Frédéric Vogel

Bio: Frédéric Vogel is an academic researcher from Paul Scherrer Institute. The author has contributed to research in topics: Supercritical fluid & Catalysis. The author has an hindex of 30, co-authored 91 publications receiving 4524 citations. Previous affiliations of Frédéric Vogel include École Polytechnique Fédérale de Lausanne & University of Applied Sciences and Arts Northwestern Switzerland FHNW.

Thermochemical biofuel production in hydrothermal media: A review of sub- and supercritical water technologies

Abstract: Hydrothermal technologies are broadly defined as chemical and physical transformations in high-temperature (200–600 °C), high-pressure (5–40 MPa) liquid or supercritical water. This thermochemical means of reforming biomass may have energetic advantages, since, when water is heated at high pressures a phase change to steam is avoided which avoids large enthalpic energy penalties. Biological chemicals undergo a range of reactions, including dehydration and decarboxylation reactions, which are influenced by the temperature, pressure, concentration, and presence of homogeneous or heterogeneous catalysts. Several biomass hydrothermal conversion processes are in development or demonstration. Liquefaction processes are generally lower temperature (200–400 °C) reactions which produce liquid products, often called “bio-oil” or “bio-crude”. Gasification processes generally take place at higher temperatures (400–700 °C) and can produce methane or hydrogen gases in high yields.

Catalytic gasification of algae in supercritical water for biofuel production and carbon capture

Abstract: There has been growing concern about the way cultivating biomass for the production of agro-biofuels competes with food production. To avoid this competition biomass production for biofuels will, in the long term, have to be completely decoupled from food production. This is where microalgae have enormous potential. Here we propose a novel process based on microalgae cultivation using dilute fossil CO2 emissions and the conversion of the algal biomass through a catalytic hydrothermal process. The resulting products are methane as a clean fuel and concentrated CO2 for sequestration. The proposed gasification process mineralizes nutrient-bearing organics completely. Here we show that complete gasification of microalgae (Spirulina platensis) to a methane-rich gas is now possible in supercritical water using ruthenium catalysts. 60–70% of the heating value contained in the algal biomass would be recovered as methane. Such an efficient algae-to-methane process opens up an elegant way to tackle both climate change and dependence on fossil natural gas without competing with food production.

Renewable Production of Methane from Woody Biomass by Catalytic Hydrothermal Gasification

Abstract: Production of synthetic natural gas (SNG) from wood by a catalytic hydrothermal process was studied in a laboratory batch reactor suitable for high feed concentrations (10−30 wt %) at 300−410 °C and 12−34 MPa with Raney nickel as the catalyst. A maximum methane yield of 0.33 (g of CH4)/(g of wood) was obtained, corresponding to the thermodynamic equilibrium yield. The carbon gasification efficiency was a function of the reaction time, and for reaction times long enough (∼90 min), complete gasification was achieved. At supercritical conditions, the remaining liquid phase always was tar-free, was colorless, and contained less than 2 wt % of the feed carbon. Analysis of the spent catalyst revealed a slight increase of carbonaceous deposits on the surface (15 atom % vs 10 atom % for the fresh catalyst).

SunCHem: an integrated process for the hydrothermal production of methane from microalgae and CO2 mitigation

Abstract: We describe a potential novel process (SunCHem) for the production of bio-methane via hydrothermal gasification of microalgae, envisioned as a closed-loop system, where the nutrients, water, and CO2 produced are recycled. The influence on the growth of microalgae of nickel, a trace contaminant that might accumulate upon effluent recycling, was investigated. For all microalgae tested, the growth was adversely affected by the nickel present (1, 5, and 10 ppm). At 25 ppm Ni, complete inhibition of cell division occurred. Successful hydrothermal gasification of the microalgae Phaeodactylum tricornutum to a methane-rich gas with high carbon gasification efficiency (68–74%) and C1–C3 hydrocarbon yields of 0.2 gC1–C3/gDM (DM, dry matter) was demonstrated. The biomass-released sulfur was shown to adversely affect Ru/C catalyst performance. Liquefaction of P. tricornutum at short residence times around 360°C was possible without coke formation.

Autothermal methanol reforming for hydrogen production in fuel cell applications

Abstract: Fuel cell powered electric cars using on-board methanol reforming to produce a hydrogen-rich gas represent a low-emissions alternative to gasoline internal combustion engines (ICE). In order to exceed the well-to-wheel efficiencies of 17% for the gasoline ICE, high-efficiency fuel cells and methanol reformers must be developed. Catalytic autothermal reforming of methanol offers advantages over endothermic steam-reforming and exothermic partial oxidation. Microreactor testing of copper-containing catalysts was carried out in the temperature range between 250 and 330°C showing nearly complete methanol conversion at 85% hydrogen yield. For the overall process a simplified model of the reaction network, consisting of the total oxidation of methanol, the reverse water-gas shift reaction, and the steam-reforming of methanol, is proposed. Individual kinetic measurements for the latter two reactions on a commercial Cu/ZnO/Al2O3 catalyst are presented.

