Band 1, Heft 2013 -

Dimerization of 1-butene in the liquid phase was studied at relatively mild conditions, 523 K under 20 bar over both microporous and embedded microporous mesoporous catalysts. Embedded catalysts were prepared by introducing Beta zeolite nuclei into the gel synthesis of mesoporous material. Three different embedded catalysts with different acidities were prepared and characterized by XRD, nitrogen adsorption, TEM, SEM, pyridine adsorption desorption and ammonia TPD. The embedded materials were shown to be thermally stable up to 1173 K, containing both micro- and mesopores and uniform pores with regular periodicity. According to ammonia TPD the acidity increased with increasing aluminium content. Due to the relatively low reaction temperature, the highest yields of C8 hydrocarbons, 33 mol% at the conversion level of 81% were achieved over an embedded micro-mesoporous catalyst containing Beta zeolite inside the mesoporous and totally 2.4 wt.% aluminium.

Ni-substituted Sr-aluminates Sr 1-x Ni x Al 11.2+x Ni 0.8-x O 19-δ (x = 0; 0.2; 0.4; 0.8) obtained by a precipitation method and calcined at 1200°C have been characterized by different physicochemical techniques and their catalytic properties have been tested in steam reformation of methane. It has been shown that substitution of Al 3+ and/or Sr 2+ by Ni 2+ in the aluminate structure results in changes of phase composition, specific surface area, and reducibility of samples. It has been established that the samples are not completely reduced in the temperature range of 30-900°C. The Sr 1-x Ni x Al 11.2+x Ni 0.8-x O 19-δ (x = 0; 0.2; 0.4) catalysts are active and stable in the steam reforming of methane at 700oC: residual amount of methane is (1.1±1.0) vol.%, while the Sr 1-x Ni x Al 11.2+x Ni 0.8-x O 19-δ (x = 0.8) sample is rapidly deactivated by coking.

The study is devoted to transesterification of Guizotia abyssinica seed oil using 1% crystalline manganese carbonate (MnCO 3 ) as catalyst at 60°C giving yield of 95%. Guizotia abyssinica as a nontraditional seed oil obtained from minor oil seed crop was explored for the potential of biodiesel synthesis. An attempt was made to use pure crystalline, ash coloured manganese carbonate as a green catalyst and heterogeneous catalyst for the production of methyl esters as fuel from Guizotia abyssinica seed oil.

Hydrodeoxygenation (HDO) process is the most promising route to upgrade pyrolysis bio-oils for producing liquid transportation fuels. The catalysts used and the quality of bio-oils have played important roles for how successful such process is. This review has addressed recent advances in HDO of pyrolysis bio-oils over many different types of catalysts, concentrating on the investigations of reasons why current catalysts have showed poor stability and have hindered pyrolysis oil HDO process in industrial scale: (i) The chemistry of model compounds from pyrolysis bio-oils is discussed in detail including aldehydes, carboxylic acids, carbohydrates, guaiacols, furfurals, alcohols, and ketones. The reactions occur via different routes over different catalysts with different products. (ii) The reaction mechanisms of different types of catalysts are elaborated, including classical sulfided hydrotreating catalysts, noble metals, sulfides, phosphides, carbides, nitrides, non-precious metals, metal oxides, bimetallic amorphous boron-based catalysts, and reduced metal oxide bronzes. Oxygen from oxy-compounds is absorbed on coordinatively unsaturated metal sites (oxygen vacancies) on metal oxide supports through Lewis acid/base interaction, or on H in -OH that is attached to non-metal oxides such as SiO 2 , or even on metal sites such as noble metals. -H donation is available directly from phosphides, carbides, nitrides, Brønsted acid -OH groups or -SH groups and from metals by H spillover. The activated H species then react with oxy-organics and give hydrodeoxygenated products. (iii) The importance of supports and contribution of different supports to HDO are also covered in this review. (iv) Catalyst deactivation mechanisms were elucidated. Coking formation is proven to be the main reason for catalyst deactivation because of polymerization and polycondensation reactions. The extent of coking formation depends on the type of oxy-compounds, nature of catalysts such as acidity, and operation conditions. A robust catalyst that withstands coking, high concentration of water and poisoning, and can be regenerated easily without losing too much activity is highly desired for pyrolysis oil HDO process and finally applied in industrial scale for raw pyrolysis oil upgrading.

