INTRODUCTION: SOCIOECONOMIC ASPECTS OF BIOMASS CONVERSION - Biomass as a Sustainable Energy Source for the Future - page 32

1.24 Would it be possible to realize a net removal of CO 2 from the atmosphere using
biomass conversion processes?

PROBLEMS

1.1 The current primary energy use is approximately 12 GTOE (Gigatonnes of oil
equivalent); what is this expressed in EJ?

1.2 From Figure 1.1, estimate the energy use per capita in the world in 2030 relative
to that in 2010. How does this compare to the values of China and India,
respectively?

year −1 carbon into the atmosphere in the form of
CO 2 . Assume the atmosphere is 20 km high. What will be the yearly increase of
the CO 2 mass fraction in the atmosphere if no additional sorption in the seas and
land can be accommodated?

1.3 Consider that man emits 7 Gt

1.4 If energy crops are going to be used to supply 100 EJ of global primary energy
input and given that an energy crop has a yield of 15 t ha −1 with an energy content

kg −1 (as received basis), how many hectares (ha) are needed as crop-
land? Comment on the result of your calculation. What might be complications
in such a scenario?

of 15 MJ

1.5 In 1977, Marchetti (1977) introduced a type of analysis of fuel source market
penetration for the global energy market, characterized by the following equation
(with F being the fraction of the market penetrated):

1
F

dF
dt =

α

ð 1 − F Þ

a. What is F as a function of t ?
b. Comment on the predictions made by this researcher concerning the current
global energy source mix.

1.6 Regarding resource availability, Hubbert development is a well-

known model (Brandt, 2007). Look up in the literature what it comprises and
provide the expression. Is this model always valid for natural resources?

' s “ peak oil ”

PROJECTS

P1.1 Investigate the literature about the usage of biomass for energy supply to man-

ufacturing processes before the Industrial Revolution. Concentrate, e.g., on the
Chinese, Greek, and Roman Empire or on Europe in medieval times.