A regenerative thermosensitive phase change adsorption system for polar oil spill recovery and its operation method

Abstract

This invention discloses a regenerative thermosensitive phase change adsorption system and its operation method for polar oil spill recovery. The system consists of an adsorption execution module, a heat storage and energy module, a regeneration and recovery module, an oil-water separation and collection device, and an intelligent control unit. The adsorption execution module includes thermosensitive particles / blankets with a phase change of -5 to 15°C and a flexible heating blanket with a phase change of 30 to 50°C, capable of efficiently adsorbing floating oil on water and condensed oil on ice, respectively. The heat storage module uses solar vacuum tube collectors and waste heat from ship engines as heat sources. A smart switching valve prioritizes the use of waste heat, storing energy in a 50-120°C phase change material heat storage tank, and releasing heat within 15 minutes. The regeneration device jacket has built-in spiral ribs, heating to 70-90°C at 0.5-2°C / s, causing the oil to desorb and enter a gravity-coalescing separation device, achieving a recovery rate of ≥90% and an oil content of <10ppm in the effluent. This invention achieves continuous, automatic, and low-energy oil spill recovery at polar low temperatures, suitable for emergency use on research vessels, research stations, and ships in the Arctic shipping route.

Description

Technical Field

[0001] The present invention belongs to the fields of oil-water separation and treatment of oil pollutants on the water surface, and particularly relates to a heat storage type thermosensitive phase change adsorption system for polar oil spill recovery and an operation method thereof. Background Art

[0002] With the development of the Arctic shipping route and the increasing frequency of polar scientific research activities, the risk of fuel leakage from ships in the polar region has increased significantly. The polar environment poses severe challenges to oil spill recovery technology: First, low temperatures (usually below -20°C) can cause the viscosity of oils such as very low sulfur fuel oil (VLSFO) with high viscosity to increase sharply or even solidify, rendering traditional adsorption materials ineffective and brittle, and resulting in a sharp drop in adsorption efficiency; Second, it is difficult to supply energy in the polar region, especially during the polar night when solar energy is scarce, making it difficult to achieve on-site thermal regeneration of adsorption materials; Finally, the operation window period in the polar environment is short and manual operation is difficult, requiring equipment to have high reliability and automation.

[0003] Currently, most of the existing oil spill recovery technologies and materials are designed for mild environments and have the following obvious defects: Single function: Existing adsorption materials or technologies usually only target one of the situations of liquid floating oil or solidified oil, lacking an integrated system that can effectively handle both polar surface floating oil and ice surface solidified oil simultaneously. Strong energy dependence: The regeneration of materials usually depends on continuous and stable external power or fuel combustion, which is costly and unreliable in the polar environment. Process fragmentation: Adsorption, recovery, regeneration and other links often require different equipment to complete, the process is not continuous, and the deployment efficiency in the harsh polar environment is low, and rapid response and continuous operation cannot be achieved.

[0004] Therefore, there is an urgent need to develop an oil spill recovery technology and equipment that can adapt to extremely low temperatures in the polar region, make full use of special polar energy, and achieve efficient and continuous operation. Summary of the Invention

[0005] The primary object of the present invention is to overcome the deficiencies of the existing technology and provide an integrated system that can efficiently recover polar surface floating oil and ice surface solidified oil simultaneously. Another object of the present invention is to provide an operation method for an oil spill recovery system with high energy utilization efficiency and capable of continuous and automated operation in the polar environment.

[0006] The present invention discloses a heat storage type thermosensitive phase change adsorption system for polar oil spill recovery, including:

[0007] An adsorption execution module, the adsorption execution module at least includes:

[0008] The temperature-sensitive adsorption unit is composed of a composite adsorption material. The composite adsorption material uses n-alkane microcapsule phase change material as the temperature control component and porous minerals as the carrier. It can be made into strips, blankets, or granules. It is used to reduce the surface energy through volume expansion when the temperature is higher than its phase change temperature, thereby accelerating the adsorption of floating oil on the water surface. The phase change temperature range of the microcapsule phase change material is -5°C to 15°C. The composite adsorption material has an oil absorption ratio of ≥25 times its own weight for solidified / semi-solidified VLSFO / MGO and other low-sulfur oil spills in an environment of -10°C.

[0009] A flexible heating adsorption unit is composed of a flexible substrate and high-temperature phase change microcapsules loaded on the flexible substrate. The phase change temperature of the high-temperature phase change microcapsules is 30-50℃. They are used to reduce the viscosity of the solidified oil layer on the ice surface after endothermic melting and to complete the adsorption simultaneously.

