C15 - Haber process

used to manufacture ammonia - for nitrogen fertiliser

hydrogen nitrogen

natural gas

air

• purified gases are passed over iron catalyst at high temp + pressure • react to form ammonia -ammonia is removed by cooling gases = liquifies • separated from unreacted gases • recycled into reaction mixture • recompressed/heated before returning to reaction vessel

• some ammonia produced breaks down

-free from air -costs to separate from other gases (fractional distillation) - cooling process air must be pressurised - expensive pumps

• react methane with steam at high temps

water = cheap - heating is expensive -methane = expensive

-volume of reactants > products - favours forward reaction

• colder temps -max pressure

expensive vessels

uses 200 atmospheres - reduces cost but reasonable yield

forward reaction = exothermic - lower temps favours forward

450 .c

rate of reaction is slowed = less frequent collisions of gas - must be quick = economical - reduces effect of iron catalyst

• speeds up both reaction • doesn’t affect yield • speeds up rate of production to be economical

to make nitric acid

reacts with more ammonia -makes ammonium nitrate fertiliser

alkali

ammonium sulfate fertiliser

-ammonium phosphate fertiliser

sulfuric phosphoric

contain formulation of compounds to provide all 3 elements - to improve agriculture -nitrogen, phosphorus, potassium