Synthesis gas fermentation clarified liquid sterilization system

Abstract

The utility model relates to a synthetic gas fermentation clarified liquor sterilization system which comprises a clarified liquor preheating unit (1), a clarified liquor heating sterilization unit (2) and a clarified liquor flash evaporation unit (3), the clarified liquor preheating unit (1), the clarified liquor heating and sterilizing unit (2) and the clarified liquor flash evaporation unit (3) are sequentially arranged along the flowing direction of the synthesis gas fermentation clarified liquor, the clarified liquor heating and sterilizing unit (2) comprises a heater (21) and a sterilizer (22) which are sequentially arranged, and the clarified liquor flash evaporation unit (3) is connected with the clarified liquor preheating unit (1) through a flash steam pipeline. Compared with the prior art, the utility model provides a process flow capable of continuously operating the clarified liquid sterilization and cooling process and reducing the CIP cleaning frequency of the heat exchanger, and has great significance for promoting the synthesis gas fermentation technology.

Description

Technical Field

[0001] The utility model relates to the technical field of syngas fermentation, in particular to a sterilization system for syngas fermentation clarified liquid. Background Art

[0002] Syngas fermentation is that anaerobic gas-eating bacteria use syngas (CO, CO2 and H2) as carbon source and energy source to reproduce and grow, and metabolize to produce biofuels such as ethanol and butanol according to different types of strains. Syngas is widely sourced from coal chemical industry, petrochemical industry, industrial waste gas (such as steel mill waste gas), municipal solid waste and biomass, etc. Therefore, applying syngas as carbon source and energy source to industrial fermentation of microorganisms can not only produce green energy, improve the economic benefits of enterprises, but also reduce the emission of carbon-containing gases, mitigate the greenhouse effect, and create environmental benefits for the society.

[0003] Currently, the syngas fermentation technology develops rapidly and has achieved industrial production in China. Syngas is bioreacted in a fermenter to generate ethanol. The fermented liquid containing ethanol is purified by a distillation system to produce high-concentration ethanol; the bottom liquid of the distillation tower without ethanol is centrifuged, and the generated solid phase is dried to produce biological protein feed; the light phase generated by centrifugation is returned to the fermenter for reuse after heating and sterilization - cooling. This production process not only saves production water but also reduces the sewage discharge.

[0004] Currently, the methods for heating, sterilizing and cooling the clarified liquid mostly achieve through heat exchangers, using steam or cooling circulating water to conduct heat exchange through the heat exchanger to realize the heating or cooling of the clarified liquid. Since the clarified liquid contains a small amount of bacteria, and its main component is protein, the protein will denature when the equipment runs for a long time or the temperature exceeds 80 °C, and adhere to the surface of the equipment in contact with it, ultimately resulting in a decline in the mass transfer and heat exchange efficiency of the heat exchanger. Therefore, during the heating, sterilizing and cooling process of the clarified liquid, it is necessary to stop the operation of the heat exchanger at intervals for CIP cleaning, which makes the fermentation production of syngas difficult to run continuously. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a sterilization system for syngas fermentation clarified liquid, which can make the sterilization and cooling process of the clarified liquid run continuously and reduce the frequency of CIP cleaning.

[0006] The purpose of the utility model can be realized by the following technical solutions: A sterilization system for syngas fermentation clarified liquid, comprising a clarified liquid preheating unit, a clarified liquid heating and sterilizing unit, and a clarified liquid flash evaporation unit;

[0007] The clarified liquid preheating unit, the clarified liquid heating and sterilizing unit, and the clarified liquid flashing unit are arranged in sequence along the flowing direction of the syngas fermentation clarified liquid. The clarified liquid heating and sterilizing unit includes a heater and a sterilizer arranged in sequence. The clarified liquid flashing unit is connected to the clarified liquid preheating unit through a flash steam pipeline.

[0008] In the present utility model, the syngas fermentation clarified liquid flows through the clarified liquid preheating unit, the clarified liquid heating and sterilizing unit, and the clarified liquid flashing unit in sequence and then forms sterilized clarified liquid and flows out. The clarified liquid flashing unit directly preheats the clarified liquid in the clarified liquid preheating unit through the flash steam generated by it.

[0009] Preferably, the clarified liquid preheating unit includes a single-stage or multi-stage preheating tower, and the clarified liquid flashing unit includes a single-stage or multi-stage flashing tank;

[0010] The flashing tank is connected to the preheating tower through a flash steam pipeline. The flash steam generated by the flashing tank is introduced into the preheating tower to preheat the clarified liquid in the preheating tower.

