Abstract: Methods and apparatuses for regulating a power converter are described. A device comprising a control circuit and a logic circuit can be integrated in a controller coupled to the power converter. The control circuit can generate a constant off-time signal based on a ramp signal and an error signal. The logic circuit can generate a control signal based on the constant off-time signal and a constant on-time signal. The logic circuit can output the control signal to the power converter. In response to an on-time period of the constant off-time signal being less than an on-time period of the constant on-time signal, the control signal can vary according to the constant on-time signal. In response to the on-time period of the constant off-time signal being greater than the on-time period of the constant on-time signal, the control signal can vary according to the constant off-time signal.

Abstract: Methods and apparatuses for regulating a power converter are described. A device comprising a control circuit and a logic circuit can be integrated in a controller coupled to the power converter. The control circuit can generate a constant off-time signal based on a ramp signal and an error signal. The logic circuit can generate a control signal based on the constant off-time signal and a constant on-time signal. The logic circuit can output the control signal to the power converter. In response to an on-time period of the constant off-time signal being less than an on-time period of the constant on-time signal, the control signal can vary according to the constant on-time signal. In response to the on-time period of the constant off-time signal being greater than the on-time period of the constant on-time signal, the control signal can vary according to the constant off-time signal.

Abstract: A converter includes a buck boost converter circuit to generate an output voltage in response to an input voltage, and an inductor current compensation circuit to generate an output current compensated inductor current signal corresponding to a sensed input current. The output current compensated inductor current signal includes a voltage gap between a boost ramp valley and a buck ramp peak. The buck boost converter circuit includes a current sensor to receive the input voltage, the current sensor to sense an input current corresponding to the input voltage, an upper buck transistor coupled to the input voltage node, an upper boost transistor coupled to an output voltage node to output the output voltage, and an inductor coupled between the upper buck transistor and the upper boost transistor. The inductor current compensation circuit adjusts the voltage gap based on an offset compensation voltage corresponding to a switching frequency.

Abstract: A buck boost converter includes a buck boost converter circuit to generate an output voltage in response to an input voltage, and a mode control logic circuit to generate a mode control signal to control an operation mode of the buck boost converter circuit to operate in one of a buck mode, a boost mode, and a buck-boost mode. The buck boost converter circuit includes an upper buck transistor coupled to an input voltage node, the input voltage node to receive the input voltage, an upper boost transistor coupled to an output voltage node, the output voltage node to output the output voltage, and an inductor coupled between the upper buck transistor and the upper boost transistor. The mode control signal is generated based on a first duty cycle of the upper buck transistor and a second duty cycle of the upper boost transistor.

Abstract: A catalyst, including a molecular sieve carrier and an active component. The active component includes: iron, manganese, copper, and a basic promoter potassium. The molecular sieve carrier is a cerium salt and/or praseodymium salt modified-aluminosilicate molecular sieve carrier and/or silica-rich molecular sieve carrier. A method for preparing a catalyst for Fischer-Tropsch synthesis, includes: 1) fully dissolving a ferric salt, a manganese salt, a copper salt, and an alkali or a salt containing potassium element in water to yield an aqueous solution, stirring and adding sodium lauryl sulfate to the aqueous solution, and continuing stirring to yield a uniform solution; and impregnating a modified molecular sieve in the uniform solution to yield a mixed solution; and 2) drying and calcining the mixed solution to yield the catalyst.

Abstract: A monolithic catalyst, including cobalt, a metal matrix, a molecular sieve membrane, and an additive. The metal matrix is silver, gold, copper, platinum, titanium, molybdenum, iron, tin, or an alloy thereof. The molecular sieve membrane is mesoporous silica SBA-16 which is disposed on the surface of the metal matrix and is a carrier of the active component and the additive. The thickness of the carrier is between 26 and 67 ?m. The additive is lanthanum, zirconium, cerium, rhodium, platinum, rhenium, ruthenium, titanium, magnesium, calcium, strontium, or a mixture thereof. A method for preparing the monolithic catalyst is also provided.

Abstract: A system for cogenerating gas-steam based on gasification and methanation of biomass, the system including a gasification unit, a shift unit, a purification unit, a methanation unit, and a methane concentration unit. A waste heat boiler is provided in an upper part of a gasifier of the gasification unit. The methanation unit includes a first primary methanation reactor, a second primary methanation reactor, a first secondary methanation reactor, and a second secondary methanation reactor connected in series. An outlet of the second primary methanation reactor is provided with two bypasses, one of which is connected to an inlet of the first primary methanation reactor, the other of which is connected to the first secondary methanation reactor. The second secondary methanation reactor is connected to the methane concentration unit.

