KR101603432B1 - System for removing volatile organosiloxane compounds - Google Patents

Abstract

The present invention relates to a system for removing a volatile organosiloxane compound. The technological purpose of the present invention is to provide the system for removing a volatile organosiloxane compound which can prevent concentration inversion of a siloxane compound in biogas. According to an embodiment of the present invention, the system for removing a volatile organosiloxane compound includes: a first pretreatment unit which removes moisture and hydrogen sulfide included in the biogas; a siloxane removal unit which includes a first adsorption tower, injected with coconut-based active carbon, a second adsorption tower injected with carbon-based active carbon, and a third adsorption tower, injected with silica gel and removes the siloxane compound from the biogas having passed through the first pretreatment unit as the first to third adsorption tower are connected to the first pretreatment unit in three-stage series; and a siloxane concentration analysis unit which measures the concentration of the biogas which have passed through input terminals and output terminals of the first adsorption tower, the second adsorption tower, and the third adsorption tower.

Description

SYSTEM FOR REMOVING VOLATILE ORGANOSILOXANE COMPOUNDS [0001]

One embodiment of the present invention relates to a volatile organosiloxane compound removal system.

Biogas, including landfill gas, is a gaseous substance generated during the anaerobic digestion process of organic wastes, and mainly consists of methane and carbon dioxide, which are greenhouse gases. In addition, biogas with a calorific value of 40 to 70% of city gas is a typical new renewable fuel and can be applied to gas engines, gas turbines, fuel cells, etc. after refining to produce electricity and heat, .

Meanwhile, the pretreatment purification system for converting biogas power generation fuel comprises a detailed process for removing moisture, hydrogen sulfide, and siloxane compounds and adjusting temperature and pressure conditions. At this time, the moisture and hydrogen sulfide create a corrosive environment.

Particularly, the siloxane compound is contained in the biogas, such as cosmetics and household products such as gypsum board. The siloxane compound is converted into SiO2 during combustion and deposited on a gas turbine blade, a heat exchanger, a catalyst, In the engine, it is necessary to remove it because it causes damage of the driving part.

In the case of MW-class biogas turbines, the concentration of siloxane compounds in the fuel gas is regulated to 5 to 10 mg Si / Nm ³ . In addition, the siloxane compound standard values are determined for each gas engine and other prime mover, and a pretreatment system for eliminating biogas power generation is separately installed.

Dry adsorption process, cooling process, wet absorption process, etc., are most widely used for the removal process of siloxane compounds, and the cooling process has been developed by Pioneer in the US, but commercialization has not been performed. In addition, the wet absorption process utilizes the fact that the siloxane compound dissolves in an organic solvent, and has not yet been commercialized. However, it has been reported that the simultaneous removal of siloxane from the hydrogen sulfide removal system using an organic solvent installed in a landfill in the United States has been reported.

Currently, the most widely used dry adsorption process can be applied to various adsorbents. At this time, examples of the adsorbent applicable to the dry adsorption process include activated carbon, silica gel, activated alumina, and mineral-based adsorbents such as Eliana and vermiculite. For example, currently, activated carbon is the most widely used in terms of price and availability.

In addition, the dry adsorption technique is most widely applied to the process of removing siloxane compounds in the biogas. Process optimization is performed considering the removal characteristics of the siloxane compound, the composition of the siloxane compound in the target biogas, and the whole biogas pretreatment process The performance of the adsorbent is deteriorated, the replacement cycle is shortened, and the rear stage power generation facilities may be seriously adversely affected.

On the other hand, in the case of commercial adsorbents, the removal efficiency of the siloxane compound is as low as 8 to 10 g / kg-absorbent, and when the process is not optimized, the removal performance is drastically lowered. Also, the dew-point temperature of the biogas greatly affects the performance of the adsorption process. That is, when the dew point temperature is high, the occurrence frequency of the liquid phase in the adsorption process is increased and the adsorption performance is greatly reduced. In particular, the temperature of the biogas changes greatly due to the outside temperature, and the removal performance of the siloxane compound in the winter is significantly lowered.

