Device for measuring water removal effect of thionyl chloride

Abstract

The invention relates to a device for measuring the water removal effect of thionyl chloride, which is characterized by comprising a water removal reactor in which a product needing water removal and thionyl chloride are placed, and the water removal reactor is provided with an air inlet and an air outlet; blowing-in gas with constant flow is introduced into a gas inlet of the water removal reactor, and the blowing-in gas is one or more mixed gas of purified air or purified gas which does not react with products in the reactor; the gas outlet pipe is communicated with a gas outlet of the water removal reactor; the HCL gas concentration analyzer or the SO2 gas concentration analyzer is arranged on the gas outlet pipe, and the water removal effect in the water removal reactor is monitored on line according to the HCL gas concentration or the SO2 gas concentration measured by the HCL gas concentration analyzer or the SO2 gas concentration analyzer. Compared with the prior art, the method has the advantages that the dewatering effect in the dewatering reactor can be monitored on line, and compared with manual analysis and assay, the real-time performance is good, sampling analysis is not needed, and the labor intensity is low.

Description

Technical Field

[0001] The invention relates to a device for measuring the water removal effect of thionyl chloride. Background Art

[0002] In recent years, the lithium battery industry has developed rapidly. The moisture content is a key quality indicator of the electrolyte in lithium batteries, and the requirements are very strict. At present, in the production of chemical products that have strict requirements on the water content of the product and it is difficult to remove the water by distillation, chemical dehydration is usually used to remove the water. Chemical dehydration is currently a widely used and unavoidable production process. The existing chemical dehydration device cannot directly monitor the dehydration effect because there is no instrument and means for online detection of the residual moisture of the product. It is difficult to judge whether the dehydration rate has reached the required level. It can only be judged by sampling and then analyzing in the laboratory to determine whether the dehydration has reached the requirements and whether the next operation can be carried out. It is time-consuming, laborious, and has poor real-time performance. Excessive residual moisture will have serious consequences for the formation of the product. Therefore, in the actual production process, manufacturers dare not rashly shorten the dehydration time. They would rather waste some time to ensure that the product is qualified to ensure that the residual moisture concentration in the product is as low as required, which will seriously affect the production efficiency of the product.

[0003] Sulfonyl chloride (dichlorothionyl) reacts with water to generate SO2 and HCL gas, so thionyl chloride is often used as a chemical dehydrating agent. The chemical reaction equation of thionyl chloride and water: SOCl2+H2O=SO2+2HCl. Sulfonyl chloride can not only remove free water but also remove crystal water that is difficult to remove by ordinary methods. The dehydration effect of thionyl chloride is good, and the residual moisture is very low, which can reach the residual moisture content within tens of ppm. Therefore, the use of thionyl chloride for dehydration is widely used when there are strict requirements on the moisture content in the product. However, in the prior art, there is still no effective method to remove thionyl chloride. Measuring the water removal effect of thionyl chloride When thionyl chloride is used to remove water, the removal time is often very long, even reaching more than 20 hours, so the existing technology needs to be further improved. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a device capable of online real-time measurement of the water removal effect of thionyl chloride in view of the above-mentioned prior art.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a device for measuring the water removal effect of thionyl chloride, characterized in that it comprises:

[0006] A dehydration reactor, in which the product to be dehydrated and thionyl chloride are placed, and the dehydration reactor is provided with an air inlet and an air outlet;

[0007] A constant flow of blowing gas is introduced into the air inlet of the dehydration reactor, and the blowing gas is purified air or one or more mixed gases of purified gas that does not react with the product in the reactor;

[0008] an air outlet pipe connected to the air outlet of the water removal reactor;

[0009] The HCL gas concentration analyzer or SO2 gas concentration analyzer arranged on the gas outlet pipe can monitor the water removal effect in the water removal reactor online by measuring the HCL gas concentration or SO2 gas concentration.

[0010] Preferably, the blowing gas is one kind of inert gas or any mixture of inert gases.

[0011] As an improvement, the present invention further comprises an air inlet pipe connected to the air inlet of the dehydration reactor and used for conveying the blowing gas into the dehydration reactor.

[0012] As a further improvement, a pressure control element or a flow control element is provided on the air intake pipe.

