Supplying energy sustainably

Question 1

what is teh main source of greenhouse gas and pollutant emissions

Answer 1

burning fossil fuels

Question 2

green house gas emissions in fuel cells vs coal-fired power stations

Answer 2

fuel cells produce a lower volume of greenhouse gases

Question 3

what are the two practical methods of generating hydrogen sustainbly

Answer 3

using electricity to convert water to hydrogen oir collecting biogas from landfill sites and converting the methane in the gas tyo hydrogen by steam refoir=rming

Question 4

steam reforming

Answer 4

where steam reacts with fossil fuels at a high temperature in the presence of a nickel catalyst to produce hydrogen

Question 5

what are the chemical equations for steam reforming

Answer 5

CH4 (g) + H2O(g) = (ni above arrow) CO (g) + 3H2 (g). the carbon monoxide generated can then be used to produce further hydrogen. CO (g) + H2O (g) = (Cu or Fe above arrow) CO2 (g) + H2 (g)

Question 6

what are the negatives of steam reforming

Answer 6

the hydrogen produced has a lower energy content than the original fuel, as some of the original chemical energy of these exothermic reactions is lost as waste heat during production. steam reforming also leads to carbon dioxide emisssions

Question 7

what is the solution to CO2 emissions in steam reforming

Answer 7

as CO2 is produced at the site of steam reforming, it can be captured at its source and stored, preventing its release to the atmosphere

Question 8

what is the new way of storing hydrogen

Answer 8

materials-based storage

Question 9

materials based storage

Answer 9

techniques that use materials, solids or liquids, that can absorb or react with hydrogen and then release it when needed