(WO9726494-A1)      A method of forming a gas hydrate comprises passing the gas into a hydrate-forming region and passing the residual unreacted gas into at least one other hydrate-forming region.    The hydrate is formed in a number of stages, each comprising at least one region connected one above another within a pressure vessel. The gas is bubbled upwardly through the water in each region at a (preferably constant) mean upward superficial velocity which is the same in all stages. The gas is supplied simultaneously to all the vessels of one region, unreacted gas from these regions being supplied simultaneously to all the regions of the successive stage, which preferably has a smaller total cross-sectional area. A preferred plant includes 3 successive stages: the first comprising vessels (A1), (A2), (A3); the second comprising (A4) and (A5); and the third comprising (A6). Pipes (c1-c6) supply gas to the vessels while (d1-d6) are gas outlet pipes. Gas hydrate is extracted through outlet pipes (e1-e6).    USE -   For producing hydrates of natural gas. Unreacted gas may be burnt to provide heat energy for driving apparatus used in the hydrate-forming plant.    ADVANTAGE -   The mean upward velocity may be the same at each stage to provide a more efficient gas to solid conversion.    (ZA9700078-A)      A method of forming a gas hydrate comprises passing the gas into a hydrate-forming region and passing the residual unreacted gas into at least one other hydrate-forming region.    The hydrate is formed in a number of stages, each comprising at least one region connected one above another within a pressure vessel. The gas is bubbled upwardly through the water in each region at a (preferably constant) mean upward superficial velocity which is the same in all stages. The gas is supplied simultaneously to all the vessels of one region, unreacted gas from these regions being supplied simultaneously to all the regions of the successive stage, which preferably has a smaller total cross-sectional area. A preferred plant includes 3 successive stages: the first comprising vessels (A1), (A2), (A3); the second comprising (A4) and (A5); and the third comprising (A6). Pipes (c1-c6) supply gas to the vessels while (d1-d6) are gas outlet pipes. Gas hydrate is extracted through outlet pipes (e1-e6).    USE -   For producing hydrates of natural gas. Unreacted gas may be burnt to provide heat energy for driving apparatus used in the hydrate-forming plant.    ADVANTAGE -   The mean upward velocity may be the same at each stage to provide a more efficient gas to solid conversion.    (EP820574-A1)      A method of forming a gas hydrate comprises passing the gas into a hydrate-forming region and passing the residual unreacted gas into at least one other hydrate-forming region.    The hydrate is formed in a number of stages, each comprising at least one region connected one above another within a pressure vessel. The gas is bubbled upwardly through the water in each region at a (preferably constant) mean upward superficial velocity which is the same in all stages. The gas is supplied simultaneously to all the vessels of one region, unreacted gas from these regions being supplied simultaneously to all the regions of the successive stage, which preferably has a smaller total cross-sectional area. A preferred plant includes 3 successive stages: the first comprising vessels (A1), (A2), (A3); the second comprising (A4) and (A5); and the third comprising (A6). Pipes (c1-c6) supply gas to the vessels while (d1-d6) are gas outlet pipes. Gas hydrate is extracted through outlet pipes (e1-e6).    USE -   For producing hydrates of natural gas. Unreacted gas may be burnt to provide heat energy for driving apparatus used in the hydrate-forming plant.    ADVANTAGE -   The mean upward velocity may be the same at each stage to provide a more efficient gas to solid conversion.    (JP10503971-W)      A method of forming a gas hydrate comprises passing the gas into a hydrate-forming region and passing the residual unreacted gas into at least one other hydrate-forming region.    The hydrate is formed in a number of stages, each comprising at least one region connected one above another within a pressure vessel. The gas is bubbled upwardly through the water in each region at a (preferably constant) mean upward superficial velocity which is the same in all stages. The gas is supplied simultaneously to all the vessels of one region, unreacted gas from these regions being supplied simultaneously to all the regions of the successive stage, which preferably has a smaller total cross-sectional area. A preferred plant includes 3 successive stages: the first comprising vessels (A1), (A2), (A3); the second comprising (A4) and (A5); and the third comprising (A6). Pipes (c1-c6) supply gas to the vessels while (d1-d6) are gas outlet pipes. Gas hydrate is extracted through outlet pipes (e1-e6).    USE -   For producing hydrates of natural gas. Unreacted gas may be burnt to provide heat energy for driving apparatus used in the hydrate-forming plant.    ADVANTAGE -   The mean upward velocity may be the same at each stage to provide a more efficient gas to solid conversion.    (GB2309227-B)      A method of forming a gas hydrate comprises passing the gas into a hydrate-forming region and passing the residual unreacted gas into at least one other hydrate-forming region.    The hydrate is formed in a number of stages, each comprising at least one region connected one above another within a pressure vessel. The gas is bubbled upwardly through the water in each region at a (preferably constant) mean upward superficial velocity which is the same in all stages. The gas is supplied simultaneously to all the vessels of one region, unreacted gas from these regions being supplied simultaneously to all the regions of the successive stage, which preferably has a smaller total cross-sectional area. A preferred plant includes 3 successive stages: the first comprising vessels (A1), (A2), (A3); the second comprising (A4) and (A5); and the third comprising (A6). Pipes (c1-c6) supply gas to the vessels while (d1-d6) are gas outlet pipes. Gas hydrate is extracted through outlet pipes (e1-e6).    USE -   For producing hydrates of natural gas. Unreacted gas may be burnt to provide heat energy for driving apparatus used in the hydrate-forming plant.    ADVANTAGE -   The mean upward velocity may be the same at each stage to provide a more efficient gas to solid conversion.    (US6111155-A)      A method of forming a gas hydrate comprises passing the gas into a hydrate-forming region and passing the residual unreacted gas into at least one other hydrate-forming region.    The hydrate is formed in a number of stages, each comprising at least one region connected one above another within a pressure vessel. The gas is bubbled upwardly through the water in each region at a (preferably constant) mean upward superficial velocity which is the same in all stages. The gas is supplied simultaneously to all the vessels of one region, unreacted gas from these regions being supplied simultaneously to all the regions of the successive stage, which preferably has a smaller total cross-sectional area. A preferred plant includes 3 successive stages: the first comprising vessels (A1), (A2), (A3); the second comprising (A4) and (A5); and the third comprising (A6). Pipes (c1-c6) supply gas to the vessels while (d1-d6) are gas outlet pipes. Gas hydrate is extracted through outlet pipes (e1-e6).    USE -   For producing hydrates of natural gas. Unreacted gas may be burnt to provide heat energy for driving apparatus used in the hydrate-forming plant.    ADVANTAGE -   The mean upward velocity may be the same at each stage to provide a more efficient gas to solid conversion.    (TW412586-A)      A method of forming a gas hydrate comprises passing the gas into a hydrate-forming region and passing the residual unreacted gas into at least one other hydrate-forming region.    The hydrate is formed in a number of stages, each comprising at least one region connected one above another within a pressure vessel. The gas is bubbled upwardly through the water in each region at a (preferably constant) mean upward superficial velocity which is the same in all stages. The gas is supplied simultaneously to all the vessels of one region, unreacted gas from these regions being supplied simultaneously to all the regions of the successive stage, which preferably has a smaller total cross-sectional area. A preferred plant includes 3 successive stages: the first comprising vessels (A1), (A2), (A3); the second comprising (A4) and (A5); and the third comprising (A6). Pipes (c1-c6) supply gas to the vessels while (d1-d6) are gas outlet pipes. Gas hydrate is extracted through outlet pipes (e1-e6).    USE -   For producing hydrates of natural gas. Unreacted gas may be burnt to provide heat energy for driving apparatus used in the hydrate-forming plant.    ADVANTAGE -   The mean upward velocity may be the same at each stage to provide a more efficient gas to solid conversion.    (JP3168013-B2)      A method of forming a gas hydrate comprises passing the gas into a hydrate-forming region and passing the residual unreacted gas into at least one other hydrate-forming region.    The hydrate is formed in a number of stages, each comprising at least one region connected one above another within a pressure vessel. The gas is bubbled upwardly through the water in each region at a (preferably constant) mean upward superficial velocity which is the same in all stages. The gas is supplied simultaneously to all the vessels of one region, unreacted gas from these regions being supplied simultaneously to all the regions of the successive stage, which preferably has a smaller total cross-sectional area. A preferred plant includes 3 successive stages: the first comprising vessels (A1), (A2), (A3); the second comprising (A4) and (A5); and the third comprising (A6). Pipes (c1-c6) supply gas to the vessels while (d1-d6) are gas outlet pipes. Gas hydrate is extracted through outlet pipes (e1-e6).    USE -   For producing hydrates of natural gas. Unreacted gas may be burnt to provide heat energy for driving apparatus used in the hydrate-forming plant.    ADVANTAGE -   The mean upward velocity may be the same at each stage to provide a more efficient gas to solid conversion.