[0010] Thermal storage and energy module, wherein the thermal storage and energy module comprises at least:

[0011] The heat source unit includes a solar vacuum tube collector and a waste heat exchanger from a ship engine, and is equipped with an intelligent switching valve to provide heat according to a waste heat priority and solar energy supplementation strategy.

[0012] A phase change heat storage tank, wherein the interior of the phase change heat storage tank is filled with a high-density phase change material, the phase change temperature of which is 50-120°C, and is used to store heat from the heat source unit in the form of latent heat.

[0013] The heat exchange fluid loop uses antifreeze as the heat transfer medium and connects the heat storage tank, the heat source unit and the regeneration device through a variable frequency pump and insulated pipeline to form a closed loop.

[0014] A regeneration and recycling module, wherein the regeneration and recycling module comprises at least:

[0015] The regeneration device is a closed container with a heating jacket, used to receive the temperature-sensitive adsorption unit and / or flexible heating adsorption unit after saturation adsorption, and to heat up and desorb the adsorbent material through the heat provided by the heat exchange fluid circuit.

[0016] An oil-water separation and collection device is connected to the bottom outlet of a regeneration device and is used to perform gravity-coalescence composite separation and recovery of desorbed oil.

[0017] and an intelligent control unit, the intelligent control unit being used for:

[0018] (a) Automatically select and deploy the corresponding adsorption units based on ambient temperature, oil spill pattern and ship operating conditions;

[0019] (b) Control the flow rate and temperature of the heat exchange fluid circuit to keep the heating rate of the adsorbent material in the regeneration device at 0.5-2℃ / s until the oil viscosity is reduced to <200 cP and desorption is completed.

[0020] (c) After desorption is completed, start the cooling fan to cool the adsorbent material to below its MPCM phase transition temperature before putting it back into use.

[0021] In one feasible implementation, the core material of the n-alkane microcapsules in the composite adsorbent material is a C12-C16 straight-chain alkane, the shell material is melamine-formaldehyde or urea-formaldehyde resin, and the microcapsules account for 15-35 wt% of the total mass of the composite material.

[0022] In one feasible implementation, the porous mineral is selected from one or more of diatomaceous earth, expanded perlite, organic aerogel or foam metal, with a BET specific surface area ≥30 m² / g and a pore size distribution peak in the range of 2-50 nm.

[0023] In one feasible implementation, the flexible substrate is PET nonwoven fabric, ceramic fiber blanket, or polymer fiber felt with a unit area mass of 80-300 g / m², the phase change temperature range of the high-temperature phase change microcapsules is 30°C to 50°C, the core phase change material is selected from paraffin or fatty acid mixtures, and the high-temperature phase change microcapsules are fixed on the surface of the flexible substrate by acrylate pressure-sensitive adhesive or silane coupling agent with a fixation amount of 20-60 g / m².

[0024] In one feasible implementation, the high-density phase change material is sodium acetate trihydrate, calcium chloride hexahydrate, or a molten salt eutectic mixture, and the phase change heat storage tank is provided with finned heat exchange tubes along the axial direction to increase the heat exchange area and reduce the heat storage / release time constant to <15 min.

[0025] In one feasible implementation, the inner wall of the heating jacket of the regeneration device is provided with spiral guide ribs to make the heat exchange fluid turbulent, thereby improving the heating uniformity of the adsorbent material, and the outer wall of the jacket is covered with an aerogel insulation layer to keep the surface temperature <45°C.

[0026] In one feasible implementation, the oil-water separation and collection device includes:

[0027] A primary gravity settling chamber, wherein an adjustable weir plate is provided at the bottom of the primary gravity settling chamber for first separating free water;

[0028] A secondary coalescing separation filter element, wherein the secondary coalescing separation filter element is a hydrophobic-oleophilic fiber bundle with a coalescing efficiency of ≥95%, is used to remove residual water droplets;

[0029] And oil storage tanks, the top of which is equipped with a breather valve and a liquid level sensor for closed-loop recycling.

[0030] On the other hand, the present invention provides an operating method for polar oil spill recovery using any of the above-mentioned systems, comprising the following steps:

[0031] S1. Adsorption operation: When oil spill on ice surface is detected, the flexible heating adsorption unit is deployed to use the ambient cold to cause the high-temperature phase change microcapsules to solidify and release heat, locally raising the temperature by 2-5°C, reducing the viscosity of the oil layer and completing the adsorption within 30 minutes; when oil spill on water surface is detected, the temperature-sensitive adsorption unit is deployed to use the heat of the water to melt the n-alkane microcapsules and absorb the oil.

