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Two Zr-modified alumina supports were synthetized containing the same amount of Zr but a different distribution of this modifier over the alumina surface. These supports, together with the unmodified alumina carrier, were used to prepare three cobalt-based catalysts which were characterized and tested under relevant Fischer–Tropsch conditions. The three catalysts presented very similar porosity and cobalt dispersion. The addition of Zr nor its distribution enhanced the catalyst reducibility. The catalyst activity was superior when using a carrier consisting of large ZrO islands over the alumina surface. The use of a carrier with a homogeneous Zr distribution had however, a detrimental effect. Moreover, a faster initial deactivation rate was observed for the Zr-promoted catalysts, fact that may explain this contradictory effect of Zr on activity. Finally, the addition of Zr showed a clear enhancement of the selectivity to long chain hydrocarbons and ethylene, especially when Zr was well dispersed. ; The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2013) under Grant Agreement No. 308733. The authors are thankful to the Spanish Ministerio de Economía y Competitividad—MINECO (references: BES-2013-062806, ENE2013-47880-C3-2-R and ENE2015-66975-C3-2-R) co-financed by FEDER funds from the European Union.

The aim of the article is to determine the properties of fuel mixtures of Fischer–Tropsch naphtha fraction with traditional gasoline (petrol) to be able to integrate the production of advanced alternative fuel based on Fischer–Tropsch synthesis into existing fuel markets. The density, octane number, vapor pressure, cloud point, water content, sulphur content, refractive index, ASTM color, heat of combustion, and fuel composition were measured using the gas chromatography method PIONA. It was found that fuel properties of Fischer–Tropsch naphtha fraction is not much comparable to conventional gasoline (petrol) due to the high n-alkane content. This research work recommends the creation of a low-percentage mixture of 3 vol.% of FT naphtha fraction with traditional gasoline to minimize negative effects—similar to the current legislative limit of 5 vol.% of bioethanol in E5 gasoline. FT naphtha fraction as a biocomponent does not contain sulphur or polyaromatic hydrocarbons nor benzene. Waste materials can be processed by FT synthesis. Fischer–Tropsch synthesis can be considered a universal fuel—the naphtha fraction cut can be declared as a biocomponent for gasoline fuel without any further necessary catalytic upgrading.

The Fischer-Tropsch (FT) process, producing long chained waxes and transportation fuels, is competing with fuels derived from crude oils and its profitability is therefore dependent on the global oil price. However, increasing the value of synthesized products could render the profitability of the FTS independent of fluctuations in the oil price (which are mostly due to global political trends). One way to achieve this, is to target fine chemicals instead of fuels. At the Catalysis Institute, this has been investigated by adding ammonia to the feed gas stream and obtaining highly valuable amines, amides and nitriles. It has been shown that the so-called nitrogen containing compounds are formed instead of the Fischer-Tropsch typical albeit minor products alcohols, aldehydes and carboxylic acids, i.e. oxygenates. Increasing the oxygenate selectivity was investigated in numerous studies as no commercial FT based process exists which produces oxygenates at a significant yield. Typically, transition metals such as Fe, Co, Rh and Ni are active for the FT synthesis. Based on reaction conditions employed, commercial Fe and Co based catalysts have been shown to produce between 6 and 12 C% oxygenates. Rh has been shown to have a high oxygenate selectivity, but the associated high raw material cost becomes prohibitive for use as a commercial FT catalyst. Catalysts other than the traditionally known FT active transition metals have shown promising results in terms of oxygenate selectivity. Transition metal carbides such as Mo2C, have been investigated under Fischer-Tropsch conditions. While the bare catalyst produces mainly methane and other hydrocarbons, upon promotion with potassium the selectivity shows a significant shift towards oxygenates. This project investigates the use of potassium promoted molybdenum carbide as a catalyst for high oxygenate selectivity in the Fischer-Tropsch synthesis. β-Mo2C was synthesized and subsequently promoted with different levels of potassium and its Fischer-Tropsch synthesis performance was evaluated in a stainless steel fixed bed reactor. The influence of catalyst synthesis protocols, reactor pressure and temperature, feed gas space velocity, and K/Mo wt.% promotion on catalyst activity and selectivity were studied. At a stable CO conversion (±10%) and its related oxygenate selectivity (±35 C%) ammonia was co-fed to the catalyst to study the conversion of oxygenates to nitrogen containing compounds. In summary, an unpromoted β-Mo2C catalyst reached CO conversions to ±40% at the conditions applied. Initial promotion of the catalyst with potassium showed a significant drop in catalyst activity, however, an increase in potassium content did not further decrease catalyst activity. The selectivity towards oxygenates was greatly enhanced from 10 C% up to 42 C% (CO2-free) at similar reaction conditions. Simultaneously, the oxygenate distribution shifted towards higher alcohols. The initial methanol content in the total oxygenate slate was around 60 C%, decreasing to about 20 C% upon potassium promotion. During co-feeding of ammonia, N-containing compounds were observed in the form of nitriles (±9 C%, CO2-free) and small traces of amides (±0.1 C%, CO2-free). Acetonitrile was the most dominating formed N-containing compound (≥58 C%). Upon the co-feeding of ammonia, the oxygenate selectivity decreased by roughly 10 C% points (CO2-free) but did not reach zero. Catalyst activity was slightly affected but recovered with time on stream. A slowly building up blockage appeared after 1-3 hours TOS simultaneously with a decreasing CO2 selectivity, suggesting the reaction with NH3 forming ammonium carbonate. This could however not be confirmed. The benefits of producing N-containing compounds using a potassium promoted β-Mo2C needs to be further investigated, trying to avoid the blockage by suppressing the WGS-activity of the catalyst. It is promising that the activity is hardly affected and that in the short period of time on stream N-containing compounds were observed.

