NO20181643A1

NO20181643A1 - Volatile organic compound recovery apparatus

Info

Publication number: NO20181643A1
Application number: NO20181643A
Authority: NO
Inventors: Sung Yoon Choi; Jun Hee Han; Si Jin Ryu
Original assignee: Samsung Heavy Ind
Priority date: 2016-06-22
Filing date: 2018-12-18
Publication date: 2018-12-18
Also published as: KR101741834B1; WO2017222239A1

Abstract

Disclosed herein is a volatile organic compound recovery apparatus designed to suppress the amount of discharged volatile organic compounds to the atmosphere and make the most of the available energy. The volatile organic compound recovery apparatus includes: a first 5 compressor configured to compress oil mist produced from a crude oil tank; a first heat exchanger configured to cool down a highpressure fluid that has passed through the first compressor; an expansion valve configured to depressurize the high-pressure fluid that has passed through the first heat exchanger or a first gas separated from the high-pressure fluid through a preprocessing unit; and a gas-liquid separator configured to separate the highpressure 10 fluid that has passed through the expansion valve or the first gas into a second gas and a second liquid to supply the second gas to a combustion engine and the second liquid to a storage tank.

Description

【DESCRIPTION】

【TITLE OF THE INVENTION】

VOLATILE ORGANIC COMPOUND RECOVERY APPARATUS

【TECHNICAL FIELD】

[1] The present disclosure relates to an apparatus for recovering volatile organic compounds, and more particularly, to a volatile organic compound recovery apparatus designed to suppress the volatile organic compounds produced in a crude oil tank, etc. from being discharged to the air and to increase the efficiency of utilization of the available energy.

【BACKGROUND ART】

[2] Volatile organic compounds (VOCs) are organic compounds that evaporate easily due to their low boiling points and contain various kinds of components depending on how they are created. Volatile organic compounds may be toxic or odorous and may contain flammable components. When such volatile organic compounds are discharged to the air, they pollute the atmosphere. Accordingly, a technique for treating them is needed.

[3] Fossil fuels such as crude oil are also sources of volatile organic compounds. There is a problem in that too much volatile organic compounds are produced from a crude oil carrier or the like which transports a great amount of crude oil. Volatile organic compounds are produced much especially when liquid cargoes, such as crude oil is loaded onto or unloaded from a ship. In addition, volatile organic compounds may be produced inside the tank to increase the pressure during transport of the crude oil. Therefore, it is required to more effectively treat such volatile organic compounds.

[4] Previously, volatile organic compounds were simply discharged or liquefied with a separate refrigerant and stored. In addition, although the amount of the discharged volatile organic compounds was reduced by adjusting the pressure of the stored liquid cargo, it was not effective. In particular, when the volatile organic compounds are liquefied, the efficiency is not high and thus the energy is wasted. In addition, the remaining of the volatile organic compounds, which was not liquefied, is released into the atmosphere, resulting in contamination. In addition, although the volatile organic compounds may have available energy, the treatment is focused on the reducing the amount or discharging more safely. Therefore, it was very inefficient in terms of energy efficiency.

【SUMMARY OF INVENTION】

【Technical Problem】

[5] In view of the above, aspects of the present disclosure provide a volatile organic compound recovery apparatus designed to suppress the emission of volatile organic compounds produced in a crude oil tank or the like and utilize the available energy as much as possible.

[6] It should be noted that objects of the present invention are not limited to the abovementioned object; and other objects of the present invention will be apparent to those skilled in the art from the following descriptions.

【Technical Solutions】

[7] According to an aspect of the present disclosure, there is provided a volatile organic compound recovery apparatus including: a first compressor configured to compress oil mist produced from a crude oil tank; a first heat exchanger configured to cool down a high-pressure fluid that has passed through the first compressor; an expansion valve configured to depressurize the high-pressure fluid that has passed through the first heat exchanger or a first gas separated from the high-pressure fluid through a preprocessing unit; and a gas-liquid separator configured to separate the high-pressure fluid that has passed through the expansion valve or the first gas into a second gas and a second liquid to supply the second gas to a combustion engine and the second liquid to a storage tank.

[8] The apparatus may further include: a second heat exchanger installed between the first heat exchanger and the expansion valve and configured to exchange heat between the second gas separated from the gas-liquid separator and the high-pressure fluid or the first gas.

[9] The apparatus may further include: a third heat exchanger installed between the second heat exchanger and the expansion valve and configured to exchange heat between the second liquid separated from the gas-liquid separator and the high-pressure fluid or the first gas.

[10] The preprocessing unit may further include a preprocessing separator installed between the first heat exchanger and the second heat exchanger and separating the first gas from the highpressure fluid to provide it to the second heat exchanger.

[11] The preprocessing unit may further include a moisture removing unit installed between the first heat exchanger and the preprocessing separator or between the preprocessing separator and the second heat exchanger.

[12] The preprocessing unit may further include a second compressor installed between the preprocessing separator and the second heat exchanger to pressurize the first gas.

[13] The apparatus may further include a fourth heat exchanger installed between the second compressor and the second heat exchanger to cool down the first gas.

