A turpentine processing process without additional water

Abstract

The application discloses an energy-saving and environment-friendly turpentine processing technology without additional water, which comprises the following steps: 1) pressure conveying: turpentine is pressed into a melting kettle by pressure difference; 2) melting: turpentine oil and oxalic acid are added into the turpentine, and the material is melted by heating and stirring of heat conducting oil; 3) precise filtration: the melted turpentine is pressed into a high-position kettle, and two-stage filtration is sequentially carried out by using the height difference; and 4) reduced-pressure distillation: the filtered turpentine is pressed into a distillation kettle, vacuum is drawn, the kettle is heated by heat conducting oil, and distillation is carried out; turpentine oil is obtained by evaporating the liquid and removing water; and colophony is obtained by releasing the substance at the bottom of the kettle. The application adopts the pressure conveying mode to replace the traditional water dilution screw conveyor; the multi-stage precise filtration is adopted to remove impurities, the water washing and multi-stage clarification procedures in the traditional process are omitted, and the problems of large water consumption and high wastewater discharge in the turpentine processing are solved. The middle-layer turpentine liquid generated by the oil-water mixture is eliminated, the post-processing procedure is omitted, and the production efficiency and resource utilization rate are improved.

Description

Technical Field

[0001] This invention relates to a rosin processing technology, particularly a rosin processing technology without the addition of external water, which belongs to the field of energy-saving and environmentally friendly processing. Background Technology

[0002] Pine resin is a traditional forestry resource in my country, ranking first globally in both annual production and application. According to industry association statistics, my country's pine resin application is estimated at 650,000 tons in 2025. Pine resin is rarely used directly; instead, it is processed into rosin and turpentine before further utilization. Therefore, pine resin processing is essential for enhancing the resource's value. Currently, pine resin processing mainly employs steam distillation, which can be divided into batch and continuous methods based on the production approach. The batch method features low equipment investment, simple operation, and flexible processes, but its production efficiency is lower, making it suitable for small to medium-scale pine resin processing. The continuous method has a more complex process flow and requires larger equipment investment, but it is easier to automate and produces stable product quality, making it suitable for large-scale pine resin processing. Enterprises with an annual output exceeding 10,000 tons typically use the continuous method. Regardless of whether it's a batch or continuous method, the main steps in pine resin processing include conveying, melting, washing, clarification, and distillation. 1) Conveying: Add appropriate amounts of turpentine and water to the rosin, and convey it from the rosin storage tank to the melter via a screw conveyor; 2) Melting: Add appropriate amounts of water, turpentine, and oxalic acid, heat to melt the rosin, filter out most of the light impurities through a slag remover, and discharge heavy impurities from the bottom of the melting pot; 3) Washing: The rosin liquid flows into a water washer through a slag remover, and is washed with hot water and agitation; 4) Clarification: After washing, the rosin liquid enters a clarification tank, and after clarification, it is filtered out of the scum through a scum filter and flows into a clean rosin storage tank. The middle layer rosin liquid flows into a middle layer rosin storage tank; 5) Distillation: After the rosin liquid enters the distillation column, it undergoes closed-steam heating and open-steam distillation. A mixture of oil and water vapor is distilled from the top or middle of the column, cooled, and separated into oil and water to obtain turpentine and water. Rosin is released from the bottom of the column. Water is required in the processes of conveying, melting, washing, and distillation. Furthermore, due to the slight water solubility of turpentine, emulsification easily occurs during washing, forming a large amount of intermediate resin liquid. To promote water-oil stratification in this intermediate liquid, one or more further water washing clarification processes are usually needed, further increasing water consumption. Statistics show that traditional pine resin processing consumes over 1.2 t / t of water, with some reaching as high as 3 t / t. High water consumption, large wastewater discharge, and unresolved pollution problems have always been serious issues facing pine resin processing. Driven by increasingly stringent environmental policies and the "dual carbon" target, pine resin enterprises face intensifying survival pressure and urgently need to develop new green and low-carbon pine resin processing technologies.

