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Renewable Energy and Biofuel

Wissenschaftliche Studie 2009 24 Seiten



Table of Contents

List of Figures

1 Preface

2 Renewable energy

3 Biofuel
3.1 Biodiesel
3.2 Vegetable oil
3.3 Bioethanol
3.4 Biofuel in the future
3.4.1 BtL
3.4.2 Biomethane
3.5 Summary of the comparison of Biofuel

4 Summary and Outlook on biofuels

List of literature

List of Figures

Figure 1: Renewable energy sources [BMU 2006]

Figure 2: CO2 - Emission source in Germany in 2008 [UBA 2008]

Figure 3: Biofuels consumption in Germany, 2007 [FNR 01]

Figure 4: Comparison of Biofuel

1 Preface

This documentation will be the first of a trilogy in which each part constitutes an independent document leaving the other parts as additional information sources.

Due to the logical development of the themes, however, all of them are interconnected, displaying the reason and history of climate changes, the biofuel and the positive aspect of the climate protection and an outlook on the biofuel in the future. The last part will be a microeconomic discussion if the production of biofuel in Germany is still profitable.

The trilogy will be as described above:

- Climate Changes and Fossil Fuel [Kleinschmidt 01]
- Renewable Energy and Biofuel (this document)
- Rentability of Biodiesel Plant (will be issued around March 09)

Quality assurance of the literature sources trough Internet and E-Books:

Some literature sources have been retrieved from the Internet home pages. Due to the fact that the quality of the source is difficult to check on the Internet, this is normally not a proper way of getting secured, good quality information. Therefore, all information from the home pages is retrieved from secured well-known providers, such as governmental home pages or officially incorporated or registered societies. The download date of the retrieved information is registered in the list of literature sources.

E-books are to be treated as normal books. Due to the fact that an increasing amount of books is distributed electronically, the quality will be the same as normal hard copy books. Whenever E-books are downloaded, the URL will be listed in the literature index, entailing which sources the documents were downloaded from. I would like to emphasize that E-books should not be seen as Internet home pages but as normal books.

2 Renewable energy

Regenerative energy discloses primary energy sources from the natural systems of the Earth, sun and moon. Energy streams are caused by releasing energy from the rays of the sun or from solar radiation, the planet gravity and planetary motion, as well as the released warmth stored in the Earth. On the base of energy streams, these energy donators can provide final energy or useful energy. In this case one can also speak of secondary energy. The result is an extensive offer of power production, which is shown in Figure 1: Renewable energy sources, page 4. Secondary energy encloses heat, power and fuel [Kaltschmitt a.o. 2006].

Regenerative energy shows the only reliable possibility to guarantee the energy supply of the earth with lasting effect and a low level of emission, as well as the execution taken from the Federal Ministry of environment, nature conservation and reactor security[1] [BMU 2006]. On a global scale, around sixfold of the whole energy consumption could already be covered by technically usable regenerative energy today [Puls 2006].

For states dependent on raw material or on energy like Germany, regenerative energy means more independence from energy used by fossil oil and natural gas [BMVEL 2005].

Abbildung in dieser Leseprobe nicht enthalten

Figure 1: Renewable energy sources [BMU 2006]

3 Biofuel

Biofuels are renewable energy sources derived from biomass. The source materials for biofuels are so-called renewable raw materials. These can be planted roughly everywhere. Therefore, there is less import dependence on suppliers for fossil energy sources [BMU 2006]. Beside technical changes in automobiles for the reduction of the fuel consumption and better exhaust gases, biofuels are the only option to substitute the fossil energy and to reduce the output of greenhouse gases, particularly CO2 [FNR 2006/236]. As illustrated in Figure 2 the portion of CO2 caused by automobiles in Germany is approx. 18 percent and therefore reveals a big potential in CO2-reduction.

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Figure 2: CO2 - Emission source in Germany in 2008 [UBA 2008]

Biofuels release only as much CO2 as the plant itself takes to grow. Therefore, biofuels are CO2 neutral. The CO2 balance of biofuels is considered more advantageous in comparison to fossil fuels, because mere factors like production or transport of raw materials or biofuels play a role in terms of causing CO2.

A range of liquid and gaseous bioenergy sources belong to the biofuels [BMU 2006]. In the following chapter some well-chosen biofuels will be described in more detail. Apart from the described biofuels, there are other quite promising biogenic fuels. In order not to expand the frame of this work, only those contemporary fuels, which are most promising, will be depicted in detail.