[0011] More preferably, the clarified liquid preheating unit includes a first-stage preheating tower and a second-stage preheating tower connected in series, and the clarified liquid flashing unit includes a first-stage flashing tank and a second-stage flashing tank connected in series;

[0012] The first-stage preheating tower, the second-stage preheating tower, the heater, the sterilizer, the first-stage flashing tank, and the second-stage flashing tank are arranged in sequence along the flowing direction of the syngas fermentation clarified liquid;

[0013] The first-stage flashing tank is connected to the second-stage preheating tower through a flash steam pipeline, and the second-stage flashing tank is connected to the first-stage preheating tower through a flash steam pipeline.

[0014] Even more preferably, the volume and heat exchange area (number of trays) of the first-stage preheating tower are larger than those of the second-stage preheating tower.

[0015] Even more preferably, the bottom of the first-stage preheating tower is connected to the second-stage preheating tower through an overflow pipeline. Since the inside of the first-stage preheating tower is in a negative pressure state during normal operation, the overflow pipeline at its bottom is designed as a "U"-shaped elbow pipe (atmospheric leg). The overflow here can be understood as flowing into the second-stage preheating tower automatically after exceeding the height set by the U-shaped pipe.

[0016] Even more preferably, the bottom of the first-stage flashing tank is connected to the second-stage flashing tank through an overflow pipeline. The overflow pipeline at the bottom of the first-stage flashing tank is designed as a "U"-shaped elbow pipe (atmospheric leg). The overflow here can be understood as flowing into the second-stage flashing tank automatically after exceeding the height set by the U-shaped pipe.

[0017] In the present utility model, the syngas clarified liquid is successively introduced into the clarified liquid heating and sterilization unit through a primary preheating tower and a secondary preheating tower, and after being heated and sterilized by the clarified liquid heating and sterilization unit, it flows out through a primary flash tank and a secondary flash tank in sequence. The flash steam generated by the primary flash tank is introduced into the secondary preheating tower, and the flash steam generated by the secondary flash tank is introduced into the primary preheating tower.

[0018] Further preferably, the preheating tower is a film type tower, and there is no internal structure in the flash tank.

[0019] Further preferably, the top of the flash tank is connected to the bottom of the preheating tower through a flash steam pipeline, and an outlet for the clarified liquid after flashing is provided at the bottom of the flash tank. The flash steam contacts the clarified liquid countercurrently in the preheating tower, and the clarified liquid after flashing flows out from the bottom of the flash tank.

[0020] Preferably, the heater is connected with a clean steam delivery pipeline, and heat transfer is achieved by mixing clean steam with the preheated clarified liquid. The heater can realize the rapid mixing and heat transfer of clean steam and the preheated clarified liquid. The clean steam enters the heater and fully contacts and mixes with the clarified liquid in the mixing chamber of the heater, thereby transferring heat to the clarified liquid.

[0021] Preferably, the sterilizer is a multi-group pipeline assembly with no internal structure in its channels, aiming to maintain the residence time of the sterilized clarified liquid.

[0022] Preferably, the system further includes a vacuum generation unit, and the vacuum generation unit is connected to the clarified liquid preheating unit.

[0023] Further preferably, the vacuum generation unit includes a vacuum pump and a condenser arranged between the clarified liquid preheating unit and the vacuum pump. The flash steam output from the clarified liquid preheating unit is cooled by the condenser, and the non-condensable gas flows out through the vacuum pump.

[0024] Even more preferably, the vacuum generation unit further includes a regulating valve for controlling the vacuum degree and an anti-backflow assembly for preventing outside air from flowing back into the system when the vacuum pump is not working properly.

[0025] Preferably, the anti-backflow assembly includes an evacuation cut-off valve and an N2 make-up valve.

[0026] Preferably, the system further includes a sterilized clarified liquid storage and output unit. The input end of the sterilized clarified liquid storage and output unit is connected to the clarified liquid flashing unit, and the output end is connected to the fermenter.

[0027] Further preferably, the sterilized clarified liquid storage and output unit includes a sterilized clarified liquid storage tank and a sterilized clarified liquid discharge pump. The input end of the sterilized clarified liquid storage tank is connected to the clarified liquid flashing unit, and the output end is connected to the fermenter through the sterilized clarified liquid discharge pump. A cooling pipe is provided on the sterilized clarified liquid storage tank.

[0028] Preferably, the input end of the clarified liquid preheating unit is connected to a clarified liquid feeding unit.

[0029] More preferably, the clarified liquid feeding unit and the clarified liquid preheating unit, the clarified liquid preheating unit and the clarified liquid heating and sterilizing unit, and the clarified liquid heating and sterilizing unit and the clarified liquid flashing unit are all connected by pipelines.

