Re-refining of Waste Oil with OSN Membranes
As industries grapple with growing calls for environmental responsibility, many traditional practices are being re-evaluated in favor of more eco-friendly alternatives. One such area of focus is waste oil re-refining, a solution that aims to mitigate the many consequences of its disposal and management.
What is Waste Oil Re-refining?
Waste oil re-refining is an important method designed to reclaim used oils and restore the base oil to a quality comparable to that of newly processed oil. Re-refining plays a role in the broader waste oil recycling process, which involves the collection, cleaning, and reprocessing of various used oils including motor oils, lubricants, and hydraulic fluids. Converting this waste into reusable products can minimize environmental impact, conserve natural resources, and generate economic benefits.
The Advantages of Waste Oil Re-Refining
1. Waste Oil Disposal
Every year, around 1.3 billion gallons of waste oil are produced in the United States, with nearly 40% of this oil ending up in disposal rather than being recycled. Waste oil, which includes both synthetic and mineral oils, often contains a mixture of contaminants. These include carbon deposits from incomplete combustion, metal particles from engine wear corrosion, water from engine operations and storage, and spent additives originally added to enhance oil’s properties. Due to these hazardous components, improper waste oil disposal can pollute the air, water, and soil, degrading the environment.
On the other hand, waste oil re-refining addresses this issue by recycling waste oil into valuable new products, supporting both environmental and economic sustainability.
2. Environmental Impact of Oil Production
Waste oil re-refining significantly diminishes the need for new raw materials, reducing the environmental impact associated with the production of base oil from crude oil. Conventional base oil production involves extensive extraction, refining, and processing of crude oil, all of which have considerable environmental costs. These include high energy consumption, greenhouse gas emissions, and habitat disruption. By recycling waste engine oil, we not only conserve valuable resources but also mitigate these environmental impacts.
3. Resource Efficiency
Re-refining waste oil is far more resource-efficient than producing base oil from crude oil. It takes just 42 liters of crude oil to produce 0.63 liters of new lubrication oil, and only 1 liter of recycled base oil to yield the same amount. In contrast, only about 8 liters of waste oil are needed to produce the same amount. This significant reduction demonstrates how re-refining makes better use of existing resources.
The Waste Oil Re-refining Process
Step 1: Collection
The re-refining process begins with the collection of waste oil from various sources, which include automotive engines, industrial machinery, heating systems, and manufacturing processes. Proper collection is essential to ensure the waste oil can be efficiently processed and recycled.
Step 2: Pre-Treatment
Once collected, the waste oil undergoes pre-treatment to prepare it for more intensive processing. This stage involves several key processes:
Dewatering
This stage involves the removal of water from waste oil. This can be achieved through gravity separation where water, being denser, settles at the bottom and is drained off. Alternatively, chemical dehydration agents can be used to facilitate water removal.
Demulsification
Waste oil often contains emulsified water. Chemical demulsifiers are used to break the emulsion and separate the water from the oil.
Filtration & Demineralization
Large contaminants such as dirt, metal particles, and other impurities are removed through filtration. This process involves passing the oil through various filters to capture and remove the contaminants. Additionally, further demineralization techniques may be used to eliminate mineral contaminants.
Step 3: Refining
The refined waste oil undergoes various methods to further purify and transform it into valuable products:
Solvent Refining
A compatible solvent is introduced to the waste oil to dissolve and remove unwanted molecules and contaminants. This process not only improves the purity and quality of the base oil but also supports sustainability, as the solvent can be recovered and reused.
Vacuum Distillation
The waste oil is heated to evaporate lighter fractions, such as water and volatiles. The remaining oil is then heated in the absence of oxygen to separate it into different components based on their boiling points. This technique helps in reducing the volume of waste and producing useful by-products, including gas and liquid fuel.
Hydrotreating
The oil is treated with hydrogen in the presence of a catalyst. This process removes impurities such as sulfur nitrogen, and oxygen, and enhances the oi’s stability, performance, and compliance with industry standards.
Step 4: Purification and Refining
Once separated, the oil is further purified and refined to remove any remaining impurities. This step involves advanced techniques to improve the quality of the oil, ensuring that the end product is both usable and compliant with industry standards.
Step 5: Blending
The base oil is then mixed with proprietary additives and other components to create finished products such as engine oil, lube oil, and other lubricants. This blending process ensures that the final product has the desired properties and performance characteristics.
How Organic Solvent Nanofiltration (OSN) Membranes Can Help
Despite numerous advantages that waste oil recycling offers, it still faces certain limitations.
Membrane-based filtration, in particular, Organic Solvent Nanofiltration (OSN) membrane technology offers several compelling advantages, including high separation efficiency, ease of scalability, a reduced footprint, and superior product quality. Therefore, OSN membranes are a revolutionary solution for making the overall industrial process of re-refining waste oil more sustainable.
How Does It Work?
OSN Membranes are employed during the solvent-refining stage of the re-refining process. Following the dewatering and fractionation process, the remaining mixture containing the base oil and other components is then treated with a suitable solvent. The solvent selectively dissolves the base oil, creating a solution that can be separated from the remaining components using OSN membranes.
The OSN membranes act as molecular sieves, allowing the base oil to pass through while retaining the solvent and other impurities. This results in a high-purity base oil product that can be blended with additives to produce new lubricants.
Benefits of Using OSN Membranes in Waste Oil Re-Refining
1. Efficient Contaminant Removal
With pores finer than 1 nanometer in size, OSN membranes offer advanced filtration capabilities, effectively separating fine particles and dissolved contaminants from the oil. This enhances the quality of the final product, resulting in a cleaner and more efficient waste oil re-refining process.
2. Greater Energy Efficiency
One of the standout benefits of OSN membranes is their exceptional energy efficiency. Unlike traditional methods, these membranes operate using a heatless, pressure-driven process, which reduces energy consumption by up to 90%. This also leads to operational cost savings of up to 50%, making them a cost-effective solution for industries aiming to enhance their sustainability practices.
3. Reduced Environmental Impact
By cutting energy consumption and decreasing the reliance on heat, these membranes lower greenhouse gas (GHG) emissions, further diminishing the overall carbon footprint of waste oil recovery.
Embracing Circularity with SepPure Technologies
As we look to the future of waste motor oil recycling equipment, it is clear that advanced technologies like OSN membranes will play an increasingly important role. By adopting these solutions, businesses can optimize their waste oil re-refining practices, reduce costs, and contribute to a more sustainable future.
For companies seeking to embrace circularity and revolutionize their operations, partner with an industry leader like SepPure Technologies. Our GreenMem® technology offers remarkable efficiency, sustainability, and cost savings in industrial operations, such as waste management, solvent recovery, and much more.
Our experts are ready to assist you. Contact us today to find out more!