JPS59100195A - Preparation of fuel gas with consistent calorific value from multi-component liquefied natural gas - Google Patents

Abstract

PURPOSE:To prepare a fuel gas with a consistent calorific value, by feeding natural gas just after vaporization to a mist evaporator, separating heavy liquid components and adding the liquid components when the calorific value of light fuel gas component is decreased. CONSTITUTION:A multi-component liquefied natural gas is sent from a tank 1 to a vaporizer 9 for vaporization and is separated into a light fuel gas component and a heavy liquid component in a mist separator 31. The heavy liquid component is stored in a cushion tank 35, while the light fuel gas component is heated to a higher temperature in an after-heater 39 and is taken out of the system through a line 41. The calorific value of the fuel gas component is measured with a measuring instrument 43 and when the calorific value has fallen below a predetermined level, a part of the high-calory heavy component stored in the cushion tank 35 is converted into high-calory gas in a vaporizer 51 and is added to the fuel gas component in the line 41 through a line 55 for increase of heat.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for obtaining fuel gas by vaporizing liquefied natural gas (hereinafter simply referred to as LNG), and more specifically to a method for producing fuel gas having a certain calorific value from LNG consisting of multiple components. Regarding how to.

Natural gas is mainly composed of methane, ethane, propane,
It is a multi-component residue containing butane, pecitane, etc. In general, natural gas has a different composition depending on where it is produced, and its calorific value also varies considerably. The source of natural waste is
It is predicted that they will become more diverse in the future, and the differences in composition and calorific value may become even larger. In addition, when producing fuel gas by vaporizing LNG, LNG
High boiling point components other than methane may be irregularly concentrated at the heat transfer interface of the boiling liquid inside the NG vaporizer.
The composition, properties, and calorific value of the fuel gas vary.

The inventor of the present invention has conducted various studies to obtain a fuel gas with a constant calorific value and stable properties regardless of differences in LNG production areas, fluctuations in the load of the vaporizer, etc. As a result, the inventor has determined that the vaporization j(f,
First, we discovered that a fuel gas with stable composition and properties could be obtained by mist-separating the natural 73 gas and feeding it into a tank to separate the heavy, high-fluorescence point components with high calorific value as a liquid. . When the fuel gas heating element is below a predetermined value, a part of the pre-separated, high calorific value, heavy, high-ff11 component stored in the cushion tank is vaporized and added to the fuel waste. It has also been found that by doing so, it is possible to maintain the heat content of the fuel gas at a constant value. That is, the present invention includes (i) a step of vaporizing liquefied natural scum consisting of multiple components; (i) misting the wet vaporized natural scum and sending it to a pallet to separate light fuel gas components and heavy liquid components; (ffl) sending the heavy liquid component to a cushion tank; and (IV)
When the calorific value of the light fuel gas component is less than a predetermined value, a part of the heavy liquid component in the cushion tank is vaporized,
This invention relates to a method for producing indoor light heat amount fuel gas from multi-component liquefied natural gas, characterized by comprising a step of adding it to a light fuel gas component to increase its heat.

The present invention will be further explained below with reference to the embodiments shown in the drawings.
1 will be explained in detail.

In Figure 1, LNG consisting of multiple components is stored in a tank (1
) to line (3), pump (5) and line (7)
is sent to the LNG vaporizer (9). The vaporizer (9) contains a heating medium such as a fluorinated hydrocarbon known as Fluorinated Hydrocarbon, Annexane or Freon (trademark), which is passed through the pipe (9) in the vaporizer (9). L A passing through ltl
' It is liquefied by heat exchange with G and stays in the bottom part of the vaporizer (9). The liquefied heat medium is sent to the evaporator On of the heat exchanger θ through line 00, and is heated to the evaporator On of the heat exchanger θ.
, heat source water (sea water, heated wastewater, river water, etc.) passing through the pipe (c) and line (a) is heated and vaporized by heat exchange, and then passed through the line (a) to the vaporizer (9). The LNG is circulated through the pipe and used again to heat the LNG flowing through the pipe α◇.