[0030] Even more preferably, a transfer pump is provided on the pipelines between the clarified liquid feeding unit and the clarified liquid preheating unit, and between the clarified liquid preheating unit and the clarified liquid heating and sterilizing unit.

[0031] Preferably, both the clarified liquid preheating unit and the clarified liquid flashing unit are connected to a CIP cleaning unit.

[0032] More preferably, spray balls are provided at the tops of the preheating tower and the flash tank, and the spray balls are connected to the CIP cleaning unit for performing CIP cleaning on the preheating tower and the flash tank before the system is started up or after it is shut down.

[0033] A method for sterilizing the clarified liquid of syngas fermentation, which is carried out using the above system, includes the following steps:

[0034] After preheating the syngas fermentation clarified liquid through the clarified liquid preheating unit, it is introduced into the clarified liquid heating and sterilizing unit, heated by a heater, and then enters a sterilizer for sterilization. The sterilized clarified liquid is introduced into the clarified liquid flashing unit for flashing. The generated flash steam is introduced into the clarified liquid preheating unit to preheat the clarified liquid therein, and the flashed clarified liquid flows out as the sterilized clarified liquid.

[0035] Preferably, after preheating the syngas fermentation clarified liquid to 80 - 110°C through the clarified liquid preheating unit, it is introduced into the clarified liquid heating and sterilizing unit.

[0036] Preferably, after the clarified liquid is heated to 95 - 135°C by the heater, it enters the sterilizer for sterilization.

[0037] Preferably, the method for sterilizing the syngas fermentation clarified liquid includes the following steps:

[0038] The syngas fermentation clarified liquid is heated to 60 - 90°C by passing through a primary preheating tower, to 80 - 110°C by passing through a secondary preheating tower, and to 95 - 135°C by passing through a heater. The heated clarified liquid is maintained in the sterilizer for 1 - 5 minutes. The clarified liquid enters a primary flash tank. The clarified liquid at 75 - 115°C after primary flashing enters a secondary flash tank. The clarified liquid at 40 - 70°C after secondary flashing enters a sterilized clarified liquid storage tank, and the temperature of the storage tank is maintained at 30 - 40°C through cooling by the external half-pipe of the storage tank.

[0039] Preferably, before the system is started up or after it is shut down, the preheating tower and the flash tank are subjected to CIP cleaning. The cleaning steps include pre-rinsing, caustic cleaning, and rinsing with clean water, and the rinsing media are recycled clean water, caustic solution, and clean water respectively.

[0040] The difficult point to be solved by the present utility model is that during the long-term operation of the heat exchanger or due to the temperature rise and denaturation of proteins, the mass transfer and heat transfer efficiency of the heat exchanger decreases, ultimately leading to the interruption of production and the need for frequent CIP flushing of the heat exchanger.

[0041] Compared with the prior art, the present utility model has the following beneficial effects:

[0042] 1. The present utility model uses a flash evaporation process flow to replace the heat exchanger for the operations of high-temperature sterilization and cooling of the clarified liquid, avoiding the situation where the mass transfer and heat transfer efficiency of the heat exchanger decreases due to the long-term operation of the heat exchanger or the temperature rise and denaturation of proteins, and the need to shut down the machine for CIP flushing.

[0043] 2. The process flow of the present utility model does not require the interruption of production, enabling the sterilization process flow of the clarified liquid to operate stably and continuously, which also reduces the number of CIP cleaning times and the usage amount of the cleaning liquid.

[0044] 3. In the present utility model, the heat exchange equipment in contact with the clarified liquid is not easily blocked, and there are no dead corners in the equipment, and the clarified liquid is not easily contaminated by bacteria.

[0045] 4. The present utility model provides a process flow that can enable the continuous operation of the sterilization and cooling process of the clarified liquid and reduce the frequency of CIP cleaning of the heat exchanger, which is of great significance for promoting the synthesis gas fermentation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic structural diagram of the synthesis gas fermentation clarified liquid sterilization system of the present utility model;

[0047] Figure 2 It is a schematic structural diagram of the clarified liquid preheating unit of the present utility model;

[0048] Figure 3 It is a schematic structural diagram of the clarified liquid heating and sterilization unit of the present utility model;

[0049] Figure 4 It is a schematic structural diagram of the clarified liquid flash evaporation unit of the present utility model;

[0050] Figure 5 It is a schematic structural diagram of the vacuum generation unit of the present utility model;

[0051] Figure 6 It is a schematic structural diagram of the sterilized clarified liquid storage and output unit of the present utility model;

[0052] Figure 7This is a schematic structural diagram of the clarified liquid feeding unit of the present utility model;

[0053] In the figure:

