Production & uses of ethylene

Production of ethylene & commercial/industrial uses

Gas phase process

• high pressure of 1000-3000 atmospheres, 300⁰C with a organic peroxide compound containing [-O–O-] which breaks to form free radicals which begin breaking the double bonds in ethylene and commences joining them together
• significant chain branching – at some carbon atoms one H atom is replaced by an alkyl group.
• alkane chains cannot pack together closely or in an orderly way: low density polyethylene

Ziegler-Natta process

• pressure of a few atmospheres, around 600C, using a catalyst which is a mixture of titanium (III) chloride and a trialkylaluminium compound.
• unbranched polyethylene molecules, which pack closely together in an orderly fashion: high density polyethylene

LDPE	HDPE
cling wrap, plastic bags, milk bottles	kitchen utensils, toys, plastic containers
insulation of wires & cables	pipes to carry natural gas
	building materials