There are more than 10 kinds of siloxane compounds contained in the biogas, and the physical properties are different according to the molecular weight and the type. Particularly, there is a difference in selectivity among dry adsorption processes most widely used for siloxane removal. For example, according to the online analysis of siloxane using biogas, some siloxanes showed a phenomenon that the concentration of the adsorption column outlet (about 4,000 ppb) exceeded the inlet concentration (about 1,000 ppb) up to 4 times, have. That is, the adsorbed low molecular weight siloxane is desorbed in a short time due to the difference in adsorption selectivity with the high molecular weight siloxane. In this case, the rear stage power generation facility is severely adversely affected.

It is impossible to detect the desorption of low molecular weight siloxanes that occur in a short time when intermittent siloxane compound analysis is performed through conventional off-line analysis (GC-MS analysis via methanol impingement).

As a result, when the cost of the biogas pretreatment is rapidly increased and the amount of the siloxane compound flowing into the power generation facility is continuously increased, the overall economical efficiency of the biogas power generation plant is greatly deteriorated.

Japanese Patent Application Laid-Open No. 10-2013-0012728 'Surface modification method and siloxane removal method of silica gel for improvement of adsorption power, and siloxane removal device of two way system using the same, Disclosed is a method and a device for removing siloxane contained in a silicon compound gas, a method and an apparatus for analyzing the content of a siloxane,

One embodiment of the present invention provides a volatile organosiloxane compound removal system capable of preventing concentration reversal of a siloxane compound in a biogas.

According to an embodiment of the present invention, there is provided a system for removing volatile organic siloxane compounds, comprising: a primary pretreatment unit for removing moisture and hydrogen sulfide contained in a biogas; A first adsorption tower to which coconut-based activated carbon is injected, a second adsorption tower to which coal activated carbon is injected, and a third adsorption tower to which silica gel is injected, and the first to third adsorption towers are connected to the first pre- A siloxane removing unit for removing the siloxane compound of the biogas that has passed through the primary pretreatment unit; And a siloxane concentration analyzing unit for measuring the concentration of the biogas passing through each of the input and output ends of the first to third adsorption towers.

The primary pre-treatment unit may include heating means for heating the biogas injected through the pipe.

The temperature of the biogas in the piping may be limited to 20 to 50 캜 .

The siloxane removal unit may include first to third PLCs for controlling the operation of the first to third adsorption towers between the siloxane removal unit and the siloxane concentration analysis unit.

The siloxane removing unit may have a pair of the first to third adsorption towers.

And an electric valve is provided between the second adsorption tower and the third adsorption tower, wherein the electric valve controls the concentration of the siloxane compound at the output stage based on the concentration value of the siloxane compound at the input and output ends of the first adsorption tower and the second adsorption tower, And the biogas passing through the second adsorption tower can be bypassed when the value is equal to or less than the reference concentration value.

The third adsorption column may be operated when the concentration of the siloxane compound at the output end of the second adsorption column is at least 10% of the concentration of the siloxane compound at the input end of the second adsorption column.

The first PLC to the third PLC may control the first to third adsorption towers to be heated to a first temperature.

The first PLC to the third PLC may control the sampling pipe to be heated to a second temperature.

The first PLC has a concentration value of a siloxane compound at the first middle of the input end of the first adsorption column, two intermediate points of the first adsorption column, and a point between the first adsorption column and the second adsorption column, The concentration value of the siloxane compound of the second middle stage is measured, and when the concentration value of the siloxane compound of the second middle stage exceeds 5% to 10% of the concentration value of the first middle stage siloxane compound, %, It is possible to determine the concentration value of the siloxane compound at the output stage and determine whether the concentration value of the siloxane compound at the output end exceeds 5% to 10% of the concentration value of the siloxane compound at the input end .

Wherein the concentration of the siloxane compound at the first middle end of the second PLC is between 5% and 10% of the concentration value of the siloxane compound at the input end of the second intermediate stage of the second adsorption column, %, It is possible to control to measure the concentration value of the siloxane compound of the second middle stage.

The temperature indicator and the pressure indicator measure the temperature and the pressure difference between the input and output ends of the first to third adsorption columns to determine the siloxane concentration of the siloxane To the concentration analyzer.

The siloxane concentration analyzing unit is connected to the input end, middle end, and output end of the first to third adsorption towers through a plurality of sampling pipes, and can analyze the siloxane compound concentration value of the biogas extracted from each sampling pipe.