[0054] 1 - Clarified liquid preheating unit, 11 - Preheating tower, 111 - Primary preheating tower, 112 - Secondary preheating tower, 12 - First clarified liquid feed port, 13 - First clarified liquid overflow pipeline, 14 - Second clarified liquid discharge port, 15 - Second clarified liquid discharge pipe, 16 - Second clarified liquid discharge pump;

[0055] 2 - Clarified liquid heating and sterilization unit, 21 - Heater, 22 - Sterilizer, 23 - Second clarified liquid output pipeline;

[0056] 3 - Clarified liquid flash evaporation unit, 31 - Flash evaporation tank, 311 - Primary flash evaporation tank, 312 - Secondary flash evaporation tank, 32 - Second clarified liquid feed port, 33 - Second clarified liquid overflow pipeline, 34 - First flash steam pipeline, 35 - Second flash steam pipeline, 36 - Third clarified liquid discharge port, 37 - Third clarified liquid discharge pipe;

[0057] 4 - Vacuum generation unit, 41 - Vacuum pump, 42 - Condenser, 43 - Third flash steam pipeline, 44 - Non - condensable gas input pipeline, 45 - Non - condensable gas output pipeline;

[0058] 5 - Sterilized clarified liquid storage and output unit, 51 - Sterilized clarified liquid storage tank, 52 - Sterilized clarified liquid discharge pump;

[0059] 6 - Clarified liquid feeding unit, 61 - Clarified liquid tank, 62 - First clarified liquid discharge port, 63 - First clarified liquid discharge pipe, 64 - First clarified liquid discharge pump, 65 - First clarified liquid output pipeline;

[0060] CWS - Circulating cooling water supply, CWR - Circulating cooling water return, TE - Thermometer, CS - Clean steam. Detailed implementation manners

[0061] The present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present utility model, and the detailed implementation manners and specific operation processes are given, but the protection scope of the present utility model is not limited to the following embodiments.

[0062] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0063] Some implementation manners of the present utility model will be described in detail below with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0064] Example 1

[0065] A sterilization system for syngas fermentation clarified liquid, comprising a clarified liquid preheating unit 1, a clarified liquid heating and sterilizing unit 2, and a clarified liquid flash evaporation unit 3 arranged in sequence along the flowing direction of the syngas fermentation clarified liquid. The clarified liquid heating and sterilizing unit 2 includes a heater 21 and a sterilizer 22 arranged in sequence, and the clarified liquid flash evaporation unit 3 is connected to the clarified liquid preheating unit 1 through a flash steam pipeline.

[0066] The syngas fermentation clarified liquid first flows through the clarified liquid preheating unit 1, and then is heated and sterilized by the heater 21 and the sterilizer 22 of the clarified liquid heating and sterilizing unit 2 in sequence. Subsequently, it undergoes flash evaporation through the clarified liquid flash evaporation unit 3. The flash steam generated by flash evaporation is introduced into the clarified liquid preheating unit 1 through the flash steam pipeline to directly preheat the clarified liquid therein, and the sterilized clarified liquid after flash evaporation flows out.

[0067] Example 2

[0068] A sterilization system for syngas fermentation clarified liquid, comprising a clarified liquid preheating unit 1, a clarified liquid heating and sterilizing unit 2, a clarified liquid flash evaporation unit 3, a vacuum generating unit 4, a sterilized clarified liquid storage and output unit 5, and a clarified liquid feeding unit 6 connected in sequence.

[0069] Wherein: The clarified liquid preheating unit 1 includes a multi-stage preheating tower 11. Specifically, the clarified liquid preheating unit 1 in this embodiment includes a first-stage preheating tower 111 and a second-stage preheating tower 112 connected in series.

[0070] The clarified liquid heating and sterilizing unit 2 includes a heater 21 and a sterilizer 22.

[0071] The clarified liquid flash evaporation unit 3 includes a multi-stage flash evaporation tank 31. Specifically, the clarified liquid flash evaporation unit 3 in this embodiment includes a first-stage flash evaporation tank 311 and a second-stage flash evaporation tank 312 connected in series.

[0072] The vacuum generating unit 4 includes a vacuum pump 41 and a condenser 42.

[0073] The sterilized clarified liquid storage and output unit 5 includes a sterilized clarified liquid storage tank 51 and a sterilized clarified liquid discharge pump 52.

[0074] The clarified liquid feeding unit 6 includes a clarified liquid tank 61.