[0032] S2. Collection and preparation: The saturated adsorption unit is recovered by a blanket roller or net bag and transported to the regeneration unit;

[0033] S3, Heat Storage and Regeneration: The intelligent control unit prioritizes the activation of the waste heat exchanger of the ship's engine to store heat in the phase change heat storage tank. When the temperature inside the tank is ≥80℃, the variable frequency pump is started to pump the high-temperature antifreeze into the jacket of the regeneration device at a flow rate of 5-15 L / min, so that the adsorbent material is heated to 70-90℃ within 15-40 minutes, and the oil is desorbed.

[0034] S4. Oil recovery: The desorbed oil-water mixture enters the oil-water separation and collection device. Under the dual action of gravity and coalescence, the oil recovery rate is ≥90% and the oil content in the effluent is <10 ppm.

[0035] S5. Cooling and Reuse: Turn on the cooling fan to cool the adsorbent material to <20℃ within 10 minutes, and then place it again to achieve recycling.

[0036] In one feasible implementation, in step S3, when the ship is in a stopped state and the outlet temperature of the solar collector is >60°C, the intelligent control unit automatically switches to solar heating mode and reduces the speed of the variable frequency pump to 30-50% of the rated value to extend the heat storage time and save energy.

[0037] On the other hand, the present invention also provides a composite adsorbent material for the above-mentioned system, which is prepared by the following method:

[0038] a) After heating n-dodecane to 50°C to melt it, add Span-80 emulsifier and emulsify at 800 rpm for 10 min to form an O / W emulsion;

[0039] b) Melamine-formaldehyde prepolymer was added dropwise to the above emulsion, the pH was adjusted to 4.5-5.0 with citric acid, and polymerization was carried out at 70°C for 2 h to obtain n-dodecane microcapsules;

[0040] c) The microcapsules are mixed with diatomaceous earth at a mass ratio of 1:2-1:4, and 5 wt% sodium silicate solution is sprayed as a binder. The mixture is then dried at 120°C to obtain a granular composite adsorbent material.

[0041] d) The oil absorption ratio of the composite adsorbent material is ≥8 g / g, and it can still maintain >60% saturated oil absorption capacity at 0℃.

[0042] In one feasible implementation, the particle size of the granular composite adsorbent material is 1-5 mm, the bulk density is 0.3-0.5 g / cm³, and the oil absorption ratio decreases by <10% after 20 adsorption-regeneration cycles.

[0043] On the other hand, the present invention also provides a flexible heating and adsorption blanket for the above-mentioned system, characterized in that it comprises:

[0044] Ceramic fiber blanket substrate, thickness 3-8 mm;

[0045] Paraffin MPCM / EVA hot melt adhesive composite layer, the composite layer is coated on one side of ceramic fiber blanket, the coating amount is 30-50g / m², and the phase change temperature is 35-45℃;

[0046] And PTFE edge banding strips, used to prevent the MPCM from falling off due to seawater erosion;

[0047] The flexible heating and adsorption blanket has a saturated oil absorption capacity of ≥2 kg / m² per unit area and can be bent 180° at -20℃ without cracking.

[0048] The technical solution provided in this application has at least the following beneficial effects:

[0049] (1) Comprehensive response scenarios: Through two complementary adsorption units, one system can cope with the two most common oil spill forms in the polar regions, greatly improving the adaptability of emergency response.

[0050] (2) Energy self-sufficiency and efficient utilization: The unique “solar energy-waste heat-phase change heat storage” multi-coordinated energy supply system transforms the intermittent and dispersed energy in the polar regions into stable and controllable heat output, realizing the spatial and temporal transfer and efficient utilization of energy, and greatly reducing operating costs and environmental impact.

[0051] (3) Automation and continuity of operation process: The system integrates the complete process from adsorption, recovery to regeneration, and achieves automated operation through intelligent control, overcoming the problem of low efficiency of manual operation in the harsh polar environment, and realizing efficient and continuous oil spill recovery operation.

[0052] (4) Active response of materials to the environment: By utilizing the latent heat characteristics of phase change materials, the adsorption material is transformed from "passive" adsorption to "active" regulation of the microenvironment, which significantly improves the efficiency and success rate of operation at extreme low temperatures. Attached Figure Description

[0053] Figure 1 This is a block diagram illustrating the overall structure and working principle of the system of the present invention.

