CAJ | 학술논문

以 MgO 为载体，采用球磨法制备了 Ce－Fe－Zr－O／MgO 粉末状氧载体，进而采用挤压成型法制备了整体型氧载体。研究了两种氧载体化学链部分氧化甲烷制合成气的性能，并通过 XRD、H2－TPR 对氧载体进行表征。结果表明，粉末状氧载体中的储氧组分以 Ce－Fe－Zr－O 固溶体形式存在，而整体型氧载体的制备过程会导致 Zr、Fe 游离氧化物的形成。粉末状氧载体和整体型氧载体上均存在表面晶格氧和体相晶格氧，其中，体相晶格氧具有高选择性氧化甲烷的性能，可以将甲烷转化成 CO 和H2。粉末状氧载体与甲烷反应活性较高，但其存在高含量的表面氧，易导致甲烷的完全氧化。整体型氧载体上体相晶格氧占据优势，可将甲烷选择性氧化为 CO 和 H2。氧化还原循环实验表明，粉末状氧载体在还原反应发生短时间内容易引起甲烷裂解导致产物气中的 H2／CO 物质的量比显著大于2．0，同时产生大量积炭，制约了其循环性能。而整体型氧载体经10次循环实验后，全程反应过程中合成气 H2／CO 物质的量比一直维持在2．0附近，显示了较高的循环稳定性能。
이 MgO 위재체，채용구마법제비료 Ce－Fe－Zr－O／MgO 분말상양재체，진이채용제압성형법제비료정체형양재체。연구료량충양재체화학련부분양화갑완제합성기적성능，병통과 XRD、H2－TPR 대양재체진행표정。결과표명，분말상양재체중적저양조분이 Ce－Fe－Zr－O 고용체형식존재，이정체형양재체적제비과정회도치 Zr、Fe 유리양화물적형성。분말상양재체화정체형양재체상균존재표면정격양화체상정격양，기중，체상정격양구유고선택성양화갑완적성능，가이장갑완전화성 CO 화H2。분말상양재체여갑완반응활성교고，단기존재고함량적표면양，역도치갑완적완전양화。정체형양재체상체상정격양점거우세，가장갑완선택성양화위 CO 화 H2。양화환원순배실험표명，분말상양재체재환원반응발생단시간내용역인기갑완렬해도치산물기중적 H2／CO 물질적량비현저대우2．0，동시산생대량적탄，제약료기순배성능。이정체형양재체경10차순배실험후，전정반응과정중합성기 H2／CO 물질적량비일직유지재2．0부근，현시료교고적순배은정성능。
With MgO as support, powdery Ce-Fe -Zr-O/MgO oxygen carrier was prepared by a bal l milling metho d and monolithic Ce-Fe-Zr-O/MgO oxygen carr ier was further obtained by extrusion molding method.The performances of both powdery and monolithic oxygen carriers in partial oxidation of methane to syngas via a chemical looping process were investigated.The results showed that the compon ent of the powd ery carrier for o xygen storage is Ce-Fe-Zr-O solid solution, whereas the free oxides of Ce, Zr and Fe may be segregated from the solid solution in mon olithic oxygen carrie r upon preparation.Two kinds of oxygen sp ecies, i.e.surface lattice oxygen and bulk lattic e oxygen, can be found on both powd ery and mono lithic oxygen carrie rs; bulk l a ttice oxyg en can sel ctively conv ert methane to CO and H2 , whereas the sur face oxygen is very active for methanec omplete oxidation.Powdery oxygen carrier owns high content of surface lattice oxygen, which results in high concentration of H2 O and CO2 in the product.Over the monolithic oxygen carrier, methane can be selectively oxidized to CO and H2 due to the high content of bulk lattice oxygen.Moreover, methane decomposition occurs easily over the powdery oxygen carrier in the redox tests, resulting in a high H2 /CO mol ratio (much higher than 2.0) in the product.On the contrary, the monolithic oxygen carrier exhibits a high redox stability andc an continuously pro duce syngas with aH 2 /CO mol ratio of 2.0 during the successive redox tests.