Abstract: A method for modifying bio-oil derived from biomass pyrolysis, the method including: 1) adding an inorganic salt and an organic demulsifier to a bio-oil; oscillating or stirring the resulting mixture, and resting the resulting mixture, to yield a lower layer being an aqueous solution and an upper layer being the bio-oil, and collecting the bio-oil; 2) employing a zeolite molecular sieve-loaded clay as a catalyst, and aging the catalyst using pure steam, to yield a modified catalyst; and 3) adding the modified catalyst obtained in 2) to a conventional catalytic cracking reactor, injecting the bio-oil obtained in 1) to the conventional catalytic cracking reactor using a piston pump, and allowing the bio-oil to react under a weight hourly space velocity (WHSV) of between 6 and 15 h?1, a temperature of between 380 and 700° C., and a pressure between 0.1 and 0.8 megapascal.

Abstract: A catalyst, including: a transition metal; and an organic solvent. The transition metal is dispersed in the organic solvent in the form of monodisperse nanoparticles; the transition metal has a grain size of between 1 and 100 nm; and the catalyst has a specific surface area of 5 and 300 m2/g. The invention also provides a method for preparing a catalyst, including: 1) dissolving an organic salt of a transition metal in an organic solvent including a polyhydric alcohol, to yield a mixture; and 2) heating and stirring the mixture in the presence of air or inert gas, holding the mixture at the temperature of between 150 and 250° C. for between 30 and 240 min, to yield the catalyst.

Abstract: A system for cogenerating gas-steam based on gasification and methanation of biomass, the system including a gasification unit, a shift unit, a purification unit, a methanation unit, and a methane concentration unit. A waste heat boiler is provided in an upper part of a gasifier of the gasification unit. The methanation unit includes a first primary methanation reactor, a second primary methanation reactor, a first secondary methanation reactor, and a second secondary methanation reactor connected in series. An outlet of the second primary methanation reactor is provided with two bypasses, one of which is connected to an inlet of the first primary methanation reactor, the other of which is connected to the first secondary methanation reactor. The second secondary methanation reactor is connected to the methane concentration unit.

Abstract: A method of surface modification of an alumina carrier. The method includes: 1) dissolving a soluble kazoe in deionized water to yield a kazoe aqueous solution; 2) submerging an alumina carrier in the kazoe aqueous solution and drying the alumina carrier in a vacuum environment; 3) placing the dried alumina carrier in a reactor, adding silicon tetrachloride and Grignard reagent dropwise to the reactor, sealing the reactor and heating it to a constant temperature, and maintaining the constant temperature for between 3 and 18 hours, where a volume ratio of the added silicon tetrachloride and the alumina carrier is between 0.5:1 and 5:1, the constant temperature is controlled to be between 160 and 350° C.; and 4) cooling the reactor, filtering, washing, and drying the alumina carrier in the vacuum environment.

Abstract: A method for cogenerating gas-steam based on gasification and methanation of biomass. The method includes: 1) mixing oxygen and water vapor with biomass, transporting the resulting mixture via a nozzle to a gasifier, gasifying the biomass to yield crude gasified gas, and transporting superheated steam having a pressure of 5-6 MPa resulting from sensible heat recovery to a steam turbine; 2) adjusting the hydrogen/carbon ratio of the crude gasified gas generated from step 1) to 3:1, and eluting the crude gasified gas whereby yield purified syngas; 3) introducing the purified syngas from step 2) to a methanation unit and transporting intermediate pressure superheated steam generated in the methanation unit to the steam turbine; and 4) concentrating methane of synthetic natural gas containing trace nitrogen and water vapor obtained from step 3) through pressure swing adsorption.

Abstract: A monolithic catalyst, including cobalt, a metal matrix, a molecular sieve membrane, and an additive. The metal matrix is silver, gold, copper, platinum, titanium, molybdenum, iron, tin, or an alloy thereof. The molecular sieve membrane is mesoporous silica SBA-16 which is disposed on the surface of the metal matrix and is a carrier of the active component and the additive. The thickness of the carrier is between 26 and 67 ?m. The additive is lanthanum, zirconium, cerium, rhodium, platinum, rhenium, ruthenium, titanium, magnesium, calcium, strontium, or a mixture thereof. A method for preparing the monolithic catalyst is also provided.

Abstract: A method for recycling exhaust gas from Fischer-Tropsch synthesis. The method includes: 1) introducing raw gas to a shift reactor to conduct a water-gas shift reaction, and collecting shift gas; 2) introducing the shift gas to a Fischer-Tropsch synthesis device to yield a hydrocarbon fuel and exhaust gas, returning part of the exhaust gas as recycle gas; 3) introducing another part of the exhaust gas to a methanation reactor, allowing a methanation reaction to happen between the part of the exhaust gas and water vapor; 4) introducing a mixed gas product from the methanation reaction to a methane reforming reactor; 5) transporting the hydrogen and carbon monoxide resulting from the methane reforming reaction to a gas separator, separating the hydrogen and obtaining a mixed gas including carbon dioxide; and 6) returning the mixed gas including carbon dioxide to the methane reforming reactor.