[0013] Preferably, the pressure control element adopts a control loop consisting of a self-operated pressure regulating valve or a pressure transmitter and a regulating valve; the flow control element adopts a flow control loop consisting of a rotor flowmeter with flow regulation or a flow limiting orifice plate or a flowmeter and a flow regulating valve.

[0014] Preferably, the HCL gas concentration analyzer or SO2 gas concentration analyzer is an online laser gas analyzer or a gas chromatograph.

[0015] Further improved, the present invention also includes a calculation unit for measuring the water concentration in the dehydration reactor, and the calculation unit calculates the water concentration C in the product to be dehydrated in the dehydration reactor according to the following formula:

[0016] C=ay+by 3 +cy 5 +d;

[0017] Where y is the HCL gas concentration value or SO2 gas concentration value output by the HCL gas concentration analyzer or SO2 gas concentration analyzer;

[0018] a, b, c, d are preset constants.

[0019] As a further improvement, a stirrer is also connected to the dewatering reactor.

[0020] Compared with the prior art, the advantages of the present invention are: by arranging an HCL gas concentration analyzer or a SO2 gas concentration analyzer on the gas outlet pipe, the HCL gas concentration or SO2 gas concentration measured by the HCL gas concentration analyzer or the SO2 gas concentration analyzer can be used to monitor the water removal effect in the water removal reactor online. Compared with manual analysis and testing, the present invention has good real-time performance, does not require sampling and analysis, and has low labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The schematic diagram of the device structure for measuring the water removal effect of thionyl chloride in the embodiment of the present invention.

[0022] Figure 2 1 is a graph showing the relationship between the concentration of reactants and time in a water removal reactor when no reactants are added and other external conditions remain unchanged in an embodiment of the present invention.

[0023] Figure 3 1 is a graph showing the relationship between the reaction rate and time of the reactants in the water removal reactor when the reactants are not supplemented and other external conditions remain unchanged in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings.

[0025] Embodiment 1

[0026] like Figure 1 The device for measuring the water removal effect of thionyl chloride shown in the figure comprises:

[0027] A dehydration reactor 1, in which the product to be dehydrated and thionyl chloride are placed, and an air inlet and an air outlet are provided on the dehydration reactor;

[0028] An air inlet pipe 2 connected to the air inlet of the dehydration reactor for conveying the blowing gas into the dehydration reactor, the air inlet of the dehydration reactor is fed with a constant flow of blowing gas through the air inlet pipe, and the blowing gas is purified air or one or more mixed gases of purified gas that does not react with the product in the reactor; in this embodiment, the blowing gas is nitrogen, of course, the blowing gas can also be other inert gases except nitrogen, and can also be a mixed gas of multiple inert gases;

[0029] A flow control element 4 is arranged on the air inlet pipe, and the flow control element adopts a flow control loop consisting of a rotor flow meter with flow regulation or a flow limiting orifice plate or a flow meter and a flow regulating valve; the flow control element 4 can also be replaced by a pressure control element, which is used to control the flow of the gas blown into the dehydration reactor to ensure that the flow of the gas blown into the dehydration reactor is constant during the entire reaction process, and the pressure control element can adopt a control loop consisting of a self-acting pressure regulating valve, a pressure transmitter and a regulating valve;

[0030] An air outlet pipe 3 connected to the air outlet of the water removal reactor;

[0031] The HCL gas concentration analyzer 5 provided on the gas outlet pipe is used to monitor the dehydration effect in the dehydration reactor online by measuring the HCL gas concentration by the HCL gas concentration analyzer; the HCL gas concentration analyzer 5 is preferably an online laser gas analyzer; the HCL gas concentration analyzer 5 can be replaced by a SO2 gas concentration analyzer or a gas chromatograph;

[0032] A stirrer 6 is also connected to the dewatering reactor.

