Method for preparing BDO, light fuel oil and coke by using BDO residual liquid

Abstract

The invention discloses a method for preparing BDO, light fuel oil and coke by using BDO raffinate, which comprises the following steps: adjusting components of the BDO raffinate through a tempering and impurity removal unit, and filtering to remove insoluble impurity components in the BDO raffinate; then the wastewater enters a neutralization extraction reactor to react with a salt capturing agent aqueous solution to neutralize alkali and sodium formate in the wastewater, sodium ions of organic sodium salt are transferred to a water phase, the water phase is separated, the generated sodium salt is recycled through filtration, the recycled sodium salt is pyrolyzed and processed into refined sodium carbonate, and after the water phase is desalted, the salt capturing agent is supplemented to return to the neutralization extraction reactor for recycling; sequentially carrying out reactive distillation and vacuum distillation on the separated oil phase to separate out a light-component solvent oil product, a refined BDO product and a high-boiling tar component; and carrying out pyrolysis condensation reaction on the separated high-boiling tar component to obtain light fuel oil and coke. The BDO waste liquid treatment process provided by the invention does not discharge waste water and solid waste, is extremely low in waste gas discharge amount, and is an environment-friendly and efficient technology for BDO waste liquid treatment.

Description

Technical Field

[0001] The invention relates to the field of environmental protection and resource utilization of organic hazardous wastes, and in particular to a method for preparing BDO, light fuel oil and coke by utilizing BDO residual liquid. Background Art

[0002] BDO residue is an organic hazardous waste generated during the production of BDO (1,4-butanediol). Its main components are high-boiling tar, salt and BDO, of which the content of high-boiling tar and salt is 40%-60%, and the content of BDO is about 50%.

[0003] At present, the main method for industrial treatment of BDO residual liquid is to recover a part of BDO through thin film evaporation and then incinerate it in an incinerator. The current treatment technology has problems such as low BDO recovery rate, low utilization level of other organic matter, scaling and corrosion of sodium salt in the incinerator, low purity and low utilization value of sodium carbonate byproducts produced by incineration, and large discharge of three wastes. There is an urgent need for high-value treatment technology with high chemical recovery rate and good product purity.

[0004] The sodium salt in the BDO residual liquid is a key factor restricting the high-value utilization of the BDO residual liquid. CN108774110A discloses a continuous recycling process for desalting and evaporating the waste liquid of a BDO production device by the Rapoport process, which uses sulfuric acid to convert the organic sodium salt in the BDO residual liquid into sodium sulfate, and then separates and utilizes the organic components. However, this process uses sulfuric acid, which is a strong acid, which causes serious equipment corrosion problems, and the by-product sodium sulfate has low value. Summary of the invention

[0005] In view of the problems existing in the resource recovery technology of BDO residual liquid treatment, the object of the present invention is to provide a method for preparing BDO, light fuel oil and coke by using BDO residual liquid. In this method, the sodium salt component in the BDO residual liquid is converted into sodium carbonate, and formic acid is converted into formate ester, so that more than 95% of BDO is recovered, and the high-boiling tar component is converted into light fuel oil and coke, thereby achieving high-value recycling of all components of the BDO residual liquid.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] The present invention provides a method for preparing BDO, light fuel oil and coke by using BDO residual liquid, comprising the following steps:

[0008] 1. Conditioning and impurity removal

[0009] The BDO residue enters the conditioning and impurity removal unit, where a conditioning solvent is added, and the conditioning solvent and water sent from the subsequent light component recovery step are combined, and the conditioned BDO residue is heated to 110°C to 180°C. The conditioning solvent is n-butanol or an alcohol similar to n-butanol, and the molar ratio of the added conditioning solvent to the sodium formate in the raw material is controlled to be 1.2 to 1.6, and the water content of the conditioning and impurity removal unit material is controlled to be about 25%);

[0010] A ceramic membrane with a screening accuracy of 0.08 to 0.5 μm, preferably a silicon carbide ceramic membrane, is used to filter and remove impurities from the BDO residual liquid after conditioning, and the BDO residual liquid after conditioning and impurity removal enters the downstream desalination and salt recovery steps;

[0011] 2. Desalination and salt recovery

[0012] The BDO residual liquid after conditioning and impurity removal in step 1 enters the neutralization extraction reactor, and undergoes a neutralization reaction with the prepared salt trapping agent to replace the sodium ions contained in organic sodium salts such as sodium formate and sodium methoxide in the BDO residual liquid with the organic phase.

