Dimetil eterraren sintesia CuO-ZnO-A12O3/y-A12O3 katalizatzaile funtzio bikoa erabiliz. Modelakuntza zinetikoa

Lan honetan urrats bakarrean egindako dimetil eterraren (DMEren) sintesia aztertu da. Bereziki, e red u zinetiko bat proposatu da , eta parametro zinetikoak kalkulatu dira. Cu0-Zn0-AIP3/y-AI20 3 da erabilitako katalizatzailea, eta bi elikadura erabili dira: sintesi-gasa (hau da, hidrogeno eta km·bono monoxidoaren nahastea) eta (H2+C02) . Ereclu zinetikoak ondo cloitzen ditu erreaktore finko isotermoan lorturiko emaitza esperimentalak, eragiketa-ba ldintzen tarte zabalean: 225-325 °C, 10-40 bar; denbora espaziala, 1,6-57 ,O (g katali zatzaile) h (mol erreakzionatzai le)- 1• Moclelakuntzarako erreakzio-urrats erabakigarriak honako hauek dira: metanolaren sintesia (H2+CO)-tik abiatuz -(H2+C02)-tik egindako sintesia ez da garrantzitsua-, metanolaren deshidratazioa (oso azkarra), eta lurrin/gas trukaketa (hau da , CO eta H20-ren arteko erreakzioa , C02 eta H2 emateko) . Uraren efektu inhibitza ilea kontuan izan da, metanolaren sintesian eta hiclrokarburoen eraketan.; A kinetic model has been proposed for the synthesis of dimethyl ether (DME) in a single reaction step from (H2+CO) ancl (H2+C02), and the kinetic parameters have been calculated for a Cu0-Zn0-AJ20/y-AI20 3 bifunctional catalyst. The kinetic model suitably fits the experimental results obtained in an isothermal fixed bed reactor within a wide range of operating conditions: 225-325 °C; 10-40 bm·; space time, 1 .6-57 .O (g of catalyst) h (mol H2)- 1. The crucial steps for modelling are the synthesis of methanol from (H2+CO) - synthesis from (H2+C02) is not important - methanol clehydration (very fast), and the water-gas shift reaction. The inhibiting effect of water has also been taken into account in the synthesis of methanol and the formation of hydrocarbons

Role of Zr loading into In2O3 catalysts for the direct conversion of CO2/CO mixtures into light olefins

The effect of the ZrO2 content on the performance (activity, selectivity, stability) of In2O3-ZrO2 catalyst has been studied on the hydrogenation of CO2/CO mixtures. This effect is a key feature for the viability of using In2O3-ZrO2/SAPO-34 tandem catalysts for the direct conversion of CO2 and syngas into olefins via oxygenates as intermediates. The interest of co-feeding syngas together with CO2 resides in jointly valorizing syngas derived from biomass or wastes (via gasification) and supplying the required H-2. The experiments of methanol synthesis and direct synthesis of olefins, with In2O3-ZrO2 and In2O3-ZrO2/SAPO-34 catalysts, respectively, have been carried out under the appropriate conditions for the direct olefins synthesis (400 ?, 30 bar, H-2/COX ratio = 3) in an isothermal fixed bed reactor at low space time values (kinetic conditions) to evaluate the behavior and deactivation of the catalysts. The Zr/In ratio of 1/2 favors the conversion of CO2 and COX, attaining good oxygenates selectivity, and prevents the sintering attributable to the over-reduction of the In2O3 (more significant for syngas feeds). The improvement is more remarkable in the direct olefins synthesis, where the thermodynamic equilibrium of methanol formation is displaced, and methanation suppressed (in a greater extent for feeds with high CO content). With the In2O3-ZrO2/SAPO-34 tandem catalysts, the conversion of COx almost 5 folds respect oxygenates synthesis with In2O3-ZrO2 catalyst, meaning the yield of the target products boosts from ~0.5% of oxygenates to > 3% of olefins (selectivity > 70%) for mixtures of CO2/COX of 0.5, where an optimum performance has been obtained.This work has been carried out with the financial support of the Ministry of Science, Innovation and Universities of the Spanish Government (PID2019-108448RB-100); the Basque Government (Project IT1645-22), the European Regional Development Funds (ERDF) and the European Commission (HORIZON H2020-MSCA RISE-2018. Contract No. 823745). A. Portillo is grateful for the grateful for the Ph.D. grant from the Ministry of Science, Innovation and Universities of the Spanish Government (BES2017-081135). The authors thank for technical and human support provided by SGIker (UPV/EHU)

Dimetil eterraren sintesia CuO-ZnO-Al2O3/y-Al2O3 katalizatzaile bifuntzionala erabiliz. Eragiketa-baldintzen eragina

