佐藤 智司

Long-term stability of catalysts is one of important factors in heterogeneous catalysis. Solid acid catalysts are widely used in various reactions in the chemical industry, whereas they readily deactivate in most cases because of coke deposition on the acid sites. Therefore, efficient methods for controlling deactivation of solid acid catalysts are highly required. A method including both the doping of transition metals and the reaction operation in H2 flow (named as Metal-H2 method) is effective for suppressing coke deposition on solid acids in various cases. Although the Metal-H2 methodology has been utilized in some processes by different research groups, it has not been systematically summarized. In this review, we originally define the Metal-H2 method, and summarize the specific applications of the Metal-H2 method for controlling deactivation in cracking, reforming, dehydration, aldol condensation, and other processes.

Global supply of 1,3-butadiene (abbreviated as BD) is faced with a problem such as variation in chemical feedstock in recent years. Many research efforts have been made to produce BD from some renewable resources to replace petroleum. Biomass-derived C4 alcohols such as 2,3-, 1,3-, and 1,4-butanediol (BDO) can be regarded as alternative resources to manufacture BD. Direct dehydration of BDOs into BD as well as two-step dehydration through the corresponding unsaturated alcohols such as 3-buten-2-ol, 2-buten-1-ol, and 3-buten-1-ol has been proposed as an alternative BD production process. 2,3-BDO and 1,4-BDO can be directly dehydrated to produce BD over Sc2O3 and Yb2O3, respectively, whereas stepwise dehydration is necessary for other BDOs. In the two-step dehydration, efficient production of unsaturated alcohols from BDOs is a key technology to form BD with high selectivity. CeO2 with a cubic fluorite phase is extremely effective for the conversion of 1,3-BDO to form 3-buten-2-ol and 2-buten-1-ol, while heavy rare earth oxides are effective for the dehydration of 1,4-BDO to produce 3-buten-1-ol. We reviewed the BD production from C4 alcohols through not only direct dehydration but also stepwise dehydration in addition to the BD production through dehydrogenation of butenes which could be produced from 1- and 2-butanol.

Production of fuels and chemicals from renewable biomass resources is an attractive way to alleviate the shortage of fossil fuels and reduce CO2 emission. Glycerol is an important biomass derivative currently produced as a by-product in the manufacture of biodiesel in a huge amount close to 10 wt% of the overall biodiesel production. The application of glycerol as a renewable raw material has attracted much attention in the last decade, and some catalytic technologies for the conversion of glycerol into useful chemicals such as methanol, epichlorohydrin, and 1,2-propanediol have been established. Acrylic acid is an important bulk chemical widely used in the manufacture of polymeric products and is currently produced in the petrochemical industry via two-step gas-phase oxidation of propylene. The depletion of fossil resources motivates developments in the production of acrylic acid from renewable raw materials. Glycerol has potential for use as a raw material for the production of acrylic acid, and the variety of glycerol derivatives provides opportunities for producing acrylic acid from glycerol through different ways. In this review, possible routes and the corresponding catalytic technologies for the conversion of glycerol to acrylic acid are primarily summarized, and the advantages as well as the challenges in each route are discussed.

Applications of renewable biomass provide facile routes to alleviate the shortage of fossil fuels as well as to reduce the emission of CO2. Glycerol, which is currently produced as a waste in the biodiesel production, is one of the most attractive biomass resources. In the past decade, the conversion of glycerol into useful chemicals has attracted much attention, and glycerol is mainly converted by steam reforming, hydrogenolysis, oxidation, dehydration, esterification, carboxylation, acetalization, and chlorination. In this review, we focused on the catalytic hydrogenolysis of glycerol into C3 chemicals, which contain many industrially important products such as 1,2-propanediol, 1,3-propanediol, allyl alcohol, 1-propanol and propylene. In the hydrogenolysis of glycerol into propanediols, advantages and disadvantages of liquid and vapor-phase reactions are compared. In addition, recent studies on catalysts, reaction conditions, and proposed pathways are primarily summarized and discussed. Furthermore, new research trends are introduced in connection with the hydrogenolysis of glycerol into allyl alcohol, propanols and propylene. (C) 2016 Elsevier B.V. All rights reserved.