Customer case study: Pat Munro

Scottish asphalt pioneer reduces carbon footprint by up to a quarter with greener fuel

One of the largest privately owned contractors in the Scottish Highlands has reduced the annual carbon emissions of their asphalt plant by 25% – and its fuel costs by almost 19% – after replacing its outdated gas oil burner system with an LPG (liquefied petroleum gas) alternative from Flogas.

As part of its operations, Alness-based Pat Munro owns and operates its own quarries and manufactures its own roadstone and concrete – working with traditional quarry materials (including sand & gravel aggregates and crushed rock), as well as recycled aggregates and its own-brand cold-lay tarmacadam.

With production creating a huge annual heat demand, the company was previously using up to half a million litres of gas oil to heat tens of thousands of tonnes of rock in its roto dryer every year (generating 1,114 tonnes of CO₂e in the process). After working with leading national energy specialist Flogas, Pat Munro is now benefiting from a cleaner, more cost-effective LPG heating system – one that has improved the efficiency of the rock drying process overall.

Assessing the clients needs

After assessing Pat Munro’s energy needs, the Flogas team project managed the switchover from start to finish.

This included specifying, designing and installing the bespoke dual-fuel system, which is made up of a 9MW Benninghoven burner (compatible with both oil and LPG) and three LPG tanks.

The tanks are each fitted with an automatic ordering telemetry system – ensuring that their LPG demand is fulfilled routinely, with supply arriving directly from the nearest Flogas depot just three miles away.

Garry Wilson, Key Accounts Manager at Flogas, says: “The team at Pat Munro were always keen to reduce their environmental impact and improve their energy performance with a move away from oil, but once we had done the initial calculations for the site the true scale of the savings opportunity really became clear.

The switch to LPG was a win-win situation for all: a seamless changeover, a smaller carbon footprint, lower fuel and maintenance costs and less air pollution.”

In fact, according to UK Government Greenhouse Gas Emissions data, the reduction in air pollution associated with switching from oil to LPG includes up to 43% fewer methane emissions, and an reduction of up to 99% of the heavily polluting nitrous oxide emissions associated with gas oil.

“Asphalt production is obviously a very energy-intensive process, so we were keen to find a new fuel solution that would not only deliver financial and carbon savings, but that would help boost the efficiency of our operations.

However, another major challenge was ensuring that we minimise production downtime, so any lengthy install that would require a long system shutdown was off the table. “Flogas’ LPG solution appealed to us because it ticked all the boxes. Initial projections showed that we could process the same volume of material but cut our yearly CO₂e emissions by 25% per tonne of asphalt, reducing costs by almost 19%.

Figures that speak for themselves! “Replacing our existing system with a dual-fuel burner meant the switchover from oil to LPG was as seamless as possible, which dealt with any worries around disruption to production.

Flogas ensured the new burner worked with our existing oil infrastructure and scheduled the install to coincide with our usual shutdown period; only switching on the LPG once everything was in place. As well as the fuel savings from using LPG, putting in a more modern burner also made sense from a long-term perspective: we’ve made a 6% efficiency saving from the new system alone.”

Steve Munro
Director at Pat Munro