CaO supported on mesoporous silicas as basic catalysts for transesterification reactions

Albuquerque, Mônica C. G.; Jiménez-Urbistondo, Inmaculada; Santamaría‐González, J.; Mérida‐Robles, J.; Moreno‐Tost, Ramón; Rodríguez‐Castellón, Enrique; Jiménez‐López, Antonio; Azevedo, Diana C. S.; Cavalcante, Célio L.; Maireles‐Torres, Pedro

doi:10.1016/j.apcata.2007.09.028

Cited by 295 publications

(126 citation statements)

References 46 publications

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“…After incorporation of the metal oxides (SnO-Al2O3 and ZnO-Al2O3) onto the nano ZSM-5 support, the BET surface areas decreased to 315 and 197 m2/g, respectively. This fact could be explained by both the partial blocking of the porous network by the metal oxides and by filling of the pores [12]. Since sodium hydroxide was used as a neutralizing agent for the acidic metal salts, the ZSM-5 supported metal oxides catalysts (SnO-Al2O3/ZSM-5 and ZnO-Al2O3/ZSM-5) inevitably contain sodium oxide residue.…”

Section: Metal Oxide Loadingmentioning

confidence: 99%

“…The catalytic activity of the heterogeneous base catalyst, in the transesterification of soybean oil, shows a striking correlation with basic strength [5,[8][9][10]. Thus, most heterogeneous catalysts for biodiesel production contain alkali or alkali earth cations [4,5,8,9,[11][12][13][14][15][16][17][18][19]. However, most of the catalysts experienced deactivation, by leaching of the alkali species from the heterogeneous catalysts to reaction medium [1,20].…”

Section: Introductionmentioning

confidence: 99%

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The effect of sodium on the catalytic activity of ZnO–Al2O3/ZSM-5 and SnO–Al2O3/ZSM-5 for the transesterification of vegetable oil with methanol

Kim

Yan

Salley

et al. 2009

Catalysis Communications

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In order to elucidate the effect of sodium on the activity of ZSM-5 supported metal oxides catalysts (ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5) for the transesterification of soybean oil with methanol, ZSM-5 supported metal oxides were prepared with and without sodium hydroxide by impregnation. The metal compositions of the ZSM-5 supported metal oxide catalysts and the metal concentrations dissolved from the catalysts to the methylester phase were measured by SEM-EDS and inductive coupled plasma spectroscopy, respectively. The catalytic activity of ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5 containing sodium did not originate from surface metal oxides sites, but from surface sodium sites or dissolved sodium leached from the catalyst surface.

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Section: Metal Oxide Loadingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The effect of sodium on the catalytic activity of ZnO–Al2O3/ZSM-5 and SnO–Al2O3/ZSM-5 for the transesterification of vegetable oil with methanol

Kim

Yan

Salley

et al. 2009

Catalysis Communications

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“…Many studies are cited in literature: CaO/MgO [11] [12], CaO/CeO [13], CaO/ ZnO [11] [14] [15], CaO/ZrO 2 [16] [17], MgO/SrO [9], CaO/aluminate [18], CaO/silicate [19] [20], Mg/Al oxides [18] [24], CaO/activated charcoal [25], CaO-KF [26] [27] [28] [29], MgO/KOH [30], Ti/MgO [31], MgO/chitosan [32], and CaO/zeolite [33].…”

mentioning

confidence: 99%

Deactivation Processes, Regeneration Conditions and Reusability Performance of CaO or MgO Based Catalysts Used for Biodiesel Production—A Review

Oueda¹,

Bonzi-Coulibaly²,

Ouédraogo³

2017

MSA

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The activity of a catalyst in transestrification reaction usually declines with repeated uses and this limits the possibility to use it many times. This paper presents a review of various techniques used to evaluate the activity changes, the recycling processes for calcium and magnesium oxides based heterogeneous catalysts for biodiesel production. The activity of calcium and magnesium oxides based catalysts declines due to leaching, surface or active sites poisoning by reactant or product molecules and modification of physical aspects. Physico-chemical methods (AAS, BET, CO 2 -TPD, EDS, FTIR, ICP-AES, SEM, TG/DTA and XRD) were used to check the catalyst modification and to confirm the deactivation. When separated from the reaction mixture by filtration, the catalyst could be reused without any treatment or recycled by washing, drying or/and recalcination. Between various recycling processes for calcium and magnesium oxides based catalysts, mixed oxides showed less leaching and performed FAME or FAEE yield >90% with reusability.