Pellets of a novel, high temperature CO 2 sorbent, made of CaO-impregnated porous Y 2 O 3 , were prepared. Yttria pellets were synthesized from a mixture of yttria powder and a softener. A combination of ethylene glycol, used as a softener, and a casting method yielded mechanically stable pellets after calcination at 800ºC. Treatment of the Y 2 O 3 support at higher temperatures further increases the pellets strength. The same effect of pellets strengthening was observed after yttria impregnation with CaO. Sorption capacity of the pellets with CaO content of 9 wt. %, measured at isothermal conditions of 740ºC, reaches 7.5 wt. % for shorter recarbonation time of 20 min and 8.5 wt. % for a longer time of 1 hour. In this respect, sorption properties of pelletized CaO/Y 2 O 3 are similar to those of powdered material. A distinctive feature of the pelletized CaO/Y 2 O 3 sorbent pretreated at high temperatures is the increase in capacity during the initial cycles.

Nickel catalysts supported on Al 2 O 3 , CeO 2 and ZrO 2 were prepared by wet impregnation method and evaluated in steam reforming of glycerol. The catalysts were characterized by chemical composition, textural analysis, crystalline structure and reducibility. The structural characterization of the catalysts revealed a good dispersion of Ni particles using the Al 2 O 3 support, needing higher reduction temperature. The reactions were performed at 500°C with 10 vol.% glycerol solution in a continuous flow reactor. All catalysts showed conversions close to 100%. The selectivity to gas products and formation of liquid by-products were found to be dependent on the type of support. The H 2 selectivity showed the following trend: ZrO 2 > Al 2 O 3 ≈ CeO 2 . The catalyst supported on CeO 2 showed low activity for water-gas shift reaction, with the highest CO selectivity. All catalysts presented a low formation of CH 4 . In the liquid phase some by-products were identified (hydroxyacetone, acetic acid, lactic acid, acetaldehyde, acrolein and ethanol) and secondary reaction routes were proposed. Coke formation was higher on Ni/Al 2 O 3 catalyst, but no deactivation was observed during 8 h of reaction.

JSC “Angarsk catalysts and organic synthesis plant” has the modern hydrodewaxing catalysts for production of the EURO diesel fuel and transformer oil. New generation of hydrodewaxing catalysts are the result of complex research. Researches of JSC “AZKiOS” performed optimization of ZSM-5 zeolite synthesis technology; the stage of promotor introduction in zeolite is performed. Increase of activity of the catalysts as a result of introduction in the promoted zeolite is established. As a result it has become possible to carry out the process at a lowered temperature, which leads to the increase in selectivity and operation cycle time.

The catalytic activity of MoVTeNbO catalyst and its constituent phases (M1, M2 and Mo 5 O 14 -like) in the oxidation of propane, as well as propylene and acrolein, which are intermediates of acrylic acid formation from propane, was studied. In all the reactions, the М1 phase shows higher activity and selectivity, compared to M2 and Mo 5 O 14 -like phases; its presence being sufficient for efficient proceeding the propane oxidation to acrylic acid.

Catalytic combustion of brown coal particulates over CuO/Al 2 O 3 /FeAlO/ FeAl honeycomb ceramometal catalyst in the fluidized bed regime with the sand as a heat transfer material has been studied during 100 hours at 973-1023 K. The catalyst before and after tests has been analyzed. The coal conversion in the presence of cermet catalyst was found to be in the range of 97.8-98.5% while without catalyst it was lower (91.2-94.6%). A substantial decrease of CO, NOx and SO 2 emissions in catalytic combustion was also demonstrated.

The paper reviews results of development of new composite foam substrates with the graded structure for the intermediate temperature SOFC and structured catalysts of fuels reforming. Ni-Al substrates with porosity of 60-80% were prepared by compressive deformation of open cell metal foams followed by pack aluminizing. Testing in corrosive media revealed advantages of Ni-Al substrates over Fechraloy ones. Button-size thin film solid oxide fuel cell supported on this substrate demonstrated promising performance in the intermediate temperature range. These substrates were shown to be compatible with nanocomposite active components for the fuel reforming comprised of Ni-based alloys strongly interacting with perovskite/fluorite complex oxides with a high oxygen mobility and reactivity. High activity and coking stability of these structured catalysts in steam/autothermal reforming of natural gas, ethanol and acetone was demonstrated without a remarkable impact of heat and mass transfer. A close performance was demonstrated for fuel cells operating on wet H 2 or in the mode of internal reforming of natural gas using these catalysts. A concept of the substrate with the graded pore structure and composition was offered.

Isoprene is a valuable monomer for the rubber and most chemical industries. The five carbon monomer is used to make synthetic latex similar to the natural and it is becoming a monomer of choice because of the possibility to manipulate its properties. The rapid development of synthetic rubber is a result of the huge demand for this material. Currently, SR is used practically in all spheres of industry and national economy with its global production exceeding 1.3 million tons per year In this paper, various methods for its production and their shortfalls were studied; the prospect for isoprene production from bio-ethanol was also highlighted.