A new method to remove the heat released during hydrate formation Supervisor : Feng Xin Reporter : Xiaofei Song

Contents The background of the subject 1 Design for the experiment 2 Estimate for the experiment 3 Thought and plan 4

The background Heat transfer Mass transfer Hydration rate ? CH 4 +nH 2 O=CH 4.nH 2 O

Several methods to remove heat in the literatures  Air bath or water bath L.-W. Zhang, G.-J. Chen, ∗, C.-Y. Sun, S.-S. Fan,Y.-M. Ding. X.-L.Wang, L.-Y.Yang. The partition coefficients of ethylene between hydrate and vapor for methane+ethylene+water and methane+ethylene+SDS+water. Chemical Engineering Science 60 (2005) 5356 –  Copper block Kazuya Fukumoto, Jun-ichiro Tobe, Ryo Ohmura, and Yasuhiko H. Mori.Hydrate Formation Using Water Spraying in a Hydrophobic Gas: a Preliminary Study. Yokohama , Japan  Thermoelectric module assembly US 2012/ A1  Heat exchanger(in the reactor or outside ) Ryo Ohmura,*,† Shigetoyo Kashiwazaki, Saburo Shiota, Hideyuki Tsuji, and Yasuhiko H. Mori. Structure-I and Structure-H Hydrate Formation Using Water Spraying. Energy & Fuels 2002, 16,  ice

The questions existed :  The temperature for hydration is about 0 ℃,if we want to obtain good heat transfer effect,the temperature of condensing medium is about -10 ℃,then water will surely freeze around the pipe,which effect heat transfer eventually.  The circulation volume is big since the heat capacity of the condensing medium is small. The fact: We can not keep the value of temperature constant even if the exchanger have sufficient capacity,thus leading to low hydration rate. Direct heat exchangePhase change material

Phase change material(PCM) The advantages compared to the conventional materials:  Require a smaller weight and volume of material for a given amount of energy.  Has the capacity to store heat of fusion at a constant or near constant temperature which correspond to the phase transition temperature of the phase change material. Tetradecane Hexadecane Melting point 5.8 ℃ 18.1 ℃ Heat of fusion 45.07kJ/mol 51.3kJ/mol Heat released during hydration:54.2kJ/mol gas(methane)

He Bo *, E. Mari Gustafsson, Fredrik Setterwall. Tetradecane and hexadecane binary mixtures as phase change materials (PCMs) for cool storage in district cooling Systems.Energy 24 (1999) 1015–1028

Table 1.The consumption of emulsion of different weight percentage when a mole methane is consumpted. The weight percentage of tetradecane(%) the weight of emusion needed(kg) The weight of tetradecane needed(kg) The mole quantities of water needed(mol)

The weight percentage of tetradecane(%) Rate of methane consumption(mol/h) Rate of emulsion consumption(kg/h) Table2.The consumption of methane and emulsion when the effective volume of the reactor is 15mL mol/h

If a methane cylinder is 40L,and the density is 1g/mL,then the using time of a methane cylinder is as follow. The weight percentage of tetradecane(%) The using time of a methane cylinder(h) The using time of a methane cylinder(days) Table 3.the using time of a methane cylinder

The weight percentage of tetradecane(%) The power of the heat exchanger (for gas)(w) The power of the heat exchanger(for emulsion)(w) Table 4.The power of the heat exchanger

The weight percentage of tetradecane(%) Heat transfer area needed(for gas)(m 2 ) Heat transfer area needed(for emulsion （ m 2 ） E E E E E E E E E E Table 5.heat transfer area of the heat exchangers

plans  Find an appropriate approch to prepare the desirable emulsion. stable do not exist or exist small undercooling do not plug in the heat changer and pipes  Think about details of the experiment goal variable improve technological process