Washcoating and packing of Co-Re catalyst particles have been employed as structuring methods of parallel channel monoliths used in the low-temperature Fischer-Tropsch synthesis (FTS). These methods were compared with regard to catalyst hold-up, heat transfer properties and pressure drop. Reactors output was assessed in terms of CO conversion, CH4 selectivity and productivity of C5+ hydrocarbons. Washcoating led to much lower pressure drops, but also resulted in considerably lower catalyst inventory. As for the reactors performance (volumetric and per catalyst mass C5+ productivities), the washcoated monoliths were more effective than the packed-bed ones. This has been attributed to their more favorable hydrodynamic behavior that facilitates the drainage of the reaction products (liquids and waxes) through the central hollow of the channels thus reducing the extra-pellet diffusional limitations. For both catalyst configurations, it has been found that the productivity of C5+ per catalyst mass unit increases as the characteristic diffusion length increases within the range of values considered in this study (below 150 µm). This indicates that a moderate level of internal mass transport restrictions is beneficial for the low-temperature FTS, which has been explained in terms of the effects of diffusional limitations on the H2/CO molar ratio, and that of this ratio on the FTS kinetics. The possible influence of thermal effects on these results has been numerically and experimentally discarded. ; Financial support of this work was undertaken by the Basque Government (IT1069-16) and the Spanish Ministerio de Ciencia, Innovación y Universidades and the European Regional Development Fund (ERDF/FEDER) (grants RTI2018-096294-B-C31, RTI2018-096294-B-C32 and CTQ2015-73901-JIN). Open Access funding provided by University of Basque Country. Luis M. Gandía wishes to thank Banco de Santander and Universidad Pública de Navarra for their financial support under the 'Programa de Intensificación de la Investigación 2018' ...

AbstractA method for leaching Co2Al9 alloy was developed and optimized to produce nonpyrophoric Raney cobalt, which is used as a component of a highly efficient granular Fischer–Tropsch synthesis catalyst. A comparative study of the laboratory‐produced Raney cobalt with commercially available analog was done using the methods of low‐temperature nitrogen sorption, thermoprogrammed reduction (TPR), thermoprogrammed ammonia desorption, thermal analysis, thermal conductivity, and scanning and transmission electron microscopy. Partial dissolution of cobalt with the formation of Co2+ and Co3+ ions was detected during aluminum leaching. It was found that incomplete purification of commercial Raney cobalt from aluminum hydroxide impurity may lead to overestimation of specific surface area. It was also found that the acidity of the molded catalyst is mainly determined not by Raney cobalt, but by elements of the composite catalyst carrier. For the first time, a linear dependence between the content of structures in a Fischer–Tropsch synthesis catalyst with TPR‐AR maxima of 500–800°C and the amount of synthesized liquid hydrocarbons has been established. It is concluded that metal nanoparticles with partial charge transfer (Coδ+) are active centers of selective formation of C5+ hydrocarbons. Obtaining the maximum number of these centers and reaching a high thermal conductivity of the composite with a developed system of transport pores is a criterion for creating an effective cobalt catalyst for low‐temperature synthesis of hydrocarbons.