[0054] Figure 2 This is a schematic diagram of the structure of one embodiment of the system of the present invention.

[0055] Figure 3 This is a flowchart of the system operation method of the present invention. Detailed Implementation

[0056] The invention will be further described below with reference to specific examples and accompanying drawings.

[0057] Example 1:

[0058] 100 g of n-dodecane and 0.8 g of Span-80 were added to a 500 mL three-necked flask and stirred in a 50 °C water bath until completely melted, yielding a colorless and transparent oil phase. The oil phase was poured into 200 mL of 60 °C deionized water and mechanically emulsified at 800 rpm for 10 min to form a stable O / W emulsion. A laser particle size analyzer measured the D50 to be 1.1 µm. 18 g of melamine-formaldehyde prepolymer was slowly added dropwise through a constant-pressure funnel, while simultaneously adjusting the pH to 4.8 with 1 mol / L citric acid. The mixture was kept at 70 °C for 2 h, and the emulsion changed from milky white to slightly blue, indicating that the wall material crosslinking was complete. The reaction solution was cooled to room temperature, filtered, washed three times with 50 °C hot water, and freeze-dried for 12 h to obtain a loose white powder with a yield of 91%. DSC measured the phase transition enthalpy to be 182 J / g. Weigh 30 g of microcapsules and 70 g of diatomaceous earth (BET 42 m² / g), place them in a V-type mixer for 15 min to obtain a homogeneous grayish-white mixture. Transfer the mixture to a small screw extruder, spray 12 g of 5 wt% sodium silicate solution while stirring; extrude through a 1 mm orifice plate, the strip falls into a spheroidizer, runs at 350 rpm for 8 min to form pellets with a diameter of Ø 1.8–2.2 mm. Dry the pellets in an oven at 120 °C for 2 h, then calcine them in a muffle furnace at 200 °C for 30 min to dehydrate and vitrify the sodium silicate. Cool and sieve to obtain the finished granules. The measured oil absorption ratio of VLSFO at -0 °C was 26.2 g / g; after soaking in seawater at 0 °C for 30 min, it maintained 63% of its saturation capacity; at -10 °C, it still reached 16.8 g / g; after 20 desorption cycles at 80 °C, the oil absorption ratio was 24.1 g / g, a decrease of 7.9%.

[0059] Example 2

[0060] 120 g of n-tetane and 1 g of Span-80 were poured into a 1 L three-necked flask and stirred in a 55 °C water bath until completely dissolved, forming a clear oil phase. The oil phase was then poured into 250 mL of 65 °C hot water and emulsified at 1000 rpm for 8 min to obtain a homogeneous milky emulsion. Next, 20 g of urea-formaldehyde prepolymer was slowly added dropwise, while simultaneously adjusting the pH to 5.0 with citric acid. The mixture was heated to 75 °C and held at this temperature for 2.5 h. The emulsion color changed from white to pale yellow, indicating the end of cross-linking of the wall material. After cooling, the reaction solution was filtered, washed three times with 60 °C hot water, and freeze-dried for 10 h to obtain a loose white microcapsule powder with a yield of 90%. The phase transition enthalpy measured by DSC was 195 J / g. 25 g of microcapsules and 75 g of expanded perlite (BET 38 m² / g) were dry-mixed in a V-type mixer for 20 min. Then, while stirring, 15 g of 10 wt% sodium silicate solution was sprayed, and the mixture was extruded through a 1.2 mm perforated plate. The extruded material was directly fed into a rounding machine and rolled at 400 rpm for 10 min to obtain pellets with a diameter of Ø 2–2.5 mm. The pellets were first dried at 120℃ for 2 h, then calcined at 200℃ for 40 min, cooled, and sieved to obtain the finished product. At 0℃, the oil absorption ratio of the MGO was 25.8 g / g; at -10℃, it remained at 17.2 g / g; after 20 desorption cycles at 80℃, the oil absorption ratio was 23.9 g / g, a decrease of 7.4%.

