Production
Industrially, propylene glycol is produced from propylene oxide, and global capacity in 1990 was 900,000 tonnes per year. Different manufacturers use either non-catalytic high-temperature process at 200 °C (392 °F) to 220 °C (428 °F), or a catalytic method, which proceeds at 150 °C (302 °F) to 180 °C (356 °F) in the presence of ion exchange resin or a small amount of sulfuric acid or alkali.
Final products contain 20% 1,2-propanediol, 1.5% of dipropylene glycol and small amounts of other polypropylene glycols. Further purification produces finished industrial grade or USP/JP/EP/BP grade propylene glycol that is typically 99.5% or greater. Propylene glycol can also be converted from glycerol, a biodiesel byproduct.
Read more about this topic: Propylene Glycol
Famous quotes containing the word production:
“... this dream that men shall cease to waste strength in competition and shall come to pool their powers of production is coming to pass all over the earth.”
—Jane Addams (1860–1935)
“In the production of the necessaries of life Nature is ready enough to assist man.”
—Henry David Thoreau (1817–1862)
“The myth of unlimited production brings war in its train as inevitably as clouds announce a storm.”
—Albert Camus (1913–1960)