13 results found
Iruretagoyena Ferrer D, Sunny N, Chadwick D, et al., 2018, Towards a low carbon economy via sorption enhanced water gas shift and alcohol reforming
Iruretagoyena Ferrer D, Hellgardt K, Chadwick D, 2018, Towards autothermal hydrogen production by sorption-enhanced water gas shift and methanol reforming: a thermodynamic analysis, International Journal of Hydrogen Energy, Vol: 43, Pages: 4211-4222, ISSN: 0360-3199
Hydrogen production by the water gas shift reaction (WGS) is equilibrium limited. In the current study, we demonstrate that the overall efficiency of the WGS can be improved by co-feeding methanol and removing CO2 in situ. The thermodynamics of the water gas shift and methanol reforming/WGS (methanol-to-shift, MtoS) reactions for H2 production alone and with simultaneous CO2 adsorption (sorption-enhanced, SEWGS and SEMtoS) were studied using a non-stoichiometric approach based on the minimisation of the Gibbs free energy. A typical composition of the effluent from a steam methane reformer was used for the shift section. The effects of temperature (450–750 K), pressure (5–30 barg), steam and methanol addition, fraction of CO2 adsorption (0–95%) and energy efficiency of the shift systems have been investigated. Adding methanol to the feed facilitates autothermal operation of the shift unit, with and without CO2 removal, and enhances significantly the amount of H2 produced. For a set methanol and CO input, the MtoS and SEMtoS systems show a maximum productivity of H2 between 523 and 593 K due to the increasing limitation of the exothermic shift reaction while the endothermic methanol steam reforming is no longer limited above 593 K. The heat of adsorption of CO2 was found to make only a small difference to the H2 production or the autothermal conditions.
Peng J, Iruretagoyena Ferrer D, Chadwick D, 2017, Hydrotalcite/SBA15 composites for pre-combustion CO2 capture: CO2, Journal of Co2 Utilization, Vol: 24, Pages: 73-80, ISSN: 2212-9820
Hydrotalcite-like compounds (HT) show potential as CO2 adsorbent materials for pre-combustion CO2 capture applications, but require improvements in stability, adsorption capacity and kinetics. In this study, HT/SBA15 hybrids (with different Mg/Al ratios varying from 0.3 to 3) have been synthesised using a two-stage grafting method to coat a mesoporous SBA15 with hydrotalcite layers. The HT/SBA15 hybrids showed significant improvement in intrinsic CO2 uptake (per mass of HT), initial uptake rate, and multicycle stability compared to unsupported HT. Compared to previously reported nanostructured carbon supports (e.g. CNF, MWCNTs), the HT/SBA15 hybrids were found to be more thermally stable and exhibit comparable adsorption uptake and rates. In particular, the use of SBA15 as a support is shown to prevent the gradual loss in weight from thermal decomposition observed for HT/MWCNT or HT/GO composites over extended cycling.
Iruretagoyena Ferrer D, 2017, Selective Sulfur Removal from Liquid Fuels Using Nanostructured Adsorbents, Nanotechnology in Oil and Gas Industries. Topics in Mining, Metallurgy and Materials Engineering., Pages: 133-150, ISBN: 978-3-319-60629-3
In recent years, there has been an increasing pressure to develop strategies to reduce the level of sulfur in transportation fuels due to stringent environmental regulations. Currently, hydrodesulfurization (HDS) is the most mature (pre-FCC) technology to remove sulfur from gasoline and diesel. However, conventional HDS can hardly produce ultra-low sulfur fuels while maintaining important fuel requirements (i.e., oxygen content, overall aromatic content, olefin content for gasoline, and cetane number for diesel). As a consequence, improvement of existing HDS processes and development of new desulfurization technologies is needed. In this regard, selective adsorption removal of sulfur (SARS) is a promising emerging approach for ultra-deep desulfurization of refinery streams by means of solid adsorbents. Contrary to HDS, SARS is usually carried out at low temperatures and pressures with minimal hydrogen consumption, preventing olefin hydrogenation and thus maintaining the properties of the fuels. This chapter presents a general overview of SARS. Emphasis is given to the use of nanostructured materials as sulfur adsorbents. Section 5.1 introduces the chapter presenting a general description of HDS, SARS and other emerging desulfurization technologies. Section 5.2 describes the two main groups of SARS (adsorption desulfurization and reactive adsorption desulfurization). Subsequently, the three main mechanisms for sulfur adsorption (π-complexation, direct sulfur–adsorption site interactions, and bulk incorporation in reactive adsorption desulfurization) are reviewed. Section 5.3 gives an overview of relevant literature concerning the use of promising groups of nanostructured adsorbents for SARS including zeolites, MOFs, mesoporous silicas, and carbon-nanostructured adsorbents. Finally, Sect. 5.4 gives some concluding remarks.