3.1 Biodiesel

Biodiesel or Fatty Acid methyl Ester (FAME) belongs to the first generation of biofuels [BMU 2006]. Biodiesel is used as a fuel substitute for diesel engine vehicles. It is currently the best-known alternative fuel for the fossil diesel in Germany [BMU 2006]. In 2007, around 72 percent of the total biofuels in Germany was biodiesel.

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Figure 3: Biofuels consumption in Germany, 2007 [FNR 01]

In Germany, rapeseed oil normally is the source product for biodiesel; through chemical processing the end product is rape methyl ester. For the processing, the so-called transesterification, approx. 10 percent of methanol is needed [FNR 2006/236]. For the production of biodiesel, other vegetable oils can also be used such as sunflowers, Soya beam, and Palm and Jatropha oils as well as old fat from food and animal fat.

The annual yield of biodiesel in Germany is approximately 1,550 l / hectare.

About 0.91 litres of normal diesel can be substituted for 1 litre of biodiesel. Therefore biodiesel has about 10 percent lower energy portion per litre than normal diesel. The annual yield of biodiesel per hectare corresponds to 1,408 l of diesel [FNR 2006/236].

If we compare the CO2 balance of normal diesel and biodiesel, we find that – through the additional consumption by the use of biodiesel and CO2 neutrality of the biodiesel - the CO2 output was reduced by about 70 percent compared with normal diesel [BTL 1999]. For example, a soot particle emission of biodiesel is approx. 30 percent and hydrocarbon emissions are about 90 percent lower than normal diesel [Geitmann 2004]. In comparison with normal diesel, no sulphur is released through the combustion of biodiesel. Biodiesel contains no benzene, no other aromatic constituents and is biodegradable [Puls 2006].

Biodiesel can be used in pure form in specially equipped engines. For standard diesel engines, a biodiesel portion of 5 percent in the normal diesel does not require any adaptation for the engine [FNR 02]. Since the 1st of January 2004, this admixture portion is also legally allowed by the oil industry [Puls 2006]. With the implementation of the legal constraint BioKraftQuG (1st of January 2007), at least 4.4 percent of biodiesel must be mixed into normal diesel. A further increase of the biodiesel quota mixed into normal diesel is expected to occur in the future [BioKraftQuoG 200601].

According to the association of German biodiesel manufacturer’s inc. society[2], the biodiesel sales in Germany increased from approx. 0.10 million tons in 1998 to 2.88 million tons in the year of 2006 [VDB 01]. In 2007, the biodiesel portion already amounts to more than 5.4 percent of the primary fuel consumption in Germany [FNR 03].

The positive development of the biodiesel among others is a result of its low sales price. Through the tax exemption of biodiesel in pure form until August 2006, the price per litre in the same year was below the price range of normal diesel [UFOP 200611]. Since August 2006, a tax of 9 ct. / l is imposed on biodiesel. From 2008 onwards, the tax will be increased yearly. Biodiesel, which will be mixed through the legal constraint of the BioKraftQuG, underlies the normal taxation for fossil fuel [BioKraftQuoG 200602].

Another reason for the positive development of the biodiesel sale manifests itself in the distinctive infrastructure with more than 1,900 filling stations all over Germany [FNR 04].

3.2 Vegetable oil

Vegetable oil like biodiesel can be assigned to the first generation of biofuels. It can be used as a fuel substitute for diesel vehicles and can be added to diesel [FNR 05].

We refer to vegetable oil in the form of rape or similar non drying vegetable oils as for example sunflower oil [Geitmann 2004]. The annual yield of vegetable oil is approx. 1,480 l / hectare.

0.96 litres of normal diesel can be substituted for 1 litre of rapeseed oil. The annual yield of vegetable oil per hectare corresponds to 1420 l of diesel. The energy portion of rapeseed oil therefore roughly corresponds to that of normal diesel. The CO2 decrease induced by vegetable oil amounts to about 80 percent compared with normal diesel and it displays a better CO2 balance than biodiesel [FNR 05]. The combustion of vegetable oil does not release any sulphur and the pollutant emissions are kept low [Geitmann 2004].


[1] Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit

[2] Verband Deutscher Biodieselhersteller e.V.


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Renewable Energy Biofuel



Titel: Renewable Energy and Biofuel