[0061] Example 3

[0062] 150 g of n-tetradecane and 1.2 g of Span-80 were weighed and added to a 2 L glass reactor. The mixture was stirred in a 60 °C water bath until completely melted, yielding a colorless oil phase. The oil phase was poured into 300 mL of 70 °C deionized water and emulsified at 1200 rpm for 7 min under high shear to form a fine O / W emulsion. 24 g of melamine-formaldehyde prepolymer was slowly added using a constant pressure funnel, while citric acid solution was added dropwise to maintain the pH at 4.7. The mixture was heated to 80 °C and reacted for 3 h. The emulsion gradually turned pale blue, indicating that the wall material was fully cross-linked. After cooling to room temperature, the mixture was filtered, washed three times with hot water at 55 °C, and freeze-dried for 12 h to obtain a white microcapsule powder with a yield of 92%. The phase transition enthalpy was measured to be 188 J / g by DSC. 35 g of microcapsules and 65 g of organic aerogel powder (BET 55 m² / g) were weighed and mixed in a V-type mixer for 15 min. While stirring, 18 g of 8 wt% sodium silicate solution was sprayed until the powder could be just formed into a ball. The mixture was extruded through a 1.5 mm perforated plate, and the strips were fed into a rounding machine and run at 450 rpm for 12 min to obtain pellets with a diameter of Ø 2.5–3 mm. The pellets were dried at 120 ℃ for 2 h, then calcined at 190 ℃ for 45 min, cooled, and sieved to obtain the finished granules. The VLSFO oil absorption ratio was 27.5 g / g at 0 ℃ and still reached 18.1 g / g at -10 ℃. After 20 desorption cycles at 80 ℃, the oil absorption ratio was 25.3 g / g, a decrease of only 8.0%.

[0063] Example 4: Shipborne Equipment

[0064] The heat storage and energy module includes a 15m² solar vacuum tube collector, fixed at a 45° angle to the deck, with an outlet temperature of 65-85℃; a 0.6m² plate heat exchanger connected in parallel to the 350kW coolant circuit of the ship's main engine, with a hot water side temperature of 90℃; and an intelligent three-way switching valve that prioritizes waste heat, bypassing the solar energy circuit when the coolant temperature is >80℃, otherwise mixing the two circuits. The phase change heat storage tank has a volume of 0.8m³, filled with sodium acetate trihydrate at a phase change temperature of 58℃, and 19 axially arranged aluminum finned heat exchange tubes with a heat release time constant of 12min; the heat exchange fluid is 50vol% ethylene glycol antifreeze, pumped by a 0.75kW variable frequency pump with a flow rate of 5-15L / min, and the entire process is a closed loop with insulated aluminum foil and rubber-plastic tubing.

[0065] The regeneration and recycling module includes a 1.5m³ horizontal drum regeneration device, lined with 316L perforated plates, with 6mm high spiral guide ribs on the inner wall of the jacket, and 20mm aerogel felt on the outer wall, with a surface temperature of 42℃; the oil-water separation and collection device includes a 0.4m³ primary gravity settling chamber, an adjustable weir plate of 0-10cm, a secondary coalescing filter element of Φ150mm×400mm hydrophobic and oleophilic PP fiber bundles, with a measured coalescing efficiency of 96%; and a 0.5m³ oil storage tank top-mounted with a breather valve and magnetic level gauge, and a normally closed nitrogen gas cushion of 5kPa.

[0066] Example 5: Shore-based equipment

[0067] The heat storage and energy module includes a 100m² solar vacuum tube collector field, connected in parallel with a 200kW diesel generator set flue gas waste heat boiler, with an intelligent switching valve prioritizing the use of flue gas; three 10m³ vertical heat storage tanks are connected in series, filled with nitrate molten salt eutectic with a phase change temperature of 95℃, each tank has 37 finned heat exchange tubes, a heat storage / release time constant of 14min, the heat exchange fluid is 55wt% ethylene glycol antifreeze, a 2.2kW variable frequency pump with a flow rate of 8-12L / min, and a closed-loop insulation system throughout the process.

[0068] The regeneration and recycling module includes a 3m³ twin-screw extruder regeneration unit with a jacketed spiral guide rib and an outer 25mm aerogel coating, with a surface temperature of 38℃; the oil-water separation and collection unit is equipped with a 1m³ primary settling chamber, an adjustable weir plate, two parallel hydrophobic and oleophilic glass fiber secondary coalescing filter elements with an efficiency of 97%, and a 2m³ oil storage tank top-mounted with a breather valve and a radar level gauge.

[0069] Operation process: The molten salt pump delivers 90℃ antifreeze into the jacket, raising the temperature of 500kg saturated blanket to 85℃ in 15 minutes, with a desorption rate of 94% and an oil content of 6ppm in the effluent.

