BIOREFINERIES: INTEGRATION OF DIFFERENT TECHNOLOGIES - Biomass as a Sustainable Energy Source for the Future - page 497

PROJECTS

P15.1 Visit an existing biorefinery, like a sugar mill or a potato factory. What
type of biorefinery is it? Try to set up mass and energy balances for
this plant.

P15.2 You can make your own biodiesel and glycerol from a biomass-derived
source. Find a synthesis description in literature. Select a vegetable oil and
perform in your lab the transesterification reaction producing this oil and
glycerol by-product. Now study the impact of air and/or light admission to
a test tube on the quality of the biodiesel obtained. Which physical character-
istics of the biodiesel can you use to perform this study as a function of time?
Which would be the best/most simple?

P15.3 Identify, by performing a literature survey, potential processes that might be

applied for processing lignin in a biorefinery completely based on biochem-
ical processes.

P15.4 This project deals with biorefining based on a cultivated crop in Kenya.
The main issue in producing biofuel from dedicated crops is that their rel-
atively high energetic value is generally directly linked to extensive
requirements with respect to growing conditions such as water and fertility
of soil and the intensive agricultural needs. This means that crops provid-
ing fuel(s) compete with food crops for nurturing a society. Furthermore,
locations that depend on large amounts of fuel are predominantly situated
in densely populated areas with limited means of agricultural activities.
Relocation to cheaper, less populated regions would induce an imbalance
regarding these locations that are prone to inequality in food yields to
start with.
Jatropha curcas is a plant that may positively address the aforemen-
tioned issues. This plant has originated in Central America and is now found
throughout the tropics, including Africa and Asia. The plant generates seeds
that are poisonous to humans and is a robust crop species, capable of grow-
ing on infertile, gravelly, sandy, or even saline soils. Therefore, it does not
require arable land, and since it thrives in warmer climates and is even tol-
erant to severe heat, it can be cultivated in areas that are not suitable for
food-based agriculture. Although it needs water to produce seeds, it can
withstand drought for as long as 2 years to regrow when irrigated. Its
robust characteristics reduce the labor effort otherwise involved in growing
vegetation and add to its benefits of yielding from otherwise arid patches
of land.
Estimates of yields of Jatropha seeds vary from 1.5 to 3.5 tonnes/ha,
which translates into roughly 540

1260 l of Jatropha oil per ha (Dar,
2007; Ofori-Boateng and Teon, 2011), with potential for improvement.
With the large amounts of oil needed, it is hard to stake claims on its pro-
duction not diverting resources away from crops that are used for food

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