The first PLC to the third PLC can control the temperature difference of the biogas between the input and output ends of the first to third adsorption towers to be maintained at 5 ° C or less.

The siloxane concentration analyzing unit can measure and analyze the concentration of biogas by applying any one of FTIR, GC-MSD, and GC-FID.

Wherein the siloxane concentration analyzing unit monitors the CO concentration value in the biogas and displays an internal fire alarm of any one of the first to third adsorption towers when the CO concentration value in the biogas is 200 ppm or more, The driving of the first to third adsorption towers can be stopped through the first to third PLCs.

The siloxane concentration analyzing unit analyzes the components of the biogas at the middle stages of the first to third adsorption towers by using an analysis algorithm, and analyzes the concentration of the introduced siloxane compound, the characteristics of the adsorbent, the flow rate of the biogas, The time point at which the adsorbent is to be replaced can be estimated by calculating the time data.

The system for removing volatile organosiloxane compounds according to an embodiment of the present invention is a system for removing siloxane compounds in a biogas by using a dry adsorption method, The removal performance of the compound and the lifetime of the adsorbent can be optimized.

1 is a view illustrating a system for removing volatile organosiloxane compounds according to an embodiment of the present invention.
2 is a flow chart showing a main control process in the volatile organic siloxane compound removal system of FIG.
FIG. 3 is a flowchart showing the order of adsorption towers and piping heating in the main control process sequence of FIG. 2. FIG.
FIG. 4 is a flowchart showing the calculation of the adsorbent replacement cycle and the notification procedure in the main control process sequence of FIG. 2. FIG.
5A to 5C are graphs showing experimental results of removing siloxane compounds for each adsorbent for selecting individual adsorption tower fillers.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which those skilled in the art can readily implement the present invention.

FIG. 1 is a view showing a system for removing volatile organosiloxane compounds according to an embodiment of the present invention, FIG. 2 is a flowchart showing a main control process in the volatile organic siloxane compound removal system of FIG. 1, FIG. 4 is a flow chart showing calculation and notification procedure of the adsorbent replacement cycle in the main process step sequence of FIG. 2. FIG. 5A to FIG. 5C are graphs showing the relationship between the adsorbent-specific siloxane compound FIG.

1, the system for removing volatile organosiloxane compounds according to an embodiment of the present invention includes a primary pretreatment unit 1, a siloxane removing unit 10, a PLC unit 900, and a siloxane concentration analyzing unit 1000 .

The primary pretreatment unit 1 removes moisture and hydrogen sulfide contained in the biogas. In addition, the primary pretreatment unit 1 includes heating means for heating the biogas injected through the pipe 800. The temperature of the biogas in the pipe 800 may be limited to 20 to 50 ° C.

The siloxane removing unit 10 includes a first adsorption tower 010 into which coconut-based activated carbon is injected, a second adsorption tower 020 into which coal-based activated carbon is injected, and a third adsorption tower 030 into which silica gel is injected. The third adsorption columns 010, 020 and 030 are connected in series to the first pre-treatment section 1 in three stages to remove the siloxane compound of the biogas that has passed through the first pre-treatment section 1.

Between the second adsorption tower 020 and the third adsorption tower 030, there are provided electric valves 331, 332 and 333. Based on the concentration values of the siloxane compounds at the input and output ends of the first adsorption column 010 and the second adsorption column 020, the electromotive valves 331, 332, and 333 determine the concentration of the siloxane compound at the output end, The biogas passing through the second adsorption tower 020 can be bypassed.

The third adsorption tower 030 may be operated when the concentration of the siloxane compound at the output end of the second adsorption tower 020 is 10% or more of the concentration of the siloxane compound at the input end of the second adsorption tower 020.

The PLC unit 900 includes a first PLC to a third PLC to control operation of the first to third adsorption towers 010, 020, and 030 between the siloxane removing unit 10 and the siloxane concentration analyzing unit 1000 910, 920, 930).

The first to third PLCs 910, 920 and 930 can control the first to third adsorption towers 010, 020 and 030 to be heated to the first temperature. In addition, the first to third PLCs 910, 920, and 930 may control the sampling pipe to be heated to a second temperature.

The first to third PLCs 910, 920 and 930 can control the temperature difference between the input and output ends of the first to third adsorption towers 010, 020, and 030 to be less than 5 degrees have.

