Hydrodeoxygenation of Furfural Over Supported Metal Catalysts: A Comparative Study of Cu, Pd and Ni
TL;DR: In this paper, the authors investigated the hydrodeoxygenation of furfural over three different metal catalysts, Cu, Pd and Ni supported on SiO2, on a continuous-flow reactor under atmospheric pressure of hydrogen in the 210-290°C temperature range.
Abstract: The hydrodeoxygenation of furfural has been investigated over three different metal catalysts, Cu, Pd and Ni supported on SiO2, on a continuous-flow reactor under atmospheric pressure of hydrogen in the 210–290 °C temperature range. The distribution of products is a strong function of the metal catalyst used. High selectivity to furfuryl alcohol is obtained over Cu/SiO2, with the formation of only small amounts of 2-methyl furan at the highest reaction temperature studied. In contrast to Cu catalyst, the conversion of furfural over Pd/SiO2 mainly produces furan by decarbonylation. Furan can further react with hydrogen to form tetrahydrofuran (THF). Finally, on Ni/SiO2 catalysts ring opening products (butanal, butanol and butane) can be obtained in significant amounts. The different product distributions are explained in terms of the strength of interaction of the furan ring with the metal surface and the type of surface intermediates that each metal is able to stabilize.
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TL;DR: In this paper, it is shown that a series of platform molecules such as levulinic acid, furans, fatty acids and polyols can be converted into a variety of fuel additives through catalytic transformations that include reduction, esterification, etherification, and acetalization reactions.
1,100 citations
TL;DR: A review of the most relevant chemical routes for converting furfural to chemicals, bio-fuels, and additives is presented in this article, focusing not only on industrially produced chemicals derived from fur, but also on other not yet commercialised products that have a high potential for commercialisation as commodities.
Abstract: The production of future transportation fuels and chemicals requires the deployment of new catalytic processes that transform biomass into valuable products under competitive conditions. Furfural has been identified as one of the most promising chemical platforms directly derived from biomass. With an annual production close to 300 kTon, furfural is currently a commodity chemical, and the technology for its production is largely established. The aim of this review is to discuss the most relevant chemical routes for converting furfural to chemicals, biofuels, and additives. This review focuses not only on industrially produced chemicals derived from furfural, but also on other not yet commercialised products that have a high potential for commercialisation as commodities. Other chemicals that are currently produced from oil but can also be derived from furfural are also reviewed. The chemical and engineering aspects such as the reaction conditions and mechanisms, as well as the main achievements and the challenges still to come in the pursuit of advancing the furfural-based industry, are highlighted.
1,079 citations
TL;DR: This review starts with the current understanding of the chemistry in fast pyrolysis of lignocellulose and focuses on the development of catalysts in catalytic fast pyrosynthesis, with the emphasis on bio-oil yields and quality.
Abstract: Increasing energy demand, especially in the transportation sector, and soaring CO2 emissions necessitate the exploitation of renewable sources of energy. Despite the large variety of new energy carriers, liquid hydrocarbon still appears to be the most attractive and feasible form of transportation fuel taking into account the energy density, stability and existing infrastructure. Biomass is an abundant, renewable source of energy; however, utilizing it in a cost-effective way is still a substantial challenge. Lignocellulose is composed of three major biopolymers, namely cellulose, hemicellulose and lignin. Fast pyrolysis of biomass is recognized as an efficient and feasible process to selectively convert lignocellulose into a liquid fuel—bio-oil. However bio-oil from fast pyrolysis contains a large amount of oxygen, distributed in hundreds of oxygenates. These oxygenates are the cause of many negative properties, such as low heating value, high corrosiveness, high viscosity, and instability; they also greatly limit the application of bio-oil particularly as transportation fuel. Hydrocarbons derived from biomass are most attractive because of their high energy density and compatibility with the existing infrastructure. Thus, converting lignocellulose into transportation fuels via catalytic fast pyrolysis has attracted much attention. Many studies related to catalytic fast pyrolysis of biomass have been published. The main challenge of this process is the development of active and stable catalysts that can deal with a large variety of decomposition intermediates from lignocellulose. This review starts with the current understanding of the chemistry in fast pyrolysis of lignocellulose and focuses on the development of catalysts in catalytic fast pyrolysis. Recent progress in the experimental studies on catalytic fast pyrolysis of biomass is also summarized with the emphasis on bio-oil yields and quality.
848 citations
TL;DR: This tutorial review is aimed at providing a general overview of processes, technologies and challenges that lie ahead for a range of different aqueous-phase transformations of some of the key biomass-derived platform molecules into liquid fuels for the transportation sector and related high added value chemicals.
