Production of Acetaldehyde via Oxidative Dehydrogenation of Ethanol in a Chemical Looping Setup.
Production of Acetaldehyde via Oxidative Dehydrogenation of Ethanol in a Chemical Looping Setup.
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DOI：
10.1021/acsengineeringau.2c00052
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发表时间：
2023-06-21
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影响因子：
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通讯作者：
Marek, Ewa J
中科院分区：
文献类型：
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作者：
Gebers, Joseph C;Abu Kasim, Abu Farhan Bin;Fulham, George J;Kwong, Kien Yi;Marek, Ewa J
一种新型化学循环（CL）工艺被证明可以通过乙醇氧化脱氢（ODH）生产乙醛（AA）。在此，乙醇的 ODH 在没有气态氧气流的情况下发生；相反，氧气由金属氧化物（ODH 催化剂的活性载体）提供。支撑材料随着反应的发生而减少，需要在单独的步骤中在空气中再生，从而形成 CL 过程。这里，使用锶铁氧体钙钛矿（SrFeO3−δ）作为活性载体，银和铜作为ODH催化剂。 Ag/SrFeO3−δ 和 Cu/SrFeO3−δ 的性能在填充床反应器中进行了研究，运行温度为 200 至 270 °C，气时空速为 9600 h–1。然后将 CL 生产 AA 的能力与裸 SrFeO3−δ（无催化剂）和包含惰性载体上的催化剂、Al2O3 上的 Cu 或 Ag 的材料的性能进行比较。 Ag/Al2O3催化剂在没有空气的情况下完全失活，证实需要从载体提供的氧气将乙醇氧化成AA和水，而Cu/Al2O3逐渐被焦炭覆盖，表明乙醇裂解。裸露的 SrFeO3−δ 对 AA 的选择性与 Ag/SrFeO3−δ 相似，但活性大大降低。对于性能最佳的催化剂 Ag/SrFeO3−δ，所获得的 AA 选择性达到 92-98%，收率高达 70%，与现有的乙醇 ODH 的 Veba-Chemie 工艺相当，但温度较低约 250 °C。 CL-ODH 设置在高效生产时间内运行（即，生产 AA 所花费的时间到再生 SrFeO3−δ 所花费的时间）。在所研究的配置中，使用 2 g CLC 催化剂和 200 mL/min 进料流量~5.8 vol% 乙醇，仅需要三个反应器即可通过 CL-ODH 伪连续生产 AA。
A novel chemical looping (CL) process was demonstrated to produce acetaldehyde (AA) via oxidative dehydrogenation (ODH) of ethanol. Here, the ODH of ethanol takes place in the absence of a gaseous oxygen stream; instead, oxygen is supplied from a metal oxide, an active support for an ODH catalyst. The support material reduces as the reaction takes place and needs to be regenerated in air in a separate step, resulting in a CL process. Here, strontium ferrite perovskite (SrFeO3−δ) was used as the active support, with both silver and copper as the ODH catalysts. The performance of Ag/SrFeO3−δ and Cu/SrFeO3−δ was investigated in a packed bed reactor, operated at temperatures from 200 to 270 °C and a gas hourly space velocity of 9600 h–1. The CL capability to produce AA was then compared to the performance of bare SrFeO3−δ (no catalysts) and materials comprising a catalyst on an inert support, Cu or Ag on Al2O3. The Ag/Al2O3 catalyst was completely inactive in the absence of air, confirming that oxygen supplied from the support is required to oxidize ethanol to AA and water, while Cu/Al2O3 gradually got covered in coke, indicating cracking of ethanol. The bare SrFeO3−δ achieved a similar selectivity to AA as Ag/SrFeO3−δ but at a greatly reduced activity. For the best performing catalyst, Ag/SrFeO3−δ, the obtained selectivity to AA reached 92–98% at yields of up to 70%, comparable to the incumbent Veba-Chemie process for ethanol ODH, but at around 250 °C lower temperature. The CL-ODH setup was operated at high effective production times (i.e., the time spent producing AA to the time spent regenerating SrFeO3−δ). In the investigated configuration with 2 g of the CLC catalyst and 200 mL/min feed flowrate ∼5.8 vol % ethanol, only three reactors would be required for the pseudo-continuous production of AA via CL-ODH.