[0003] The team developed a low-water-consumption, low-emission pine resin processing method (ZL 202010887527.6). Through optimization of the entire process, the water consumption for pine resin processing is reduced to below 0.5 t / t, saving more than 85% of water compared with traditional processing methods. The water-saving technologies mainly include: 1) Water-saving transportation: No water is added; a plunger pump is used instead of a screw conveyor to transport the pine resin; 2) Water-saving melting: No liquid water is added; high-temperature steam heating is used to generate mixed steam to melt the pine resin; 3) Water-saving washing: No large amount of water is added at once; hot water is added in small amounts multiple times and combined with forced stirring for washing; 4) Water-saving distillation: No steam distillation is used; heat transfer oil is used for vacuum distillation; 5) Water-saving treatment of the middle layer of pine resin: No water washing clarification is used; turpentine oil is heated and dissolved, combined with centrifugal separation to separate the water and oil layers and recover the resin liquid. This invention further optimizes the technology by replacing pump transportation with pressurized transportation, thereby improving the efficiency of rosin transportation. By introducing a multi-stage precision filter to remove impurities from the rosin, the need for water washing and multi-stage clarification processes is eliminated, and the intermediate resin liquid generated by oil-water mixing is also eliminated. This develops a rosin processing technology that does not require the addition of external water, fundamentally solving the long-standing problems of high water consumption and large wastewater discharge in rosin processing. This enhances the competitive potential of rosin enterprises under the "dual carbon" target and is conducive to promoting technological innovation and industrial upgrading in the rosin industry. Summary of the Invention

[0004] This invention provides an energy-saving and environmentally friendly rosin processing technology that requires no external water addition. The specific technical solution is as follows: A resin processing technology that does not require the addition of external water. The first step, pressurized delivery: the rosin is delivered to the melting kettle under pressure; The second step is to heat the heat transfer oil: add turpentine and oxalic acid to the rosin, heat and stir, and continue heating until the rosin is completely melted; The third step is filtration: the melted grease is transferred to a high-level pot under pressure and kept at a temperature of 90-100°C. It is then passed through two filters in sequence, and the filtrate is transferred to a metering tank. Step 4, vacuum distillation: The resin liquid in the metering vessel is transferred to the distillation kettle under pressure, a vacuum is drawn and the temperature is raised to 155-160 ℃ to distill off the water and some turpentine in the resin liquid. The temperature is then raised to 195-200 ℃ to distill off the remaining water and the remaining turpentine in the resin liquid. After distillation is completed, the distillation kettle is cooled, the vacuum is released, and the material in the kettle is released from the bottom to obtain rosin. Step 5, condensation: The mixture of turpentine and water distilled in step 4 is condensed and then enters an oil-water separator. After standing and separating, turpentine and water are obtained separately.

[0005] Step 6: Open the filter, remove the filter screen, collect mechanical impurities, clean the filter screen, and then reinstall it into the filter.

[0006] In the first, third, and fourth steps, the pressurized conveying operation involves filling the material storage container with air to a pressure of 0.2–0.3 mPa, then opening the connection passage and using the pressure difference to press the material into another container.

[0007] In the second step, the amount of turpentine added is 10% to 20% of the pine resin content, and the amount of oxalic acid added is 0.1% to 0.3% of the pine resin content. Among them, the oxalic acid is first dissolved in 3 times its mass of water before being added to the resin solution. The water used for dissolution is obtained from the condensation and separation recovery in the fifth step.

[0008] In the third step, the filter passes through two filters in sequence. The first filter has a mesh size of 80, and the second filter has a mesh size of 250.

[0009] In the fourth step, vacuum distillation is carried out with a vacuum degree of -0.093 to -0.090 mPa. The distillation time is 30 to 45 min in the range of 155 to 160 ℃ and 30 to 45 min in the range of 195 to 200 ℃. The heating method is heat transfer oil heating.

[0010] The total mass of turpentine, rosin, water, and mechanical impurities obtained from the processing accounts for 98% to 100% of the pine resin content, and no intermediate resin is generated during the processing.

[0011] The sixth step, collecting mechanical impurities, involves first directly removing large-volume impurities, and then dissolving and cleaning small impurities adhering to the mesh surface or mesh openings with turpentine. The cleaning solution is then filtered and separated, and the turpentine is recovered for use in the second step, resin melting. Beneficial effects

[0012] 1. This invention provides a water-free rosin processing technology, which significantly reduces water consumption compared to traditional processes and completely eliminates environmental pollution problems caused by wastewater. Furthermore, since there is no emulsification of the resin due to water-oil miscibility, the formation of intermediate resin is reduced, eliminating the intermediate resin treatment process, shortening production steps, lowering production costs, and improving rosin utilization.