Abstract: Global warming issues and the medium-term depletion of fossil fuel reserves are stimulating researchers around the world to find alternative sources of energy and organic carbon. Biomass is considered by experts the only sustainable source of energy and organic carbon for our industrial society, and it has the potential to displace petroleum in the production of chemicals and liquid transportation fuels. However, the transition from a petroleum-based economy to one based on biomass requires new strategies since the petrochemical technologies, well-developed over the last century, are not valid to process the biomass-derived compounds. Unlike petroleum feedstocks, biomass derived platform molecules possess a high oxygen content that gives them low volatility, high solubility in water, high reactivity and low thermal stability, properties that favour the processing of these resources by catalytic aqueous-phase technologies at moderate temperatures. This tutorial review is aimed at providing a general overview of processes, technologies and challenges that lie ahead for a range of different aqueous-phase transformations of some of the key biomass-derived platform molecules into liquid fuels for the transportation sector and related high added value chemicals.
700 citations
TL;DR: In this paper, the development of active, selective, and stable hydrotreating catalysts is problematic due to the poor quality of current pyrolysis bio-oil feedstock (i.e., high oxygen content, molecular complexity, coking propensity, and corrosiveness).
Abstract: Considerable worldwide interest exists in discovering renewable energy sources that can substitute for fossil fuels. Lignocellulosic biomass, the most abundant and inexpensive renewable feedstock on the planet, has a great potential for sustainable production of fuels, chemicals, and carbon-based materials. Fast pyrolysis integrated with hydrotreating, one of the simplest, most cost-effective, and most efficient processes to convert lignocellulosic biomass to liquid hydrocarbon fuels for transportation, has attracted significant attention in recent decades. However, effective hydrotreating of pyrolysis bio-oil presents a daunting challenge to the commercialization of biomass conversion via pyrolysis-hydrotreating. Specifically, the development of active, selective, and stable hydrotreating catalysts is problematic due to the poor quality of current pyrolysis bio-oil feedstock (i.e., high oxygen content, molecular complexity, coking propensity, and corrosiveness). Significant research has been conducted to...
586 citations
References
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TL;DR: The biochemical route, being less mature, probably has a greater cost reduction potential than the thermo-chemical route, but here a wider range of synthetic fuels can be produced to better suit heavy truck, aviation and marine applications.
1,379 citations
TL;DR: In this article, a biphasic batch reactor system was proposed for the conversion of carbohydrate feedstocks to liquid alkanes by the combination of dehydration, aldol-condensation/hydrogenation, and de-watering.
494 citations
TL;DR: In this paper, the hydrogenation/hydrodeoxygenation of furfural was studied on a Cu/SiO 2 catalyst at 230-290 ˚C. Detailed kinetics, density function (DFT) calculations, and spectroscopic studies were combined to investigate this reaction.
457 citations
TL;DR: In this paper, the influence of temperature on the compounds existing in liquid products obtained from biomass samples via pyrolysis were examined in relation to the yield and composition of the product bio-oils.
371 citations
TL;DR: In this article, the decomposition mechanisms of oxygenates on transition metal surfaces focusing primarily on metals of Groups VIII and IB are reviewed and deviations from these serve to illustrate the patterns of oxygenate reactions, and major divisions in the preferred pathways can be rationalized in terms of the affinities of metals for making metaloxygen and metal-hydrogen bonds.
Abstract: The importance of various oxygenates as fuels and as chemical intermediates and products continues to grow. Alcohols and aldehydes have also been the subjects of numerous surface reactivity studies. We review here the decomposition mechanisms of oxygenates on transition metal surfaces focusing primarily on metals of Groups VIII and IB. Common pathways as well as deviations from these serve to illustrate the patterns of oxygenate reactions. Several major divisions in the preferred pathways can be rationalized in terms of the affinities of metals for making metal–oxygen and metal–hydrogen bonds. Other important factors determining oxygenate reactivities include surface crystallographic structure and the detailed molecular structure of the oxygenate. Differences in product distribution between metals are frequent, even in cases where many of the reaction steps are common, primarily because of the plethora of elementary reaction steps usually involved in oxygenate decomposition on transition metal surfaces. As a result, differences late in the reaction sequence can obscure important similarities in the overall reaction network. Spectroscopic identification of common surface reaction intermediates including alkoxides, acyls, and oxametallacycles, has become increasingly important in revealing the underlying similarities in seemingly diverse oxygenate reaction pathways on transition metal surfaces.
347 citations