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“…Trabalhos posteriores, à base de combinações do Cao como Cao.mgo; 144 Cao.Ceo 2 ; 145 Cao.Zno; 45 Cao suportado em sílica mesoporosa, 146 não mencionam sequer a possibilidade de perda de atividade catalítica por lixivição ou em função de uma possível reação com ácidos graxos livres que possam estar presentes. É possível que as características desses catalisadores sejam diferentes em função da mudança estrutural ao combinar Cao com óxidos de outros metais, podendo resultar em catalisadores totalmente heterogêneos.…”

Section: Catálise Heterogênea áCida E Alcalinaunclassified

Biodiesel: visão crítica do status atual e perspectivas na academia e na indústria

Dabdoub¹,

Bronzel²,

Rampin³

2009

Quím. Nova

104

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Recebido em 27/2/09; aceito em 31/3/09; publicado na web em 7/4/09 BioDiESEL: A CRiTiCAL oVERViEW oN THE CURRENT STATUS AND PERSPECTiVES AT THE ACADEmY AND iNDUSTRY. This article presents a bibliographic review of research carried out on different alternative processes for biodiesel production. The supercritical and subcritical (non catalytic) reaction conditions, the use of solid basic, solid acid and other heterogeneous catalysts, including the use of immobilized enzymes and whole-cell catalysts are also critically compared with the traditional homogeneous alkaline or acid catalysts that are common on industrial applications. Advantages and limitations of all these processes for the transference from the laboratory to the industry are discussed. A correlation of the chemical composition with the quality parameters of the produced biodiesel is done with aim to stablish adequate procedures for the right selection of the rawmaterial. Castor bean oil is used as an example of inappropriate oil in order to produce a B100 that fulfill all the international physicochemical quality standards. in this article are presented research results to adequate the values of viscosity, density and iodine number of the castor and soybean biodiesel to the international standard limits by means blending these both biodiesels at the right ratio.Keywords: transesterification; biodiesel; catalysts. introduÇãoAumento da demanda mundial por combustíveis líquidos, aquecimento global, segurança energética, vontade política por desenvolvimento nos campos agrícola, social e também energético são pontos que abrem novas áreas de interesse e oportunidades para pesquisas e desenvolvimento na Academia e na indústria, pois são as forças motoras responsáveis pelo renovado interesse na produção de biocombustíveis.Um dos grandes destaques da atualidade na área de biocombustí-veis é o interesse pelo uso de recursos naturais baseados em materiais lignocelulósicos 1-3 para a produção de etanol ou por fontes produtoras de lipídeos usados para a produção de biodiesel.Biodiesel é o nome dado a ésteres alquílicos de ácidos graxos desde que atendam certos parâmetros de qualidade. 4-8 Além de esses ésteres serem derivados de fontes biológicas como plantas e animais, atuam como combustível substituto ao diesel de petróleo, com desempenho muito próximo, não exigindo modificações nos motores. Tradicionalmente o biodiesel é produzido através das reações de transesterificação de triglicerídeos, usando geralmente catalisadores alcalinos, 9 ou da esterificação de ácidos graxos livres, sendo que neste último caso, os ácidos graxos livres (AGLs) são submetidos à reação direta com um álcool de 4 carbonos ou menos, na presença de catalisadores ácidos. 10-12 mais recentemente o uso de diversos catalisadores heterogêneos tem sido descrito na literatura. 13 Transesterificação é o processo de transformação de um éster carboxílico em outro, através da troca do grupo Ro -presente no éster original, por outro grupo semelhante proveniente de um álcool na presença de um catalisa...

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CaO supported on mesoporous silicas as basic catalysts for transesterification reactions

Cited by 295 publications

References 46 publications

The effect of sodium on the catalytic activity of ZnO–Al2O3/ZSM-5 and SnO–Al2O3/ZSM-5 for the transesterification of vegetable oil with methanol

The effect of sodium on the catalytic activity of ZnO–Al2O3/ZSM-5 and SnO–Al2O3/ZSM-5 for the transesterification of vegetable oil with methanol

Deactivation Processes, Regeneration Conditions and Reusability Performance of CaO or MgO Based Catalysts Used for Biodiesel Production—A Review

Biodiesel: visão crítica do status atual e perspectivas na academia e na indústria

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