Download presentation
Presentation is loading. Please wait.
1
等离子体在催化反应中的应用 陶旭梅 刘改焕 齐凤伟 李代红 印永祥 四川大学 化工学院 成都
2
主要内容 1 等离子体技术与催化过程结合的可能性 2 等离子体技术应用于催化剂制备 3 等离子体与催化剂协同作用于化学反应 4 结论与展望
3
1 等离子体与催化过程结合
4
1. 等离子体与催化过程相结合 1.1 等离子体催化材料制备 超细催化剂制备、表面改性、快速还原 1.2 等离子体诱导的化学反应特征
1.1 等离子体催化材料制备 超细催化剂制备、表面改性、快速还原 1.2 等离子体诱导的化学反应特征 快速、非平衡低温、选择性不易控制 1.3 催化反应特征 需要较高温度,选择性好
5
2 等离子体应用于催化剂制备
6
2. 等离子体技术应用于催化剂制备 2.1 热等离子体直接合成超细颗粒催化剂 2.2 等离子体喷涂技术制备负载型催化剂
2.1 热等离子体直接合成超细颗粒催化剂 2.2 等离子体喷涂技术制备负载型催化剂 2.3 催化剂表面处理 2.4 等离子体还原催化剂
7
2.1 热等离子体直接合成超细颗粒催化剂 Fig.1 Schematic drawing of the plasma-chemical installation for synthesis and regeneration of catalysts 1. electric-arc dc plasmatron CW PCR quenching device copper water-cooled sections for the quenching device 5. power-trapping chamber filter vibration power-feeding device current rectifier flow-meters 10. bottles with plasma-forming, powder carrying and quenching gases G.P.Vissokov,M.I.Panayotova.Plasma-chemical synthesis and regeneration of catalysts for reforming natural gas.Catalysis Today,2002,72:
8
2.1 热等离子体直接合成超细颗粒催化剂 Fig.2 SEM micrographs (a) (b) (c)
(a) alumina prior to plasma treatment (b) Pd/alumina after passage through an argon plasma (c) enlargement
9
Fig.3 Plasma spraying applied for catalyst preparation
2.2 等离子体喷涂技术制备负载型催化剂 Fig.3 Plasma spraying applied for catalyst preparation Chang-jun Liu,Gheorghi P. Vissokov,Ben W.-L. Jang.Catalyst preparation using plasma technologies.Catalysis Today,2002,72:
10
2.3 催化剂表面处理 Fig.4 The schematic representative of setup for glow discharge catalyst treatment Dang-guo Cheng,Xinli Zhu,Yuheng Ben,Fei He,Lan Cui,Chang-jun Liu.Carbon dioxide reforming of methane over Ni/Al2O3 treated with glow discharge plasma.Catalysis Today,2006,115:
11
Fig.5 Apparatus schematic diagram of plasma jet
2.4 等离子体还原催化剂 首次以高频冷等离子体炬处理Ni/γ-Al2O3催化剂,代替常规制备方法中的焙烧和还原过程。 Fig.5 Apparatus schematic diagram of plasma jet
12
2.4 等离子体还原催化剂 12%Ni/γ-Al2O3 催化剂的制备 浸渍: γ- Al2O3+ 常规浸渍法(C) 等离子体还原法(PR)
2.4 等离子体还原催化剂 12%Ni/γ-Al2O3 催化剂的制备 常规浸渍法(C) 等离子体还原法(PR) 等离子体焙烧还原法(PCR) 浸渍:γ- Al2O3+ Ni(NO3)2 干燥:at 110 ℃ for 5 h 焙烧:at 550 ℃ for 5 h 还原:at 750 ℃ for 2h 浸渍:γ- Al2O3+ Ni(NO3)2 干燥:at 110 ℃ for 5 h 焙烧:at 550 ℃ for 5 h 等离子体还原:for 10min 浸渍: γ- Al2O3+ Ni(NO3)2 干燥:at 110 ℃ for 5 h 等离子体还原:for 10min
13
Fig.6 Effect of reaction temperature on catalytic activity
2.4 等离子体还原催化剂 Fig.6 Effect of reaction temperature on catalytic activity Reaction condition: m catalyst=200mg, wt Ni%=12%, T=600~900℃, GHSV=3.0×104 mL/(g·h), CH4/CO2=4/6.