[0013] The salt trapping agent is an aqueous solution of oxalic acid, and the water in the neutralization extraction reactor is controlled to account for 25% to 30% of the mass fraction of the material, and the molar ratio of oxalic acid to sodium ion is 1.2:2 to 1.5:2;

[0014] In the neutralization extraction reactor, the organic sodium salts such as sodium formate and sodium methoxide in the BDO residual liquid react with the oxalic acid in the water phase to be converted into sodium oxalate, and the water phase and the oil phase are obtained by liquid separation. The separated water phase is cooled to 40-60° C. and enters the crystallizer for crystallization, and then filtered and recovered by a centrifuge. The water phase without sodium oxalate crystals is heated to 90-120° C., supplemented with a salt trap, and then returned to the neutralization extraction reactor for recycling;

[0015] The by-product sodium oxalate salt is further processed into soda ash by high-temperature pyrolysis: the sodium oxalate salt recovered from the crystallizer is sent to a rotary calcination device for high-temperature pyrolysis to generate refined sodium carbonate. The rotary calcination device is preferably an electromagnetic heating rotary kiln. The high-temperature pyrolysis operation temperature of the sodium oxalate salt is 500°C to 800°C, and the operating pressure is -5KPa to 1KPa. The tail gas generated by the pyrolysis is sent to the downstream tar heating furnace for incineration. The refined sodium carbonate is used as a raw material for the BDO device or sold as a product;

[0016] The separated organic phase is filtered through a 0.05-0.1 μm membrane and sent to the downstream light component recovery unit, and the filtered and intercepted crystallized salt is discharged into the crystallizer;

[0017] 3. Light component recovery

[0018] The organic phase after desalting in step 2 enters the reactive distillation tower, and formic acid and the conditioning solvent n-butanol react in the BDO residual liquid in the reactive distillation tower to generate n-butyl formate. The ternary azeotrope of n-butyl formate, n-butanol and water, and light component mixed alcohol and ether impurities are extracted from the top of the reactive distillation tower, and BDO and heavy tar components are extracted from the bottom of the reactive distillation tower. The operating pressure of the reactive distillation tower is 100-300KPa, the operating temperature of the top of the tower is 90℃-130℃, and the operating temperature of the bottom of the tower is 180℃-230℃. The ternary azeotrope and light component impurities extracted from the top of the reactive distillation tower are separated into the water phase and excess n-butanol and returned to the conditioning and impurity removal unit in step 1 for recycling as the conditioning solvent. The oil phase enters the formate refining tower to separate the refined formate product and the light fuel oil product. The BDO and heavy tar components extracted from the bottom of the reactive distillation tower enter the downstream BDO recovery step;

[0019] 4. BDO recovery

[0020] The BDO and heavy tar components obtained after the treatment in step 3 enter a BDO recovery tower, the operating pressure of the BDO recovery tower is controlled to be 5KPa-15KPa, the operating temperature of the tower top is 140°C-170°C, and the operating temperature of the tower bottom is 180°C-230°C, a refined BDO product with a purity greater than 96% is extracted from the BDO recovery tower, and the recovery rate of BDO is greater than 95%, and a heavy tar with a BDO content of less than 5% is extracted from the tower bottom to remove the heavy tar treatment step;

[0021] 5. Heavy tar treatment

[0022] The heavy tar obtained in step 4 is sent to a heating furnace for heating and then enters a coking tower for delayed coking to produce coke and cracked oil and gas products.

[0023] The heating furnace is a gas heating furnace and / or an electromagnetic heating furnace. The fuel used by the heating furnace is the non-condensable gas produced by the cracking of the tar in the coking tower and the tail gas from the decomposition of the sodium oxalate in step 2. The coking temperature of the coking tower is controlled by electromagnetic heating, and the coking temperature of the coking tower is controlled to be 450°C to 650°C.

[0024] Compared with the prior art, the present invention has the following effects:

[0025] 1. The present invention has a higher recovery rate of valuable components in the BDO residual liquid and a higher recovery value. For example, the recovery rate of the main component BDO reaches 95%, and the recovery rates of light fusel alcohols and ethers are nearly 100%. In particular, the invention creatively adopts reactive distillation to recover the formic acid component and the by-product formic ester, which avoids the problem of low-value formic acid wastewater with low utilization value formed by directly recovering formic acid in the prior art; in addition, the present invention completely converts the heavy tar component into coke and light alcohol, ether, and ester oil products, which is more conducive to subsequent utilization; the present invention achieves resource utilization of all components of the BDO residual liquid without generating additional solid waste, wastewater, or waste gas.