[14] The apparatus may further include: a branch pipe branching off from a pipe channel through which the first gas flows between the second compressor and the gas-liquid separator; and a high-pressure tank connected to the branch pipe and storing the first gas therein.

[15] The apparatus may further include: a shut-off valve formed in the branch pipe and configured to adjust a pressure of the first gas introduced into the high-pressure tank.

[16] The apparatus may further include: an evaporator installed between the first heat exchanger and the second heat exchanger and configured to exchange heat between liquefied natural gas (LNG) and the high-pressure fluid or the first gas to transform the LNG into natural gas (NG).

[17] The preprocessing separator may be a three-phase separator that separates the highpressure fluid into the first gas, water, and a first liquid composed of components having a specific gravity smaller than that of the water.

[18] The apparatus may further include: a filtering unit installed between the crude oil tank and the first compressor to remove solid foreign substances and liquid foreign substances contained in the oil mist.

【Advantageous Effects】

[19] According to an exemplary embodiment of the present disclosure, the volatile organic compounds produced in a crude oil tank or the like can be treated via a series of successive processes to reduce the amount of the discharged volatile organic compounds. In addition, energy can be recovered through multiple stages in various ways during the treatment process, so that the available energy of the volatile organic compounds can be obtained to improve the energy efficiency greatly and to increase the operation efficiency of the ships, the facilities, or other various apparatuses.

【BRIEF DESCRIPTION OF DRAWINGS】

[20] FIG. 1 is a block diagram of a volatile organic compound recovery apparatus according to a first exemplary embodiment of the present disclosure.

[21] FIG. 2 is a block diagram of a volatile organic compound recovery apparatus according to a second exemplary embodiment of the present disclosure.

[22] FIG. 3 is a block diagram of a volatile organic compound recovery apparatus according to a third exemplary embodiment of the present disclosure.

[23] FIG. 4 is a block diagram of a volatile organic compound recovery apparatus according to a fourth exemplary embodiment of the present disclosure.

[24] FIG. 5 is a block diagram of a volatile organic compound recovery apparatus according to a fifth exemplary embodiment of the present disclosure.

[25] FIG. 6 is a block diagram of a volatile organic compound recovery apparatus according to a sixth exemplary embodiment of the present disclosure.

【DESCRIPTION OF EMBODIMENTS】

[26] Advantages and features of the present disclosure and methods to achieve them will become apparent from the descriptions of exemplary embodiments herein below with reference to the accompanying drawings. However, the present invention is not limited to exemplary embodiments disclosed herein but may be implemented in various different ways. The exemplary embodiments are provided for making the disclosure of the present invention thorough and for fully conveying the scope of the present invention to those skilled in the art. It is to be noted that the scope of the present invention is defined only by the claims. Like reference numerals denote like elements throughout the descriptions.

[27] Hereinafter, first to sixth exemplary embodiments of the present disclosure will be described in detail with reference to FIGS. 1 to 6. In the drawings, solid arrows connecting components with one another represent "flows" of fluids as well as "pipe channels" through which the fluids flow. Therefore, it is to be understood that pipe channels are formed along the solid line arrows even if they are not marked with reference symbols. In addition, as used herein, a second gas and a second liquid are defined as fluids separated by a gas-liquid separator.

[28] Firstly, a volatile organic compound recovery apparatus according to a first exemplary embodiment of the present disclosure will be described in detail with reference to FIG.1.

[29] FIG. 1 is a block diagram of a volatile organic compound recovery apparatus according to a first exemplary embodiment of the present disclosure.

[30] The volatile organic compound recovery apparatus 1 according to the exemplary embodiment of the present disclosure continuously treats oil mist produced from a crude oil tank A (which may contain inert gas, etc since it is stored in the tank along with volatile organic compounds produced from a crude oil) via a series of successive processing steps. The processing steps include a pressurization step, a depressurization step, a fluid temperature control step, a phase-change and separation step of fluids having different phases, a fluid temperature control step by heat exchange between different fluids, etc. The volatile organic compound recovery apparatus 1 includes a plurality of components that are organically connected to one another to perform such processing steps. By performing the series of processing steps by the operation of such components, the volatile organic compound recovery apparatus 1 can recover the volatile organic compounds to suppress the amount of discharged volatile organic compounds. In addition, it is possible to maximally recover the available energy of the volatile organic compounds, thereby greatly improving the energy efficiency.

[31] Referring to FIG. 1, the volatile organic compound recovery apparatus according to the first exemplary embodiment of the present disclosure is configured as follows: The volatile organic compound recovery apparatus 1 includes: a first compressor 10 for compressing oil mist supplied from a crude oil tank A; a first heat exchanger 20 for cooling down a high-pressure fluid B that has passed through the first compressor 10; an expansion valve 30 for depressurizing the high-pressure fluid B that has passed through the first heat exchanger 20 or a first gas separated from the high-pressure fluid B through a pre-processing unit; and a gas-liquid separator 40 for separating the high-pressure fluid B that has passed the expansion valve 30 or the first gas into a second gas C1 and a second liquid C2 to supply the second gas C1 into a combustion engine D and the second liquid C2 into a storage tank 100. With this configuration, it is possible to generate the second gas C1 and the second liquid C2 in the gas-liquid separator 40 and supply them into the combustion engine D or store them in the storage tank 100 for later use.