Thermochemical biofuel production in hydrothermal media: A review of sub- and supercritical water technologies

Abstract: Hydrothermal technologies are broadly defined as chemical and physical transformations in high-temperature (200–600 °C), high-pressure (5–40 MPa) liquid or supercritical water. This thermochemical means of reforming biomass may have energetic advantages, since, when water is heated at high pressures a phase change to steam is avoided which avoids large enthalpic energy penalties. Biological chemicals undergo a range of reactions, including dehydration and decarboxylation reactions, which are influenced by the temperature, pressure, concentration, and presence of homogeneous or heterogeneous catalysts. Several biomass hydrothermal conversion processes are in development or demonstration. Liquefaction processes are generally lower temperature (200–400 °C) reactions which produce liquid products, often called “bio-oil” or “bio-crude”. Gasification processes generally take place at higher temperatures (400–700 °C) and can produce methane or hydrogen gases in high yields.

A review of catalytic upgrading of bio-oil to engine fuels

Abstract: As the oil reserves are depleting the need of an alternative fuel source is becoming increasingly apparent. One prospective method for producing fuels in the future is conversion of biomass into bio-oil and then upgrading the bio-oil over a catalyst, this method is the focus of this review article. Bio-oil production can be facilitated through flash pyrolysis, which has been identified as one of the most feasible routes. The bio-oil has a high oxygen content and therefore low stability over time and a low heating value. Upgrading is desirable to remove the oxygen and in this way make it resemble crude oil. Two general routes for bio-oil upgrading have been considered: hydrodeoxygenation (HDO) and zeolite cracking. HDO is a high pressure operation where hydrogen is used to exclude oxygen from the bio-oil, giving a high grade oil product equivalent to crude oil. Catalysts for the reaction are traditional hydrodesulphurization (HDS) catalysts, such as Co–MoS2/Al2O3, or metal catalysts, as for example Pd/C. However, catalyst lifetimes of much more than 200 h have not been achieved with any current catalyst due to carbon deposition. Zeolite cracking is an alternative path, where zeolites, e.g. HZSM-5, are used as catalysts for the deoxygenation reaction. In these systems hydrogen is not a requirement, so operation is performed at atmospheric pressure. However, extensive carbon deposition results in very short catalyst lifetimes. Furthermore a general restriction in the hydrogen content of the bio-oil results in a low H/C ratio of the oil product as no additional hydrogen is supplied. Overall, oil from zeolite cracking is of a low grade, with heating values approximately 25% lower than that of crude oil. Of the two mentioned routes, HDO appears to have the best potential, as zeolite cracking cannot produce fuels of acceptable grade for the current infrastructure. HDO is evaluated as being a path to fuels in a grade and at a price equivalent to present fossil fuels, but several tasks still have to be addressed within this process. Catalyst development, understanding of the carbon forming mechanisms, understanding of the kinetics, elucidation of sulphur as a source of deactivation, evaluation of the requirement for high pressure, and sustainable sources for hydrogen are all areas which have to be elucidated before commercialisation of the process.

Engineering Carbon Materials from the Hydrothermal Carbonization Process of Biomass

Abstract: Energy shortage, environmental crisis, and developing customer demands have driven people to find facile, low-cost, environmentally friendly, and nontoxic routes to produce novel functional materials that can be commercialized in the near future. Amongst various techniques, the hydrothermal carbonization (HTC) process of biomass (either of isolated carbohydrates or crude plants) is a promising candidate for the synthesis of novel carbon-based materials with a wide variety of potential applications. In this Review, we will discuss various synthetic routes towards such novel carbon-based materials or composites via the HTC process of biomass. Furthermore, factors that influence the carbonization process will be analyzed and the special chemical/physical properties of the final products will be discussed. Despite the lack of a clear mechanism, these novel carbonaceous materials have already shown promising applications in many fields such as carbon fixation, water purification, fuel cell catalysis, energy storage, CO(2) sequestration, bioimaging, drug delivery, and gas sensors. Some of the most promising examples will also be discussed here, demonstrating that the HTC process can rationally design a rich family of carbonaceous and hybrid functional carbon materials with important applications in a sustainable fashion.