The first PLC 910 is connected to the input terminal of the first adsorption tower 010 and the two simple points of the first adsorption tower 010 and the concentration of the siloxane compound at the point between the first adsorption tower 010 and the second adsorption tower 020 Measure the value. At this time, when the concentration value of the siloxane compound at the intermediate stage exceeds 5% to 10% of the concentration value of the siloxane compound at the input end, the first PLC 910 measures the concentration value of the siloxane compound at the output end, It is judged whether or not the concentration value of the siloxane compound exceeds 5% to 10% of the concentration value of the siloxane compound at the input end of the first adsorption tower (010).

The second PLC 920 measures the concentration value of the siloxane compound at the intermediate two points of the second adsorption tower 020, the point between the second adsorption tower 020 and the third adsorption tower 030. If the concentration value of the siloxane compound at the first middle stage of the second adsorption column 020 exceeds 5% to 10% of the concentration value of the siloxane compound at the input end, Of the siloxane compound is measured. Through this process, the first adsorption column 010 to the third adsorption column 030 are sequentially operated.

Temperature indicators 501 to 504 and pressure indicators 601 to 604 are provided between the siloxane removing unit 10 and the siloxane concentration analyzing unit 1000, respectively. The temperature indicators 501 to 504 and the pressure indicators 601 to 604 measure the temperature and pressure difference between the input and output ends of the first to third adsorption towers 010 to 020, Lt; / RTI >

The siloxane concentration analyzing unit 1000 measures the concentration of the biogas passing through the input and output ends of the first to third adsorption towers 010, 020 and 030, respectively. The siloxane concentration analyzing unit 1000 includes a plurality of sampling pipes 811 to 814, 821 to 823, and 831 to 833 at the input end, middle end, and output end of the first to third adsorption towers (010, And the siloxane compound concentration values of the biogas extracted from the respective sampling pipes 811 to 814, 821 to 823, and 831 to 833 are analyzed.

The siloxane concentration analyzing unit 1000 may be any one of Fourier transform infrared spectroscopy (FTIR), gas chromatography-mass selective detector (GC-MSD), and gas chromatography- Can be measured and analyzed.

The siloxane concentration analyzing unit 1000 monitors the CO concentration value in the biogas, and when the CO concentration value in the biogas is 200 ppm or more, the siloxane concentration analyzing unit 1000 determines whether any of the first to third adsorption towers 010, 020, And the driving of the first to third adsorption towers 010, 020, and 030 can be stopped through the first to third PLCs 910, 920, and 930 when the CO concentration value is 500 ppm or more.

The siloxane concentration analyzer 1000 analyzes the components of the biogas at the middle stages of the first to third adsorption towers (010, 020, and 030) using an analysis algorithm, , The characteristics of the adsorbent, the flow rate of the biogas, and the saturation time data to predict the replacement time of the adsorbent.

Hereinafter, the siloxane removal process using the system for removing volatile organic siloxane compounds according to one embodiment of the present invention will be described in detail with reference to FIGS. 2 to 5C.

First, the variable siloxane removal process applied to the present invention comprises a first pretreatment unit 1, a three-stage adsorption tower for removing siloxane (i.e., first to third adsorption towers 010 to 020 and 030), GC-FID or FTIR (I.e., a siloxane concentration analyzing unit 1000), and an adsorption tower and various piping heating systems (i.e., first to third PLCs 910, 920, and 930).

Different adsorbents are used for the first to third adsorption towers (010, 020, 030). That is, silica gel, coal-based activated carbon, and coconut-based activated carbon are injected into the first to third adsorption towers (010, 020, and 030), respectively. At this time, the first adsorption tower 010 and the second adsorption tower 020 are always in operation, and the third adsorption tower 030 is a variable operation facility for removing low molecular weight siloxane compounds desorbed in the preceding adsorption process.

The adsorbent for each step in the first to third adsorption towers (010, 020, and 030) is selected based on the test results of the siloxane compound removal characteristics shown in FIGS. 5A to 5C. As shown in FIGS. 5A to 5C, in the experiment of adsorption equilibrium, the cyanide-based activated carbon (A1) was the most excellent in the case of the L2 siloxane, and the coal-based activated carbon (A2) and the silica gel (NCA1) Performance.