The vaporized natural gas reached in the vaporizer (9) has a high heat generation h(
Since the high Il 1 point ■ (contains quality components as mist), the air is sent to the mist separator ((υ) through the line ◆, where it is separated into light fuel gas components and heavy liquid components. The heavy liquid component is stored in the cushion tank 49 from the mist separator (01) through the line 01.The light fuel gas component is stored in the cushion tank 49 through the mist separator ((υ to line (ri) in red). , heat exchange is performed again with the Tsubame source water supplied to the pipe (c) from the aftersameter of the heat exchanger θη (sent to +pae, line &]), and then
R- applied to high temperature. Then, the heated 124 F+
Commercial gas components are taken out of the prefecture after passing through a liner.

As mentioned above, the composition of natural waste varies considerably depending on the production area, so it is important to avoid variations in the composition of LNG supplied from the tank (1). Therefore, since the calorific value of the gas component obtained from the line 0υ also fluctuates, in the present invention, the calorific value of the gas component for fuel flowing through the line 0υ is appropriately measured ηλ- is monitored by a sonic force O leakage meter.If the calorific value falls below a predetermined value, the button is opened as appropriate based on the data fed back through 9 lines. Cushion tank (high heat generation 1 increased by +1 to 9;
(A part of the heavy components of
The lunistone exothermic Iλ gas obtained by supplying the gas to the fuel gas component in the line ←, the opened valve and the line Q'1) is added to the fuel gas component in the line 01), ,
) Increase the heat.

It is preferable that the light gas with a specific gravity of 2 generated in the cushion tank (1) be mixed with the fuel gas component flowing through the line (θυ) through the line (6'7) using the thread (f).

In addition, if an excessive amount of heavy liquid components is generated, the liquid components are sent from the cushion tank (2) through the line (i value and line 0) to the storage tank (not shown) to reduce the heat generated. It can be used for purposes such as increasing the heat of twisted feed gas.

When using the 3-stroke 1] palator in the 6-stroke method (variable 8-3-stroke pallet), the angle of the variable blade can be adjusted as appropriate.
By adjusting the iq, it is possible to control the amount of highly emissive (heavy components) separated and removed, thereby suppressing fluctuations in the light and heat ratio of vaporized natural gas caused by fluctuations in the composition of LNG.

According to the method of the present invention, a fuel gas with a constant heat generation value can be easily produced from multi-component LNG with different compositions and heat generation values depending on the production area, using an extremely simple mechanism.

Example 1 Using the loading code "'j shown in FIG. 1, "iQ * K', I I 000 "a(! /
A fuel gas of Nrn' was produced.

Multi-component L stored in tank (1) at an astigmatic temperature of approximately -160°C
NG (I I I O0kta (1/Nm3) at a pressure of 35 kg/cd s flow%'i 0 Q ton/
After feeding the hr TeLA'G vaporizer (9),
The vaporized natural gas is sent to a mist separator, and the gas component with a calorific value of 105 Q Q heal / Nm' is 43 ton / hr and a heat generation MI 80
00 heal/Nm3 liquid component i 2ton/
I got hr. After adding the gaseous component to the temperature of the heat source water, on line 00, mix the liquid component with a vaporized amount of about 10/σn/hr, and heat the water to a heating value of 1.
10004cal/Nm3 fuel gas approx. 581on
/kr was obtained.

Approximately 2 tons/hr of excess liquid component was stored in a storage tank.

[Brief explanation of drawings]

FIG. 1 is a D-sheet showing one example of an embodiment of the present invention. (1)...LNG Tasik (5)...I-NG
Pump (9)...LNG vaporizer (1,7)...
Heat exchanger 01...Evaporation 8ac3υ...Three-stroke t Palator-C (I-Il/Cushion tank →...After-sales temperature Kll...Heat generation 1ill) Constant 41,1 unit
Riff) ... Valve q5'I) ... Vaporization 8+ C or higher)

Claims (1)

[Claims] ■(i) A process of vaporizing liquefied natural gas consisting of multiple components; (i) sending wet vaporized natural gas to a three-stroke separator to produce a light fuel gas component and a heavy liquid component; (ii) a step of sending the heavy liquid component to the cushion tank, and (1v) a step of separating the heavy liquid component into a cushion tank when the heat M of the light fuel gas component becomes less than a predetermined value. A method for producing indoor light calorific fuel from multi-component liquefied natural gas, characterized in that a part of the component is vaporized and added to a light fuel gas component to increase its heat.