[32] The volatile organic compound recovery apparatus 1 may be formed with or without a pre-processing unit for separating the first gas from the high-pressure fluid B that has passed through the first compressor 10 to involve it in the recovery process. According to the first and second exemplary embodiments of the present disclosure, the volatile organic compound recovery apparatus does not includes the preprocessing unit. According to the first and second exemplary embodiments of the present disclosure, the available energy is directly recovered from the high-pressure fluid B that has passed through the first compressor 10 and the first gas is not produced and thus is not involved in the energy recovery process. Hereinafter, the components and operation of the volatile organic compound recovery apparatus 1 according to the first exemplary embodiment of the present disclosure will be described in detail with reference to FIG.1.

[33] The first compressor 10 pressurizes and compresses the oil mist supplied from the crude oil tank A. The crude oil is stored in the crude oil storage tank A, and the oil mist may contain volatile organic compounds produced in the crude oil and some other substances (such as an inert gas injected into the tank). The first compressor 10 pressurizes the oil mist to transform it into a high-pressure fluid B. For example, the first compressor 10 may be implemented, for example, to increase the pressure of the fluid by using a rotary vane rotating in a pressurizing chamber, or may be implemented as a reciprocating compressor using a cylinder. However, the type of the compressor is not limited to the above. Various types of compressors can be employed by selectively using a variety of various structures as long as it can compress a fluid. The high-pressure fluid B compressed in the first compressor 10 is supplied to the first heat exchanger 20.

[34] A filtering unit 90 is disposed at the previous stage of the first compressor 10. The filtering unit 90 may be installed between the crude oil tank A and the first compressor 10 to remove solid foreign substances and liquid foreign substances contained in the oil mist. Unnecessary foreign substances contained in the oil mist can be removed by the filtering unit 90, so that a purer gas containing the volatile organic compounds can be supplied to the first compressor 10 to thereby improve the compression ratio and the energy recovery capability. The filtering unit 90 may include a scrubber, a centrifugal separator, etc. The foreign substances such as soot and liquid droplets may be removed from the oil mist by using the filtering unit 90 and then may be supplied to the first compressor 10.

[35] The crude oil tank A may be, but is not limited to being, installed on a ship such as a crude oil carrier. The crude oil tank A encompasses crude oil refining facilities, transportation facilities, storage facilities, and various other types of facilities capable of storing and retrieving crude oil. The crude oil tank A stores crude oil that produces volatile organic compounds therein, and the volatile organic compound recovery apparatus 1 according to the exemplary embodiment of the present disclosure can effectively recover the volatile organic compounds produced from the crude oil and the available energy included therein. Since the crude oil tank A is a facility for storing substances that produces volatile organic compounds such as crude oil, it is to be understood that the applications of the volatile organic compound recovery apparatus 1 are not limited to the crude oil tank A. In other words, although the crude oil tank A is described herein as an example, the technical idea of the present disclosure can be applied to various other facilities where volatile organic compounds are produced, and is not limited to the storage facilities for crude oil.

[36] The first heat exchanger 20 cools down the high-pressure fluid B that has passed through the first compressor 10. The temperature of the high-pressure fluid B is increased as it has passes through the first compressor 10 and then the high-pressure fluid B is cooled down through the first heat exchanger 20. The first heat exchanger 20 may include one or more paths connected thereto to allow heat exchange. A path in which the high-pressure fluid B flows may be in contact with a path in which cooling water flows to allow heat exchange. The cooling water supplied to the first heat exchanger 20 may be clear water, distilled water, etc. Sea water may be used as the cooling water when the present disclosure is employed to a facility such as a ship. Depending on the situations, the high-pressure fluid B may be cooled by exchanging heat with various kinds of cooling water.

[37] The high-pressure fluid B that has passed through the first heat exchanger 20 passes through the expansion valve 30 and its pressure is reduced. That is to say, the high-pressure fluid B pressurized by the first compressor 10 is expanded by the expansion valve 30 to depressurize and rapidly lower the temperature. By doing so, the temperature of the fluid can be lowered to a temperature at which it can be easily treated in the gas-liquid separator 40 at the subsequent stage. The expansion valve 30 may be, for example, one that employs the Joule-Thomson effect that reduces the pressure by passing the pressurized fluid through a nozzle and cools it down. The depressurization rate of the expansion valve 30 can be appropriately set or adjusted in consideration of the operating temperature and the pressure of the gas-liquid separator 40.

