Patent classifications
B01J27/055
Vanadium-based catalyst and preparation method therefor
A vanadium-based catalyst comprises an active phase carried on a carrier. The active phase comprises vanadium oxide, potassium sulfate, sodium sulfate, and assistants. The carrier comprises ultra-large-pore silicon dioxide and diatomite, the average pore size of the ultra-large-pore silicon dioxide ranges from 100 nm to 500 nm, and the diatomite is a refined diatomite having a silicon dioxide content of higher than 85% after refinement. The preparation method for the vanadium-based catalyst comprises: 1) mixing potassium vanadium and potassium hydroxide, and allowing a prepared mixed solution and sulfuric acid to carry out a neutralization reaction; and 2) mixing a neutralization reaction product in step 1) with the carrier and sodium sulfate, and carrying out rolling, band extrusion, drying and roasting to prepare the vanadium-based catalyst, assistant compounds being added in step 1) and/or step 2).
Process-scale synthesis of urolithin A
Disclosed are methods for preparing a salt of urolithin A and, in turn, urolithin A. The methods are advantageous for the large-scale preparation of urolithin A or a pharmaceutically acceptable salt thereof.
Process-scale synthesis of urolithin A
Disclosed are methods for preparing a salt of urolithin A and, in turn, urolithin A. The methods are advantageous for the large-scale preparation of urolithin A or a pharmaceutically acceptable salt thereof.
Economical methods for performing oxidative catalytic pretreatment of plant biomass using a single-stage two oxidant process
An improved alkaline pretreatment of biomass is provided that is a single-stage, two oxidant alkaline oxidative pretreatment process. The process uses a homogenous catalyst with at least two oxidants (Hydrogen peroxide and enhanced levels of oxygen) in an alkaline environment to catalytically pretreat lignocellulosic biomass in a single-stage oxidation reaction. The provided single-stage alkaline-oxidative pretreatment improves biomass pretreatment and increase enzymatic digestibility to improve the economic feasibility of production of lignocellulose derived sugars.
Economical methods for performing oxidative catalytic pretreatment of plant biomass using a single-stage two oxidant process
An improved alkaline pretreatment of biomass is provided that is a single-stage, two oxidant alkaline oxidative pretreatment process. The process uses a homogenous catalyst with at least two oxidants (Hydrogen peroxide and enhanced levels of oxygen) in an alkaline environment to catalytically pretreat lignocellulosic biomass in a single-stage oxidation reaction. The provided single-stage alkaline-oxidative pretreatment improves biomass pretreatment and increase enzymatic digestibility to improve the economic feasibility of production of lignocellulose derived sugars.
SHAPED CATALYST BODY IN THE FORM OF TETRALOBES HAVING A CENTRAL THROUGH-PASSAGE
The invention relates to a shaped catalyst body in the form of a tetralobe having four outer through-passages and a ratio of diameter to height of the shaped body of from 0.25 to 1.0 and having a central fifth through-passage. It is used for the oxidation of S02 to S03.
Method for producing isocyanates
The invention relates to a method for producing an isocyanate, wherein a carbamate or thiolcarbomate is converted, in the presence of a catalyst, with separation of an alcohol or thioalcohol, at a temperature of at least 150 C., to the corresponding isocyanate, wherein a compound of the general formula (X)(Y)(ZH) is used as a catalyst, in particular characterized in that the compound has both a proton donor function and a proton acceptor function. In the catalysts according to the invention, a separable proton is bound to a heteroatom, which is more electronegative than carbon. Said heteroatom is either identical to Z or a component thereof. In the catalysts according to the invention, there is additionally a proton acceptor function which is either identical to X or a component thereof. According to the invention, the proton donator and proton acceptor function are connected to each other by the bridge Y.
Method for producing isocyanates
The invention relates to a method for producing an isocyanate, wherein a carbamate or thiolcarbomate is converted, in the presence of a catalyst, with separation of an alcohol or thioalcohol, at a temperature of at least 150 C., to the corresponding isocyanate, wherein a compound of the general formula (X)(Y)(ZH) is used as a catalyst, in particular characterized in that the compound has both a proton donor function and a proton acceptor function. In the catalysts according to the invention, a separable proton is bound to a heteroatom, which is more electronegative than carbon. Said heteroatom is either identical to Z or a component thereof. In the catalysts according to the invention, there is additionally a proton acceptor function which is either identical to X or a component thereof. According to the invention, the proton donator and proton acceptor function are connected to each other by the bridge Y.
METHOD FOR PRODUCING ISOCYANATES
The invention relates to a method for producing an isocyanate, wherein a carbamate or thiolcarbomate is converted, in the presence of a catalyst, with separation of an alcohol or thioalcohol, at a temperature of at least 150 C., to the corresponding isocyanate, wherein a compound of the general formula (X)(Y)(ZH) is used as a catalyst, in particular characterized in that the compound has both a proton donor function and a proton acceptor function. In the catalysts according to the invention, a separable proton is bound to a heteroatom, which is more electronegative than carbon. Said heteroatom is either identical to Z or a component thereof. In the catalysts according to the invention, there is additionally a proton acceptor function which is either identical to X or a component thereof. According to the invention, the proton donator and proton acceptor function are connected to each other by the bridge Y.
METHOD FOR PRODUCING ISOCYANATES
The invention relates to a method for producing an isocyanate, wherein a carbamate or thiolcarbomate is converted, in the presence of a catalyst, with separation of an alcohol or thioalcohol, at a temperature of at least 150 C., to the corresponding isocyanate, wherein a compound of the general formula (X)(Y)(ZH) is used as a catalyst, in particular characterized in that the compound has both a proton donor function and a proton acceptor function. In the catalysts according to the invention, a separable proton is bound to a heteroatom, which is more electronegative than carbon. Said heteroatom is either identical to Z or a component thereof. In the catalysts according to the invention, there is additionally a proton acceptor function which is either identical to X or a component thereof. According to the invention, the proton donator and proton acceptor function are connected to each other by the bridge Y.