[0013] 2. The process of this invention adopts pressurized conveying, which has significant advantages compared with traditional screw conveyor or pump conveying methods: 1) It improves conveying efficiency, and the material can be transferred between two devices in a shorter time under the action of pressure difference; 2) It has a high degree of material conveying, which reduces the mechanical impurities remaining in equipment and pipelines and reduces the frequency of slag cleaning; 3) Rosin is a viscous semi-fluid substance, which is very easy to adhere to the equipment and pipelines it flows through during the conveying process. In particular, when using a screw conveyor, the rotation process cannot avoid rosin splashing everywhere, which causes environmental pollution and often results in poor cleanliness of the rosin production line. The pressurized conveying in a sealed system of this invention greatly alleviates the above problems.

[0014] 3. Compared with the currently commonly used rosin processing technology, the process of this invention has a simpler equipment composition, eliminating large-volume equipment such as washing kettles and clarification pots. The added filtration equipment is small in size and can be directly connected to the existing system after processing, making it easy to transform and upgrade the traditional processing system, and has the advantage of wide promotion. Attached Figure Description

[0015] Figure 1 The process flow diagram for processing rosin in this invention.

[0016] Figure 2 Flowchart of traditional rosin processing technology.

[0017] Detailed Description of the Invention: This invention relates to an energy-saving and environmentally friendly rosin processing technology that requires no external water addition. The specific operating steps of this invention are as follows: The first step is to fill the rosin storage tank with air until the pressure reaches 0.2-0.3 mPa, open the connection between the storage tank and the melting kettle, and force the rosin into the melting kettle; The second step is to add 10% to 20% of the pine resin by weight of turpentine oil to the pine resin, dissolve 0.1% to 0.3% of the pine resin by weight of oxalic acid in 3 times the weight of water, add the oxalic acid-water solution to the pine resin, heat to 70°C, start stirring, and continue heating to 100 to 120°C to completely melt the pine resin. The third step involves filling the melting kettle with air until the pressure reaches 0.2–0.3 MPa. Then, open the connection between the melting kettle and the high-level pot, and force the rosin into the high-level pot. Maintain the rosin temperature at no less than 95°C, and use the height difference to pass it through two filters sequentially. The first filter has a mesh size of 80 (approximately 178 mesh). μ m), with a volume of 1.0–2.0 m³. 3 The second filter has a mesh size of 250 (approximately 61). μ m), with a volume of 0.6–1.5 m³. 3 The filtrate is transferred to a metering tank; Fourth, pressurize the metering vessel with air to a pressure of 0.2–0.3 mPa, open the connection between the metering vessel and the distillation vessel, and force the rosin from the metering vessel into the distillation vessel. Evacuate to a vacuum level of -0.093 to -0.090 mPa, raise the temperature to 155–160 °C, and distill for 30–45 minutes to remove water and some turpentine from the rosin solution. Continue heating to 195–200 °C and distill for 30–45 minutes to remove residual water and the remaining turpentine from the rosin solution. After distillation, lower the temperature inside the distillation vessel to 160 °C, release the vacuum, and discharge the material from the bottom of the vessel to obtain rosin. Fifth step: The mixture of turpentine oil and water distilled in the fourth step is condensed and then enters an oil-water separator. After standing and separating, turpentine oil and water are obtained separately. Step 6: Open the filter, remove the filter screen, collect mechanical impurities, clean the filter screen, and then reinstall it into the filter.

[0018] Example 1 1500 kg of wet pine resin (determined according to LY / T 3157—2023 "Test Method for Pine Resin" with turpentine content of 22.3%, water content of 4.7%, and mechanical impurity content of 1.2%, resulting in a calculated rosin content of 71.8%) was pressurized into a melting kettle under air pressure. 300 kg of wet pine turpentine and 12 kg of oxalic acid-water solution (containing 3 kg of oxalic acid and 9 kg of water) were added to the melting kettle, heated to 70 °C, stirred, and heated further to 120 °C until all the resin was melted. The melted resin was then pressurized under air pressure and transferred to a high-level vessel. Maintaining the resin temperature at approximately 95 °C, the resin was passed sequentially through 80-mesh and 250-mesh filters using potential energy. After filtration, the resin entered a metering vessel. The resin in the metering vessel was then pressurized under air pressure and transferred to a distillation vessel. A vacuum was evacuated to -0.09 mPa, and heating was initiated, maintaining the temperature between 155 and 160 °C. Distilled at ℃ for 45 min, yielding 531 kg of liquid (after condensation and separation, 503 kg of turpentine oil and 28 kg of water were obtained); the temperature was further increased to 195–200 ℃, and distillation continued for 45 min, yielding 121 kg of liquid (after condensation and separation, 71 kg of turpentine oil and 50 kg of water were obtained); the temperature of the distillation vessel was lowered to 160 ℃ by circulating cooling oil, the vacuum was released, and rosin was released from the bottom of the vessel, totaling 1093 kg. The filter screen was disassembled and cleaned, and 43 kg of mechanical impurities were collected. The key indicators of turpentine oil and rosin were determined according to GB / T12902—2026 "Analytical Method for Turpentine Oil" and GB / T 8146—2022 "Test Method for Rosin", respectively. Turpentine oil: colorless, transparent, free of impurities, acid value 0.91 mg / g, benzene ( α -pinene+ β The pinene content was 88.7%, meeting the requirements for Grade I turpentine in GB / T 12901—2006 "Turpentine Oil"; rosin: color grade II, softening point 79.8 ℃, acid value 165.6 mg / g, unsaponifiable matter 2.55%, ethanol insoluble matter 0.012%, ash content 0.023%, meeting the requirements for Grade II rosin in GB / T 8145—2021 "Turpentine Oil". A total of 274 kg of turpentine oil (total mass of distilled turpentine oil minus the mass of turpentine oil added during melting), 1093 kg of rosin, and 78 kg of water were distilled out, and 43 kg of mechanical impurities were recovered. The total mass of turpentine oil, rosin, water, and mechanical impurities was 1488 kg, with a rosin utilization rate of 99.2%.

