At the collective and individual level, measures should be taken to avoid misuse
of energy. In the day-to-day life, each of us can adopt attitudes that would be very
useful to all. Switching lights off in an empty room, avoiding superheating and
supercooling of private buildings, avoiding seasonal heating (cooling) of interiors
with open windows and doors, using domestic washing machines with full load,
and avoiding use of electricity at any time is possible.
The transport sector is much improving the use of energy with a number of
measures for upgrading the performance of cars, trucks, and buses. Lighter materials, aerodynamics, low rolling resistance of tyres, and several other smart solutions may increase the fuel mileage that is nowadays more than doubled with
respect to 30 years ago. Even engines have been much improved with continuous
transmission direct injection, stop and go, turbo-injection, valve timing, and
cylinder deactivation that reduces the fuel consumption and, thus, emissions.
Driving behaviors also impact the fuel economy. Using collective transport means
instead of using personal cars and whenever possible sharing cars reduce the
amount of fuel burned. Removing unneeded accessories (i.e., roof racks) and cargo,
actioning smooth acceleration and deceleration, and use of high gears when at a
steady speed are some examples which reduce fuel consumption. The driving
behavior that perhaps gives the largest potential contribution to fuel efficiency,
across nearly all vehicle types, is idle reduction, especially in cities. Idling for long
periods of time wastes fuel and poses a health risk to people in and around the
vehicle. For example, a typical idling bus or even school bus diesel engine burns
about 2–3 L of fuel per hour. Vehicle diesel engines are generally tuned for optimum operation at traveling speeds, so they combust fuel less efficiently when
idling. Idling results in more pollutants per liter, and these pollutants are concentrated in one place because the vehicle is stationary. These are typically places
where vulnerable people, such as school children, are gathered. Diesel exhaust
contains particulate matter which lodges in lung tissue when inhaled and is believed
to cause or exacerbate numerous health problems, including cancer, asthma,
reduced lung function, and premature death.
4.5 Quasi-zero-Carbon Emission Sources of Energy: Use
of Biomass
In the last years, there has been a world campaign promoting so-called “zero CO 2
emission” fuels. They are derived from a variety of biomass, said to be formed from
atmospheric CO 2 (see Fig. 2.1): the general view is that the CO 2 formed in the
combustion will be fixed back in the newly formed biomass. Such biofuels can
cover the full range of fuels derived from fossil-C and, in principle, can substitute:
solid fuels (wood instead of coal), liquid fuels (ethanol and long-chain hydrocarbons instead of gasoline and long-chain fatty esters instead of diesel), and gaseous
fuels (biomethane replacing natural gas). It is worth considering that wood has a
quite lower energy density with respect to coal, while liquid biofuels and
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4 Reduction of the CO 2 Production
of energy. In the day-to-day life, each of us can adopt attitudes that would be very
useful to all. Switching lights off in an empty room, avoiding superheating and
supercooling of private buildings, avoiding seasonal heating (cooling) of interiors
with open windows and doors, using domestic washing machines with full load,
and avoiding use of electricity at any time is possible.
The transport sector is much improving the use of energy with a number of
measures for upgrading the performance of cars, trucks, and buses. Lighter materials, aerodynamics, low rolling resistance of tyres, and several other smart solutions may increase the fuel mileage that is nowadays more than doubled with
respect to 30 years ago. Even engines have been much improved with continuous
transmission direct injection, stop and go, turbo-injection, valve timing, and
cylinder deactivation that reduces the fuel consumption and, thus, emissions.
Driving behaviors also impact the fuel economy. Using collective transport means
instead of using personal cars and whenever possible sharing cars reduce the
amount of fuel burned. Removing unneeded accessories (i.e., roof racks) and cargo,
actioning smooth acceleration and deceleration, and use of high gears when at a
steady speed are some examples which reduce fuel consumption. The driving
behavior that perhaps gives the largest potential contribution to fuel efficiency,
across nearly all vehicle types, is idle reduction, especially in cities. Idling for long
periods of time wastes fuel and poses a health risk to people in and around the
vehicle. For example, a typical idling bus or even school bus diesel engine burns
about 2–3 L of fuel per hour. Vehicle diesel engines are generally tuned for optimum operation at traveling speeds, so they combust fuel less efficiently when
idling. Idling results in more pollutants per liter, and these pollutants are concentrated in one place because the vehicle is stationary. These are typically places
where vulnerable people, such as school children, are gathered. Diesel exhaust
contains particulate matter which lodges in lung tissue when inhaled and is believed
to cause or exacerbate numerous health problems, including cancer, asthma,
reduced lung function, and premature death.
4.5 Quasi-zero-Carbon Emission Sources of Energy: Use
of Biomass
In the last years, there has been a world campaign promoting so-called “zero CO 2
emission” fuels. They are derived from a variety of biomass, said to be formed from
atmospheric CO 2 (see Fig. 2.1): the general view is that the CO 2 formed in the
combustion will be fixed back in the newly formed biomass. Such biofuels can
cover the full range of fuels derived from fossil-C and, in principle, can substitute:
solid fuels (wood instead of coal), liquid fuels (ethanol and long-chain hydrocarbons instead of gasoline and long-chain fatty esters instead of diesel), and gaseous
fuels (biomethane replacing natural gas). It is worth considering that wood has a
quite lower energy density with respect to coal, while liquid biofuels and
52
4 Reduction of the CO 2 Production