Process and device for producing anode material coke from by-product heavy phase and co-producing anode material modifier

Abstract

A process and device for producing anode material coke as a by-product and co-producing an anode material modifier. The heavy phase by-produced by the needle coke pretreatment unit is mixed with a mixed solvent. The evenly mixed heavy phase oil enters a centrifuge for centrifugal treatment. After the clean oil product is distilled, pitch can be obtained, which can be subjected to coking treatment to prepare anode material or enter a reprocessor to prepare an anode material modifier; the heavy slag is sold externally for use in coal blending and coking; the mixed solvent distilled out by the distillation tower is pumped into a mixed solvent tank for recycling; the light phase obtained by the treatment of the reprocessor is sold externally. The anode material coke prepared by the process of the present invention has the characteristics of adjustable structure, high rate performance, high specific capacity, and low cost. At the same time, the produced modifier can be used as an anode material coating agent and granulating agent, because of its higher aromaticity and better adhesion. Moreover, the process method of the present invention is simple, feasible and continuous in production, and is an excellent raw material and modifier for rate-type and capacity-type battery devices.

Description

Technical Field

[0001] The present invention belongs to the field of anode materials, and particularly relates to a production process and device for preparing anode material coke and anode material modifier by using by-product heavy phase for co-production of anode materials. Background Art

[0002] With the increasing depletion of fossil fuels and the gradual deterioration of the environment, there is an urgent need for environmentally friendly renewable energy to replace the traditional fossil energy that is currently being used on a large scale. As a green new energy battery, the secondary ion battery has been widely used in the fields of consumer electronics, power tools, medical electronics, rail transit, aerospace, ships, industrial energy conservation, green buildings, hybrid electric vehicles, space technology, etc. due to its high energy density, environmental friendliness, high safety, long cycle life, no memory effect, small size, light weight, high specific capacity, diverse structures, low price, and no heavy metal harmful substances such as tin, lead, and mercury. It has become a new generation of sustainable green energy.

[0003] Artificial graphite mainly has a graphite microcrystalline structure after high-temperature graphitization treatment of coke materials such as needle coke and petroleum coke, endowing it with good ion diffusion performance, large lithium storage capacity, excellent rate performance and cycle performance, making it a high-quality anode material for lithium-ion batteries and also considered to be the most potential anode material for lithium-ion batteries in the future. It is estimated that the production capacity will reach 2.05 million tons in 2020. Due to the rapid expansion of the needle coke production capacity, its price has dropped from 20,000 yuan / ton to 8,000 yuan / ton, and the net profit has decreased by 50-60% year-on-year. At the same time, the by-product heavy-phase pitch of needle coke has characteristics such as high quinoline insoluble matter and high ash content. Due to its poor quality, the heavy-phase pitch can only be blended with a small amount for producing binders or fuel oils, and its market recognition is not high. The serious backlog has seriously affected the normal production of the needle coke pretreatment unit and reduced the economic benefits of the enterprise. There is an urgent need to take effective measures to ensure the smooth production of needle coke.

[0004] In view of this, the present invention intends to use by-product heavy phase as a raw material and modify it by a special treatment process to prepare coke for lithium-ion battery anode materials and anode material modifiers. Summary of the Invention

[0005] The present invention provides a production method and device for producing a negative electrode material modifier by using by-product heavy phase to co-produce negative electrode material coke. The by-product heavy phase from the needle coke pretreatment unit enters the centrifugal system after mixing and modulation. After centrifugation and distillation, purified heavy phase asphalt is obtained. The purified heavy phase asphalt can directly enter the coking tower to produce negative electrode material coke or directly undergo reprocessing to obtain a negative electrode material modifier. The negative electrode material coke prepared by the process of the present invention has the characteristics of adjustable structure, high rate performance, high specific capacity, and low cost. At the same time, the produced modifier can be used as a coating agent and granulating agent for negative electrode materials because of its higher aromaticity and better adhesion. Moreover, the process method of the present invention is simple, feasible and can be continuously produced, and it is an excellent raw material and modifier for rate-type and capacity-type battery devices.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A process for producing negative electrode material coke by using by-product heavy phase to co-produce negative electrode material modifier, the specific process steps include:

[0008] 1) Mixing and modulation: The by-product heavy phase is pumped into a heavy phase storage tank, and then jointly pumped into an intermediate tank with a mixed solvent for mixing and preparation. After being uniformly mixed in the intermediate tank, heavy phase oil is obtained for use.

