5.6.1a Other Fuels Hydrogen Alcohol

Other Fuels Hydrogen CH4 + H2O = 3 H2 + CO Production Method 1 Steam Reforming of Natural Gas CH4 + H2O = 3 H2 + CO In presence of a suitable catalyst

Other Fuels Production Method 2 Electrolysis of Water using dilute H2SO4 as catalyst forms at cathode [negative electrode] Overall H2O = H2 + 1/2 O2 Too expensive in most parts of world

Other Fuels Production Method 3 During cat-cracking of long chain alkanes not a very important method

Other Fuels Uses of Hydrogen Haber Process for producing ammonia N2 + 3 H2 = 2 NH3 Hydrogenating vegetable oils Organic synthesis

Other Fuels Fuel - about 10% of worlds production of hydrogen is used as fuel Environmentally friendly Water is the only product of combustion H2 + 1/2 O2 = H2O Major problem it is explosive with air Difficulties with storage and transport due to this and pressure

Challenger Click here to see Challenger

Click button to see hydrogen car video

Hindenburg Click here to see the Hindenburg

Petrol versus Hydrogen Hydrogen 1299 kJ mol-1 [Heat of combustion] Petrol 5512 kJ mol-1 [Heat of combustion] 1kg petrol 48350 kJ 1 kg hydrogen 649500 kJ [kilogram calorific value] Hydrogen gives 13.4 times more heat per kg

Alcohol C2H5OH + 3½ O2 = 2 CO2 + 3 H2O Can be made from waste sugar cane or any other natural sugar source e.g. sugar beet Doesn’t really add to greenhouse effect Growing plants removes C from the air and then returns it. Can add up to 20% alcohol to petrol without changing engine [Gasohol] common in South America

Biodiesel Made from rape seed oil and used cooking fat. Doesn’t add to greenhouse effect Plants remove C from air then return it Available now in some european countries