As part of Rock Oil’s long-term commitment to sustainability and energy efficiency, a strategic review of our blending processes identified an urgent need to reduce our carbon footprint. Historically, lubricant blending relied on mechanical agitation and steam heat – a process that consumed large amounts of energy, required constant boiler maintenance, and emitted up to 80 kg of CO₂ per metric tonne of blended product.
In 2023, Rock Oil invested in ultrasonic blending technology – an innovative process supported by the Industrial Energy Transformation Fund (IETF). The initiative formed part of a broader company-wide carbon reduction programme, aiming for a 90% cut in total site emissions within seven years.
Technology Overview: What is Ultrasonic Blending?
Ultrasonic blending uses high-frequency sound waves to create microscopic cavitation bubbles that collapse with intense energy. This action:
- Enhances additive dispersion
- Reduces particle size
- Improves product homogeneity
Unlike traditional methods reliant on heat and prolonged mixing, ultrasound operates at ambient temperature, minimising fossil fuel use and enabling a cleaner, faster process. The units also require minimal electrical energy – just 3 kWh – making them a highly efficient addition to Rock Oil’s operations.
Project Objectives
The trial set out to:
- Compare CO₂ emissions per metric tonne blended versus 2022/23 baseline
- Evaluate mixing time and production efficiency
- Assess Right First Time (RFT) pass rates and overall product stability
- Monitor operational uptime, especially during boiler servicing windows
Implementation
The new system was installed with support from the IETF Phase 2 programme. While the technology is now the default for the majority of blends, steam has not been entirely eliminated. The existing boiler system remains in place to serve the heated tanks, hotbox, and a limited number of blends requiring temperatures above the ultrasonic threshold of 70°C.
Nonetheless, the shift to point-of-use ultrasonic energy has significantly reduced the need for high-volume, energy-intensive heating and has allowed Rock Oil to:
- Substantially reduce reliance on steam
- Complete a site-wide installation safely and without production disruption
- Reduce minimum batch sizes from 4 metric tonnes to as low as 660 kg, supporting more flexible, strategic raw material usage and reduced stockholding requirements
Results Summary – Comparing 2022/23 to 2024/25
| Metric | 2022/23 | 2024/25 | Change |
|---|---|---|---|
| Average Blending Time (mins) | 219 | 107 | ↓ 51% |
| CO₂ (kg/MT Blended) | 80 | 63* | ↓ 21.36% |
| Total MT Blended | 5,262.67 | 6,168.63 | ↑ 17.2% |
*Site-wide average. Individual blends now achieve as low as 15 kg/MT. While a temporary increase in CO₂ emissions was reported in one of our IETF six-monthly updates due to specific operational factors, the annual figure remains on track and reflects a meaningful reduction overall.
Operational Efficiency
- No downtime linked to boiler maintenance or breakdown
- Improved scheduling and output capacity
- Consistent ‘On Time In Full’ customer deliveries maintained throughout the trial
Product Quality
| Metric | 2022/23 | 2024/25 | Change |
|---|---|---|---|
| RFT (%) | 94.0 | 95.1 | ↑ 1.1 |
- Less rework, less waste, and reduced energy used per batch
- Superior lubricant performance and product shelf-life
- Greater consistency in blending across engine oils, hydraulic fluids, and metalworking emulsions
Environmental and Safety Gains
- Up to 70% reduction in total energy used per tonne blended
- Elimination of hot surfaces in blending area – improving plant safety
- Improved air quality for operators
- Clear alignment with Scope 1 and 2 emission reductions
Reflections and Industry Impact
Rock Oil’s adoption of ultrasonic blending – in a sector where traditional practices dominate – signals a decisive step towards leadership in sustainable British manufacturing.
The move demonstrates that decarbonising industrial processes is not only possible but commercially and operationally viable – with benefits that extend across supply chains and customer relationships.
Next Steps
- Continue optimising ultrasound parameters for wider blend types
- Expand tracking of CO₂ savings across product ranges
- Collaborate with industry partners and the government to share findings
To find out more about Rock Oil’s sustainability programme or to explore our ultrasound blending capabilities, please get in touch with our team.