[38] The gas-liquid separator 40 separates the high-pressure fluid B that has passed through the expansion valve 30 (i.e., the fluid that is compressed to be in a high-pressure state and then depressurized while passing through the expansion valve as described above) into a second gas C1 and a second liquid C2. The second gas C1 is supplied to the combustion engine D, and the second liquid C2 is supplied to the storage tank 100. The second gas C1 and the second liquid C2 are collected by separating the oil mist containing the above-mentioned volatile organic compounds into the gas-phase and the liquid-phase and contain combustible components. Therefore, they may be directly used as the fuel for the combustion engine or may be used as the fuel after being transformed to the gaseous state. The gas-liquid separator 40 may separate the second base C1 from the second liquid C2 by different densities. The gas-liquid separator 40 may be in the form of a container or a drum such that the second gas C1 is discharged from the top while the second liquid C2 is discharged from the bottom.

[39] As such, the fluid supplied to the gas-liquid separator 40 after being depressurized and cooled down by the expansion valve 30 may be separated into the gas-phase and the liquid-phase and can be directly used as the fuel or may be stored to be used as the fuel. In addition, before being used or stored as the fuel, the fluid may be used to lower the temperature by heat exchange with the high-pressure fluid B (see second to sixth exemplary embodiments to be described later). Specifically, the gas phase and the liquid phase components (the second gas and the second liquid) produced by the cooling process of the expansion valve 30 and the phase separation process of the gas-liquid separator 40 are provided as the fuel, such that the available energy can be effectively recovered via one or more paths. The second gas C1 is supplied to the combustion engine D and consumed after cooling down the high-pressure fluid B in the second heat exchanger 50. The second liquid C2 is used to cool down again the high-pressure fluid B cooled down in the second heat exchanger 50 again in the third heat exchanger 60 and then is stored in the storage tank 100. In this manner, the fluid containing the volatile organic compounds can be treated stepwise to recover the available energy and to greatly reduce the amount of the discharged volatile organic compounds.

[40] The combustion engine D for introducing and consuming the second gas C1 may include a gas turbine or a gas burner. When the combustion engine D is implemented as an engine generating a rotary power such as a gas turbine, it is possible to produce electric power by combining a generator with the rotary shaft of the gas turbine. In addition, a heat recovery steam generator (HRSG) for generating energy, which produces steam by recovering the waste heat to generate electricity by using it, may be coupled to the subsequent stage of the gas turbine, thereby greatly increasing the energy recovery rate. In addition, the combustion engine D may include a gas turbine, a gas burner, or the like and selectively connect them to drive a generator coupled to the gas turbine or to utilize thermal energy produced from the gas burner. In addition, the second liquid C2 stored in the storage tank 100 may pass through the heater 80 to be transformed into a gaseous state and then supplied to the combustion engine D. Alternatively, a part of the second liquid C2 in the storage tank 100 that evaporates in a gaseous state may be supplied directly to the combustion engine D without passing through the heater 80 in accordance with the operation state or load fluctuation of the combustion engine D. By utilizing the recovered available energy in a variety of ways as described above, the energy efficiency can be greatly improved.

[41] Hereinafter, a volatile organic compound recovery apparatus according to a second exemplary embodiment of the present disclosure will be described in detail with reference to FIG.

2. For simplicity and clarity, the following description will focus on the differences from the above exemplary embodiment of the present disclosure and identical elements will not be described to avoid redundancy.

[42] Referring to FIG. 2, the volatile organic compound recovery apparatus 1 – 1 according to the second exemplary embodiment of the present disclosure is configured as follows: The volatile organic compound recovery apparatus 1 - 1 includes: a first compressor 10 for compressing oil mist supplied from a crude oil tank A; a first heat exchanger 20 for cooling down a high-pressure fluid B that has passed through the first compressor 10; an expansion valve 30 for depressurizing the high-pressure fluid B that has passed through the first heat exchanger 20 or a first gas separated from the high-pressure fluid B through a pre-processing unit; a gasliquid separator 40 for separating the high-pressure fluid B that has passed the expansion valve 30 or the first gas into a second gas C1 and a second liquid C2 to supply the second gas C1 into a combustion engine D and the second liquid C2 into a storage tank 100; a second heat exchanger 50 installed between the first heat exchanger 20 and the expansion valve 30 and for exchanging heat between the second gas C1 separated from the gas-liquid separator 40 and the high-pressure fluid B or the first gas; and a third heat exchanger 60 installed between the second heat exchanger 50 and the expansion valve 30 and for exchanging heat between the second liquid C2 separated from the gas-liquid separator 40 and the high-pressure fluid B or the first gas.

[43] In the volatile organic compound recovery apparatus 1-1 according to the second exemplary embodiment, the second heat exchanger 50 and the third heat exchanger 50 are installed between the first heat exchanger 20 and the expansion valve 30, to cool down the fluid stepwise. The second heat exchanger 50 and the third heat exchanger 60 may utilize the second gas C1 and the second liquid C2 separated from each other in the gas-liquid separator 40 to greatly increase the cooling efficiency of the fluid injected into the expansion valve 30. The other components than the second heat exchanger 50 and the third heat exchanger 60 are substantially identical to those described above; and, therefore, the redundant description will be omitted. Hereinafter, the configuration of the second heat exchanger 50 and the third heat exchanger 60 and the operation and effects of the recovery apparatus including the same will be described in detail.