Gero eta an·eta gehiago eskaintzen ari zaio dimetil eterrari (DME), aplikazio anitzeko erregai bezala erabil daitekeelako, eta petrolioaren ordezko energia-iturrietatik (ikatza, gas naturala eta biomasatik) ekoizten delako.Lan honetan erreakzio-etapa bakarrean egindako DMEren sintesia aztertuko da. CuO-ZnO-Al2O3/y-Al2O3 da erabilitako katali zatzailea, zeinak bi funtzio baititu: H2, CO eta CO2-tik abiatuz metanola ekoizteko funtzio metalikoa, eta DME sortzeko metanolaren deshidratazioa egiteko funtzio azidoa.Elkarren segidako bi erreakzio-etapatan egiten den prozesuaren aurrean, erreakzioetapa bakarrean egindako DMEren sintesiak abantaila termodinamikoak ditu. Izan ere, etapa bakarreko prozesuak oreka termodinamikoa desplazatzen du, metanola in situ eraldatzen delako. Ondorioz, metanolaren sintesiarekin alderatuz, prozesu berri hori tenperatura altuagoak eta presio baxuagoak erabiliz egin daiteke. Gainera, prozesu horrek CO2 lehengai gisa erabiltzea ahalbidetzen du eta horrela, baliagarria gertatzen da berotegi efektuaren ondorioz gertatzen den klima-aldaketa arintzeko. Eragiketa-baldintzek (hau da, tenperaturak, presioak eta elikaduraren konposizioak) DMEren sintesian duten eragina ikertu da. Aztertu diren parametroak honako hauek dira: CO eta C02-ren konbertsioa, DMEren hautakortasuna eta etekina eta produktuen banaketa. Lortu diren konbertsio baloreak bi erreaktoreetan egiten den DMEren sintesian lortutakoak baino askoz altuagoak dira. Abantai la nabarmena du metanolaren deshidratazioa erreaktore berean egiteak; izan ere, 30 bar eta 275 °C-an eta (H2+CO) elikatzen denean, % 60tik gorako DMEren etekina eta% 5eko metanolaren etekina lortu dira

Katalizatzaileen prestakuntza industri prozesuetarako

Prozesu katalitikoak gero eta gehiago erabiltzen ari dira industria eskalan. Prozesu hauetan erabiltzen diren katalizatzaileak arreta handiz prestatu behar dira, solidoak ezaugarri fisiko-kimiko (aktibotasun, hautakortasun ete egonkortasun) onak eduki ditzan, eta erreakzio katalitikoa egoki gerta dadin. Artikulu honetan industria eskalan masa-katalizatzaileak eta katalizatzaile inpregnatuak prestatzeko normalean erabiltzen diren metodoak deskribatzen dira eta prestakuntza-etapa bakoitza zertan datzan aztertzen da

A review on the valorization of CO2. Focusing on the thermodynamics and catalyst design studies of the direct synthesis of dimethyl ether

The direct synthesis of dimethyl ether (DME) on bifunctional catalysts is highly attractive for valorizing CO2 and syngas derived from biomass gasification and is a key process to reduce greenhouse gas emissions. DME economy (conventionally based on its use as fuel) arouses growing interest, in parallel with the development of different routes for its conversion into hydrocarbons (fuels and chemicals) and H-2 production. This review, after analyzing different routes and catalytic processes for the valorization of CO2, focuses on studies regarding the thermodynamics of the direct synthesis of DME and the advances in the development of new catalysts. Compared to the synthesis of methanol and the synthesis of DME in two stages, carrying out the reactions of methanol synthesis and its dehydration to DME in the same reactor favors the formation of DME from CO2 and from CO2 co-fed with syngas. Starting from the experience for syngas feedstocks, numerous catalysts have been studied. The first catalysts were physical mixtures or composites prepared by extrusion of methanol synthesis catalysts (CuO-ZnO with different carriers and promoters) and dehydration catalysts (mainly gamma-Al2O3 and HZSM-5 zeolite). The performance of the catalysts has been progressively improved with different modifications of the composition and properties of the components to upturn the activity (lower for the hydrogenation of CO2 than for CO) and selectivity, and to minimize the deactivation by coke and by sintering of the metallic function. The core-shell configuration of the bifunctional catalyst allows physically separating the environments of the reactions of methanol synthesis and its conversion into DME. The confinement facilitates the extent of both reactions and improves the stability of the catalyst, since the synergies of the deactivation mechanisms are eliminated.This work has been carried out with the financial support of the Ministry of Science, Innovation and Universities of the Spanish Government (PID2019-108448RB-100); the Basque Government (Project IT1645-22); the European Regional Development Funds (ERDF); and the European Commission (HORIZON H2020-MSCA RISE-2018. Contract No. 823745)