[0075] A method for sterilizing syngas fermentation clarified liquid:

[0076] When the system starts up, the syngas fermentation clarified liquid in the clarified liquid tank 61 flows through the first-stage preheating tower 111 and the second-stage preheating tower 112 of the clarified liquid preheating unit 1 in sequence and then flows to the clarified liquid heating and sterilizing unit 2 (at this time, the clarified liquid is not preheated). After being heated by the heater 21, it enters the sterilizer 22 for sterilization. The sterilized clarified liquid is flashed through the first-stage flash tank 311 and the second-stage flash tank 312 of the clarified liquid flashing unit 3 in sequence. The flash steam generated by the first-stage flash tank 311 is introduced into the second-stage preheating tower 112 to preheat the clarified liquid therein, and the flash steam generated by the second-stage flash tank 312 is introduced into the first-stage preheating tower 111 to preheat the clarified liquid therein. The flashed clarified liquid flows to the sterilized clarified liquid storage tank 51 as the sterilized clarified liquid.

[0077] When the system is operating normally, due to the action of the flash steam generated by the clarified liquid flashing unit 3, the syngas fermentation clarified liquid in the clarified liquid tank 61 will be preheated by the clarified liquid preheating unit 1 and then flows to the clarified liquid heating and sterilizing unit 2 for heating and sterilization.

[0078] Moreover, during the above process, the first-stage preheating tower 111 and the second-stage preheating tower 112 are in a vacuum state by the vacuum pump 41, and the flash steam extracted from the first-stage preheating tower 111 and the second-stage preheating tower 112 is cooled by the condenser 42. The sterilized clarified liquid in the sterilized clarified liquid storage tank 51 can be transported to the fermentation tank by the sterilized clarified liquid discharge pump 52.

[0079] Example 3

[0080] A syngas fermentation clarified liquid sterilization system:

[0081] The clarified liquid preheating unit 1 further includes a clarified liquid first feed port 12, a clarified liquid first overflow pipeline 13, a clarified liquid second discharge port 14, a clarified liquid second discharge pipe 15, and a clarified liquid second discharge pump 16.

[0082] The clarified liquid heating and sterilizing unit 2 further includes a clarified liquid second output pipeline 23.

[0083] The clarified liquid flashing unit 3 further includes a clarified liquid second feed port 32, a clarified liquid second overflow pipeline 33, a flash steam first pipeline 34, a flash steam second pipeline 35, a clarified liquid third discharge port 36, and a clarified liquid third discharge pipe 37.

[0084] The vacuum generating unit 4 further includes a flash steam third pipeline 43, a non-condensable gas input pipeline 44, and a non-condensable gas output pipeline 45.

[0085] The clarified liquid feeding unit 6 further includes a clarified liquid first discharge port 62, a clarified liquid first discharge pipe 63, a clarified liquid first discharge pump 64, and a clarified liquid first output pipeline 65.

[0086] Specifically, the syngas fermentation clarified liquid in the clarified liquid tank 61 is successively sent to the first clarified liquid feed port 12 provided on the first-stage preheating tower 111 through the first clarified liquid discharge port 62, the first clarified liquid discharge pipe 63, the first clarified liquid discharge pump 64, and the first clarified liquid output pipeline 65. After passing through the first-stage preheating tower 111, the clarified liquid gravitates and flows into the second-stage preheating tower 112 through the first clarified liquid overflow pipeline 13, and then is successively sent to the heater 21 for heating through the second clarified liquid discharge port 14, the second clarified liquid discharge pipe 15, and the second clarified liquid discharge pump 16. The heated clarified liquid enters the sterilizer 22 for sterilization, and the sterilized clarified liquid flows to the second clarified liquid feed port 32 provided on the first-stage flash tank 311 through the second clarified liquid output pipeline 23. The sterilized clarified liquid flashes in the first-stage flash tank 311, and the generated flash steam is sent to the second-stage preheating tower 112 through the second flash steam pipeline 35 to preheat the clarified liquid. The sterilized clarified liquid after flashing gravitates and flows into the second-stage flash tank 312 through the second clarified liquid overflow pipeline 33 for flashing, and the generated flash steam is sent to the first-stage preheating tower 111 through the first flash steam pipeline 34 to preheat the clarified liquid. The sterilized clarified liquid after flashing successively enters the sterilized clarified liquid storage tank 51 through the third clarified liquid discharge port 36 and the third clarified liquid discharge pipe 37. After being cooled in the sterilized clarified liquid storage tank 51, the sterilized clarified liquid can be transported to the fermentation tank through the sterilized clarified liquid discharge pump 52.

[0087] Moreover, in this embodiment, the tops of the first-stage preheating tower 111 and the second-stage preheating tower 112 are connected to the condenser 42 and the vacuum pump 41 through the third flash steam pipeline 43. The flash steam in the first-stage preheating tower 111 and the second-stage preheating tower 112 is extracted by the vacuum pump 41, and the flash steam is cooled by the condenser 42. Specifically, the vacuum pump 41 evacuates the non-condensable gas through the non-condensable gas input pipeline 44 and the non-condensable gas output pipeline 45, and controls the vacuum degrees of the first-stage preheating tower 111 and the second-stage preheating tower 112 through valves. The rest is the same as in Embodiment 2.

