The company is installing rendering machinery in the 1121sq m building and expects to commission the facility next month.
The technology was designed to reduce the company's energy and operating costs, as well as improve product recovery.
The new plant was the first stage in a larger rendering development project and two further stages are proposed.
The complete project would save 9000 tonnes of lignite and more than 1.5 million KWh of electricity a year - enough to power 170 homes every year.
The plant represented the largest single investment at Lorneville for more than a decade, Alliance processing managing John Brader said.
"Completion of the building marks a major milestone for the development. Rendering remains a significant contributor to Alliance Group's income and the investment in the latest technology will ensure we maximise revenue in this area," he said.
Since 2000, Alliance Group has reduced greenhouse gas emissions from energy use at its processing plants by 26% per unit of production and total fuel use has been reduced by 32%.