This work examines the technical and economic feasibility of Biomass-To-Liquid (BTL) processes for the manufacture of liquid hydrocarbon fuels. Six BTL systems are modelled and evaluated which are based on pressurised oxygen gasification of woody biomass, and specifically on circulating fluidised bed and entrained flow gasification systems. Three fuel synthesis technologies are considered: Fischer-Tropsch synthesis, methanol conversion followed by Methanol to Gasoline (MTG) and the Topsoe Integrated Gasoline (TIGAS) synthesis.Published modelling studies of BTL systems based on gasification have only used deterministic estimates of fuel production costs to assess economic viability without accounting for uncertainties of their model parameters. Unlike other studies, the present techno-economic assessment examines and quantifies the effect of uncertainty of key parameters on the fuel production costs. The results of this analysis show that there is a realistic chance (8–14%) of concepts based on Fischer-Tropsch synthesis meeting the cost of conventional fuels; that this probability could be increased to 50% with moderate tax incentives (an 8% reduction in the tax rate); but that deterministic estimates may be systematically underestimating likely production costs.The overall energy efficiency and production costs of the BTL designs evaluated range from 37.9% to 47.6% LHV and €17.88–25.41 per GJ of produced fuels, respectively. The BTL concept with the lowest production costs incorporates CFB gasification and FT synthesis. The model deterministic estimates of production costs of this design indicate that a BTL process is not yet competitive with conventional refineries since the biofuel production costs are approximately 8% higher than current market prices. Large scale biofuel production may be possible in the long term through subsidies, crude oil price rises and legislation.

[Context] How simple organic matter appeared on Earth and the processes by which it transformed into more evolved organic compounds, which ultimately led to the emergence of life, is still an open topic. Different scenarios have been proposed, the main one assumes that simple organic compounds were synthesized, either in the gas phase or on the surfaces of dust grains, during the process of star formation and they were incorporated into larger bodies in the protoplanetary disk. The transformation of these simple organic compounds in more complex forms is still a matter of debate. Recent discoveries have pointed to catalytic properties of dust grains present in the early stellar envelope, which can nowadays be found in the form of chondrites. The significant infall of chondritic meteorites during the early periods of Earth suggests that the same reactions could have taken place in certain environments on the Earth's surface, with conditions more favorable for organic synthesis. [Aims] This work attempts to synthesize simple organic molecules, such as hydrocarbons and alcohols via Fischer-Tropsch-type reactions supported by different chondritic materials under early-Earth conditions, to investigate if organic synthesis can likely occur in this environment and to determine what the differences are in selectivity when using different types of chondrites. [Methods] Fischer-Tropsch-type reactions are investigated from mixtures of CO and H2 at 1 atm of pressure on the surfaces of different chondritic samples. The different products obtained are analyzed in situ by gas chromatography. [Results] Different Fischer-Tropsch reaction products are obtained in quantitative amounts. The formation of alkanes and alkenes being the main processes. The formation of alcohols also takes place in a smaller amount. Other secondary products were obtained in a qualitative way. [Conclusions] Chondritic material surfaces have been proven as good supports for the occurrence of organic synthesis. Under certain circumstances during the formation of Earth, they could have produced a suitable environment for these reactions to occur. ; J.M.T.-R. acknowledges financial support from research project PGC2018-097374-B-I00, funded by FEDER/Ministerio de Ciencia e Innovación – Agencia Estatal de Investigación. J.L. is grateful to ICREA Academia program and funding from Generalitat de Catalunya (2017 SGR 128). A.R. is indebted to the "Ramón y Cajal" program, MINECO project CTQ2017-89132-P, DIUE project 2017SGR1323, and funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 865657) for the project "Quantum Chemistry on Interstellar Grains" (QUANTUMGRAIN).

Includes bibliographical references (p. 99-102). ; Increasingly stringent legislation has been applied to transportation fuels to minimise or eliminate aromatics and sulphur compounds in diesel fuel. This has led to manufacturers determining alternative production methods to comply to legislation. Part of the current diesel fuel is being produced by hydrocracking heavier fractions derived from crude oil. These hydrocracking processes utilise bi-functional catalysts which have a metal (hydrogenating/dehydrogenating) function and an acid (cracking) function. The most common of these hydrocracking catalysts are combinations of either noble metals and acid zeolites, such as Pt/ HY, or combined sulphides of group VIA and VIIIA metals on amorphous acidic supports, such as CoMo/SiO2-Al2O3. For good quality diesel, the fuel should have a high cetane number and the aromatics and sulphur content should also be kept to a. minimum (e.g. EU legislation: sulphur content must be below 10 ppm (wt) by 2008). Fischer-Tropsch wax is made up predominantly of long-chain linear paraffins with exceptionally low aromatics and heteroatom content (sulphur and nitrogen-containing compounds) and therefore a good source for very 'clean', good quality diesel. The objective of this study was therefore to investigate the suitability of a conventional bi-functional hydrocracking catalyst namely, CoMo/SiO2-Al2O3 in unsulphided form for the hydrocracking of Fischer-Tropsch wax using n-tetradecane as a model compound. The purpose of using the catalyst in unsulphided form was not to introduce any sulphur to the already sulphur-free feedstock.