[44] The second heat exchanger 50 and the third heat exchanger 60 are installed on the path through which the high-pressure fluid B flows toward the expansion valve 30 as shown in FIG.2. The second heat exchanger 50 is installed between the first heat exchanger 20 and the expansion valve 30 and introduces the second gas C1 separated from the gas-liquid separator 40 to perform heat exchange with the high-pressure fluid B. The third heat exchanger 60 is installed between the second heat exchanger 50 and the expansion valve 30 and introduces the second liquid C2 separated from the gas-liquid separator 40 to perform heat exchange with the high-pressure fluid B. The second heat exchanger 50 and the third heat exchanger 60 may also include one or more paths connected thereto to allow heat exchange. The second heat exchanger 50 and the third heat exchanger 60 may include paths in which the high-pressure fluid B flows, and paths in which the second gas C1 and the second liquid C2 flow, respectively, such that they are in contact with each other to allow heat exchange.

[45] As such, the fluid supplied to the gas-liquid separator 40 after being depressurized and cooled down by the expansion valve 30 may be separated into the gas-phase and the liquid-phase and directly used as the fuel or may be stored to be used as the fuel. In addition, it may be used to lower the temperature by heat exchange with the high-pressure fluid B before being used or stored as fuel. Specifically, the gas-phase and the liquid-phase components (the second gas and the second liquid) produced by the cooling process by the expansion valve 30 and the phase separation process by the gas-liquid separator 40 are used to perform heat exchange stepwise at the previous stage of the expansion valve 30, so that the cooling efficiency of the high-pressure fluid B is greatly improved. Then, it is supplied as fuel so that the available energy is effectively recovered through various paths. The second gas C1 is supplied to the combustion engine D and consumed after cooling down the high-pressure fluid B in the second heat exchanger 50. The second liquid C2 is used to cool down the high-pressure fluid B cooled down in the second heat exchanger 50 again in the third heat exchanger 60 and then is stored in the storage tank 100. In this manner, the fluid containing the volatile organic compounds can be treated stepwise to recover the available energy and to greatly reduce the amount of the discharged volatile organic compounds.

[46] Hereinafter, a volatile organic compound recovery apparatus according to a third exemplary embodiment of the present disclosure will be described in detail with reference to FIG.

3. For simplicity and clarity, the following description will focus on the differences from the above exemplary embodiment of the present disclosure and identical elements will not be described to avoid redundancy.

[47] FIG. 3 is a block diagram of a volatile organic compound recovery apparatus according to a third exemplary embodiment of the present disclosure.

[48] Referring to FIG.3, a volatile organic compound recovery apparatus 1 – 2 according to a third exemplary embodiment of the present disclosure includes a preprocessing unit 70 that separates a first gas from the high-pressure fluid B having passed through the first compressor 10 to participate it in the recovery process. According to this exemplary embodiment of the present disclosure, the high-pressure fluid B having passed through the first compressor 10 is separated into the first gas B1 and the first liquid B2 in the preprocessing unit 70. The first gas B1 is collected as the second gas C1 and the second liquid C2 via processes such as pressure change, thermal change and phase change, and the first liquid B2 is stored in the storage tank 100. By employing the preprocessing unit 70, the fluid treatment capacity at the subsequent stage can be reduced, such that energy of each process can be reduced and the amount of recovered available energy can be increased. Hereinafter, the components and operation of the volatile organic compound recovery apparatus 1 - 2 according to the third exemplary embodiment of the present disclosure will be described in detail with reference to FIG.3.

[49] The preprocessing unit 70 is disposed between the first heat exchanger 20 and the second heat exchanger 50 as shown in FIG. 3. The preprocessing unit 70 separates the highpressure fluid B having passed through the first heat exchanger 20 into the first gas B1 and the first liquid B2 and provides the first gas B1 to the second heat exchanger 50. The preprocessing unit 70 includes a preprocessing separator 71. The preprocessing separator 71 is installed between the first heat exchanger 20 and the second heat exchanger 50 to separate from the first gas B1 from the high-pressure fluid B and provides it to the second heat exchanger 50. The first gas B1 separated by the preprocessing separator 71 is supplied to the expansion valve 30 via an additional treatment process and is depressurized in the expansion valve 30 so that its temperature is greatly lowered. After being depressurized and cooled down, the first gas B1 flows into the gas-liquid separator 40 and is separated into the second gas C1 and the second liquid C2. By doing so, it is supplied to the second heat exchanger 50 and the third heat exchanger 60 for heat exchange with the first gas B1.

[50] The first gas B1 at the subsequent stage of the preprocessing unit 70 passes through the second heat exchanger 50, the third heat exchanger 60, the expansion valve 30 and the gas-liquid separator 40 and is subjected to the substantially same processes as those of the high-pressure fluid B through the second heat exchanger 50, the third heat exchanger 60, the expansion valve 30, the gas-liquid separator 40, and the like. Therefore, the detailed description thereof will not be given to avoid redundancy. That is to say, the first gas B1 supplied from the preprocessing unit 70 to the second heat exchanger 50 is cooled down by heat exchange with the second base C1 supplied to the second heat exchanger 50, and is then applied to the third heat exchanger 60 from the second heat exchanger 50, such that heat is exchanged with the second liquid C2 supplied to the third heat exchanger 60 to be cooled down again. The first gas B1 cooled down stepwise is depressurized as it passes through the expansion valve 30 so that the temperature is rapidly lowered, and is separated into the second base C1 and the second liquid C2 in the gasliquid separator 40. As described above, after having passed through the second heat exchanger 50 and the third heat exchanger 60, the second base C1 and the second liquid C2 are consumed in the combustion engine D or are stored in the storage tank 100 for later use.