[0026] 2. The present invention removes sodium salt from BDO residual liquid more efficiently and thoroughly, and in particular provides a method for desalting with oxalic acid under mild conditions and producing sodium oxalate as a by-product, and the high-temperature pyrolysis of sodium oxalate as a by-product of soda ash can realize the recycling of alkali in the BDO industry chain, avoiding the conventional technology of using sulfuric acid to produce a large amount of worthless sodium sulfate waste salt, and is a green process.

[0027] 3. The present invention is also quite advanced in the treatment of heavy tar. Compared with the incineration treatment of the prior art which generates a large amount of waste gas and particulate matter emissions, the present invention converts all heavy tar into light oil and coke, with basically no three wastes discharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the embodiments are intended to explain the present invention rather than to limit it.

[0030] Example 1

[0031] This embodiment provides a method for treating Reppe process BDO waste liquid to prepare chemicals:

[0032] The BDO waste liquid raw material comes from the distillation residue of a certain company's Reppe process BDO unit. The material composition is shown in the following table:

[0033] Table 1 Main material components of BDO waste liquid:

[0034] Element BDO High boiling tar Sodium formate Sodium hydroxide Content (W%) 51 26.2 22.2 0.6

[0035] Proceed as follows:

[0036] 1. Conditioning and impurity removal:

[0037] Add water to the BDO wastewater: add desalted water at a water to raw material mass ratio of 1:4 and stir evenly;

[0038] Adding n-butanol to the BDO waste liquid: adding n-butanol at a mass ratio of n-butanol to raw material of 1:3 and stirring evenly to form a BDO waste liquid conditioning material;

[0039] The BDO waste liquid conditioning material is pressurized to ≈0.8 MPa and heated to ≈145°C;

[0040] The BDO waste liquid conditioning material is filtered through a 0.1 μm precision silicon carbide membrane to obtain a BDO waste liquid conditioning material clear liquid;

[0041] 2. Desalination and salt recovery:

[0042] According to 15% to 20% of the raw material mass, a 50% oxalic acid aqueous solution at a temperature of 130°C is prepared as a salt trap;

[0043] The BDO waste liquid conditioning material clear liquid obtained in step 1 is mixed with the above-mentioned salt scavenging agent in a neutralization extraction kettle to obtain a mixture and fully stirred, and the temperature of the mixture is controlled at 120° C. to 150° C.;

[0044] The mixture is allowed to stand for stratification to separate an organic phase and an aqueous phase;

[0045] The aqueous phase is fed into a crystallization reactor;

[0046] The organic phase is filtered through a 0.05 μm precision aluminum oxide membrane, and the wastewater obtained by filtration is separated from the entrained oil phase and then incorporated into the crystallization reactor;

[0047] The material in the crystallization reactor is cooled to 45°C, kept for 2 to 3 hours, and then sent to a centrifuge for separation to obtain solid salt and mother liquor;

[0048] The mother liquor is heated to 120°C and fresh oxalic acid is added at 15% of the raw material mass, and then fed to the neutralization extraction kettle for cyclic desalination;

[0049] The solid salt separated by the centrifuge is sent to a tubular electric furnace for thermal decomposition at 680°C and slightly negative pressure to obtain a soda ash product with a purity of 95.8%. The sodium carbonate yield calculated based on sodium is 99.8%.

[0050] 3. Recovery of light components:

[0051] The organic phase obtained in step 2 enters a reaction distillation tower, and is treated under the conditions of a tower top operating temperature of 120°C, a tower bottom operating temperature of 200°C to 210°C, and an organic phase residence time of 1.5 to 2.2 hours, and a light component is obtained from the tower top, and BDO and heavy tar components are obtained from the tower bottom. The material extracted from the top of the reaction distillation tower is cooled to about 90°C and then separated into two layers, and the lower water phase is separated and heated to 130°C and sent to the first step to add to the BDO waste liquid; the upper oil phase enters a formate refining tower, and under the conditions of a tower operating pressure of 100 to 150KPa, a tower top operating temperature of 62°C, and a tower bottom operating temperature of 105°C to 120°C, the residual water and light components are separated from the tower top, and a 96.8% purity n-butyl formate product is obtained at the tower bottom, and the n-butyl formate yield (based on the formic acid content in the raw material) is 95.2%. After the light component product obtained from the top of the formate refining tower is cooled and stratified, the lower water phase and the top of the reactive distillation tower are separated and hydrated and used as a circulating conditioning solvent, and the upper oil phase is collected as a light oil product.