[0033] During the whole dehydration process, thionyl chloride and the product to be dehydrated are stirred by a stirrer 6 in the dehydration reactor 1. The thionyl chloride contacts water molecules and undergoes a hydrolysis reaction to generate HCL and SO2 gas. A constant flow of nitrogen is always blown into the dehydration reactor 1. Nitrogen, HCL and SO2 form a mixed gas and enter the downstream alkali solution absorption device through the outlet pipe 3. Due to the presence of nitrogen, the water in the downstream alkali solution absorption device cannot enter the dehydration reactor R1. For the relationship between the concentration of reactants and time in the dehydration reactor without adding reactants and other external conditions remaining unchanged, see Figure 2 For a graph showing the relationship between the reaction rate of a reactant and time, see Figure 3 As shown. It can be seen that under stable external conditions, the concentration of reactants and the generation rate of reaction products are positively correlated. The reaction of thionyl chloride and water in the dehydration reactor is an intermittent reaction. During the entire dehydration process, no reactant water is added. The external conditions of the reaction, such as reaction temperature and reaction pressure, remain unchanged. The gas part of the reaction product is continuously taken away by nitrogen. Since the amount of nitrogen blown in is stable, the concentration of the reaction products (HCL and SO2) in the mixed gas can reflect the dehydration effect in the dehydration reactor.

[0034] This embodiment uses a constant amount of inert gas to mix with the reaction product gas, and obtains the residual moisture content in the reactor by measuring the content of the reaction product gas in the mixed gas, so that the water removal effect in the water removal reactor can be monitored online. Compared with manual analysis and testing, it has good real-time performance, does not require sampling and analysis, and has low labor intensity.

[0035] Embodiment 2

[0036] Different from the first embodiment, it further includes a calculation unit for measuring the water concentration in the dehydration reactor. The measurement result of the HCL gas concentration analyzer 4 is input into the calculation unit. The calculation unit calculates the water concentration C in the product to be dehydrated in the dehydration reactor according to the following formula:

[0037] C=ay+by3 +cy 5 +d;

[0038] Where y is the HCL gas concentration value output by the HCL gas concentration analyzer; a, b, c, d are preset constants.

[0039] Of course, a display unit connected to the calculation unit may also be included to display the water concentration C in the product to be dehydrated in the dehydration reactor in real time.

Claims

1. A device for measuring the water removal effect of thionyl chloride, characterized in that include: A dehydration reactor, in which the product to be dehydrated and thionyl chloride are placed, and the dehydration reactor is provided with an air inlet and an air outlet; A constant flow of blowing gas is introduced into the air inlet of the dehydration reactor, and the blowing gas is purified air or one or more mixed gases of purified gas that does not react with the product in the reactor; an air outlet pipe connected to the air outlet of the water removal reactor; The HCL gas concentration analyzer or SO2 gas concentration analyzer arranged on the gas outlet pipe can monitor the water removal effect in the water removal reactor online by measuring the HCL gas concentration or SO2 gas concentration.

2. The device for measuring the water removal effect of thionyl chloride according to claim 1, wherein: The blowing gas is one kind of inert gas or any mixed gas of inert gases.

3. The device for measuring the water removal effect of thionyl chloride according to claim 1, wherein: It also includes an air inlet pipe which is communicated with the air inlet of the dehydration reactor and is used for conveying the blowing gas into the dehydration reactor.

4. The device for measuring the water removal effect of thionyl chloride according to claim 3, is characterized in that: The air inlet pipe is provided with a pressure control element or a flow control element.

5. The device for measuring the water removal effect of thionyl chloride according to claim 4, is characterized in that: The pressure control element adopts a control loop composed of a self-operated pressure regulating valve, a pressure transmitter and a regulating valve; the flow control element adopts a flow control loop composed of a rotor flowmeter with flow regulation, a flow limiting orifice plate, or a flowmeter and a flow regulating valve.

6. The device for measuring the water removal effect of thionyl chloride according to claim 1, characterized in that: The HCL gas concentration analyzer or SO2 gas concentration analyzer is an online laser gas analyzer or a gas chromatograph.

7. The device for measuring the water removal effect of thionyl chloride according to claim 1, characterized in that: It also includes a calculation unit for measuring the water concentration in the dehydration reactor, wherein the calculation unit calculates the water concentration C in the product to be dehydrated in the dehydration reactor according to the following formula: C=ay+by 3 +cy 5 +d; Where y is the HCL gas concentration value or SO2 gas concentration value output by the HCL gas concentration analyzer or SO2 gas concentration analyzer; a, b, c, d are preset constants.

8. The device for measuring the water removal effect of thionyl chloride according to claim 1, characterized in that: The dewatering reactor is also connected with a stirrer.

Images