In addition, the silica gel, which is an adsorbent used in the first adsorption tower 010, can compensate for the stable adsorption of siloxane and adsorbent characteristics of the adsorbent of the second adsorption tower 020 through the water-removing effect of the silica gel. In addition, the coconut-based activated carbon is most suitable for a variable-operation equipment because it has the best adsorption removal performance of a typical low molecular weight siloxane compound L2.

The siloxane concentration analyzer 1000 detects a desorption phenomenon of the low molecular weight siloxane compound and provides an operation signal for the third adsorption tower 030, which is a variable operation siloxane removal facility, through the third PLC 930. The siloxane concentration analyzing unit 1000 may employ thermal desorption-gas chromatography-FID or FTIR. That is, when the signal is given by the gas analysis, the siloxane concentration analyzer 1000 removes the low-molecular-weight siloxane compound that biogas is sent to the third adsorption tower 030 and is instantaneously desorbed. Therefore, Is prevented.

In the present invention, in order to control the temperature difference between the input and output stages of the first to third adsorption towers (010, 020, and 030) within ± 5 ° C, it is kept at 25 to 50 mm in the case of the piping and kept at 75 to 100 mm . According to the present invention, it is possible to raise the temperature up to 50 ° C in order to cope with outside temperature in winter, thereby minimizing the generation of moisture in the process and maximizing the adsorption performance.

Particularly, the gas sampling pipes 811 to 814, 821 to 823, and 831 to 830 provided between the first to third adsorption towers 010, 020, and 030 and the first to third PLCs 910, 920, 833) are configured to be heated to a maximum of 180 DEG C to improve measurement accuracy. This is to minimize the tendency of the siloxane compound to adhere to the surfaces of the sampling pipes 811 to 814, 821 to 823, and 831 to 833. The concentrations of D3 + L3, D4 and D5 were changed as shown in Table 1 when the temperature of the Teddler bag injected with gas was increased to 22 ℃, 60 ℃ and 100 ℃, respectively.

[Table 1]

In addition, the present invention can optimize the removal performance of the siloxane compound and the lifetime of the adsorbent so that the siloxane compound in the biogas is removed by the dry adsorption method, the adsorption process is performed in two stages / .

1, the system includes a primary pretreatment unit 1 for pretreating an incoming biogas, a first adsorption column to a third adsorption column 010 for removing the biogas siloxane compound, 0201, and 030, pressure gauges 111 to 114, safety valves 211, 221 and 231, electric valves 311 to 313 and 321 to 323 and 331 to 333, temperature indicators 501 to 504, The gas sampling pipes 811 to 814, 821 to 823, and 831 to 833, the integrated control computer 900, Solenoid motor control panels 910, 920 and 930, a gas analyzer 1000, and the like.

The primary pretreatment unit 1 takes charge of water / hydrogen sulphide removal in the biogas and includes a compression system if necessary. The biogas in the entire system is supplied through a pipe 800 which is kept at a thickness of 25 to 50 mm and heated up to 50 ° C by a hot wire or the like.

The siloxane concentration analyzing unit 1000 is an online analyzing system to which a system such as FTIR, GC-FID, GC-MS and thermal desorbing system is applied and removes siloxane through gas sampling pipes 811 to 814, 821 to 823, and 831 to 833 Analyze the concentration of siloxane at the input, intermediate, and output stages of the system.

The first to third adsorption towers 010, 020, and 030 are configured in three stages in series. That is, coconut-based activated carbon is injected into the first adsorption tower 010, coal-based activated carbon is injected into the second adsorption tower 020, and silica gel is injected into the third adsorption tower 030. In this case, the injected silica gel should have a minimum water absorption capacity of 4.0 to 5.5%, 8.0 to 11.0%, 16.0 to 19.0%, and 23.0 to 28.0%, respectively, for relative humidity of 10%, 20%, 40% and 60%. In addition, the residual moisture content should not be more than 6.5% and the bulk should be at least 720 kg / m3.

In addition, the first to third adsorption towers 010, 020, and 030 may be configured in pairs to be redundant. At this time, each adsorption tower is heated to a thickness of 75 to 100 mm, and the adsorption tower itself is heated to a maximum of 50 ° C by heat rays.