[0052] 4. BDO recovery

[0053] The bottom BDO and heavy tar components obtained by the reaction distillation tower in step 3 enter the BDO recovery tower, the operating pressure of the BDO recovery tower is controlled to be 5KPa-10KPa, the top operating temperature is 147°C, and the bottom operating temperature is 190°C-210°C, the refined BDO product is extracted from the top of the tower, and the heavy tar product is extracted from the bottom of the tower; the purity of the top BDO product is 97%, and the BDO recovery rate (based on the BDO content in the raw material) is 94.8%; the BDO content of the heavy tar extracted from the bottom of the tower is less than 5%, and the heavy tar yield (based on the heavy tar content in the raw material) is 110%;

[0054] 5. Heavy tar treatment

[0055] The heavy tar obtained in step 4 is sent to a delayed coking tower, and a vertical electromagnetic heater is set at the bottom of the delayed coking tower to control the coking temperature. The coking temperature is increased from 200° C. to 550° C. by gradient heating, and the heating rate is controlled at 25° C. / h, and the coking time is 15 to 20 hours. Finally, the solid carbonization product yield (based on the heavy tar feed amount) is 19.5%, the liquid pyrolysis oil yield (based on the heavy tar feed amount) is 68.9%, and the pyrolysis gas yield (based on the heavy tar feed amount) is 11.6%.

[0056] Example 2

[0057] This embodiment provides a process for processing BDO residue to produce chemicals:

[0058] The raw material comes from the BDO tar discharged from the BDO residual liquid reduction and recovery unit of a certain enterprise. It is the remaining residue discharged after the BDO device residual liquid is subjected to primary vacuum distillation and secondary scraped film evaporation to recover BDO. The material component is characterized by high salt content and BDO with recovery value.

[0059] The material components are shown in the following table:

[0060] Table 2 Main material components of BDO residue:

[0061]

[0062] Proceed as follows:

[0063] 1. Conditioning and impurity removal:

[0064] Temperature adjustment: heat the BDO residue to 120-150°C;

[0065] Water injection: Add 30% of the raw material mass into desalted water at 130°C and stir evenly;

[0066] Adding conditioning solvent: adding n-butanol at a temperature of 130°C according to 58% to 65% of the raw material mass and stirring evenly to form BDO waste liquid conditioning material;

[0067] The pressure of the BDO waste liquid conditioning material is increased to ≈0.6MPa, and the temperature is controlled to ≈140°C;

[0068] The BDO waste liquid conditioning material is treated by a 0.1 μm precision silicon carbide membrane filter to obtain a BDO waste liquid conditioning material clear liquid;

[0069] 2. Desalination and salt recovery:

[0070] According to 35% of the raw material mass, a 50% oxalic acid aqueous solution at a temperature of 130°C was prepared as a salt trap;

[0071] The BDO waste liquid conditioning material clear liquid obtained in step 1 is mixed with the above-mentioned salt scavenging agent in a neutralization extraction kettle to obtain a mixture and fully stirred, and the temperature of the mixture is controlled at 130° C. to 150° C.;

[0072] The mixture is allowed to stand for stratification to separate an organic phase and an aqueous phase;

[0073] The aqueous phase is fed into a crystallization reactor;

[0074] The organic phase is filtered through a 0.05 μm precision aluminum oxide membrane, and the wastewater obtained by filtration is separated from the entrained oil phase and then incorporated into the crystallization reactor;

[0075] The material in the crystallization reactor is cooled to 45°C, kept for 2 to 3 hours, and then sent to a centrifuge for separation to obtain solid salt and mother liquor;

[0076] The mother liquor is heated to 100°C and fresh oxalic acid is added at 27% of the raw material mass, and then fed to the neutralization extraction kettle for circulation desalination; in particular, the concentration of the circulating salt-collecting agent oxalic acid fed into the neutralization extraction kettle is controlled to be 40% to 50%;

[0077] The solid salt separated by the centrifuge is sent to a tubular electric furnace for thermal decomposition at 650°C and slightly negative pressure to obtain a soda ash product with a purity of 95.5%. The sodium carbonate yield calculated based on sodium is 99.5%.