[0009] 2) Centrifugation: The heavy phase oil is pumped into a centrifuge for centrifugation to obtain purified heavy phase oil and heavy slag. The purified heavy phase oil is pumped into a distillation tower.

[0010] 3) Fractionation: The purified heavy phase oil entering the distillation tower is subjected to vacuum distillation to obtain purified heavy phase asphalt and a mixed solvent. The purified heavy phase asphalt is pumped into an asphalt storage tank for standby, and the mixed solvent is pumped into a mixed solvent storage tank for the preparation of the mixed solvent in step 1).

[0011] 4) Coking treatment or reprocessing of the purified heavy phase asphalt obtained in step 3):

[0012] Coking treatment: The purified heavy phase asphalt in the asphalt storage tank is pumped into a coking tower for coking treatment to obtain negative electrode material coke.

[0013] Reprocessing: The purified heavy phase asphalt in the asphalt storage tank is pumped into a reprocessor to obtain a negative electrode material modifier, and the light phase oil enters the storage tank.

[0014] It is characterized in that the by-product heavy phase is a mixture of by-product heavy phase asphalt from the needle coke pretreatment unit and a mixed solvent, and the weight ratio of the by-product heavy phase to the mixed solvent after dilution in the above step 1) is 1:0.2 - 2.

[0015] It is characterized in that the mixing temperature of the intermediate tank in the above step 1) is 70 - 150 °C.

[0016] It is characterized in that the mixed solvent is a mixture of kerosene and wash oil.

[0017] It is characterized in that in the above step 2), the centrifugation temperature is 70 to 200 °C, and the rotating speed of the centrifuge drum is 1000 to 5000 rpm.

[0018] It is characterized in that the softening point of the heavy-phase purified asphalt obtained in the above step 3) is 25 to 80 °C, the quinoline insoluble content is 0 to 5 wt%, the ash content is 0 to 0.5 wt%, and the coking value > 40%.

[0019] The indexes of the anode material modifier obtained by reprocessing in the above step 4) are that the softening point is 25 to 300 °C, the quinoline insoluble content is 0 to 5 wt%, the ash content is 0 to 0.5 wt%, and the coking value > 40%.

[0020] The anode material modifier obtained by reprocessing in the above step 4) can be used as an anode material coating agent or an anode material granulating agent.

[0021] The device used in the process of co-producing anode material coke and anode material modifier from by-product heavy phase includes a heavy-phase storage tank, a mixed solvent storage tank, an intermediate tank, a centrifuge, a heavy slag tank, a distillation column, a heavy-phase purified asphalt tank, a coking tower, and a reprocessor; the heavy-phase storage tank and the mixed solvent tank are connected to the intermediate tank, the intermediate tank is connected to the centrifuge, the discharge port of the centrifuge is connected to the distillation column, the centrifuge slag discharge port is connected to the heavy slag tank, the heavy-phase outlet of the distillation column is connected to the heavy-phase purified asphalt tank, the light-phase discharge port of the distillation column is connected to the mixed solvent storage tank, and the heavy-phase purified asphalt tank is connected to the coking tower and / or the reprocessor.

[0022] Compared with the existing technology, the beneficial effects of the present invention are:

[0023] 1) The anode material prepared from anode material coke has high safety performance, high energy density, good cycle performance, good high and low temperature performance, good fast charging performance, good rate performance, and outstanding anti-attenuation ability. It is an excellent raw material for lithium battery anode materials with considerable economic benefits;

[0024] 2) The parameters of the anode material modifier prepared by the present invention are controllable, and the anode material modified with it has good fast charging performance, excellent high and low temperature performance, and good cycle performance.

[0025] 3) The raw material pretreatment unit of the present invention provides a new and short-process anode material raw material purification production process, simplifies the control factors, and is easy to operate in industrial production.

[0026] 4) The coking tower adopted by the present invention is a continuous production device, realizing continuous production and ensuring the maximization of production capacity;

[0027] 5) The mixed solvent fractionated by the distillation column adopted by the present invention can be recycled, and the light-phase oil distilled by the reprocessor can be sold;

[0028] 6) The heavy-phase purified asphalt from the distillation column of the present invention can be pumped into the pre-treatment refined asphalt storage tank and mixed to produce needle coke. Not only is the performance of the needle coke excellent, but its output is also increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is the process flow chart of the present invention.