In addition, the pressure gauges 111 to 114 and the safety valves 211, 221 and 231 play an essential role in the field safety check and safety accident prevention, and the temperature indicators 501 to 504 and the pressure indicators 601 to 604 The temperature and pressure difference of the input and output stages of the first to third adsorption towers to the third adsorption towers 010, 020 and 030 are measured and data necessary for the system operation is provided to the integrated PLC unit 900.

The electric valves 311 to 313 and 321 to 323 and 331 to 333 and the solenoid valves 711 to 714 and 721 to 723 and 731 to 733 are connected to the input ends of the first to third adsorption towers 010, The siloxane removal adsorption tower which operates according to the control signal of the PLC unit 900 reflecting the operation data of the output stage and the sampling point for gas analysis are optimally configured.

The gas sampling pipes 811 to 814 and 821 to 823 and 831 to 833 are constituted by the input end and the output end of the first to third adsorption towers 010 to 020 and 030 and the intermediate two points of the respective adsorption towers, It is heated up to 180 ° C to improve accuracy.

Meanwhile, the biogas 100 generated during the anaerobic digestion process of the organic waste is subjected to the pretreatment process of the primary pretreatment unit 1 such as water removal. At this time, the supply temperature of the biogas through the biogas pipe 800 is configured and controlled to be limited to 20 to 50 ° C.

The inlet and the final outlet concentration of the present system are measured by the siloxane concentration analyzing unit 1000, the gas sampling pipes 811 and 843, and the solenoid valves 711 and 743. If the concentration of the siloxane compound at the inlet is low enough that it will not affect the biogas-utilizing power plant at all (typically between 0.1 and 1 mg Si / Nm ³ ), bypass piping is used to prevent the biogas from passing through the siloxane removal facility Can be configured.

The volatile organosiloxane compound removal system controls the electric valves 331 to 332 such that the first adsorption tower and the second adsorption tower 010 and 020 are operated in series and the third adsorption tower 030 is bypassed. At this time, the concentration of the intermediate siloxane compound is measured through the gas sampling pipe 812 and the solenoid valve 712. The siloxane compound concentration value at the output end of the first adsorption column 010 is measured through the gas sampling pipe 813 and the solenoid valve 714. At this time, when the concentration value of the siloxane compound at the middle outlet (that is, middle stage) exceeds 5 to 10% of the concentration value of the siloxane compound at the input end of the first adsorption tower 010, The gas sampling piping and the solenoid valves are switched to the following gas sampling piping and solenoid valves 813 and 713. When the concentration value of the siloxane compound at the output end exceeds 5 to 10% of the concentration value of the siloxane compound at the input end of the first adsorption column 010, the concentration is sequentially changed. In this case, the order of switching may be sequentially performed from 811/711? 812/712? 813/713? 814/714? 821/721? 822/722? 823/723? 831/731? 832/732? 833/733 have. Further, when the concentration measuring point at the intermediate stage is switched to the gas sampling pipe 822 and the solenoid valve 722, it indicates the imminent change of the adsorption tower and the replacement of the adsorbent.

If the light siloxane compound such as L2 or D3 exceeds 5 to 10% of the inlet concentration value at the siloxane compound concentration value at the output end of the first adsorption column 010, removal of the L2, D3, etc. desorbed by the adsorption of the heavy siloxane compound The state of the electric valves 331 to 332 is changed and the third adsorption tower 030 is operated. Simultaneously with the operation of the third adsorption tower 030, the concentration measurement of the output stage of the first adsorption tower 010 is stopped and the concentration value of the output stage of the third adsorption tower 030 is switched to the gas sampling pipeline 833 and the solenoid valve 733 Lt; / RTI > When the concentration value of the output stage of the second adsorption tower 020 for L2, D3, etc. exceeds 5% of the concentration value of the input stage of the second adsorption tower 020, the operation of the adsorption tower is switched to an auxiliary facility and the adsorbent is replaced .

Also, the siloxane concentration analyzing unit 1000 may calculate the predicted replacement point of the adsorbent for siloxane compound removal considering the concentration value of the siloxane compound at the input end, the amount of the adsorbent per each sampling point, and the measurement time at each point. Also, the siloxane concentration analyzing unit 1000 instructs the inspection system, the sampling piping or the biogas piping to be checked when the intermediate outlet concentration value is lower than the final outlet concentration value. At this time, when the difference between the concentration value at the input end and the concentration at the intermediate outlet is smaller than the difference between the intermediate outlet concentration and the final outlet concentration, the siloxane concentration analyzer 1000 instructs the sampling point switching abnormality or the adsorbent replacement check do.