[0019] The types and quality of raw materials used in Examples 2 to 8, as well as the specific production process, are the same as in Example 1. Other process parameters and results are shown in Table 1.

[0020] Table 1. Process parameters and results of Examples 1 to 8

Claims

1. A rosin processing technology without added water, characterized in that: The first step, pressurized delivery: the rosin is delivered to the melting kettle under pressure; The second step is to heat the heat transfer oil: add turpentine and oxalic acid to the rosin, heat and stir, and continue heating until the rosin is completely melted; The third step is filtration: the melted grease is transferred to a high-level pot under pressure and kept at a temperature of 90-100°C. It is then passed through two filters in sequence, and the filtrate is transferred to a metering tank. Step 4, vacuum distillation: The resin liquid in the metering vessel is transferred into the distillation kettle under pressure, a vacuum is drawn and the temperature is raised to 155-160°C to distill off the water and some of the turpentine in the resin liquid. The temperature is then raised to 195-200°C to distill off the remaining water and the remaining turpentine in the resin liquid. After distillation is complete, the distillation kettle is cooled, the vacuum is released, and the material in the kettle is released from the bottom to obtain rosin. Step 5, condensation: The mixture of turpentine oil and water distilled in step 4 is condensed and then enters an oil-water separator. After standing and separating, turpentine oil and water are obtained separately. Step 6: Open the filter, remove the filter screen, collect mechanical impurities, clean the filter screen, and then reinstall it into the filter.

2. The rosin processing technology without added water as described in claim 1, characterized in that, In the first, third, and fourth steps, the pressurized conveying operation involves filling the material storage container with air to a pressure of 0.2–0.3 mPa, then opening the connection passage and using the pressure difference to press the material into another container.

3. The rosin processing technology without added water as described in claim 1, characterized in that, In the second step, the amount of turpentine added is 10% to 20% of the pine resin content, and the amount of oxalic acid added is 0.1% to 0.3% of the pine resin content. Among them, the oxalic acid is first dissolved in 3 times its mass of water before being added to the resin solution. The water used for dissolution is obtained from the condensation and separation recovery in the fifth step.

4. The rosin processing technology without added water as described in claim 1, characterized in that, In the third step, the filter passes through two filters in sequence. The first filter has a mesh size of 80, and the second filter has a mesh size of 250.

5. The rosin processing technology without added water as described in claim 1, characterized in that, In the fourth step, vacuum distillation is carried out with a vacuum degree of -0.093 to -0.090 mPa. The distillation time is 30 to 45 min in the range of 155 to 160 ℃ and 30 to 45 min in the range of 195 to 200 ℃. The heating method is heat transfer oil heating.

6. The rosin processing technology without added water as described in claim 1, characterized in that, The total mass of turpentine, rosin, water, and mechanical impurities obtained from the processing accounts for 98% to 100% of the pine resin content, and no intermediate resin is generated during the processing.

7. The rosin processing technology without added water as described in claim 1, characterized in that, The sixth step, collecting mechanical impurities, involves first directly removing large-volume impurities, and then dissolving and cleaning small impurities adhering to the mesh surface or mesh openings with turpentine. The cleaning solution is then filtered and separated, and the turpentine is recovered for use in the second step, resin melting.

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