14
Fig.6 Effect of reaction temperature on catalytic activity
2.4 等离子体还原催化剂 Fig.6 Effect of reaction temperature on catalytic activity Reaction condition: m catalyst=200mg, wt Ni%=12%, T=600~900℃, GHSV=3.0×104 mL/(g·h), CH4/CO2=4/6.
15
(A) C; (B) PC; (C) PCR (△) γ-Al2O3; (○) Ni
2.4 等离子体还原催化剂 Fig.7 XRD patterns (A) C; (B) PC; (C) PCR (△) γ-Al2O3; (○) Ni
16
2.4 等离子体还原催化剂 Fig.8 H2-TPD (A) C; (B) PC; (C) PCR
17
2.4 等离子体还原催化剂 Fig.9 CO2-TPD (A) C; (B) PC; (C) PCR
18
2.4 等离子体还原催化剂 (A) (B) (C) Fig.10 TGA profile of Ni/γ-Al2O3 catalyst after reaction at 800℃ for 5h (A) C; (B) PC; (C) PCR
19
Table 1 The TGA analyses of used catalyst
2.4 等离子体还原催化剂 Table 1 The TGA analyses of used catalyst Conditions: Reaction temperature=800℃,GHSV=3.0×104 mL/(g·h), CH4/CO2=4/6, reaction time=5h.
20
2.4 等离子体还原催化剂 耗时短 高分散度 结论 更好的低温活性 更好的抗积碳性
21
3 等离子体和催化剂协同作用
22
3. 等离子体和催化剂协同作用 脉冲电晕放电 1 2 介质阻挡放电 3 微波放电 4 射频放电 5 冷等离子体炬 6 热等离子体
23
Fig.11 Schematic diagram of experimental process
3. 等离子体和催化剂协同作用 冷等离子体炬CH4-CO2重整制合成气 Fig.11 Schematic diagram of experimental process 1. CH4;2. CO2;3.N2;4.needle nozzle;5.rotormeter; 6.mixing device;7.power supply;8.reactor;9.catalyst bed;10 cooling system
24
Fig.12 Effect of catalyst on the reaction
3. 等离子体和催化剂协同作用 冷等离子体炬CH4-CO2重整制合成气 Fig.12 Effect of catalyst on the reaction Reaction condition: CH4 flux =0.2m3/h, CO2 flux =0.3m3/h,N2 flux =0.5m3/h , input power=770W, GHSV=6.67×104 mL/(g·h) (pl-plasma, catalyst: 12%Ni/Al2O3)
25
Fig.13 Thermal plasma processing system
3. 等离子体和催化剂协同作用 热等离子体CH4-CO2重整制合成气 Fig.13 Thermal plasma processing system 1. plasma generator 2. feed inlet ring 3. adiabatic fixed bed reactor 4. cooling system 5. DC power supply 6. gas chromatograph
26
Figure 14 Effect of total feed flux on the reaction
3. 等离子体和催化剂协同作用 热等离子体CH4-CO2重整制合成气 Figure 14 Effect of total feed flux on the reaction Reaction condition: m catalyst=60g , CH4/CO2=4/6 ,N2 flux =1.7m3/h ,input power=9.6kW (catalyst: commercial Z107 Ni/Al2O3 )
27
4 结论及展望
28
4. 结论及展望 结论 等离子体既可以应用于制备新的催化剂,也可以用于已有催化剂的表面改性和还原。
“等离子体”催化剂具有比表面大、还原速率快、催化组分晶格缺陷等优点,从而导致催化活性的提高。 1 2 等离子体与催化剂协同作用: 在等离子体反应系统中加入一定量的催化剂,可以提高反应性能,同时催化剂的选择性活化可以改变产物的分配。
29
4. 结论及展望 展望 等离子体与催化剂的协同作用机理有待进一步研究
30
谢谢!
Similar presentations