text: The process has a high energy consumption, for example around  of electricity per tonne of sodium hydroxide produced. Because the process yields equivalent amounts of chlorine and sodium hydroxide (two moles of sodium hydroxide per mole of chlorine), it is necessary to find a use for these products in the same proportion. For every mole of chlorine produced, one mole of hydrogen is produced. Much of this hydrogen is used to produce hydrochloric acid, ammonia, hydrogen peroxide, or is burned for power and/or steam production.
  History
  The chloralkali process has been in use since the 19th century and is a primary industry in the United States, Western Europe, and Japan. It has become the principal source of chlorine during the 20th century. The diaphragm cell process and the mercury cell process have been used for over 100 years but are environmentally unfriendly through their use of asbestos and mercury, respectively. The membrane cell process, which was only developed in the past 60 years, is a superior method with its improved energy efficiency and lack of harmful chemicals.
  Although the first formation of chlorine by the electrolysis of brine was attributed to chemist William Cruikshank in 1800, it was 90 years later that the electrolytic method was used successfully on a commercial scale. Industrial scale production began in 1892. In 1833, Faraday formulated the laws that governed the electrolysis of aqueous solutions, and patents were issued to Cook and Watt in 1851 and to Stanley in 1853 for the electrolytic production of chlorine from brine.