Question

assume as students that you each use 1000 watts of power for 12 hours each day (lights, computers, class room air conditioning, etc). much of this energy in thailand is generated from coal. assume that the process is only 50% efficient, and if you use 1000 watts it really requires 2000 watts of coal power. calculate how much co2 is going into that atmosphere to maintain you at this level of energy consumption for each year and put your answer in metric tones/year co2.

How much deuterium would be necessary to supply your energy needs for one year ? 2 ²H------> ³He + ¹n

Answer 1

1000 watts= 1000 joule/sec

12 hours =12*60 =720 second

hence power for 12 hours= 1000 j/sec*720 sec =720000 joules

per year accounting for 365 days, power = 720000*365 joules=2.63*10⁸ joules

since the proces is 50% efficienct, hence power required = 2.628*10⁸*2 joules =5.256*10⁸ joules

Assuning calorific value of coal as 17000 joules/gm

coal required to supply the required power = 5.256*10⁸/17000 =30917.6 gm, moles of C= 2576.5 gmmoles

the combustion of C to CO2 is C+O2---->CO2

moles of CO2 generated= 2576.5 gmoles, mass of CO2 generated= 2576.5*44 gm=113364.5 gm =113.34 Kg CO2

D + D -> ³He + n + 3.27 MeV, equal to = 5.239117*10^-13 joules

2 moles of Deutirium produces 5.23*10^-13 joules. Energy required = 5.256*10⁸ joules

moles of deutirium required = 5.256*10⁸/ 5.23*10-13 =1.0*10²¹ moles=1*10²¹*2.014gm=2.014*10²¹ gm