Abstract: A method for recycling a noble metal from Fischer-Tropsch synthesis products. The method includes: 1) filtering a reaction product in a Fischer-Tropsch synthesis reactor by an inner filter; discharging a filtered reaction product to a first filtration buffer tank; separating a gas phase product or a part of a liquid phase product from the reaction product; introducing the liquid-solid two-phase product to a refining filter for product refining; 2) introducing a liquid phase product containing a catalyst slurry to a dynamic filter, collecting the filtered liquid phase product including a waste catalyst and noble metal ions; introducing the liquid phase product to a second filtration buffer tank; and introducing the filtered liquid phase product to the refining filter; and 3) forming a clay filter cake on a filter disk; and refining the products introduced into the refining filter in 1) and 2).

Abstract: A method for modifying bio-oil derived from biomass pyrolysis, the method including: 1) adding an inorganic salt and an organic demulsifier to a bio-oil; oscillating or stirring the resulting mixture, and resting the resulting mixture, to yield a lower layer being an aqueous solution and an upper layer being the bio-oil, and collecting the bio-oil; 2) employing a zeolite molecular sieve-loaded clay as a catalyst, and aging the catalyst using pure steam, to yield a modified catalyst; and 3) adding the modified catalyst obtained in 2) to a conventional catalytic cracking reactor, injecting the bio-oil obtained in 1) to the conventional catalytic cracking reactor using a piston pump, and allowing the bio-oil to react under a weight hourly space velocity (WHSV) of between 6 and 15 h?1, a temperature of between 380 and 700° C., and a pressure between 0.1 and 0.8 megapascal.

Abstract: A cobalt-based nano catalyst including a metal combination as a core and a porous material as a shell. The metal combination includes a first metal component Co, a second metal component selected from Ce, La, and Zr, and a third metal component selected from Pt, Ru, Rh, and Re. The catalyst includes between 10 and 35 wt. % of the first metal component, between 0.5 and 10 wt. % of the second metal component, between 0.02 and 2 wt. % of the third metal component, and a carrier. The carrier is a porous material such as nano silica or alumina. The carrier is in the shape of a spheroid, has a pore size of between 1 and 20 nm and a specific area of between 300 and 500 m2/g. The active component of the catalyst has a particle size of between 0.5 and 20 nm.

Abstract: A catalyst, including a molecular sieve carrier and an active component. The active component includes: iron, manganese, copper, and a basic promoter potassium. The molecular sieve carrier is a cerium salt and/or praseodymium salt modified-aluminosilicate molecular sieve carrier and/or silica-rich molecular sieve carrier. A method for preparing a catalyst for Fischer-Tropsch synthesis, includes: 1) fully dissolving a ferric salt, a manganese salt, a copper salt, and an alkali or a salt containing potassium element in water to yield an aqueous solution, stirring and adding sodium lauryl sulfate to the aqueous solution, and continuing stirring to yield a uniform solution; and impregnating a modified molecular sieve in the uniform solution to yield a mixed solution; and 2) drying and calcining the mixed solution to yield the catalyst.

Abstract: A liquid catalyst for methanation of carbon dioxide, including an amphiphilic ionic liquid and a metal active component dispersed in the amphiphilic ionic liquid. The metal active component is dispersed in the amphiphilic ionic liquid in the form of stable colloid. The colloid is spherical and has a particle size of between 0.5 and 20 nm. The metal active component includes a first metal active component and a second metal active component. The first metal active component includes nickel. The second metal active component is selected from the group consisting of lanthanum, cerium, molybdenum, ruthenium, ytterbium, rhodium, palladium, platinum, potassium, magnesium, or a mixture thereof. The molar ratio of the first metal active component to the second metal active component is between 10:0.1 and 10:2.

Abstract: A method for recycling exhaust gas from Fischer-Tropsch synthesis. The method includes: 1) introducing raw gas to a shift reactor to conduct a water-gas shift reaction, and collecting shift gas; 2) introducing the shift gas to a Fischer-Tropsch synthesis device to yield a hydrocarbon fuel and exhaust gas, returning part of the exhaust gas as recycle gas; 3) introducing another part of the exhaust gas to a methanation reactor, allowing a methanation reaction to happen between the part of the exhaust gas and water vapor; 4) introducing a mixed gas product from the methanation reaction to a methane reforming reactor; 5) transporting the hydrogen and carbon monoxide resulting from the methane reforming reaction to a gas separator, separating the hydrogen and obtaining a mixed gas including carbon dioxide; and 6) returning the mixed gas including carbon dioxide to the methane reforming reactor.