Abstract: The operation of a plant for producing a gas hydrate is stabilized by making the gas phase within a downstream step have the same equilibrium composition as that of the gas phase within a generation step. The gas phase within a mixed-gas hydrate generation step is circulated to the gas phase within a downstream step located downstream of the mixed-gas hydrate generation step, and the gas phase within each step is thereby made to have the same equilibrium composition as that of the gas phase within the generation step.

Abstract: The operation of a plant for producing a gas hydrate is stabilized by making the gas phase within a downstream step have the same equilibrium composition as that of the gas phase within a generation step. The gas phase within a mixed-gas hydrate generation step is circulated to the gas phase within a downstream step located downstream of the mixed-gas hydrate generation step, and the gas phase within each step is thereby made to have the same equilibrium composition as that of the gas phase within the generation step.

Abstract: The composition of raw mixed gas and the gas composition of produced mixed gas hydrate are uniformed as rapidly as possible. The process for producing a mixed gas hydrate comprises the gas hydrate forming step of reacting a mixed gas (g) with water (w) to thereby obtain a gas hydrate in slurry form; the dewatering step of removing the water (w) from the gas hydrate slurry (s); the palletizing step of forming the gas hydrate after water removal into pellets; the freezing step of chilling the gas hydrate pellets (p) to the freezing point or below to thereby freeze the same; and the pressure reduction step of depressurizing the frozen gas hydrate to storage pressure, wherein the mixed gas (g) fed to the gas hydrate forming step is diluted by diluent gas (m) as a constituent of the principal components of the mixed gas (g).

Abstract: The composition of raw mixed gas and the gas composition of produced mixed gas hydrate are uniformed as rapidly as possible. The process for producing a mixed gas hydrate comprises the gas hydrate forming step of reacting a mixed gas (g) with water (w) to thereby obtain a gas hydrate in slurry form; the dewatering step of removing the water (w) from the gas hydrate slurry (s); the palletizing step of forming the gas hydrate after water removal into pellets; the freezing step of chilling the gas hydrate pellets (p) to the freezing point or below to thereby freeze the same; and the pressure reduction step of depressurizing the frozen gas hydrate to storage pressure, wherein the mixed gas (g) fed to the gas hydrate forming step is diluted by diluent gas (m) as a constituent of the principal components of the mixed gas (g).

Abstract: A method of exhaust gas denitration in which nitrogen oxides contained in a low-temperature exhaust gas are removed at a high NOx removal efficiency. A injection pipe (11) is disposed in a flue (10) for an exhaust gas (x) so that the pipe protrudes from the inner wall of the flue. A hydrocarbon compound (b) and a nitrogen compound (a) are supplied through the injection pipe (11) into the flue (10). The hydrocarbon compound (b) is burned to form a combustion region (s). In this combustion region (s), amine radicals are produced from the nitrogen compound (a). These amine radicals are mixed with nitrogen oxides contained in the exhaust gas (x) to reductively remove the nitrogen oxides.

Abstract: A denitration process for removing nitrogen oxides contained in low-temperature exhaust gas at a high denitration rate; namely, a denitration process for reductively removing nitrogen oxides contained in an exhaust gas (x) containing nitrogen monoxide and sulfur dioxide. The process comprises a preliminary step 2 of partially oxidizing nitrogen monoxide in the exhaust gas to form nitrogen dioxide, a radical formation step 3 of adding a nitrogen compound and a hydrocarbon compound to a high-temperature zone 22 to form amine radicals (r), and a denitration step 4 of mixing the amine radicals (r) with the pretreated gas (p) containing nitrogen monoxide and nitrogen dioxide that was discharged from the preliminary step 2. As a result, nitrogen oxides in the exhaust gas (x) are reductively decomposed.

Abstract: A denitration process for removing nitrogen oxides contained in low-temperature exhaust gas at a high denitration rate; namely, a denitration process for reductively removing nitrogen oxides contained in an exhaust gas (x) containing nitrogen monoxide and sulfur dioxide. The process comprises a preliminary step 2 of partially oxidizing nitrogen monoxide in the exhaust gas to form nitrogen dioxide, a radical formation step 3 of adding a nitrogen compound and a hydrocarbon compound to a high-temperature zone 22 to form amine radicals (r), and a denitration step 4 of mixing the amine radicals (r) with the pretreated gas (p) containing nitrogen monoxide and nitrogen dioxide that was discharged from the preliminary step 2. As a result, nitrogen oxides in the exhaust gas (x) are reductively decomposed.

Abstract: A method of exhaust gas denitration in which nitrogen oxides contained in a low-temperature exhaust gas are removed at a high NOx removal efficiency. A injection pipe (11) is disposed in a flue (10) for an exhaust gas (x) so that the pipe protrudes from the inner wall of the flue. A hydrocarbon compound (b) and a nitrogen compound (a) are supplied through the injection pipe (11) into the flue (10). The hydrocarbon compound (b) is burned to form a combustion region (s). In this combustion region (s), amine radicals are produced from the nitrogen compound (a). These amine radicals are mixed with nitrogen oxides contained in the exhaust gas (x) to reductively remove the nitrogen oxides.