[51] That is to say, the volatile organic compound recovery apparatus 1 - 2 according to the third exemplary embodiment of the present disclosure separates the first gas B1 from the highpressure fluid B through the preprocessing unit 70, to participate it in the recovery processes. The first gas B1 is produced by separating water and liquid components from the high-pressure fluid B by using the preprocessing separator 71. By supplying the first gas B1 which is a gasphase component to the subsequent stage treatment process, it is possible to reduce the fluid treatment capacity and save the energy consumed in the process. In addition, the preprocessing unit 70 includes a second compressor 73 for further pressurizing the first gas B1 at the subsequent stage of the preprocessing separator 71, to compress the first gas B1 to a higher pressure and increase the depressurization effects by the gas-liquid separator 30. Accordingly, the first gas B1 can be cooled to a sufficiently low temperature and supplied to the gas-liquid separator 40. In this manner, the cooling efficiency of the second heat exchanger 50 and the third heat exchanger 60 can be improved. Hereinafter, each of the components of the preprocessing unit 70 will be described in detail.

[52] The preprocessing unit 70 includes the preprocessing separator 71, a moisture removing unit 72, the second compressor 73, and a fourth heat exchanger 74. As shown in FIG. 3, the preprocessing separator 71 is installed between the first heat exchanger 20 and the second heat exchanger 50 and introduces the high-pressure fluid B having passed through the first heat exchanger 20 to separate it into the first gas B1, the water B3, and the first liquid B2. The preprocessing separator 71 is implemented as a three-phase separator that introduces the highpressure fluid B and separates it into the first gas B1, the water B3 and the first liquid B2 composed of components having a specific gravity smaller than that of the water B3. The separated first gas B1 is subjected to additional processes through the moisture removing unit 72, the second compressor 73 and the fourth heat exchanger 74 to be supplied to the second heat exchanger 50. As shown in FIG.3, the first liquid B2 is stored in the storage tank 100 and used together with the second liquid C2 as desired. The first liquid B2 and the second liquid C2 may be stored together in the storage tank 100 or may be stored separately. The water B3 may be stored in a wastewater storage tank, for example, a slop tank in a crude oil carrier, for example.

[53] The moisture removing unit 72 is installed between the preprocessing separator 71 and the second heat exchanger 50 to remove moisture from the first gas B1. In this manner, the first gas B1 is transformed into a more pure gas-phase component and thus it is easy to further compress it. The second compressor 73 is installed between the preprocessing separator 71 and the second heat exchanger 50 and disposed at the subsequent stage of the water removing unit 72. After moisture is removed from the first gas B1 through the moisture removing unit 72, the first gas B1 is compressed to a higher pressure while passing through the second compressor 73. That is to say, the oil mist passes through the first compressor 10 to produce the high-pressure fluid B, and the high-pressure fluid B passes through the preprocessing separator 71 so that the gas-phase component (the first gas) is separated therefrom. Then, the separated first gas B1 is pressurized again by the second compressor 73 so that the first gas B1 can be supplied to the expansion valve 30 in the high-press state after such multi-stage compression processes. The second compressor 73 may also be implemented, for example, to increase the pressure of the fluid by using a rotary vane rotating in a pressurizing chamber, or may be implemented as a reciprocating compressor using a cylinder. It is, however, to be understood that the above is merely illustrating and the present disclosure is not limited thereto. Various types of compressors can be employed by selectively using a variety of various structures as long as it can compress a fluid. The second compressor (73) compresses the first gas B1 which is the liquid component separated from the high-pressure fluid B and thus may have a small amount of driving energy and a relatively small capacity.

[54] After the first gas B1 passes through the second compressor 73, it passes through the fourth heat exchanger 74 and is cooled down firstly. The fourth heat exchanger 74 is installed between the second compressor 73 and the second heat exchanger 50 and forms a multi-stage cooling structure for cooling down the first gas B1, together with the second heat exchanger 50 and the third heat exchanger 60 at the subsequent stage. By doing so, it is possible to easily cool down the temperature of the first gas B1 compressed to a high pressure to a more appropriate temperature. The fourth heat exchanger 74 may also include a path structure, in which a path where the first gas B1 flows is in contact with a path where cooling water flows, so as to allow heat exchange. The cooling water may be clear water, distilled water, etc. Sea water may be used as the cooling water when the present disclosure is employed to a facility such as a ship. Various kinds of cooling water may be provided to the fourth heat exchanger 74 to cool down the first gas B1 depending on implementations.