[0078] 3. Recovery of light components:

[0079] The organic phase obtained in step 2 enters a reaction distillation tower, and the organic phase is treated under the conditions of a tower top operating temperature of 120°C, a tower bottom operating temperature of 200°C to 210°C, and an organic phase residence time of 2 hours to 2.5 hours, and a light component is obtained from the tower top, and BDO and heavy tar components are obtained from the tower bottom. The material produced from the top of the reaction distillation tower is cooled to about 70°C and then separated into two layers, and the lower water phase is separated and heated to 130°C and sent to the first step to add to the BDO waste liquid; the upper oil phase enters a formate refining tower, and under the conditions of a tower operating pressure of 100 to 150KPa, a tower top operating temperature of 61.7°C, and a tower bottom operating temperature of 105°C to 120°C, the residual water and light components are separated from the tower top, and a 94.8% purity n-butyl formate product is obtained at the tower bottom, and the n-butyl formate yield (based on the formic acid content in the raw material) is 95.1%. After the light component product obtained from the top of the formate refining tower is cooled and stratified, the lower water phase and the top of the reactive distillation tower are separated and hydrated and used as a circulating conditioning solvent, and the upper oil phase is collected as a light oil product.

[0080] 4. BDO recovery

[0081] The bottom BDO and heavy tar components obtained by the reaction distillation tower in step 3 enter the BDO recovery tower, the operating pressure of the BDO recovery tower is controlled to be 5KPa-10KPa, the top operating temperature is 151°C, and the bottom operating temperature is 190°C-210°C, the refined BDO product is extracted from the top of the tower, and the heavy tar product is extracted from the bottom of the tower; the purity of the top BDO product is 96.8%, and the BDO recovery rate (based on the BDO content in the raw material) is 94.5%; the BDO content of the heavy tar extracted from the bottom of the tower is less than 5%, and the heavy tar yield (based on the heavy tar content in the raw material) is 113%;

[0082] 5. Heavy tar treatment

[0083] The heavy tar obtained in step 4 is sent to a delayed coking tower, and the delayed coking tower adopts electromagnetic heating at the bottom of the tower, and the temperature is increased gradually from 200° C. to 550° C. The heating rate is controlled at 25° C. / h, and the coking time is 15 to 20 hours. Finally, the solid carbonization product yield (based on the heavy tar feed amount) is 28.4%, the liquid pyrolysis oil yield (based on the heavy tar feed amount) is 60.9%, and the pyrolysis gas yield (based on the heavy tar feed amount) is 10.7%.