[0088] Embodiment 4

[0089] A syngas fermentation clarified liquid sterilization system, as Figures 1 to 7 shown, includes a clarified liquid feeding unit 6, a clarified liquid preheating unit 1, a clarified liquid heating and sterilizing unit 2, a clarified liquid flashing unit 3, a vacuum generating unit 4, and a sterilized clarified liquid storage and output unit 5.

[0090] The clarified liquid feeding unit 6 includes a clarified liquid tank 61 and a first clarified liquid discharge pump 64. The first clarified liquid discharge pump 64 is connected through the first clarified liquid discharge pipe 63 and the first clarified liquid discharge port 62; the first clarified liquid discharge pump 64 is also connected through the first clarified liquid output pipeline 65 and the first clarified liquid feed port 12 to transport the clarified liquid to the first-stage preheating tower 111.

[0091] The clarified liquid preheating unit 1 includes a primary preheating tower 111 and a secondary preheating tower 112. The interior of the preheating tower is a membrane tower structure, which is not easily blocked and has no dead ends. The clarified liquid preheating unit 1 also includes a second clarified liquid discharge pump 16. The second clarified liquid discharge pump 16 is connected through a second clarified liquid discharge pipe 15 and a second clarified liquid discharge port 14. The second clarified liquid discharge pump 16 transports the clarified liquid through a heater 21 and a sterilizer 22.

[0092] The clarified liquid heating and sterilizing unit 2 includes a heater 21 and a sterilizer 22. Among them, the clarified liquid is heated to a certain temperature in the heater 21, and the heated clarified liquid is maintained for a certain time in the sterilizer 22. The sterilizer 22 is connected to a second clarified liquid feed port 32 through a second clarified liquid output pipeline 23, and transports the heated clarified liquid to a primary flash tank 311.

[0093] The clarified liquid flash evaporation unit 3 includes a primary flash tank 311 and a secondary flash tank 312. There is no internal structure in the flash tank.

[0094] The vacuum generating unit 4 includes a condenser 42 and a vacuum pump 41. The condenser 42 is connected to the tops of the primary preheating tower 111 and the secondary preheating tower 112 through a third flash steam pipeline 43. The circulating cooling water cools the flash steam through the condenser 42, and the generated condensed water is discharged or returned to the clarified liquid tank 61; the vacuum pump 41 evacuates the non-condensable gas through a non-condensable gas input pipeline 44 and a non-condensable gas output pipeline 45, and controls the vacuum degree of the primary preheating tower 111 and the secondary preheating tower 112 through valves. An evacuation cut-off valve and an N2 make-up valve are provided on the non-condensable gas transmission pipeline, which can prevent outside air from flowing back into the system in case of failure of the vacuum pump 41 or sudden power failure.

[0095] The sterilized clarified liquid storage and output unit 5 includes a sterilized clarified liquid storage tank 51 and a sterilized clarified liquid discharge pump 52. Among them, the sterilized clarified liquid storage tank 51 is connected through a third clarified liquid discharge pipe 37 and a third clarified liquid discharge port 36; the sterilized clarified liquid storage tank 51 is designed with an external half-pipe, that is, a half-pipe channel is provided on the outer wall of the storage tank, and cooling water flows in it, which can take away the heat of the clarified liquid in the storage tank and maintain the storage tank at a certain temperature. The sterilized clarified liquid discharge pump 52 transports the sterilized and cooled clarified liquid to the fermentation tank.

[0096] When the system starts up, the unheated clarified liquid flows from the first-stage preheating tower 111 into the second-stage preheating tower 112 through the first overflow pipeline 13 of the clarified liquid, and then enters the first-stage flash tank 311 after being heated and sterilized by the heater 21 and the sterilizer 22 in sequence. The clarified liquid flows from the first-stage flash tank 311 into the second-stage flash tank 312 through the second overflow pipeline 33 of the clarified liquid. The flash steam generated by the second-stage flash tank 312 heats the first-stage preheating tower 111 through the first flash steam pipeline 34. The flash steam generated by the first-stage flash tank 311 heats the second-stage preheating tower 112 through the second flash steam pipeline 35, so that the clarified liquid subsequently introduced into the first-stage preheating tower 111 and the second-stage preheating tower 112 from the clarified liquid feeding unit 6 is directly preheated by the flash steam. The clarified liquid directly preheated by the flash steam enters the clarified liquid heating and sterilizing unit 2.