The temperature of each piping and the adsorption tower is controlled so that the temperature difference between the input and output of each of the first to third adsorption towers (010, 020, 030) is not more than ± 5 ° C according to the measured values of the temperature indicators (501 to 504) 1 PLC to the third PLCs 910, 920, 930. In addition, when the differential pressure reaches 50% or more of the design value due to the measurement values of the pressure indicators 601 to 604, the clogging phenomenon check is instructed.

On the other hand, Table 2 shows the result of the calculation of the amount of the post-stage inflow when the low molecular weight siloxane compound is desorbed. That is, when the present invention is not applied, a considerable amount of siloxane compound is introduced before the end of the adsorbent design life, causing damage to the downstream equipment.

[Table 2]

When the siloxane compound removal equipment is designed and operated by intermittent gas analysis in the conventional manner, the power generation equipment used at the rear end is seriously damaged regardless of the type. The type and price per unit capacity of the biogas power generation facility to be protected by the present invention are the same as those in Table 3 (U.S. EPA, 2009, LFG Energy Project Development Handbook, US EPA).

[Table 3]

In addition, when the present invention is applied, the replacement cycle of the adsorbent can be maximized. Assuming that the breakthrough of the adsorbent occurred due to the desorption of the low molecular weight siloxane compound after 36 hours for the system for treating the biogas as shown in Table 4 with the low molecular weight siloxane compound and the high molecular weight siloxane compound having a concentration of about 3: .

[Table 4]

When the present invention is applied to construct a three-stage adsorption tower and the two-stage operation unit (i.e., the first adsorption tower and the second adsorption tower) and the first-stage variable operation unit (third adsorption tower) are configured with an adsorbent weight ratio of 7: 3, Is calculated to be 43.2 hours, it is possible to extend the adsorbent replacement period of 20% or more.

In addition, according to the adsorption equilibrium experiment results of siloxane adsorbents shown in Figs. 5A to 5C, the removal efficiency for a typical low molecular weight siloxane compound L2 is greatly different according to the adsorbent. That is, the average removal efficiency of the coconut-based activated carbon is about 96%, but the average of the coal-based activated carbon is 84%. In the case of the silica gel, the removal rate is 20% or less with respect to the same weight. Therefore, when the coconut-based activated carbon is injected into the third adsorption column, which is a variable operating unit, the removal efficiency and replacement cycle can be maintained at 20% higher.

On the other hand, when the silica gel is used as the adsorbent in the first adsorption tower 010 for the biogas flowing into the saturated state because moisture compete with the siloxane compound at the adsorption surface, the relative humidity in the biogas is reduced as well as siloxane removal, It is possible to optimally maintain the adsorption performance of the coal-based activated carbon of (010). The above effect is more remarkable when the adsorption tower and the piping are kept warm and warmed and the front and rear temperature are maintained at 占 5 占 폚.

As can be seen from Table 1, the siloxane compound adsorbed on the surface tends to be measured to have a lower concentration than the actual dose when the temperature of the thermoset back is low. As a result, relatively low molecular weight siloxane compounds, D3 and L3, were found to have a concentration lower than 30% of the actual dose. Therefore, when the volatile organosiloxane compound removal system is applied to the present invention, the sampling pipe is heated to a temperature of 180 ° C, the measurement accuracy of the siloxane compound can be maintained high.