Claims

1. A method for preparing BDO, light fuel oil and coke using BDO residual liquid, characterized in that: The steps include: (1) Tempering and impurity removal The residual liquid from the BDO unit enters the conditioning and impurity removal unit, where conditioning solvent and desalted water are added to dilute and reduce viscosity, and the material temperature is adjusted to 110℃~180℃; The insoluble impurities in the BDO residual liquid after conditioning are removed by filtration using a ceramic membrane with a screening accuracy of 0.08 to 0.5 μm; (2) Desalination and salt recovery The BDO residual liquid after the conditioning and impurity removal treatment in step (1) is pumped into a neutralization extraction reactor to undergo a neutralization reaction with the prepared salt trapping agent to replace the sodium ions contained in the organic sodium salts of sodium formate and sodium methoxide in the BDO residual liquid with the organic phase; The salt-collecting agent is an aqueous solution of sulfuric acid or oxalic acid; the amount of sulfuric acid or oxalic acid in the salt-collecting agent is determined according to a molar ratio of sulfuric acid or oxalic acid to sodium ions in the residual liquid of 1.2:2 to 1.5:2, and the sodium salt filtered and recovered from the crystallizer is sodium sulfate or sodium oxalate; After neutralization and extraction, the BDO residual liquid was separated into layers to obtain a lower aqueous phase and an upper organic phase; The separated water phase is cooled to 40-60°C and then enters the crystallizer for crystallization, and then filtered and recovered by a centrifuge to obtain a water phase from which the sodium salt crystals are removed. The water phase is heated to 90-120°C, supplemented with a salt trap, and then returned to the neutralization extraction reactor for recycling; The separated organic phase is filtered through an inorganic membrane with a screening accuracy of 0.05 to 0.1 μm, and the filtered and intercepted crystallized salt is discharged into a crystallizer; (3) Light component recovery The organic phase after the desalting treatment in step (2) is sent to a reactive distillation tower, in which formic acid and a conditioning solvent in the BDO residual liquid undergo an esterification reaction to form an ester, the ester product is extracted from the top of the reactive distillation tower and refined to obtain a formic ester, and BDO and a heavy tar component are extracted from the bottom of the reactive distillation tower; The operating pressure of the reactive distillation tower is 100-300 KPa, the operating temperature of the tower top is 90°C-130°C, and the operating temperature of the tower bottom is 180°C-230°C; The top product of the reactive distillation tower is a ternary azeotrope of ester, alcohol and water and light component impurities, which is cooled to 60°C to 100°C to separate into an aqueous phase layer and an organic phase layer, the aqueous phase and excess alcohol are separated and returned to the conditioning and impurity removal unit in step (1) for recycling as a conditioning solvent, and the organic phase is separated and enters a formate refining tower to recover a refined formate product and a light fuel oil product; The operating pressure of the formate refining tower is 100-150KPa, the operating temperature of the tower top is 60°C-65°C, and the operating temperature of the tower bottom is 105°C-120°C. The residual water and light component oil are separated from the tower top, the water is combined with the water phase separated from the top of the reactive distillation tower, and the light component oil is collected as a product; the formate refining tower bottom obtains a n-butyl formate product with a purity of more than 96%; (4) BDO recovery The BDO and heavy tar components extracted from the bottom of the reaction distillation tower in step (3) are sent to a BDO recovery tower, the operating pressure of the BDO recovery tower is controlled to be 5KPa-15KPa, the operating temperature of the tower top is 140°C-170°C, and the operating temperature of the tower bottom is 180°C-230°C, and a refined BDO product with a purity greater than 96% is extracted from the BDO recovery tower, and heavy tar with a BDO content of less than 5% is extracted from the tower bottom; (5) Heavy tar treatment The heavy tar obtained in step (4) is sent to a heating furnace for heating and then enters a coking tower for delayed coking to produce coke and cracked oil and gas products.

2. A process for preparing high-value chemicals using BDO residual liquid according to claim 1, characterized in that The conditioning solvent in step (1) is an alcohol compound, and the molar ratio of the added conditioning solvent to the sodium formate in the raw material is controlled to be 1.2 to 1.

6.

3. A process for preparing high-value chemicals using BDO residual liquid according to claim 2, characterized in that: The alcohol compound is n-butanol or an alcohol similar to n-butanol.

4. The process for preparing high-value chemicals using BDO residual liquid according to claim 1, characterized in that: The amount of desalted water added in step (1) is controlled to be between 22% and 30% according to the total water content of the material before filtration.

5. The process for preparing high-value chemicals using BDO residual liquid according to claim 1, characterized in that: The ceramic membrane in step (1) is a silicon carbide ceramic membrane.

6. The process for preparing high-value chemicals using BDO residual liquid according to claim 1, characterized in that: The sodium oxalate salt obtained by crystallization separation in step (2) is sent to a rotary calcination device for high-temperature pyrolysis to generate refined sodium carbonate. The high-temperature pyrolysis operation temperature of the sodium oxalate salt is 500°C to 800°C, and the operation pressure is -5KPa to 1KPa. The purity of the refined sodium carbonate product is greater than 95%, and the impurity metal content is less than 5mg / Kg.

7. A process for preparing high-value chemicals using BDO residual liquid according to claim 6, characterized in that: The rotary calcining equipment adopts an electromagnetic heating rotary kiln.

8. A process for preparing high-value chemicals using BDO residual liquid according to claim 1, characterized in that: The heating furnace in step (5) is a gas heating furnace and / or an electromagnetic heating furnace, and a part of the fuel used in the heating furnace is the non-condensable gas produced by the cracking of the tar in the coking tower and the tail gas from the decomposition of the sodium oxalate in step (2); the coking temperature of the coking tower is controlled by electromagnetic heating, and the coking temperature of the coking tower is controlled to be 450°C to 650°C.

9. A process for preparing high-value chemicals using BDO residual liquid according to claim 8, characterized in that: In the step (5), the coking tower is heated in a gradient manner, the coking temperature of the coking tower increases from 200°C to 450°C to 650°C, the heating rate is controlled at 20°C / h to 25°C / h, and the coking time is 15 to 20 hours.

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