[0097] Example 5

[0098] A synthesis gas fermentation clarified liquid sterilization system, comprising:

[0099] A clarified liquid feeding unit 6, comprising a clarified liquid tank 61, a first clarified liquid discharge pump 64, a first clarified liquid discharge port 62, a first clarified liquid discharge pipe 63, and a first clarified liquid output pipeline 65.

[0100] A clarified liquid preheating unit 1, comprising a first-stage preheating tower 111, a second-stage preheating tower 112, a first overflow pipeline 13 of the clarified liquid, a first clarified liquid feed port 12, a second clarified liquid discharge port 14, a second clarified liquid discharge pipe 15, and a second clarified liquid discharge pump 16.

[0101] A clarified liquid heating and sterilizing unit 2, comprising a clarified liquid heater 21, a clarified liquid sterilizer 22, and a second clarified liquid output pipeline 23.

[0102] A clarified liquid flash evaporation unit 3, comprising a second clarified liquid feed port 32, a first-stage flash tank 311, a second-stage flash tank 312, a second overflow pipeline 33 of the clarified liquid, a first flash steam pipeline 34, a second flash steam pipeline 35, a third clarified liquid discharge port 36, and a third clarified liquid discharge pipe 37.

[0103] A vacuum generating unit 4, comprising a third flash steam pipeline 43, a condenser 42, a non-condensable gas input pipeline 44, a non-condensable gas output pipeline 45, and a vacuum pump 41.

[0104] A sterilized clarified liquid storage and output unit 5, comprising a sterilized clarified liquid storage tank 51 and a sterilized clarified liquid discharge pump 52.

[0105] When the flash evaporation process flow in this embodiment runs, the clarified liquid is sent to the first-stage preheating tower 111 by the first discharge pump 64 of the clarified liquid, and then flows into the second-stage preheating tower 112 by gravity. Then, the clarified liquid is heated to a certain temperature by direct steam heating and maintained for a certain period of time. The clarified liquid further heated and sterilized by the clarified liquid heater 21 and the clarified liquid sterilizer 22 is pumped to the first-stage flash evaporation tank 311 and flows into the second-stage flash evaporation tank 312 by gravity. The vacuum pump 41 runs, and the flash steam generated by the second-stage flash evaporation tank 312 heats the first-stage preheating tower 111, and the flash steam generated by the first-stage flash evaporation tank 311 heats the second-stage preheating tower 112. The unused waste heat after heat exchange is condensed by the condenser 42, and the generated condensed water is discharged as sewage or returned to the clarified liquid tank 61.

[0106] Preferably, in order to reduce the clarified liquid after flash evaporation to the required process temperature, triple-effect flash evaporation or quadruple-effect flash evaporation (or more effects) can be used.

[0107] Example 6

[0108] Use the double-effect flash evaporation sterilization system described in Example 5 to carry out the sterilization treatment of the syngas fermentation clarified liquid:

[0109] In this embodiment, the main component of the syngas fermentation clarified liquid is water, which contains a small amount of cell protein (volume ratio less than 1%). The flow rate of the fermentation clarified liquid is 100 - 600m 3 / h, and the temperature is 50 - 80 °C.

[0110] The syngas fermentation clarified liquid is heated to 60 - 90 °C through the first-stage preheating tower 111, heated to 80 - 110 °C through the second-stage preheating tower 112, and heated to 95 - 135 °C through the heater 21. The heated clarified liquid is maintained in the sterilizer 22 for 1 - 5 minutes. The clarified liquid enters the first-stage flash evaporation tank 311. The clarified liquid at 75 - 115 °C after the first-stage flash evaporation enters the second-stage flash evaporation tank 312, and the clarified liquid at 40 - 70 °C after the second-stage flash evaporation enters the sterilized clarified liquid storage tank 51. The temperature of the storage tank is maintained at 30 - 40 °C through the external half-pipe cooling of the storage tank. The vacuum pump 41 can generate a negative pressure of -10 kPa to -70 kPa after the condenser 42 to match the heat exchange of the flash evaporation and preheating systems.

[0111] This system can operate continuously (8000 h / year) without the need to stop for CIP cleaning in the middle. Only after the entire production device stops, the preheating tower and the flash evaporation tank can be subjected to CIP cleaning, and the cleaning frequency is 1 - 2 times / year. Comparing with the application of a conventional heat exchanger in the heating-cooling process of the fermentation clarified liquid, the operation of this system needs to be stopped every 1 - 2 weeks for CIP cleaning of the heat exchanger, resulting in the forced interruption of production. The utility model effectively solves the problem of the production interruption caused by the frequent CIP flushing of the heat exchanger, optimizes the production process and generates economic benefits.

