Page 208 - Biofuels Refining and Performance

Chapter
7

Ethanol and Methanol as Fuels

in Internal Combustion Engines

B. B. Ghosh and Ahindra Nag

7.1 Introduction
The increasing industrialization and motorization of the world has led to
a steep rise in the demand of petroleum products. Petroleum-based fuels
are stored fuels in the earth. There are limited reserves of these stored
fuels, and they are irreplaceable. Figure 7.1 shows the difference in
demand and supply of petroleum products, and how this depletion will
create a problem before the world within a decade or two.
Geologists throughout the world have been searching for further
deposits. Although the present reserves seem vast, the accelerating con-
sumption is challenging the world to create new types of fuels to replace
the conventional ones. New oil reserves appear to grow arithmetically
while consumption is growing geometrically. Under this situation, when
consumption overtakes discovery, the world will be heading toward an
industrial disaster.
Apart from the problems of fast-vanishing reserves and the irre-
placeable nature of petroleum fuels, another important aspect of their
use is the extent and nature of environmental pollution caused by com-
bustion in vehicular engines. Petroleum-fueled vehicles discharge sig-
, soot, lead compounds,
nificant amounts of pollutants like CO, HC, NO x
and aldehydes.
A light-vehicular engine (car engine) discharges 1–2 kg of pollutants
a day, and a heavy automobile discharges 660 kg of CO a year. CO is
highly toxic, and exposure for a couple of hours to concentrations of 30 ppm
can cause measurable impairments to physiological functions.

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