Graca I, Iruretagoyena D, Chadwick D, 2017, Glucose isomerisation into fructose over magnesium-impregnated NaY zeolite catalysts, Applied Catalysis B: Environmental, Vol: 206, Pages: 434-443, ISSN: 0926-3373
The performance of magnesium-impregnated NaY zeolite catalysts for the glucose isomerisation into fructose at 100 °C has been evaluated. Although crystallinity and textural properties of the zeolites are reduced through Mg addition, glucose conversion improves (6–49%) by increasing magnesium content (0–15 wt.%) due to an increase of the number of basic sites. Conversely, selectivity to fructose drops (96–66%). Nevertheless, good fructose yields were still reached with 10 and 15 wt.% of magnesium (about 32%), being similar or even higher than those found for a commercial hydrotalcite and a pure magnesium oxide. Catalysts lose performance through carbon retention and cations leaching. Deactivation of magnesium-based zeolites was further investigated by consecutive reaction runs. If no regeneration of the catalyst is performed, the activity of the zeolites decreases mainly as a result of cations leaching, the effect reducing with the number of runs. Regeneration allows the catalyst to recover almost totally its initial activity. Interestingly, used samples show higher fructose selectivity due to the additional pore opening resulting from cations leaching and/or carbon removal. Cations leaching results in a homogeneous catalytic reaction which is most significant for the highest magnesium content. Magnesium-based NaY zeolites are revealed as potential catalysts for glucose isomerisation into fructose with high fructose productivities and good performance in consecutive reactions combined with intermediate regeneration.
Menzel R, Iruretagoyena D, Wang Y, et al., 2016, Graphene oxide/mixed metal oxide hybrid materials for enhanced adsorption desulfurization of liquid hydrocarbon fuels, Fuel, Vol: 181, Pages: 531-536, ISSN: 0016-2361
A series of mixed metal oxides (MMOs) adsorbents (MgAl-, CuAl- and CoAl-MMOs) were supported on graphene oxide (GO) through in-situ precipitation of layered double hydroxides (LDHs) onto exfoliated GO, followed by thermal conversion. The study shows that GO is an excellent support for the LDH-derived MMOs due to matching geometry and charge complementarity, resulting in a strong hybrid effect, evidenced by significantly enhanced adsorption performance for the commercially important removal of heavy thiophenic compounds from hydrocarbons. Fundamental liquid-phase adsorption characteristics of the MMO/GO hybrids are quantified in terms of adsorption equilibrium isotherms, selectivity and adsorbent regenerability. Upon incorporation of as little as 5 wt% GO into the MMO material, the organosulfur uptake was increased by up to 170%, the recycling stability was markedly improved and pronounced selectivity for thiophenic organosulfurs over sulfur-free aromatic hydrocarbons was observed.
Iruretagoyena D, Huang X, Shaffer MSP, et al., 2015, Influence of Alkali Metals (Na, K, and Cs) on CO2 Adsorption by Layered Double Oxides Supported on Graphene Oxide, INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, Vol: 54, Pages: 11610-11618, ISSN: 0888-5885
Iruretagoyena D, Shaffer MSP, Chadwick D, 2015, Layered Double Oxides Supported on Graphene Oxide for CO2 Adsorption: Effect of Support and Residual Sodium, INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, Vol: 54, Pages: 6781-6792, ISSN: 0888-5885
Iruretagoyena D, Shaffer MSP, Chadwick D, 2014, Adsorption of carbon dioxide on graphene oxide supported layered double oxides, ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY, Vol: 20, Pages: 321-330, ISSN: 0929-5607
Garcia-Gallastegui A, Iruretagoyena D, Gouvea V, et al., 2012, Graphene Oxide as Support for Layered Double Hydroxides: Enhancing the CO2 Adsorption Capacity, CHEMISTRY OF MATERIALS, Vol: 24, Pages: 4531-4539, ISSN: 0897-4756
Garcia-Gallastegui A, Iruretagoyena D, Mokhtar M, et al., 2012, Layered Double Hydroxide supported on Multi-wall Carbon Nanotubes: preparation and CO2 sorption characteristics, J. Mater. Chem., Vol: 22
Celaya Sanfiz A, Garcia-Gallastegui A, Iruretagoyena D, et al., 2012, Self condensation of acetone over Mg-Al layered double hydroxide supported on multi-walled carbon nanotube catalysts
Iruretagoyena Ferrer D, 2009, Dimerizacion de pentenos con alumina fluorada
Dimerisation of isoamylenes coming from a pentane catalytic dehydrogenation process is an option to transform these branched olefins into unsaturated compounds of ten carbons (diisoamylenes). Dimers derivatives have a wide range of industrial applications. The present research sets the basis for the development of a feasible process of branched pentene dimerisation using fluorinated alumina as catalyst. Experimental tests were carried out in a packed bed reactor. 2-methyl-2-butene was used as model reactant. The effluent composition was followed by gas chromatography and mass spectroscopy. Solid characterization was done by means of surface area, total acidity, elemental and thermogravimetric analysis.
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