Apparatus for producing gas hydrate pellet and process for producing gas hydrate pellet with the same

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 6 a and 6 b , thereby cooling the rolls 6 a and 6 b , 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 6 a and 6 b ; 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 6 a and 6 b.

1 . An apparatus for producing gas hydrate pellets which compression-molds a powdery gas hydrate powder into gas hydrate pellets of a substantially spherical shape or the like, the gas hydrate powder being generated by contacting and reacting a raw-material gas and raw-material water with each other,
 the production apparatus characterized by comprising:   a hopper chamber which houses the gas hydrate powder;   a pair of compression rolls which are disposed below an opening portion of the hopper chamber; and   a push-in device which feeds the gas hydrate powder in the hopper chamber to the compression rolls,   the apparatus characterized in that heating means is provided on at least one side of the hopper chamber.   
   
   
       2 . The apparatus for producing gas hydrate pellets according to  claim 1 , wherein the heating means supplies hot water to the pair of compression rolls from a lower portion of the at least one side of the hopper chamber, and discharges the water from a lower portion of another side thereof. 
   
   
       3 . The apparatus for producing gas hydrate pellets according to  claim 1 , wherein a nozzle for jetting any one of the hot water and water is provided in the lower portion of the at least one side of the hopper chamber. 
   
   
       4 . A roll-type gas-hydrate-pellet production apparatus which compression-molds a gas hydrate powder to produce gas hydrate pellets, the gas hydrate powder being generated by contacting and reacting a raw-material gas and raw-material water with each other,
 the gas-hydrate-pellet production apparatus comprising:   a hopper chamber which houses the gas hydrate powder;   a pair of compression rolls which are disposed below an opening portion of the hopper chamber; and   a push-in device which supplies the gas hydrate powder in the hopper chamber to the compression rolls,   the gas-hydrate-pellet production apparatus further comprising a roll-cooling mechanism which causes cooling water to flow through an outer peripheral portion and/or an inside of each roll so as to cool the roll, and which cools the cooling water discharged after the flow by use of a cooler.   
   
   
       5 . The apparatus for producing gas hydrate pellets according to  claim 1 , the production apparatus comprising a roll-cooling mechanism which causes cooling water to flow through an outer peripheral portion and/or an inside of each roll so as to cool the roll, and which cools the cooling water discharged after the flow by use of a cooler. 
   
   
       6 . A process for producing gas hydrate pellets by contacting and reacting a raw-material gas and raw-material water with each other so as to generate a gas hydrate powder, and by compression-molding the gas hydrate powder with a roll-type gas-hydrate-pellet production apparatus,
 the process comprising:   causing cooling water to flow through an outer peripheral portion and/or an inside of a roll of the gas-hydrate-pellet production apparatus so as to cool the roll;   cooling the cooling water discharged after the flow by use of a cooler; and   supplying the cooled cooling water to the outer peripheral portion and/or the inner portion of the roll.   
   
   
       7 . The process for producing gas hydrate pellets according to  claim 6 , wherein
 the cooling water is supplied to a hopper chamber from which the gas hydrate powder is fed to the roll,   the cooling water is thereby brought into contact with the outer peripheral portion of the roll, and   the cooling water is discharged from a cooling-water outlet of the hopper chamber.   
   
   
       8 . The process for producing gas hydrate pellets according to  claim 6 , wherein
 a cooling bath is disposed below the roll,   the cooling water is supplied to the cooling bath, and   the cooling water is brought into contact with the outer peripheral portion of the roll.   
   
   
       9 . The process for producing gas hydrate pellets according to  claim 6 , wherein
 the cooling water is supplied to a cooling-water jacket provided inside the roll so as to cool the roll.   
   
   
       10 . The process for producing gas hydrate pellets according to  claim 6 , wherein
 the temperature difference T−T 0  between the temperature T of the gas hydrate pellets and the temperature T 0  of the gas hydrate powder is set to be below 3° C.   
   
   
       11 . The process for producing gas hydrate pellets according to  claim 6 , wherein
 the amount of heat removed by the cooler is set to be not less than the amount of heat Q 1  obtained by the following expression (I):
     Q 1=( T−T   0 ) cM+qM β/100  (I), 
   (in the expression (I),   Q 1  is the amount of heat [w] which the gas hydrate powder receives in the pelletization,   c is the specific heat [kJ/kgK],   q is the decomposition heat [kJ/kg],   M is the pelletization speed [kg/s] for the gas hydrate powder, and   β is the degree of decomposition [%] in the pelletization of the gas hydrate powder).