[55] From the preprocessing unit 70 thus configured, the first gas B1 of a high-pressure state is provided to the second heat exchanger 50. The first gas B1 is cooled down and depressurized through the above-described process, is rapidly depressurized from the high-pressure state, and is supplied to the gas-liquid separator 40 with a sufficiently low temperature. In this manner, the second gas C1 and the second liquid C2 at a lower temperature can be produced. As described above, after the second gas C1 and the second liquid C2 pass through the second heat exchanger 50 and the third heat exchanger 60, they may be supplied to the combustion engine D or stored in the storage tank 100 for later use. In addition, the first liquid B2 may be stored in the storage tank 100 together with the second liquid C2 or may be separately stored and used as desired. As such, it is possible to more efficiently recover the available energy of the volatile organic compound, thereby increasing the energy efficiency and reducing the amount of discharged volatile organic compounds.

[56] Hereinafter, a volatile organic compound recovery apparatus according to a fourth exemplary embodiment of the present disclosure will be described in detail with reference to FIG.

4. For simplicity and clarity, the following description will focus on the differences from the above exemplary embodiment of the present disclosure and identical elements will not be described to avoid redundancy.

[57] FIG. 4 is a block diagram of a volatile organic compound recovery apparatus according to a fourth exemplary embodiment of the present disclosure.

[58] Referring to FIG. 4, a volatile organic compound recovery apparatus 1 - 3 according to the fourth exemplary embodiment of the present disclosure includes a branch pipe branching off from a pipe channel in which the first gas B1 flows between the second compressor 73 and the gas-liquid separator 40, and a high-pressure tank 110 connected to the branch pipe 111 and storing the first gas B1 therein. The high-pressure tank 110 may introduce and store the first gas B1 compressed to a high-pressure state through the branch pipe 111 and may discharge it as desired. The branch pipe 111 may include a shut-off valve 120 to adjust the pressure of the first gas B1 flowing into the high-pressure tank 110. As shown in FIG.4, the branch pipe 111 may branch off from the pipe connecting the fourth heat exchanger 74 with the second heat exchanger 50.

[59] The first gas B1 stored in the high-pressure tank 110 can be provided to, for example, the combustion engine D. Although not shown in the drawings, a supply pipe channel (not shown) for connecting the high-pressure tank 110 with the combustion engine D may be formed, and a valve capable of depressurizing may be added to the supply pipe at the previous stage of the combustion engine D such that the pressure of the first gas B1 may be adjusted before it is supplied to the combustion engine D. In particular, when the combustion engine D is implemented as a gas turbine or the like, it can react the load fluctuation of the turbine and the first gas B1 stored in the high-pressure tank 110 can be quickly supplied to the combustion engine D by employing the configuration. A pipe channel (not shown) for discharging liquid components, which are produced if the first gas B1 in the high-pressure tank 110 is condensed, to the storage tank 100 may be further formed. In this way, the available energy can be recovered through the configuration including the high-pressure tank 110 and can be utilized more effectively.

[60] Hereinafter, a volatile organic compound recovery apparatus according to a fifth exemplary embodiment of the present disclosure will be described in detail with reference to FIG.

5. For simplicity and clarity, the following description will focus on the differences from the above exemplary embodiment of the present disclosure and identical elements will not be described to avoid redundancy.

[61] FIG. 5 is a block diagram of a volatile organic compound recovery apparatus according to a fifth exemplary embodiment of the present disclosure.

[62] Referring to FIG. 5, a volatile organic compound recovery apparatus 1 - 4 according to the fifth exemplary embodiment of the present disclosure includes an evaporator that is installed between the first heat exchanger 20 and the second heat exchanger 50 to transform liquefied natural gas (LNG) into natural gas (NG) by exchanging heat between the LNG and the high pressure fluid B or the first gas B1. The evaporator 130 may include a path structure in which paths are interconnected to allow heat exchange. In the structure, the first gas B1 may be introduced into a pipe channel on one side, and the LNG E1 may be introduced into a pipe channel on another side, such that heat may be exchanged therebetween. The cryogenic LNG E1 is subjected to the heat exchange with the first gas B1 to be vaporized and transformed to NG E2, to be supplied to a consuming place F. Although the evaporator 130 shown in FIG. 5 exchanges heat between LNG E1 and the first gas B1 to transform it into the NG E2, if the preprocessing unit 70 is not employed, a pipe channel may be connected between the first heat exchanger 20 and the evaporator 130, such that the high-pressure fluid B is introduced into the evaporator 130 and heat is exchange with the LNG E1 so that it is transformed into NG E2.

[63] That is to say, when the volatile organic compound recovery apparatus 1 - 4 is employed in a ship or a facility that has an LNG storage tank E or the like to vaporize the LNG E1 to use it as a fuel or the like, it is possible to greatly increase the cooling efficiency by utilizing cryogenic LNG E1 as refrigerant. In addition, it is not necessary to additionally install a vaporizer for vaporizing the LNG E1 in the consuming place F, which is effective in terms of the apparatus configuration. The LNG E1 may be supplied to the evaporator 130 by a pump 140 connected between the evaporator 130 and the LNG storage tank E. NG E2 vaporized in the evaporator 130 may be supplied to and used in the consuming place F. The consuming place F includes an internal combustion engine, a boiler, a turbine and the like that can use NG E2 as fuel and may control the pump 140 and adjust the amount of supplied NG E2 in accordance with the load fluctuations. As such, , the volatile organic compound recovery apparatus 1-4 can be easily applied to a facility including the LNG storage tank E and the like.

