Editing Sulfuric acid (section)

=== Contact process ===
In 1831, British [[vinegar]] merchant Peregrine Phillips patented the [[contact process]], which was a far more economical process for producing sulfur trioxide and concentrated sulfuric acid. Today, nearly all of the world's sulfuric acid is produced using this method.<ref name="z1">{{cite book |author=Philip J. Chenier |url=https://books.google.com/books?id=KlziQA-yx3gC&pg=PA28 |title=Survey of industrial chemistry |date=1 April 2002 |publisher=Springer |isbn=978-0-306-47246-6 |pages=28– |access-date=23 December 2011}}</ref>

In the early to mid 19th century "vitriol" plants existed, among other places, in [[Prestonpans]] in Scotland, [[Shropshire]] and the [[Lagan Valley]] in [[County Antrim]], [[Northern Ireland]], where it was used as a bleach for linen. Early bleaching of linen was done using lactic acid from sour milk but this was a slow process and the use of vitriol sped up the bleaching process.<ref>{{cite book|title=A history of lactic acid making: a chapter in the history of biotechnology|last=(Harm)|first=Benninga, H.|date=1990|publisher=Kluwer Academic Publishers|isbn=9780792306252|location=Dordrecht [Netherland]|oclc=20852966|page=4}}</ref>