Cellulose Based Biofuels

As indicated above, we need to base an increasing amount of our future energy needs on biofuels, produced from cellulose. We already possess a number of alternative fuels that could be used, using different technologies, from distillation of ethanol, to the production of a number of different hydrocarbons from wood. In the case of methanol, we already have a process, which is available for the large-scale production of this product. As mentioned already, methanol can be used as an additive to petroleum. Similar to ethanol, methanol can be added in quantities of up to 30 percent to gasoline, without requiring any modifications of the engines.

In the case of ethanol, we already have some global production of this fluid, based on grain as the raw material, but at present, we do not have an economically viable process for the production of ethanol from cellulose. This process has been under development for decades, without success, and we do not know when one will be available. In the energy transformation it will be important for a steering committee to understand why this effort, so far, has failed, and what the prospects for success are in the near future. If we want a cellulose-based additive to gasoline, methanol may turn out to represent a more rapid path toward sustainability and financial gain than ethanol.

All in all, there are substantial resources in our global forests, both in the form of wood and waste from forestry. One of the problems is that the raw materials are scattered across large areas and that there is a high cost, both in terms of energy and money, involved in collecting it. Based on rough estimates, the available waste from forestry amounts in terms of energy to one-sixth of the total current primary energy supply from oil, coal and biomass. However, the net energy content is only 30 percent when the energy needed for the production has been subtracted. In addition to this, this energy is spread out across the forests of the world. In order to produce this energy in an efficient manner, we need to build a number of plants for biofuel production that are close to the forests and we need to invest in resources for the collection of the waste materials on location.

Collecting raw materials is not the only challenge. In order to produce fuels from cellulose at a scale that would be financially justifiable, each plant would need deliveries of 450 truckloads of wood per day. The number would be higher if we plan to use waste materials from forestry for production. These loads would have to be supplied by truck, because forests in general are not located along train lines or close to harbors. They are also spread out so that large railway systems would be needed in order to serve a large forest area, which may not be a viable solution compared to truck transportation. In order to produce enough fuel to supply Poland with 20 percent of its current fuel needs, three plants of the mentioned size would be necessary. In order to supply the 15 largest economies in Europe with 15 percent of their needs, 122 plants would be needed and in order to supply 100 percent of European needs 1000 plants would be needed. Since most of the forests in Europe are located in the north, this type of system would present a tremendous challenge from a logistics perspective.5

Box 18.3 A Comparison between Different Biofuels

The global leader in the truck industry, Volvo, sees the transition to renewable energy sources as a critical move to ensure the future sus-tainability of transportation. In early 2007, the company announced plans to launch a range of prototypes for hybrid and biofuel-powered trucks. This is only one measure taken by the company in order to contribute to the development and large-scale implementation of sustainable technologies for transportation.

According to Volvo CEO, Leif Johansson, what is now needed is a large-scale development effort to produce and distribute renewable fuels. He also calls for coordination between producers and legislators, across national borders, in order to ensure a long-term commitment to a universal set of fuel standards for the future. In order for Volvo to succeed in becoming one of the solutions to the climate problem, and participate in the development of carbon dioxide-free transportation technologies, broad agreements at a high political and industrial level are necessary.6

In a booklet published by Volvo in the spring of 2007, the company published an analysis of the road forward in the case of carbon dioxide-free and renewable fuels. In the booklet, the advantages and disadvantages of each of the following fuels are recounted in a brief and very accessible way.

- Biodiesel, which is diesel based on vegetable oil, such as rape and sunflower seed oil.

- Synthetic diesel, which is made through the synthetic production of hydrocarbons, based on the gasification of biological material.

- Dimethyl ether (DME), which is a gas, which could be distributed as a fluid under low pressure. DME is also produced from gasified biological material.

- Methanol, produced through the gasification of biomass, and ethanol, produced through the fermentation of vegetables that are high in sugar and starch.

- Biogas, which could be produced in several ways from biomass from sewage treatment facilities, and at waste deposit stations, and in other places where biological material can be gasified. Biogas needs to be compressed to 200 bar, and then it requires the engine to be fitted with a spark plug, which gives it lower energy efficiency than the other alternatives.

