Pilbara-based AshOil and catering group ESS Support Services Worldwide have won a major state environmental award.
The businesses have received the state government’s Golden Gecko award for environmental excellence, for cutting carbon emissions by recycling cooking oil.
The two parties, which signed an exclusive agreement last year, recycle 200,000 litres of ESS's used cooking oil each year.
The joint venture production began about four years ago, with ESS increasing its supply of cooking oil to AshOil once the arrangement was finalised under an exclusive agreement.
It also has a sponsorship agreement with BP, which has allowed AshOil to operate its used cooking oil collection truck.
Mines and Petroleum Minister Bill Marmion said the biodiesel project, which saves about 500 tonnes of greenhouse gasses a year, was the equivalent of taking 100 cars off the road permanently.
"We have ambitions to use a byproduct of the biodiesel production, which is called glycerol, into soap manufacture," Mr Milburn said.
"ESS is heavily involved in the collection of soap ends from their villages and returning those to our plant. Whilst that development is in its infancy, it is also an exciting and challenging aspect ... which would mean that we would have no waste on any product that comes into our plant."
Franmarine Underwater Services and the Department of Fisheries won a certificate of merit from the Golden Gecko awards.
They were recognised for their trial that cleans the hulls of large vessels while they remain in water.
The Golden Gecko awards are named after the lizard species, whose return to industrially developed areas once they are rehabilitated can often indicate a return to a healthy ecosystem.