Challenges of Raney Nickel Catalyst Filtration in the Edible Oil Industry
Case Study
Raney Nickel (RN) is widely employed in the edible oil industry, primarily for hydrogenation reactions that modify the unsaturation levels of oils and fats. Despite its prevalent use, the filtration and recovery of RN pose significant challenges. These challenges stem from the fine particle size of the catalyst, its tendency to agglomerate, and the residual oil left in the filter cake, all of which complicate the separation process. The inability to efficiently recover the catalyst leads to higher consumption and operational inefficiencies, which significantly impact both costs and the environment.
Characteristics of Edible Oils & Filtration Process Conditions
The filtration process for hydrogenated oils is highly demanding. The viscosity of edible oils typically ranges from 40 to 80 cP, depending on the oil type and temperature. The hydrogenation process occurs at temperatures between 110°C and 180°C, with operating pressures generally between 1 and 5 bar. Filtration flux typically ranges from 50 to 80 L/m²/h, depending on the type of filter and the viscosity of the oil. The particle size of Raney Nickel catalyst typically varies from 1 to 10 microns, further complicating the filtration and recovery process.
Challenges in Raney Nickel Filtration
The challenges in Raney Nickel filtration arise primarily due to the characteristics of both the catalyst and the oils used in hydrogenation. These challenges include:
- High Catalyst Losses: Traditional filtration systems struggle to recover fine RN particles, leading to significant catalyst losses.
- Clogging of Filters: The fine particles of RN and the high viscosity of the oil cause frequent clogging of the filter media.
- High Oil Retention in Cake: Conventional filters retain substantial amounts of oil in the cake, which reduces the overall yield.
- Operational Downtime: The frequent replacement of filter media results in higher downtime and increased labour costs.
- Waste Management Issues: Spent RN catalyst and oil-laden filter cakes create disposal challenges, contributing to environmental concerns.
Real-Life Challenges & Approach by Diva Envitec
A major edible oil producer was facing significant RN filtration challenges using traditional leaf filters. These included:
- Frequent clogging and low flux rates (~50 L/m²/h).
- High oil retention in filter cake (~5-7%).
- Catalyst loss of around 15-20% per batch.
To address these issues, Diva Envtec implemented CONTUFILT-RN technology by optimising filtration parameters to enhance separation efficiency. The company replaced the existing leaf filters with CONTUFILT-RN for continuous operation and optimised vacuum settings to achieve a catalyst recovery rate exceeding 98%.
Existing Filtration Technologies
The edible oil industry has relied on various filtration technologies to address the challenges of Raney Nickel recovery, though each has its limitations:
- Leaf Filters: Widely used but prone to clogging and requiring frequent maintenance.
- Pressure Nutsches: Effective for small-scale operations but inefficient for large volumes.
- Candle Filters: Provide better separation but struggle with fine RN particles.
- Centrifuges: Require high capital investment and offer only moderate separation efficiency, making them less practical for some operations.
Transition to CONTUFILT-RN Vacuum Fused Metallic Filtration
In response to these challenges, CONTUFILT-RN was introduced as an advanced vacuum-based fused metallic filtration technology. Designed for high-efficiency separation of RN catalyst from hydrogenated oils, CONTUFILT-RN offers a significant improvement over traditional methods.
Advantages of CONTUFILT-RN
The implementation of CONTUFILT-RN technology provides several key benefits, including:
- High Catalyst Recovery (>98%): This drastically reduces catalyst consumption and lowers operational costs.
- Low Oil Retention: The filter media is optimised to reduce oil loss in the cake, improving yield.
- Self-Cleaning Mechanism: This feature reduces operational downtime and extends the life of the filter.
- Continuous Operation: Unlike batch-based systems, CONTUFILT-RN allows for continuous processing, improving overall efficiency.
- Lower Maintenance & Waste Generation: The durable metallic construction reduces the need for filter replacements and minimises environmental impact.
Key Benefits Achieved
The implementation of CONTUFILT-RN led to several measurable improvements:
- Increased Flux: The filtration flux increased to 150-200 L/m²/h, reducing processing time and enhancing efficiency.
- Reduced Oil Loss: Oil retention in the filter cake was reduced to less than 1%, increasing yield.
- Cost Savings: Catalyst consumption was reduced by 30%, leading to significant cost savings.
- Environmental Compliance: Waste generation was reduced, improving sustainability and reducing environmental impact.
Conclusion
The transition from traditional filtration methods to CONTUFILT-RN technology has proven to be highly beneficial for the edible oil industry. By improving filtration efficiency, reducing operational costs, and enhancing sustainability, CONTUFILT-RN effectively addresses the challenges of Raney Nickel catalyst recovery and oil processing. Diva Envtec demonstrated how advanced filtration solutions can transform operations, yielding both economic and environmental benefits. For edible oil manufacturers seeking to optimise filtration efficiency, reduce costs, and ensure compliance with environmental standards, CONTUFILT-RN offers a compelling solution.