- Biogas and biodiesel in combination, which are stored in separate tanks, and injected by different injection systems. A small amount of biodiesel is used in order to ignite by compression. In this solution the biogas is kept in a cold and fluid form.

- Hydrogen gas and biogas in combination. The hydrogen is added in small proportions (in the case studied by Volvo, 8 percent) to compressed biogas. Hydrogen could be produced through the gasification of biomass, or through electrolysis of water, using renewable electricity. This alternative requires the engine to be fitted with a spark plug.

In the study performed by Volvo the seven alternatives were compared across seven criteria related to their development and use in future energy systems:

1. Effects on the climate

2. Energy efficiency

3. Efficient use of land

4. Fuel potential

5. Necessary adaptation of vehicles

6. Fuel cost

7. Infrastructure for distribution

In the study, each fuel was evaluated, using a five-degree scale, for each of the criteria.

The renewable fuel that came out as the most successful alternative of the study was DME, which received high ratings along all criteria, except infrastructure. In the case of fuel cost, the rating is dependent on the production process. Gasification, in order to produce methanol and DME, is relatively expensive, compared to alternative production processes.

The infrastructure, Volvo remarks, may be important in the short run, but it does not represent a problem in the long run, since the infrastructure for gasoline and diesel also needs to be maintained and invested in. However, it is clear that the investment in new infrastructure will need substantial investments and that this needs to be taken into account in the program, since money will be a scarce resource.

Needless to say, all alternatives could be used in combination with hybrid power train technology. In this way, the energy generated as cars and trucks brake is conserved and reused in order to fuel the vehicles. Thus, all investments that we make in the further development of hybrid engines, the expansion of production resources and the sales of vehicles equipped with hybrid engines will pay off into the distant future in combination with a number of different types of fuel.

This study, and other similar studies for other areas, will provide important guidelines for the transformation program. However, we must not draw the conclusion that we need to identify the best alternative, and then apply it to 100 percent. In situations where we could use a particular raw material for a number of different fuels, we need to select the best alternative. We do, however, possess a number of different raw materials and we sometimes have access to those in medium-sized quantities as by-products from various production processes. Black liquor is one such by-product from the cellulose industry, which could be used as a raw material for fuel production. In such a case, fuel plants could be located close to cellulose factories, to take advantage of the synergies. In the case of hydrogen and other gases, which are necessary in the production of synthetic diesel, they could be found as by-products from different chemical production processes.

In the future, we will need to make use of a number of different energy sources and fuels, and we may need individual distribution infrastructures for each of them. Along the line of argument of this book, the transition from the current situation to a future situation, using renewable fuels, will require an overall plan and a system of goals and means to reach the goals, which can be communicated and worked toward by all the people who need to participate in the change program. As noted above, the CEO of Volvo, Leif Johansson, agrees.

Instead of drawing one prioritization matrix for each of the biological fuels, I draw one that may represent the biological fuels taken together (see Figure 18.5). This is done in order to illustrate the relative project status of biofuels compared to hybrid power trains and electricity. Below, matrices for all alternatives in the other streams will not be presented. A method, such as the prioritization matrix, needs to be used in order to compare different alternative projects with one another, but at this point we have too little information available in order to make this evaluation for all alternatives. This needs to be done as part of the strategy development phase of the transformation program.


Value of energy use


High Low

Cost of reduction

Size of saving

Time to saving (in years)

M Complexity (High, medium, low)

Figure 18.5 Diagram illustrating the potential savings, time frame, cost and complexity of a large-scale transformation project based on biofuels

Even though states may decide to not actively provide government financing of projects in a particular area, the minimum requirement of the program is that the steering committee of each stream define the long-term goals for different renewable energy alternatives. As argued by Volvo, this is the minimum requirement in order to make it possible for Volvo and other truck and car companies to become part of the solution to the climate issue.

Guide to Alternative Fuels

Guide to Alternative Fuels

Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.

Get My Free Ebook

Post a comment