The Indian United Biodiesel (UB) subsidiary of Californian renewable fuels and biochemicals firm Aemetis has reached a production milestone of 1M lbs (453 tonnes) of advanced enzymatic biodiesel from low-grade waste feedstocks.

Produced at a 50M gallon (227.3M litre) capacity plant in Kakinada, Andra Pradesh, the fuel was produced from high-free fatty acid (FFA) waste oils, including brown grease, low-grade used cooking oil (UCO) palm fatty acid distillate and other waste plant oils, UB said in a 5 October statement.

The UB facility developed the patent-pending enzymatic biodiesel process technology, designed and built the process reactors and was now converting the feedstock into biodiesel.

“Through our internal development of pre-treatment processing of low quality waste oil feedstocks, we were able to unlock the advanced enzymatic biodiesel technology potential for commercial viability,” said Sanjeev Gupta, UB managing director.

“Using enzymes in our unique process technology opens new feedstock opportunities that will increase profitability,” he added.

The high-FFA feedstocks were typically not economical to convert into biodiesel, but the Aemetis technology lowered production costs due to the pre-treatment conversion process using less energy and fewer chemicals, according to the company.

Additionally, the low-grade feedstocks cost only about one-third of the price of traditional feedstocks and had less price volatility as alternative market avenues for them were limited, which Aemetis anticipated to have a positive effect on its profit margins.

The process technology also had a low capital cost, which could allow for its widespread and low-cost adoption throughout the biodiesel industry.

The waste oils were delivered to the Kakinada plant by BP Singapore, which also sold the produced biodiesel forward to Europe and the USA, as per a three-year contract between Aemetis and BP Singapore signed in May.

Aemetis filed a patent for the pretreatment process used by UB in April 2017.