As described above, the present invention is not limited to the above-described embodiment, but rather may be applied to a system for removing volatile organosiloxane compounds according to the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

1: Primary Pretreatment Part 10: Siloxane Rejection
900: PLC part 1000: Siloxane concentration analyzing part
010, 020, 030: first adsorption tower, second adsorption tower, third adsorption tower
910, 920, 930: the first PLC, the second PLC, the third PLC

Claims (17)

A first pretreatment unit for removing moisture and hydrogen sulfide contained in the biogas;
The first adsorption tower to which coconut-based activated carbon is injected, the second adsorption tower to which coal activated carbon is injected, and the third adsorption tower to which silica gel is injected, and the first to third adsorption towers are connected to the first pre- A siloxane removing unit for removing the siloxane compound of the biogas that has passed through the primary pretreatment unit; And
And a siloxane concentration analyzing unit for measuring the concentration of the biogas passing through each of the input and output ends of the first to third adsorption towers, wherein a motorized valve is provided between the second adsorption tower and the third adsorption tower, When the siloxane compound concentration value at the output stage is equal to or lower than the reference concentration value based on the concentration value of the siloxane compound at the input end and the output end of each of the first adsorption tower and the second adsorption tower, the biogas passing through the second adsorption tower is bypassed Wherein the volatile organic siloxane compound removal system comprises:
The method according to claim 1,
Wherein the primary pretreatment unit comprises heating means for heating the biogas injected through the piping.
3. The method of claim 2,
Wherein the temperature of the biogas in the piping is limited to 20 to 50 占 폚.
The method according to claim 1,
And a first PLC to a third PLC for controlling operations of the first to third adsorption towers between the siloxane removing unit and the siloxane concentration analyzing unit.
The method according to claim 1,
Wherein the siloxane removing unit is configured such that each of the first adsorption tower to the third adsorption tower can be configured as a pair.
delete The method according to claim 1,
Wherein the third adsorption column is operated when the siloxane compound concentration value at the output end of the second adsorption column is at least 10% of the siloxane compound concentration value at the input end.
5. The method of claim 4,
Wherein the first PLC to the third PLC controls the first to third adsorption towers to be heated to a first temperature.
5. The method of claim 4,
A gas sampling pipe is provided between the first adsorption tower and the third adsorption tower and between the first PLC and the third PLC, and the first PLC to the third PLC controls the sampling pipe to be heated to a second temperature Volatile organosiloxane compound removal system.
The method according to claim 1,
Wherein the concentration of the siloxane compound at the first middle of the input end of the first adsorption column, the intermediate end of the first adsorption column, and the point between the first adsorption column and the second adsorption column, The concentration of the siloxane compound at the second middle stage is measured, and when the concentration value of the siloxane compound at the second middle stage exceeds the concentration value of the siloxane compound at the first middle stage The concentration value of the siloxane compound at the output end is measured, and if the concentration value of the siloxane compound at the output end exceeds 5% to 10% of the concentration value of the siloxane compound at the input end Wherein the volatile organosiloxane compound removal system comprises:
11. The method of claim 10,
Wherein the concentration of the siloxane compound at the first middle end of the second PLC is between 5% and 10% of the concentration value of the siloxane compound at the input end of the second intermediate stage of the second adsorption column, %, The concentration of the second intermediate siloxane compound is controlled to be measured.
The method according to claim 1,
The temperature indicator and the pressure indicator measure the temperature and the pressure difference between the input and output ends of the first to third adsorption columns to determine the siloxane concentration of the siloxane Wherein the volatile organosiloxane compound removal system comprises a volatile organic siloxane compound removal system.
The method according to claim 1,
The siloxane concentration analyzing unit is connected to the input end, the middle end, and the output end of the first to third adsorption columns through a plurality of sampling pipes, and analyzes the siloxane compound concentration value of the biogas extracted from each sampling pipe Volatile organosiloxane compound removal system.
5. The method of claim 4,
Wherein the first PLC to the third PLC controls the temperature difference of the biogas between the input and output ends of the first to third adsorption towers to be maintained at 5 ° C or less.
The method according to claim 1,
Wherein the siloxane concentration analyzer measures and analyzes the concentration of the biogas by applying any one of FTIR, GC-MSD, and GC-FID.
5. The method of claim 4,
Wherein the siloxane concentration analyzing unit monitors the CO concentration value in the biogas and displays an internal fire alarm of any one of the first to third adsorption towers when the CO concentration value in the biogas is 200 ppm or more, The driving of the first to third adsorption towers is stopped through the first to third PLCs.
The method according to claim 1,
The siloxane concentration analyzing unit analyzes the components of the biogas at the middle stages of the first to third adsorption towers by using an analysis algorithm, and analyzes the concentration of the introduced siloxane compound, the characteristics of the adsorbent, the flow rate of the biogas, And estimating the time point of replacement of the adsorbent by calculating time data.

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