Sorption-enhanced steam reforming of toluene using multifunctional perovskite phase transition sorbents in a chemical looping scheme
Sorption-enhanced steam reforming of toluene using multifunctional perovskite phase transition sorbents in a chemical looping scheme
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DOI：
10.1088/2515-7655/acdbe9
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发表时间：
2023-06
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影响因子：
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通讯作者：
Leo Brody;Mahe Rukh;R. Cai;Azin Saberi Bosari;R. Schomäcker;Fanxing Li
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作者：
Leo Brody;Mahe Rukh;R. Cai;Azin Saberi Bosari;R. Schomäcker;Fanxing Li
利用催化CO2吸附剂进行甲苯吸附强化蒸汽重整（SESR）是将木质纤维素生物质气化过程中产生的芳香焦油副产物转化为氢气（H2）或富H2合成气的一种很有前途的途径。常用的吸附剂，如CaO，在最初捕获二氧化碳时是有效的，但由于在高温下烧结，在重复循环中容易失去其吸附能力。在这里，我们展示了在化学环方案中使用a位和B位掺杂Sr1−x a′x Fe1−y B′y O3−δ （a′= Ba, Ca; B′= Co）钙钛矿的SESRT。结果表明，在钙钛矿表面浸渍5 ~ 10%的Ni，可以有效提高甲苯的转化率。然而，在循环后，浸渍的Ni倾向于迁移到体中并失去活性。这促使采用双床配置，在吸附剂上游使用NiO/ γ-Al2O3催化剂的预床。对等温操作和更传统的变温模式进行了比较，后者在5个SESR循环中平均吸附量为~ 38%，产物合成气的H2: CO x > 4.0证明了这一点。对Sr0.25Ba0.75Fe0.375Co0.625O3-δ新鲜样品和循环样品的XRD分析表明，该材料是一种有效的相变吸附剂，能够循环捕获和释放CO2，而不会发生不可逆的相变。
Sorption-enhanced steam reforming (SESR) of toluene (SESRT) using catalytic CO2 sorbents is a promising route to convert the aromatic tar byproducts formed in lignocellulosic biomass gasification into hydrogen (H2) or H2-rich syngas. Commonly used sorbents such as CaO are effective in capturing CO2 initially but are prone to lose their sorption capacity over repeated cycles due to sintering at high temperatures. Herein, we present a demonstration of SESRT using A- and B-site doped Sr1−x A’ x Fe1−y B’ y O3−δ (A’ = Ba, Ca; B’ = Co) perovskites in a chemical looping scheme. We found that surface impregnation of 5–10 mol% Ni on the perovskite was effective in improving toluene conversion. However, upon cycling, the impregnated Ni tends to migrate into the bulk and lose activity. This prompted the adoption of a dual bed configuration using a pre-bed of NiO/γ–Al2O3 catalyst upstream of the sorbent. A comparison is made between isothermal operation and a more traditional temperature-swing mode, where for the latter, an average sorption capacity of ∼38% was witnessed over five SESR cycles with H2-rich product syngas evidenced by a ratio of H2: CO x > 4.0. XRD analysis of fresh and cycled samples of Sr0.25Ba0.75Fe0.375Co0.625O3-δ reveal that this material is an effective phase transition sorbent—capable of cyclically capturing and releasing CO2 without irreversible phase changes occurring.