Submarine gas-liquid-solid multiphase fluidization separating method for natural gas hydrate

Abstract

The invention discloses a gas-liquid-solid multiphase separating system involved in a deep sea natural gas hydrate extraction process. The system mainly comprises a fluidized bed, a feeding lock hopper, a cyclone separator, a sand lock hopper, a gas distribution plate, a heating plate, a control valve and the like. Firstly, hydrate sediment is mechanically crushed into hydrate particles, the hydrate particles and an appropriate amount of seawater are mixed to form hydrate slurry stored in the feeding lock hopper, and the hydrate slurry flows into the fluidized bed through a feeding gate valve;methane serving as fluidizing gas enters the fluidized bed through the gas distribution plate from the bottom of the fluidized bed; the hydrate particles, the seawater and the fluidizing gas form stable gas-liquid-solid multiphase fluidization in the fluidized bed; and the hydrate particles are subjected to thermal decomposition under the action of the high-temperature seawater and an internal heating component, the methane gas is released, the coarse methane gas is further separated through the cyclone separator and then delivered to an offshore platform, and the sediment remaining after decomposition is backfilled to the seabed through the sand lock hopper.

Description

technical field [0001] The invention relates to a method for seabed exploitation, decomposition and separation of deep-sea shallow natural gas hydrate. Background technique [0002] With the decrease of conventional energy such as coal, oil, and natural gas, people began to seek various alternative energy sources. As one of the unconventional energy sources, natural gas hydrate is considered as an important potential energy source because of its large reserves, wide distribution and cleanness. According to the preliminary statistics of the International Natural Gas Potential Commission, the total amount of gas hydrates in the world's oceans is about 1.8-2.1×10 methane gas 16 m 3 , roughly equivalent to twice the total reserves of coal, oil and natural gas in the world. According to estimates, the natural gas hydrate resources in the South my country Sea are 70 billion tons of oil equivalent, equivalent to about half of China's total onshore oil and natural gas resources. ...

AI Technical Summary

Problems solved by technology

First of all, this method needs to lift the hydrate together with the sand and seawater to the sea, and transporting the worthless sand and seawater to the offshore operation platform will greatly increase the cost of energy consumption; secondly, in the gas-liquid-solid multiphase flow pipeline There are phase changes in the process, and it is difficult to achieve steady-state transportation

[0004] To sum up, neither the clogging of sand particles and hydrates in the mining process nor the stable production of methane and the energy consumption cost of mining have not been effectively solved by the existing mining technologies under development.

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