Shell Chemical LP began construction Tuesday on its $717 million linear alpha olefins manufacturing plant in Geismar.

The plant will produce about 468,000 tons of alpha olefins a year. The new facility will make Shell’s Geismar campus the largest single-site producer of alpha olefins in the world, with more than 1.4 million tons in annual production capacity.

The project will add 20 new jobs paying an average of $104,000 to the 650 jobs already at Shell Geismar, as well as generating an estimated 93 indirect jobs.

Shell announced the project in late 2015. Alpha olefins are chemicals used to produce a variety of consumer and industrial products, including stronger and lighter plastics for packaging and bottles as well as engine and industrial oils and drilling fluids.

Shell has three alpha olefins units on its 800-acre Geismar site, which lies on the east bank of the Mississippi River.