[64] Hereinafter, a volatile organic compound recovery apparatus according to a sixth exemplary embodiment of the present disclosure will be described in detail with reference to FIG.

6. For simplicity and clarity, the following description will focus on the differences from the above exemplary embodiment of the present disclosure and identical elements will not be described to avoid redundancy.

[65] FIG. 6 is a block diagram of a volatile organic compound recovery apparatus according to a sixth exemplary embodiment of the present disclosure.

[66] Referring to FIG. 6, in a volatile organic compound recovery apparatus 1 - 5 according to the sixth exemplary embodiment of the present disclosure, a moisture removing unit 72 is disposed at the previous stage of a preprocessing separator 71. Specifically, the moisture removing unit 72 is disposed between the first heat exchanger 20 and the preprocessing separator 71 to remove moisture contained in the high-pressure fluid B introduced into the preprocessing separator 71 before it is introduced into the preprocessing separator 71. Accordingly, it is not necessary to form the preprocessing separator 71 as the three-phase separator as described above, but the preprocessing separator 71 may be implemented as a gas-liquid separator for introducing the high-pressure fluid B to separate it into the first gas B1 and the first liquid B2. In this manner, it is possible to suppress unnecessarily produced adducts and to improve the efficiency of the apparatus configuration. In addition, it is possible to more efficiently recover the available energy of the volatile organic compounds and suppress the amount of the discharged volatile organic compounds through the processes as described above.

[67] Although the exemplary embodiments of the present invention has been described with reference to the accompanying drawings, those skilled in the art will appreciate that various modifications and alterations may be made without departing from the spirit or essential feature of the present invention. Therefore, it should be understood that the above-mentioned embodiments are not limiting but illustrative in all aspects.

Claims

WHAT IS CLAIMED IS:

[Claim 1]

A volatile organic compound recovery apparatus comprising:

a first compressor configured to compress oil mist produced from a crude oil tank;

a first heat exchanger configured to cool down a high-pressure fluid that has passed through the first compressor;

an expansion valve configured to depressurize the high-pressure fluid that has passed through the first heat exchanger or a first gas separated from the high-pressure fluid through a preprocessing unit; and

a gas-liquid separator configured to separate the high-pressure fluid that has passed through the expansion valve or the first gas into a second gas and a second liquid to supply the second gas to a combustion engine and the second liquid to a storage tank.
[Claim 2]

The apparatus of claim 1, further comprising:

a second heat exchanger installed between the first heat exchanger and the expansion valve and configured to exchange heat between the second gas separated from the gas-liquid separator and the high-pressure fluid or the first gas.
[Claim 3]

The apparatus of claim 2, further comprising:

a third heat exchanger installed between the second heat exchanger and the expansion valve and configured to exchange heat between the second liquid separated from the gasliquid separator and the high-pressure fluid or the first gas.
[Claim 4]

The apparatus of claim 3, wherein the preprocessing unit further comprises a preprocessing separator installed between the first heat exchanger and the second heat exchanger and separating the first gas from the high-pressure fluid to provide it to the second heat exchanger.
[Claim 5]

The apparatus of claim 4, wherein the preprocessing unit further comprises a moisture removing unit installed between the first heat exchanger and the preprocessing separator or between the preprocessing separator and the second heat exchanger.
[Claim 6]

The apparatus of claim 4, wherein the preprocessing unit further comprises a second compressor installed between the preprocessing separator and the second heat exchanger to pressurize the first gas.
[Claim 7]

The apparatus of claim 6, further comprising:

a fourth heat exchanger installed between the second compressor and the second heat exchanger to cool down the first gas.
[Claim 8]

The apparatus of claim 6, further comprising:

a branch pipe branching off from a pipe channel through which the first gas flows between the second compressor and the gas-liquid separator; and a high-pressure tank connected to the branch pipe and storing the first gas therein.
[Claim 9]

The apparatus of claim 8, further comprising:

a shut-off valve formed in the branch pipe and configured to adjust a pressure of the first gas introduced into the high-pressure tank.
[Claim 10]

The apparatus of claim 3, further comprising:

an evaporator installed between the first heat exchanger and the second heat exchanger and configured to exchange heat between liquefied natural gas (LNG) and the high-pressure fluid or the first gas to transform the LNG into natural gas (NG).
[Claim 11]

The apparatus of claim 4, wherein the preprocessing separator is a three-phase separator that separates the high-pressure fluid into the first gas, water, and a first liquid composed of components having a specific gravity smaller than that of the water.
[Claim 12]

The apparatus of claim 1, further comprising:

a filtering unit installed between the crude oil tank and the first compressor to remove solid foreign substances and liquid foreign substances contained in the oil mist.