摘要
采用连续共沉淀方法制备了Fe-Cu-K-SiO_2催化剂,并考察了陈化时间对催化剂的结构和织构性质的影响。采用X射线衍射、N_2吸附和程序升温还原(H_2-TPR)和X射线荧光光谱(XRF)等表征手段研究了不同陈化时间的催化剂样品的织构。结果表明,陈化时间在0.5～3.0h时,催化剂的主要物相是α-Fe_2O_3。随着陈化时间的缩短,催化剂的α-Fe_2O_3晶粒减小,比表面积逐渐增加,并且助剂铜趋于表面,使催化剂中α-Fe_2O_3易于还原。催化剂在n(H_2)/n(CO)=1.5、GHSV=3000 h^(-1)、p=1.6MPa、T=240℃下的固定床费托(F-T)合成反应评价结果表明,缩短陈化时间可明显提高催化剂的CO转化率。
A Fe-Cu-K-SiO2 catalyst for Fischer-Tropsch synthesis （FTS） was prepared by continuous co-precipitation method. The effect of aging time on the catalyst structure, texture property and catalytic performance was investigated. Catalysts obtained at different agent time were characterized by means of X-ray diffraction, N2 adsorption, X-ray fluorescence spectroscopy （XRF）, energy dispersive analysis system of X-ray （EDS） and H2 temperature-programmed reduction. It was found that during the aging time range of 0.5 h to 3 h, α-Fe2O3 was the main iron phase in these catalysts. With the decrease of aging time, the crystal size of α-Fe2O3 reduced, the specific surface area of the catalyst increased and promoter Cu ions trended to stay in the surface of catalyst, which resulted in an easy reduction of the bulk α-Fe2O3. The catalytic performance of the catalyst for FTS was evaluated in a fixed bed reactor under the reaction conditions of n（H2 ）/n（CO） = 1.5, GHSV=3 000 h^-1, p= 1.6 MPa and T=240 ℃. The evaluation results showed that the CO conversion of the catalyst increased significantly with the decrease of aging time.
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2010年第10期26-32,共7页
Petroleum Processing and Petrochemicals
关键词
费托合成
沉淀铁催化剂
共沉淀法
陈化时间
Fischer-Tropsch synthesis
precipitated iron-based catalyst
co-precipitation
aging time