[0070] Example 6: Integrated Oil Spill Recovery System for Polar Research Vessels

[0071] Figure 1 The overall structure and working principle block diagram of the system of the present invention are given, including:

[0072] Adsorption execution module: Equipped with an 80-square-meter temperature-sensitive adsorption unit (made of n-dodecane MPCMs / diatomaceous earth composite material) and a 40-square-meter flexible heating adsorption unit (made of RT44 paraffin MPCMs / ceramic fiber felt).

[0073] Thermal storage and energy module: The thermal storage unit is a 0.8 cubic meter phase change thermal storage module filled with sodium acetate trihydrate with a phase change temperature of 58°C. The heat source includes a 15-square-meter solar vacuum tube collector and a plate heat exchanger connected to the coolant circuit of the research vessel's main engine.

[0074] Regeneration and recycling module: The regeneration device is a jacketed drum cleaning device with an effective volume of 1.5 cubic meters, and the oil-water separation device is a horizontal sedimentation tank with a volume of 2 cubic meters.

[0075] Operation process:

[0076] During its voyage, the research vessel discovered solidified oil on the ice surface, covering an area of ​​approximately 30 square meters.

[0077] Operators deployed four rolls (totaling 30 square meters) of flexible heating and adsorption units to cover the oil-contaminated area. Before deployment, the phase change material (phase change temperature 44°C) inside the unit was briefly preheated to complete melting using the ship's power supply, and then continuously released heat for 2 hours relying on its own latent heat.

[0078] Two hours later, the oil slick had fully liquefied and separated from the ice surface. The operators then retrieved the adsorption unit and sent it to the regeneration device via a conveyor belt.

[0079] At this time, the control system detects that the ship's engine is running and prioritizes the waste heat recovery, using high-temperature coolant to charge the heat storage tank and maintain its temperature above 70°C.

[0080] The regeneration process is initiated, and a 70°C ethylene glycol solution is pumped into the jacket of the regeneration unit to heat the internal adsorption blanket for approximately 40 minutes. The desorbed oil flows into a settling tank, where it is allowed to settle and separate, recovering approximately 0.9 tons of fuel oil, with a regeneration recovery rate of approximately 92%.

[0081] After being regenerated, the absorbent blanket is cooled and stored for later use, and the system is put into standby mode.

[0082] Example 5: Fixed Shore-Based Treatment Center for Polar Research Stations

[0083] (1) System configuration and scenarios:

[0084] This embodiment is deployed near an Arctic research station as a regional oil spill emergency response and waste oil recovery center. The system is designed to process 50 tons of mixed oil spills annually.

[0085] Adsorption execution module: 500 square meters of temperature-sensitive adsorption units (based on decanoic acid MPCMs / expanded perlite composite material) and 200 square meters of flexible heated adsorption units (based on fatty acid / ceramic fiber felt with a phase change temperature of 38°C). All units are designed as standardized modules for easy gripping and deployment by the robotic arm.

[0086] Thermal storage and energy modules: This is the core innovation of this project. The thermal storage unit consists of three 10-cubic-meter vertical phase change thermal storage modules, filled with molten nitrate salt with a phase change temperature of 95°C. The heat source system is diversified, including:

[0087] 1) A 100-square-meter solar vacuum tube collector field.

[0088] 2) Connect to the flue gas waste heat boiler of the main generator set of the scientific research station.

[0089] 3) Connect the auxiliary heating circuit of the geothermal source pump in the station area (as a backup heat source during polar night).

[0090] Regeneration and recycling module: Equipped with a continuous recycling production line, including a feeding device, a twin-screw extrusion regeneration machine (with integrated heat exchange jacket), and a high-efficiency centrifugal oil-water separator.

[0091] (2) Operation process and effects:

[0092] One day, a diesel leak occurred in a transport vehicle in the station area. Some of the oil spilled into the nearby waters, forming an oil slick, while some of it solidified on the ice on the shore.

[0093] The emergency response team simultaneously deployed temperature-sensitive adsorption units to treat floating oil and flexible heating adsorption units to treat oil spills on the ice surface. Due to the ambient temperature dropping to -25°C, the temperature-sensitive units relied on their own phase change to release heat, efficiently adsorbing floating oil from the water surface within 30 minutes.

[0094] The recovered saturated adsorbent material was transported to an onshore processing center. At this time, during the end of the polar day, the control system prioritized the use of thermal energy from the solar collectors and stored sufficient heat in molten salt storage tanks.

