Page 8 - Shimadzu Renewable Fuels Industry

Algae as a Renewable Fuel Source

The key to algae’s potential as a renewable fuel source lies in the high productivities of algal biomass that can be grown in a
given area; some researchers say algae could be 10 or even 100 times more productive than traditional bioenergy feedstocks.
Achieving the potential for these high productivities in real-world systems is a key challenge to realizing the promise of sustainable
and affordable algal biofuels. Once harvested, algae can be readily processed into the raw material to make fuel for cars, trucks,
trains, and planes.
Global warming due to the excessive use of fossil fuels is becoming a problem that has prompted and accelerated the search for
alternative fuels. Among the more attractive alternatives is biomass fuel, which is attracting considerable attention. Microalgae
can be used for the production of oil without competing with food production, and to a greater extent than other biofuels, its
productivity per unit time and area is high, while arable land selection possibilities are great. As for the practical use of microalgal
biomass, various studies have been conducted at each stage of its production, including stock selection and breeding, cultivation,
harvesting, oil extraction, and purification.

200
1
Carbon Content / Turbidity (mg/L) 100 TC TOC/TC or IC/TC (ratio) 0.6 TOC/TC
150
0.8

IC
IC/TC
TOC
50
0.4

0

-50 0.2 0
0 2 4 6 8 10 0 2 4 6 8 10
Culture Period (days)
Culture Period (days)
Changes in TC, IC, TOC Quantity in Microalgae Cells Changes in TOC/TC and IC/TC in Microalgae Cells
(Conversion value per turbidity unit)

The figure on the left shows the measurement results for the total carbon (TC), total organic carbon (TOC) and inorganic carbon
(IC) associated with the cell mass during the culture period. The ratios of TOC to IC in the microalgae cells are shown in the figure
on the right. From these results, it was possible to obtain information regarding the increase and decrease of TC, IC and TOC
values associated with the microalgae cells throughout the culture process.
One essential element in the practical realization of microalgal biomass is establishment of the culture conditions, and it is clear
from this study that information regarding the carbon balance can be obtained using a TOC analyzer.

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