Abstract: A molding machine for production of gas hydrate pellets under a high pressure in gas hydrate forming conditions, which is inexpensive through minimizing of the use of expensive mechanical seal. The molding machine comprises two forming rolls each fitted to a rotary shaft whose both ends are supported by bearings; a drive unit for rotating the forming rolls; a screw transfer unit for supplying powder to the forming rolls; and a high-pressure vessel, wherein the bearings, the rotary shaft and the forming rolls are all disposed in the high-pressure vessel.

Abstract: In producing gas hydrate pellets by compression-molding a gas hydrate powder, heat generated in a compressing part is removed with a simple method so as to reduce the degree of gas hydrate decomposition, and a gas hydrate aggregate blocking the compressing part is promptly and easily removed. A gas-hydrate-pellet production apparatus A is characterized by including: a roll-cooling mechanism which causes cooling water to flow through outer peripheral portions and/or insides of rolls 6a and 6b, thereby cooling the rolls 6a and 6b, and also cools the cooling water 43 discharged after the flow and supplies the cooled cooling water 43 to the outer peripheral portion and/or the inner portion of each of the rolls 6a and 6b; and/or heating means provided in a part of a hopper chamber 5 from which the gas hydrate powder n is fed to the rolls 6a and 6b.

Abstract: A molding machine for production of gas hydrate pellets under a high pressure in gas hydrate forming conditions, which is inexpensive through minimizing of the use of expensive mechanical seal. The molding machine comprises two forming rolls each fitted to a rotary shaft whose both ends are supported by bearings; a drive unit for rotating the forming rolls; a screw transfer unit for supplying powder to the forming rolls; and a high-pressure vessel, wherein the bearings, the rotary shaft and the forming rolls are all disposed in the high-pressure vessel.