[0030] In the figure: 1. Heavy-phase storage tank, 2. Mixed solvent storage tank, 3. Intermediate tank, 4. Centrifugal device, 5. Heavy slag material tank, 6. Distillation column, 7. Heavy-phase purified asphalt tank, 8. Reprocessor, 9. Light-phase storage tank, 10. Modifier storage tank, 11. Coking tower, 12. Green coke pond. DETAILED DESCRIPTION OF THE INVENTION

[0031] The following further illustrates the embodiments of the present invention in conjunction with specific embodiments:

[0032] The production process of using by-product heavy phase to produce anode material coke and co-producing anode material modifier specifically includes the following process steps:

[0033] 1) Mixing and modulation: The by-product heavy phase is pumped into the heavy-phase storage tank by a pump, and then jointly pumped into the intermediate tank with the mixed solvent for mixing and blending. After being evenly mixed in the intermediate tank, heavy-phase oil is obtained for use.

[0034] 2) Centrifugation: The heavy-phase oil is pumped into a centrifuge for centrifugation to obtain heavy-phase purified oil and heavy slag material. The heavy-phase purified oil is pumped into the distillation column, and the heavy slag material is sold externally.

[0035] 3) Fractionation: The heavy-phase purified oil entering the distillation column is subjected to vacuum distillation to obtain heavy-phase purified asphalt and mixed solvent. The heavy-phase purified asphalt is pumped into the asphalt storage tank for standby, and the mixed solvent is pumped into the mixed solvent storage tank for the preparation of the mixed solvent in step 1).

[0036] 4) Coking treatment or treatment by a reprocessor is carried out on the heavy-phase purified asphalt obtained in step 3):

[0037] Coking treatment: The heavy-phase purified asphalt in the asphalt storage tank is pumped into the coking tower for coking treatment to obtain anode material coke.

[0038] Reprocessing: The heavy-phase purified asphalt in the asphalt storage tank is pumped into the reprocessor to obtain an anode material modifier with suitable physical and chemical indexes. The light-phase oil enters the storage tank and is sold externally.

[0039] The by-product heavy phase is a mixture of by-product heavy-phase asphalt from the needle coke pre-treatment unit and the mixed solvent. The weight ratio of the by-product heavy phase to the mixed solvent after dilution in step 1) is 1:0.2 - 2.

[0040] It is characterized in that the mixing temperature of the intermediate tank in step 1) is 70 - 150 °C.

[0041] It is characterized in that the mixed solvent is a mixture of kerosene and wash oil.

[0042] It is characterized in that in the above step 2), the centrifugation temperature is 70 - 200 °C, and the rotational speed of the centrifuge drum is 1000 - 5000 rpm.

[0043] It is characterized in that the softening point of the heavy-phase purified pitch obtained in the above step 3) is 25 - 80 °C, the content of quinoline insoluble matter (QI) is 0 - 5 wt%, the ash content is 0 - 0.5 wt%, and the coking value > 40%.

[0044] The indexes of the negative electrode material modifier obtained by reprocessing in the above step 4) are that the softening point is 25 - 300 °C, the content of quinoline insoluble matter (QI) is 0 - 5 wt%, the ash content is 0 - 0.5 wt%, and the coking value > 40%.

[0045] The negative electrode material modifier obtained by reprocessing in the above step 4) can be used as a negative electrode material coating agent or a negative electrode material granulating agent.

[0046] See Figure 1 , the device used in the production process of producing negative electrode material coke by by-product heavy phase and co-producing negative electrode material modifier includes a heavy-phase storage tank, a mixed solvent storage tank, an intermediate tank, a centrifuge, a heavy slag tank, a distillation column, a heavy-phase purified pitch tank, a coking tower, and a reprocessor; the heavy-phase storage tank and the mixed solvent tank are connected to the intermediate tank, the intermediate tank is connected to the centrifuge, the discharge port of the centrifuge is connected to the distillation column, the centrifuge slag discharge port is connected to the heavy slag tank, the heavy-phase outlet of the distillation column is connected to the heavy-phase purified pitch tank, the light-phase discharge port of the distillation column is connected to the mixed solvent storage tank, and the heavy-phase purified pitch tank is connected to the coking tower and / or the reprocessor.

[0047] There are two coking towers.

[0048] The reprocessing process equipment is a short-path distiller.