[0095] The saturated adsorbent material enters the continuous regeneration production line. Molten salt at 95°C heats the heat transfer oil to 85°C through a heat exchanger, and then pumps it into the jacket of the twin-screw regenerator. Under the synergistic effect of stirring and extrusion, the adsorbent material completes desorption and regeneration within 15 minutes, and the recovered oil has a purity of over 95%.

[0096] The system innovatively recovers the waste heat from the regenerated high-temperature adsorbent material (approximately 60°C) through a heat exchanger to use part of the heating water for the preheating station buildings, achieving cascaded utilization of energy and improving overall energy efficiency by approximately 15%.

[0097] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A regenerative thermosensitive phase change adsorption system for polar oil spill recovery, characterized in that, include: Adsorption execution module, the adsorption execution module comprising at least: The temperature-sensitive adsorption unit is composed of a composite adsorption material. The composite adsorption material uses n-alkane microcapsule phase change material as the temperature control component and porous minerals as the carrier. It can be made into strips, blankets, or granules. It is used to accelerate the adsorption of floating oil on the water surface by reducing the surface energy through volume expansion when the temperature is higher than its phase change temperature. The phase change temperature range of the microcapsule phase change material is -5°C to 15°C. The composite adsorption material has an oil absorption ratio of ≥25 times its own weight for solidified / semi-solidified VLSFO / MGO low-sulfur oil spills in an environment of -10°C. A flexible heating adsorption unit is composed of a flexible substrate and high-temperature phase change microcapsules loaded on the flexible substrate. The phase change temperature of the high-temperature phase change microcapsules is 30-50℃. They are used to reduce the viscosity of the solidified oil layer on the ice surface after endothermic melting and to complete the adsorption simultaneously. Thermal storage and energy module, wherein the thermal storage and energy module comprises at least: The heat source unit includes a solar vacuum tube collector and a waste heat exchanger from a ship engine, and is equipped with an intelligent switching valve to provide heat according to a waste heat priority and solar energy supplementation strategy. A phase change heat storage tank, wherein the interior of the phase change heat storage tank is filled with a high-density phase change material, the phase change temperature of which is 50-120°C, and is used to store heat from the heat source unit in the form of latent heat. The heat exchange fluid loop uses antifreeze as the heat transfer medium and is connected to the heat storage tank, the heat source unit and the regeneration device through a variable frequency pump and insulated pipeline to form a closed loop. A regeneration and recycling module, wherein the regeneration and recycling module comprises at least: The regeneration device is a closed container with a heating jacket, used to receive the temperature-sensitive adsorption unit and / or flexible heating adsorption unit after saturation adsorption, and to heat up and desorb the adsorbent material through the heat provided by the heat exchange fluid circuit. An oil-water separation and collection device is connected to the bottom outlet of a regeneration device and is used to perform gravity-coalescence composite separation and recovery of desorbed oil. and an intelligent control unit, the intelligent control unit being used for: (a) Automatically select and deploy the corresponding adsorption units based on ambient temperature, oil spill pattern and ship operating conditions; (b) Control the flow rate and temperature of the heat exchange fluid circuit to keep the heating rate of the adsorbent material in the regeneration device at 0.5-2℃ / s until the oil viscosity is reduced to <200 cP and desorption is completed. (c) After desorption is completed, start the cooling fan to cool the adsorbent material to below its MPCM phase transition temperature before putting it back into use.

2. The system according to claim 1, characterized in that, The core material of the n-alkane microcapsules in the composite adsorbent material is a C12-C16 straight-chain alkane, and the shell material is melamine-formaldehyde or urea-formaldehyde resin, and the microcapsules account for 15-35 wt% of the total mass of the composite material.

3. The system according to claim 1 or 2, wherein the porous mineral is selected from one or more of diatomaceous earth, expanded perlite, organic aerogel or foam metal, and has a BET specific surface area ≥30 m² / g and a pore size distribution with a main peak in the range of 2-50 nm.

4. The system according to claim 1, wherein the flexible substrate is PET nonwoven fabric, ceramic fiber blanket or polymer fiber felt, with a unit area mass of 80-300 g / m², the phase change temperature range of the high-temperature phase change microcapsules is 30°C to 50°C, the core phase change material is selected from paraffin or fatty acid mixture, and the high-temperature phase change microcapsules are fixed on the surface of the flexible substrate by acrylate pressure-sensitive adhesive or silane coupling agent, with a fixing amount of 20-60 g / m².

5. The system according to claim 1, characterized in that, The high-density phase change material is one or more of a molten salt mixture or a composite hydrated salt, and the phase change heat storage tank is provided with finned heat exchange tubes along the axial direction to increase the heat exchange area and reduce the heat storage / release time constant to <15 min.