CO2-aren balorizazio zuzena hidrokarburoak ekoizteko

Mitigating the climate change caused by fossil fuels burning is one of the major challenges of today’s society. The most abundant (75 %) of the greenhouse gases emitted by these combustions is carbon dioxide (CO2). Therefore, reducing its emissions and capturing what already has been emitted, known as CCU (Carbon dioxide Capture and Utilization) technology, is essential for minimizing the environmental damage caused by climate change. Among the processes that use CO2 as a feedstock, its catalytic conversion has good potential for implementation in the short term. Among the catalytic processes, the most common is its hydrogenation to obtain hydrocarbons. One of the most interesting features of this process is its versatility, as different hydrocarbons can be selectively produced; such as olefins, heavy paraffins or aromatics. The operating conditions, types of catalysts and their characteristics, as well as the CO2 conversion degrees obtained, depend on the hydrocarbons to be produced.; Erregai fosilen errekuntzek eragindako klima-aldaketa pairatzea da egungo gizartearen erronka nagusietariko bat. Errekuntza horiek isuritako berotegi-efektuko gasen artean ugariena karbono dioxidoa (CO2) da, haien % 75 inguru. Beraz, honen emisioak murriztea eta dagoeneko isuritakoa bahitzea ezinbestekoa da klima-aldaketak eragindako ingurumen-kaltea ahalik eta gehien murrizteko. Horretarako, ezinbestekoak dira CCU teknologiak (karbono dioxidoaren bahiketa eta erabilera). CO2-a erabiltzen duten prozesuen artean, bihurtze katalitikoak etorkizun laburrean ezartzeko aukera onak ditu. Prozesu katalitikoen artean, ohikoena CO2-aren hidrogenazioa da, hidrokarburoak lortuz. Prozesu honen moldakortasuna da bere ezaugarri interesgarrienetakoa; izan ere, modu hautakorrean hidrokarburo ezberdinak ekoizten dira; besteak beste, olefinak, parafina astunak zein arinak eta aromatikoak. Operazio baldintzak, katalizatzaile motak eta beren ezaugarriak, zein lorturiko CO2-aren balorizazio-mailak ekoiztu nahi den hidrokarburoaren araberakoak dira

Alternative acid catalysts for the stable and selective direct conversion of CO2/CO mixtures into light olefins

Different acid catalysts (silicoaluminophosphates (SAPOs) -34, −18, and − 11, and HZSM-5 zeolite) were tested as components of In2O3-ZrO2/acid tandem catalysts in the direct synthesis of light olefins by hydrogenation of CO2, CO and their mixture. The conversion and olefins yield and selectivity evidence that the presence of the large amount of strongly acidic sites in SAPO-34 favors the extent of the reaction mechanism with methanol as intermediate, minimizing secondary methanation reactions. In addition, the shape selectivity of SAPO-34 boosts olefins selectivity (mainly of propylene), limiting the extent of the secondary reactions for the formation of other hydrocarbons. Using SAPOs as acid catalysts enhances olefins selectivity when co-feeding CO2 with CO. Despite all tandem catalysts undergo deactivation by coke deposition (mostly in the acid catalyst), a pseudo-steady state of stable remaining activity is acquired. From the study of the coke nature, soft and hard coke were discerned. For the complete regeneration of the SAPO-34 in the tandem catalyst, the stripping of the soft coke is not sufficient and the combustion at 500 °C of the hard coke (little developed) deposited on the micropores is required.This work has been carried out with the financial support of the Ministry of Science, Innovation and Universities of the Spanish Government (PID2019-108448RB-100); the Basque Government (Project IT1645-22), the European Regional Development Funds (ERDF) and the European Commission (HORIZON H2020-MSCA RISE-2018. Contract No. 823745). A. Portillo is grateful for the grateful for the Ph.D. grant from the Ministry of Science, Innovation and Universities of the Spanish Government (BES2017-081135). The authors thank for technical and human support provided by SGIker (UPV/EHU)

Ohizko energiak vs. energia berriztagarriak

Fosil-erregaien erreserbak gero eta urriagoak dira eta munduko leku mugatuetan baino ez daude. Gainera, erregai mota hau erabiltzen duten prozesuak oso kutsatzaileak izan ohi dira. Arazo hauek dira medio, gizartean energia aurrezteko konpromisoa gero eta finkatuago dago (batez ere herrialde industrializatuetan) eta gero eta energia lor tzeko prozesu eraginkorragoak eta garbiagoak diseina tzen ari dira. Hala ere, oraindaino energia garbia eta ugaria lor tzeko lehendabiziko pausuak baino ez dira eman. Lan honetan ohizko energiak eta energia berriztagarriak deskribatzen dira eta bai eta energia mota bakoi tzaren abantailak eta desabantailak