Alternative Fuels

Powertrain technologies and the types of fuels discussed, which are partly realized today, give a picture of utmost confusion. At times the picture is one of brain storming — we are in search of the optimum solutions. There will be many different possible combinations, driven by local (country) conditions. Figure 13 gives an overview of the different fuels. SynFuel is a fuel that is produced based on natural gas. SunFuel, as the name indicates, is a fuel based on biomass converted into gas, forming the basis for other fuels. Not all fuels indicated in Figure 13 make sense everywhere. Again, this depends very much on local conditions. It certainly makes sense to convert natural gas into a diesel-like fuel of very high quality (gas-to-liquid process (GTL)), if this gas would otherwise be flared off. There is no doubt, for decades to come, that fossil fuels will be the primary source of energy, with a gradual phase-in of more natural gas and finally followed by SunFuel. By the way, natural gas with very big reserves in the Middle East, Europe and Eurasia are also problematic due to political unrest.

Figure 14 shows schematically the different pathways from biomass and natural gas to different products. The charm of natural gas is the possibility to use the existing infrastructure to feed into gas produced based on biomass. This scheme is being used in Switzerland. The different processes shown in Figure 13 are quite well understood today — various plants are in operation or planned.

Non-renewable

SynFuel

SunFuel

CNG

Natural Gas

Gas

LPG

DME

DME

DME

Naphtha

GTL Naphtha

GTL Naphtha

Kerosene

GTL Kerosene

GTL Kerosene

Diesel

GTL Diesel

GTL Diesel

Gasoline

Gasoline

Methanol

Methanol

Hydrogen

Ethanol

RME

Hydrogen

Source: ETHZ GTL: Gas-to-liquid

Fig. 13. Different kind of fuels

Source: ETHZ GTL: Gas-to-liquid

Fig. 13. Different kind of fuels

Natural gas pipeline

SunFuel Methan

Biomass

Gasifi-

Synthesis-

cation

Gas

Fermentation

Biogas

Gas-

Fermentation

Biogas

Gas-purification

Fischer-Tropsch

Methana-tion

Shift-reactor

HT-FC

SunFuel Methanol, Aethanol, ...

H2-Sep.

hani

s

Reformer

SynFuel/SunFuel diesel, . SynFuel hydrogen, —

LT-FC

Fig. 14. Energy conversion chains, biomass and natural gas

GTL Process

Natural Gas

Syngas Manufacture

Synthesis

Hydro-cracking

Hydro-cracking

SynFuel

LT-FC

Diesel

Electric powe

Electrolysis

SynFuel/SunFuel

LT-FC

Fig. 15. Energy conversion chains, GTL process and electrolysis

Figure 15 shows the GTL process and the production of hydrogen by means of electrolysis. Again, these processes are well understood and in operation. As mentioned before, not everything makes sense everywhere — there is by no means only one way to go.

A word about GTL fuels. They are of extremely high quality with no sulphur, no aromatics, a narrow boiling range and they can be mixed with ordinary fuels. These fuels show an excellent trade-off between NOx and particulate emissions. The well-to-wheel CO2 emissions are better than those for gasoline but somewhat worse compared to diesel. The costs are higher than diesel, but lower than biomass based fuels. And plants are already in operation in Malaysia and the US.

Figure 16 gives an indication about well-to-wheel CO2-equivalent emissions of different fuels, expressed per unit of distance travelled on one hand with a car equipped with an internal combustion engine and on the

Rel. CO2_aeq. emissions per unit of distance, FTP-Cycle o

Gasoline (reference)

Diesel

GTL-Diesel

Natural gas

Methanol

Gasoline/Hybrid

Methanol (natural gas) Methanol (short rotation forestry) Methanol (waste wood)

Hydrogen (natural gas) Hydrogen (nuclear energy) Hydrogen (photovoltaic)_

c) conventional

Sesrces: PSH ETHZ, Opel, etc.

Fig. 16. Relative well-to-wheel CO2-equivalent emissions of cars equipped with internal combustion engines (ICE) and low temperature fuel cells (LT-FC)

Gasoline unleaded, Rotterdam, 13.02.03 Gasoline with taxes (CHF 1.40/l): 100 %

Fuel gas (organic garbage)

Methanol (natural gas) Methanol (short rotation forestry) Methanol (waste wood)

Hydrogen (natural gas) Hydrogen (short rotation forestry) Hydrogen (waste wood) Hydrogen (nuclear energy) Hydrogen (photovoltaic Ch) Hydrogen (photovoltaic Spain) Hydrogen (solar chemistry North Africa)

0 100 200 400 600%

Sources: PSI, Kompogas

Fig. 17. Relative fuel costs without taxes related to unity of energy other hand with a car equipped with a low temperature fuel cell (LT-FC). These data have to be considered with a lot of caution — they give just a rough estimate. Here again, the assumptions that go into these calculations vary quite a bit from author to author. Nevertheless, the use of biomass, all elements included, makes definite sense. Be reminded that the reference gasoline engine (Figure 16) is a standard one, not including all the possible improvements mentioned earlier.

Quite often it is said alternative fuels would be much more expensive compared to fossil fuels today. This is true to a certain extent. As indicated in Figure 17, the use of waste wood and biogenic garbage (Switzerland) are definitely valid options. If one would not levy a tax on gasoline or only at a reduced rate, alternatives are competitive today. And they will be even more so in the future, assuming further increases in cost of gasoline or diesel fuel. Without going into much further discussions, biomass is definitely a source that has to be used much more. If in Switzerland all biogenic garbage (grass, household, not wood) would be fermented, about 10% of all passenger cars could be driven with methane. I personally do not believe one should use crops that can be used to feed people to produce fuel. Furthermore, in Switzerland, if fully-integrated internationally, conditions regarding climate, topography, remuneration and structure do not justify in an economically-viable way the production of fuel based on crops.

Now for some comments about hydrogen. I do believe hydrogen is being talked about with far too much enthusiasm. Hydrogen is certainly a clean fuel with numerous applications. However, as pointed out earlier, hydrogen has its drawbacks because of its very low density and its having to be produced in a sustainable manner in order to make sense. Hydrogen is

0 100 200 400 600%

Fig. 17. Relative fuel costs without taxes related to unity of energy

Easy Draw Wheelchair Front

Sources: H.Michelet, l'Inventeur Issac de Rivaz, Martigny 1965 E.Schmid, Schweizer Autos, Edita SA., Lausanne 1978

Fig. 18. The first "mechanical wagon" ever run on hydrogen, designed by Isaac de Rivaz

Sources: H.Michelet, l'Inventeur Issac de Rivaz, Martigny 1965 E.Schmid, Schweizer Autos, Edita SA., Lausanne 1978

Fig. 18. The first "mechanical wagon" ever run on hydrogen, designed by Isaac de Rivaz not a new idea. The Swiss Isaac de Rivaz (1752-1829) designed in 1805 the first "mechanical wagon" run on hydrogen. Figure 18 shows the concept.

Distribution and storage of hydrogen are obstacles still difficult to overcome. And the cost of a fuel cell is still far too high per kW. Much more research and development is needed to make hydrogen a viable option. Hydrogen is not going to save us in the decades to come. In other words, we have to do everything to reduce primary energy use — this is the most cost-effective way to go. It is not very exciting, but it is the most sensible thing to do. And secondly, we do have to phase in alternatives based on solar energy and geothermal sources. Keep in mind we will need much more electricity in the future to provide options to reduce our dependence on fossil fuels. In general, electric home heating as well as home heating with oil should be the exception.

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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