Environmental Engineering Reference
In-Depth Information
Chapter 12
Automated electrified transportation
A great deal of attention is being paid to more electric vehicles, higher levels of
vehicle electrification and also to automated electrified transportation systems. The
purpose of this chapter is to shed light on just what automated and electrified
transportation is about, who some of the participants are and just how electric
power can be transmitted to moving vehicles in order to make all this possible.
First, to recap the topics that we covered earlier in this topic, is that hybridized
propulsion is about emissions reductions and second, about having more efficient
modes of transportation available. We know that when it comes to transportation
systems of any mode and the objective is elimination of hydrocarbon fuels that the
only options available are to use energy carriers of hydrogen or electricity.
Hydrogen and its use in fuel cell vehicles has already been covered, but for now let
us look at this from a different perspective: Will hydrogen play a significant role in
future transportation systems? Members of the National Hydrogen Association
(NHA) think so and offer these key findings [1]:
Transportation modes available today will continue serving us well into the
future. In fact, gasoline PHEVs can help reduce GHG emissions, but the NHA
believes 'only if batteries are affordable and electricity from the grid becomes
greener'.
●
All the hydrogen needed to fuel hydrogen powered vehicles can be produced
from domestic energy sources.
●
Hydrogen is generated today by reforming natural gas, or using electricity for
electrolysis of water, both of which are emission sources. Hydrogen produced
using a reformer produces only half the well-to-wheel (WTW) emissions as a
conventional gasoline fuelled ICE vehicle.
●
Fahimi [2] offers a method to reform hydrogen from ethanol on-board a
vehicle using a plasma technique. In this system, ethanol and water are fed into a
plasma reactor and out of this come H
2
and CO
2
in the proportion of 6 moles of
hydrogen and 2 moles of CO
2
. If the ethanol is simply combusted in air, as it would
be in an ICE, its lower heating value (LHV) of 18 kJ/g
46 g/mol
1 mol
(ethanol)
!
828 kJ of energy. However, as Fahimi shows, the reformed hydrogen
produced amounts to over 1,400 kJ, a 75% energy improvement. In this plasma
reactor, an input of about 30 W electrical yields 120 W equivalent of H
2
, a net of
approximately 90 W. It is important that we clarify the meaning of LHV and its
