도교저적최화제유리우최산、순발생가경탈탄반응。Ru/Al2O3최화제운행500 h후실활,XRD、SEM화N2-물리흡부표명,재체결구물상화직구성질적개변이급활성조분적류실시도치최화제실활적주요인소。
Removal of oxygenates in aqueous phase product of Fischer-Tropsch (F-T) process was studied by the catalytic hydrogenation over supported Ru catalysts. The catalytic performance of several Ru catalysts supported on different metal oxides such as ZrO2, TiO2, SiO2 andγ-Al2O3 was investigated. In the catalytic hydrogenation processes, aldehydes, ketones and esters are more readily to be transformed than carboxylic acid and alcohol. The Ru/ZrO2 and Ru/TiO2 catalysts exhibited excellent hydrogenation activity, and under the conditions of 200℃, 9.8 MPa pressure and 3.0 h-1 WHSV, the carboxylic acids, aldehydes, alcohols, ketones and esters all are transformed to C1- C6 alkanes with overall conversion of above 92%. However, the Ru/Al2O3 catalyst displays the lowest activity towards alcohols with below 30% of conversion at the same conditions, although other oxygenates, including carboxylic acids, aldehydes, ketones and esters, are transformed with considerable conversion of above 87%, indicating that the Ru/Al2O3catalyst was of selectivity for the conversion of oxygenates and the most of alcohols can not be transformed. The results from H2-TPR and NH3-TPD reveal that the synergy between metal and alumina is conductive to the hydrogenation of carboxylic acids and inhibits the hydrogenation-decarbonylation of alcohols. On the contrary, the catalysts with weak metal-support interaction and low acidity improve the hydrogenation activity for carboxylic acids and alcohols. However, there was a good stability of 400 h for Ru/Al2O3catalyst, although the degeneration of catalytic activity was also observed after running 400 h. The results from X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2 physisorption show that the change of textural and structural properties is the key factors for activity degeneration of Ru/Al2O3catalyst, because of the transformation ofγ-alumina to boehmite and of the great decrease of surface area from 197 m2·g-1 to 21 m2·g-1 and loss of porosity.