6. The system according to claim 1, characterized in that, The inner wall of the heating jacket of the regeneration device is provided with spiral guide ribs to make the heat exchange fluid form turbulence, improve the heating uniformity of the adsorbent material, and the outer wall of the jacket is covered with an aerogel insulation layer to keep the surface temperature <45℃.

7. The system according to claim 1, characterized in that, The oil-water separation and collection device includes: A primary gravity settling chamber, wherein an adjustable weir plate is provided at the bottom of the primary gravity settling chamber for first separating free water; A secondary coalescing separation filter element, wherein the secondary coalescing separation filter element is a hydrophobic-oleophilic fiber bundle with a coalescing efficiency of ≥95%, is used to remove residual water droplets; And oil storage tanks, the top of which is equipped with a breather valve and a liquid level sensor for closed-loop recycling.

8. An operating method for using the system according to any one of claims 1-7 for polar oil spill recovery, characterized in that, Includes the following steps: S1. Adsorption operation: When oil spill on ice surface is detected, the flexible heating adsorption unit is deployed to use the low ambient temperature to solidify the high temperature phase change microcapsules and release latent heat, locally raising the temperature by 2-5°C, reducing the viscosity of the oil layer and completing adsorption within 30 minutes; when oil spill on water surface is detected, the temperature-sensitive adsorption unit is deployed to use the heat of the water to melt the n-alkane microcapsules and absorb the oil. S2. Collection and preparation: The saturated adsorption unit is recovered by a blanket roller or net bag and transported to the regeneration unit; S3, Heat Storage and Regeneration: The intelligent control unit prioritizes the activation of the waste heat exchanger of the ship's engine to store heat in the phase change heat storage tank. When the temperature inside the tank is ≥80℃, the variable frequency pump is started to pump the high-temperature antifreeze into the jacket of the regeneration device at a flow rate of 5-15 L / min, so that the adsorbent material is heated to 70-90℃ within 15-40 minutes, and the oil is desorbed. S4. Oil recovery: The desorbed oil-water mixture enters the oil-water separation and collection device. Under the dual action of gravity and coalescence, the oil recovery rate is ≥90% and the oil content in the effluent is <10 ppm. S5. Cooling and Reuse: Turn on the cooling fan to cool the adsorbent material to <20℃ within 10 minutes, and then place it again to achieve recycling.

9. The method according to claim 8, characterized in that, In step S3, when the ship is in a stopped state and the outlet temperature of the solar collector is >60°C, the intelligent control unit automatically switches to solar heating mode and reduces the speed of the variable frequency pump to 30-50% of the rated value to extend the heat storage time and save energy.

10. A composite adsorbent material for use in the system of claim 1, characterized in that, Prepared by the following method: a) After heating n-dodecane to 50°C to melt it, add Span-80 emulsifier and emulsify at 800 rpm for 10 min to form an O / W emulsion; b) Melamine-formaldehyde prepolymer was added dropwise to the above emulsion, the pH was adjusted to 4.5-5.0 with citric acid, and polymerization was carried out at 70°C for 2 hours to obtain n-dodecane microcapsules; c) The microcapsules are mixed with diatomaceous earth at a mass ratio of 1:2-1:4, and 5 wt% sodium silicate solution is sprayed as a binder. The mixture is then dried at 120°C to obtain a granular composite adsorbent material. d) The oil absorption ratio of the composite adsorbent material is ≥25 g / g, and it can still maintain >60% saturated oil absorption capacity at 0℃.

11. The composite adsorbent material according to claim 10, characterized in that, The particulate composite adsorbent material has a particle size of 1-5 mm, a bulk density of 0.3-0.5 g / cm³, and an oil absorption ratio decrease of <10% after 20 adsorption-regeneration cycles.

12. A flexible heating and adsorption blanket for use in the system of claim 1, characterized in that, include: Ceramic fiber blanket substrate, thickness 3-8 mm; Paraffin MPCM / EVA hot melt adhesive composite layer, the composite layer is coated on one side of ceramic fiber blanket, the coating amount is 30-50 g / m², and the phase change temperature is 35-45℃; And PTFE edge banding strips, used to prevent the MPCM from falling off due to seawater erosion; The flexible heating and adsorption blanket has a saturated oil absorption capacity of ≥2 kg / m² per unit area and can be bent 180° at -20℃ without cracking.

Images