[0112] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the utility model. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present utility model is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present utility model according to the disclosure of the present utility model should be within the protection scope of the present utility model.

Claims

1. A synthesis gas fermentation clarified liquid sterilization system, characterized in that: It comprises a clarified liquid preheating unit (1), a clarified liquid heating and sterilizing unit (2) and a clarified liquid flash evaporation unit (3); The clarified liquid preheating unit (1), the clarified liquid heating and sterilizing unit (2) and the clarified liquid flash evaporation unit (3) are arranged in sequence along the flow direction of the synthesis gas fermentation clarified liquid. The clarified liquid heating and sterilizing unit (2) comprises a heater (21) and a sterilizer (22) which are arranged in sequence. The clarified liquid flash evaporation unit (3) is connected to the clarified liquid preheating unit (1) via a flash steam pipeline.

2. The synthesis gas fermentation clarified liquid sterilization system according to claim 1, characterized in that: The clarified liquid preheating unit (1) comprises a single-stage or multi-stage preheating tower (11), and the clarified liquid flash unit (3) comprises a single-stage or multi-stage flash tank (31); The flash tank (31) is connected to the preheating tower (11) via a flash steam pipeline.

3. The synthesis gas fermentation clarified liquid sterilization system according to claim 2, characterized in that: The clarified liquid preheating unit (1) comprises a primary preheating tower (111) and a secondary preheating tower (112) connected in series, and the clarified liquid flash unit (3) comprises a primary flash tank (311) and a secondary flash tank (312) connected in series; The primary preheating tower (111), the secondary preheating tower (112), the heater (21), the sterilizer (22), the primary flash tank (311) and the secondary flash tank (312) are arranged in sequence along the flow direction of the synthesis gas fermentation clarified liquid; The primary flash tank (311) is connected to the secondary preheating tower (112) via a flash steam pipeline, and the secondary flash tank (312) is connected to the primary preheating tower (111) via a flash steam pipeline.

4. The synthesis gas fermentation clarified liquid sterilization system according to claim 2, characterized in that: The preheating tower (11) is a membrane tower, the flash tank (31) has no structure inside, the top of the flash tank (31) is connected to the bottom of the preheating tower (11) via a flash steam pipeline, and the bottom of the flash tank (31) is provided with an outlet for the clarified liquid after flashing to flow out.

5. The synthesis gas fermentation clarified liquid sterilization system according to claim 1, characterized in that: The system further comprises a vacuum generating unit (4), which is connected to the clarified liquid preheating unit (1).

6. The synthesis gas fermentation clarified liquid sterilization system according to claim 5, characterized in that: The vacuum generating unit (4) comprises a vacuum pump (41) and a condenser (42) arranged between the clarified liquid preheating unit (1) and the vacuum pump (41). The vacuum generating unit (4) further comprises a regulating valve for controlling the vacuum degree and an anti-backflow component for preventing external air from backflowing into the system when the vacuum pump (41) is not operating normally.

7. The synthesis gas fermentation clarified liquid sterilization system according to claim 1, characterized in that: The system further comprises a sterilized clarified liquid storage and output unit (5), the input end of the sterilized clarified liquid storage and output unit (5) being connected to the clarified liquid flash unit (3), and the output end being connected to the fermentation tank.

8. The synthesis gas fermentation clarified liquid sterilization system according to claim 7, characterized in that: The sterilized clarified liquid storage and output unit (5) comprises a sterilized clarified liquid storage tank (51) and a sterilized clarified liquid discharge pump (52); the input end of the sterilized clarified liquid storage tank (51) is connected to the clarified liquid flash unit (3); the output end is connected to the fermentation tank via the sterilized clarified liquid discharge pump (52); and a cooling pipe is provided on the sterilized clarified liquid storage tank (51).

9. The synthesis gas fermentation clarified liquid sterilization system according to claim 1, characterized in that: The input end of the clarified liquid preheating unit (1) is connected to a clarified liquid feeding unit (6); the clarified liquid feeding unit (6) and the clarified liquid preheating unit (1), the clarified liquid preheating unit (1) and the clarified liquid heating and sterilizing unit (2), and the clarified liquid heating and sterilizing unit (2) and the clarified liquid flash unit (3) are all connected via pipelines; and a delivery pump is provided on the pipeline between the clarified liquid feeding unit (6) and the clarified liquid preheating unit (1), and between the clarified liquid preheating unit (1) and the clarified liquid heating and sterilizing unit (2).

10. The synthesis gas fermentation clarified liquid sterilization system according to claim 1, characterized in that: The clarified liquid preheating unit (1) and the clarified liquid flash evaporation unit (3) are both connected to a CIP cleaning unit.

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