[0049] The negative electrode material coke prepared by the process of the present invention has the characteristics of adjustable structure, high rate performance, high specific capacity, and low cost. At the same time, the produced modifier can be used as a coating agent and granulating agent for the negative electrode material. Due to its higher aromaticity and better adhesion, a high-performance negative electrode material with a core-shell or "cluster-type" structure can be prepared to meet the high-capacity characteristics, high rate performance, excellent high and low temperature performance, and good orientation of artificial graphite negative electrode materials, etc., to meet the actual needs of the negative electrode material market. At the same time, the production process of the present invention can be directly applied to the industrial production of needle coke. Therefore, the heavy-phase purified pitch from the distillation tower can be pumped into the pretreatment refined pitch storage tank and mixed to produce needle coke. Not only is the performance of the needle coke excellent, but its output is also increased. The present invention not only improves the added value of the heavy phase by-produced from needle coke, broadens its application fields, but also improves the overall technical level of the industry. At the same time, it meets the demand for the development of high-performance lithium-ion negative electrode materials, promotes the development of the new energy industry, and has great practical significance.

[0050] Examples:

[0051] Using the production process and device of the present invention for producing negative electrode material coke from by-produced heavy phase and co-producing a modifier for negative electrode materials, the main indicators of 3 batches of heavy-phase purified pitch were recorded, as shown in Table 1;

[0052] Table 1 Main indicators of each batch of heavy-phase purified pitch

[0053]

[0054] The indicators of the negative electrode materials in each batch in the examples are shown in Table 2

[0055] Table 2 Main indicators of negative electrode materials

[0056] Batch <![CDATA[D 50 (μm)]]> d002 (nm) Charge specific capacity (mAh / g) Efficiency (%) 1 14.50 0.3361 364.8 95.49 2 16.20 0.3365 365.0 96.22 3 17.85 0.3359 362.8 96.58

[0057] The indicators of the modifiers for negative electrode materials in each batch in the examples are shown in Table 3

[0058] Table 3 Main indicators of modifiers for negative electrode materials

[0059] Batch Modifier name Softening point (°C) QI (wt%) Ash content (wt%) 1 Coating agent 185 0.08 0.05 2 Coating agent 255 0.13 0.12 3 Granulating agent 120 0.58 0.17

[0060] The above examples are implemented on the premise of the technical solution of the present invention. They are only preferred embodiments of the present invention, and not limitations on other forms of the present invention. Any person skilled in the art, without departing from the content of the technical solution of the present invention, any simple modification, equivalent transformation, and modification made according to the technical essence and concept of the present invention still fall within the protection scope of the present invention.

Claims

1. Process for producing a negative electrode material modifier by co-producing a negative electrode material from a by-product heavy phase, characterized in that, The specific process steps include: 1) Mixing and modulation: The by-product heavy phase is pumped into the heavy-phase storage tank, and then jointly pumped into the intermediate tank with the mixed solvent for mixing and blending. After being evenly mixed in the intermediate tank, the heavy-phase oil is obtained for standby; 2) Centrifugation: The heavy-phase oil is pumped into a centrifuge for centrifugation to obtain purified heavy-phase oil and heavy slag. The purified heavy-phase oil is pumped into the distillation column; 3) Fractionation: The purified heavy-phase oil entering the distillation column is subjected to vacuum distillation to obtain purified heavy-phase asphalt and the mixed solvent. The purified heavy-phase asphalt is pumped into the asphalt storage tank for standby, and the mixed solvent is pumped into the mixed-solvent storage tank for the preparation of the mixed solvent in step 1); 4) The purified heavy-phase asphalt obtained in step 3) is processed through a reprocessor: Reprocessing: The purified heavy-phase asphalt in the asphalt storage tank is pumped into the reprocessor to obtain a negative electrode material modifier, and the light-phase oil enters the storage tank; The reprocessing process equipment is a short-path distiller; The by-product heavy phase is the by-product heavy-phase asphalt from the needle coke pretreatment unit. The weight ratio of the by-product heavy phase to the mixed solvent after dilution in step 1) is 1:2; The mixing temperature in the intermediate tank in step 1) is 70~150°C; The centrifugation temperature in step 2) is 70~200°C, and the rotational speed of the centrifuge drum is 1000~5000 rpm; The softening point of the purified heavy-phase asphalt obtained in step 3) is 25~80°C, the quinoline insoluble content is 0.02~0.1 wt%, the ash content is 0.03~0.04 wt%, and the coking value > 40%; The indexes of the negative electrode material modifier obtained by reprocessing in step 4) are: the softening point is 25~300°C, the quinoline insoluble content is 0~0.58 wt%, the ash content is 0~0.17 wt%, the coking value > 40%, and the negative electrode material modifier is used as a negative electrode material coating agent or granulating agent.

2. The process for co-producing a negative electrode material modifier from a by-product heavy phase to produce a negative electrode material coke according to claim 1, characterized in that, The mixed solvent is a mixture of kerosene and wash oil.

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