A method of charging and/or discharging energy in reusable fuel workpieces or particles includes a solar furnace with counter-flowing workpieces and gas, to exchange heat therebetween, with the exiting gas and workpieces being at about ambient temperature. A further aspect employs a production plant including a reduction reactor configured to use excess electrical energy generated by renewable power generators to charge and/or discharge solid-state thermochemical fuel. Another aspect includes a fuel flow control valve using air pulses. An oxygen-deprived and reusable fuel, such as magnesium manganese oxide, or magnesium iron oxide, is also provided. In another aspect, an apparatus for producing a solid-state fuel includes a reduction reactor including a reactor chamber configured to receive concentrated solar energy, and a reactor tube having a recuperation zone, a reduction zone, and a quenching zone, wherein the reduction zone passes through the reactor chamber. A discharged solid-state fuel is configured to be fed down the reactor tube and a low-oxygen gas is configured to flow up the reactor tube.

A method of charging and/or discharging energy in reusable fuel workpieces or particles includes a solar furnace with counter-flowing workpieces and gas, to exchange heat therebetween, with the exiting gas and workpieces being at about ambient temperature. A further aspect employs a production plant including a reduction reactor configured to use excess electrical energy generated by renewable power generators to charge and/or discharge solid-state thermochemical fuel. Another aspect includes a fuel flow control valve using air pulses. An oxygen-deprived and reusable fuel, such as magnesium manganese oxide, or magnesium iron oxide, is also provided. In another aspect, an apparatus for producing a solid-state fuel includes a reduction reactor including a reactor chamber configured to receive concentrated solar energy, and a reactor tube having a recuperation zone, a reduction zone, and a quenching zone, wherein the reduction zone passes through the reactor chamber. A discharged solid-state fuel is configured to be fed down the reactor tube and a low-oxygen gas is configured to flow up the reactor tube.

Fine coal is cleaned of its mineral matter impurities and dewatered by mixing the aqueous slurry containing both with a hydrophobic liquid, subjecting the mixture to a phase separation. The resulting hydrophobic liquid phase contains coal particles free of surface moisture and droplets of water stabilized by coal particles, while the aqueous phase contains the mineral matter. By separating the entrained water droplets from the coal particles mechanically, a clean coal product of substantially reduced mineral matter and moisture contents is obtained. The spent hydrophobic liquid is separated from the clean coal product and recycled. The process can also be used to separate one type of hydrophilic particles from another by selectively hydrophobizing one.

A fuel composition that provides a renewable biofuel energy source for reducing dependence on fossil fuels and improving air quality by reducing the amount of carbon monoxide released into the air during combustion. The fuel composition includes an energy crop comprising: a solid granular component being suspended in a liquid non-petroleum plant based fuel. The liquid fuel containing the granular component is efficacious in releasing copious quantities of vapor for burning. The vapor provides a more complete and efficient burn. The fuel composition further comprises an oxidizing agent for removing a plurality of electrons from the granular component during combustion, and/or an additive that imparts a change in the physical properties of the fuel composition.

An experimental method for coal desulfurization and deashing using permeation and solvating power of a supercritical fluid includes the following steps. The coal sample is ground and loaded into an extraction kettle with a cover. An inlet valve and an outlet valve of the extraction kettle are opened to circulate the supercritical CO.sub.2 fluid in the extraction kettle. The extraction kettle is sealed. By adjusting a temperature and a pressure in the extraction kettle, the supercritical CO.sub.2 fluid is kept at its critical point and permeates the coal sample to dissolve organic sulfur, inorganic sulfur and ash in the coal sample. The extraction kettle is depressurized, and the temperature in the extraction kettle is adjusted to gasify the supercritical CO.sub.2 fluid. The organic sulfur, the inorganic sulfur and part of the ash are separated from the supercritical CO.sub.2 fluid and precipitated at a bottom of the extraction kettle.

An experimental method for coal desulfurization and deashing using permeation and solvating power of a supercritical fluid includes the following steps. The coal sample is ground and loaded into an extraction kettle with a cover. An inlet valve and an outlet valve of the extraction kettle are opened to circulate the supercritical CO.sub.2 fluid in the extraction kettle. The extraction kettle is sealed. By adjusting a temperature and a pressure in the extraction kettle, the supercritical CO.sub.2 fluid is kept at its critical point and permeates the coal sample to dissolve organic sulfur, inorganic sulfur and ash in the coal sample. The extraction kettle is depressurized, and the temperature in the extraction kettle is adjusted to gasify the supercritical CO.sub.2 fluid. The organic sulfur, the inorganic sulfur and part of the ash are separated from the supercritical CO.sub.2 fluid and precipitated at a bottom of the extraction kettle.

The present invention is provided with: a first processing device main body (111) that processes carbonized coal (1) by means of processing gas (103) of which the oxygen concentration has been adjusted by blowers (113,115); a second processing device main body (121) that processes primary processed carbonized coal (2a), which results from being processed at the first processing device main body, by means of air (102) fed by a blower (122); a second-processing-gas state detection means that detects the state of the air used within the second processing device main body; and a control device (130) that, on the basis of information from the second-processing—gas state detection means, controls the blowers (113,115) in a manner so as to adjust the oxygen concentration in the processing gas when the state of the air has diverged from a predetermined state.

The present invention is provided with: a first processing device main body (111) that processes carbonized coal (1) by means of processing gas (103) of which the oxygen concentration has been adjusted by blowers (113,115); a second processing device main body (121) that processes primary processed carbonized coal (2a), which results from being processed at the first processing device main body, by means of air (102) fed by a blower (122); a second-processing-gas state detection means that detects the state of the air used within the second processing device main body; and a control device (130) that, on the basis of information from the second-processing—gas state detection means, controls the blowers (113,115) in a manner so as to adjust the oxygen concentration in the processing gas when the state of the air has diverged from a predetermined state.

A method for producing low-sulfur coal having an excellent desulfurization effect. In the production method, coal is brought into contact with a chemical agent that is a mixed solution of hydrogen peroxide and acetic acid to remove sulfur in the coal. It is preferred that the molar ratio of the acetic acid to the hydrogen peroxide ((acetic acid)/(hydrogen peroxide)) is 1.2 to 60.0 inclusive. It is preferred that the acetic acid is mixed with the hydrogen peroxide before the chemical agent is brought into contact with the coal and the chemical agent is brought into contact with the coal after 30 minutes or more has elapsed since the mixing is performed.

A method for producing low-sulfur coal having an excellent desulfurization effect. In the production method, coal is brought into contact with a chemical agent that is a mixed solution of hydrogen peroxide and acetic acid to remove sulfur in the coal. It is preferred that the molar ratio of the acetic acid to the hydrogen peroxide ((acetic acid)/(hydrogen peroxide)) is 1.2 to 60.0 inclusive. It is preferred that the acetic acid is mixed with the hydrogen peroxide before the chemical agent is brought into contact with the coal and the chemical agent is brought into contact with the coal after 30 minutes or more has elapsed since the mixing is performed.