The pages listed below will give you a first insight into the facts on renewable raw materials.

Content

1. Renewable raw materials
 1.1. Definition
 1.2. History
 1.3. Why are renewable raw materials important?
 1.4 Lines of Products

2. Energy from biomass
 2.1. Introduction
 2.2. Advantages
 2.3. Solid fuels
  2.3.1. Wood
  2.3.2. Energy crops
  2.3.3. Wood combustion
 2.4. Liquid fuels
  2.4.1. Two alternatives
  2.4.2. Usable biodiesel
 2.5. Gaseous fuels

4. Prospects

1. Renewable Raw Materials

1.1. Definition

Renewable raw materials (also known as biomass) are organic materials from vegetable or animal sources which can be used in part or as a whole as raw materials for industry or as energy carriers. Unlike fossil raw materials they are renewed annually or in easily comprehensible periods of time.

1.2. History

Renewable raw materials are not an invention of our present time. Until the discovery of coal, plants and animals not only provided food, but also building materials, basic material for clothing and chemistry, as well as energy.

Since the discovery of coal, and especially since 1900, when we started using mineral oil, renewable raw materials have been largely driven out of the market.

The energy crises of the 70s resulted in a cautious re-focussing on natural materials, when the vulnerability of our own economy, which mainly depends on the import of raw materials, became clear. When the price for mineral oil went back to "normal", however, efforts in that direction very quickly came to a halt again.

1.3. Why are renewable raw materials important?

In the 80s, the surplus production of the agricultural sector instigated interest in the topic of renewable raw materials, which is still an ongoing process. As a consequence, areas which had been shut down for food production could now be used for growing renewable raw materials, while the farmers were still entitled to the bonus for closing down their food production. However, the programmes for shutting down areas for food production work with fluctuating bonuses, which recently prevented rather than supported a steady production of raw materials.

Environmental problems such as the greenhouse effect, increasing amounts of waste and the excessive usage of fossil raw materials provided crucial arguments in the discussion about renewable raw materials. Nowadays environmental reasons are often considered more important than agricultural reasons. Many lines of production which are based on renewable raw materials show an approach which gives some consideration to environmentally friendly economizing within the natural cycle.

An increase in the use of biomass could also benefit our economy, through the export of technology for biomass utilization for example.

1.4. Lines of Products

Renewable raw materials can be used as industrial materials (industry plants), as well as for the production of heat, steam, electricity and petrol.

Selected native plants¹⁾ for industrial and energetic usage and their raw materials which can be used in the production of various products

¹⁾plants which can be grown in Germany

 

2. Energy from Biomass

2.1. Introduction

Biomass is stored solar energy. Biomass is produced by plants through the process of photosynthesis. The energy necessary for this process is provided by the sun. That means that biomass is a renewable energy carrier.

When biomass is used for the generation of energy, almost no additional carbon dioxide is set free; the carbon dioxide that does get set free through the energetic utilization of biomass is equal to the amount that the plant absorbed from the atmosphere.

Biomass can easily be stored in large amounts. That is what distringuishes it from other renewable energy carriers like solar energy, wind- and water-power.

2.2. Advantages

The main source of biomass used for energetic purposes nowadays is wood. But what most people still think of in combination with the combustion of wood are smoking wood furnaces and the arduous task of chopping wood. But those are things of the past. Highly-developed biomass heating (and power) stations and modern small-scale heating systems are standard nowadays. Technology in these areas achieves excellence in both comfort and environmental protection.

In the area of wood combustion a wide range of technology is used. There are tiled stoves and log wood burners, automatic wood chip furnaces and central biomass heat (and power) stations. It is mainly medium-sized companies who speed up the improvement of the technology with their own innovative developments.

The nearly closed cycle of CO₂ counteracts the greenhouse effect.

The immense "hunger" for energy in highly industrialized societies is the reason why the fossil resources, which have been built up over millions of years, have nearly been used up within only a few decades. Whoever uses biomass for energetic purposes, makes a contribution towards protecting the remains of these by now scarce and highly valuable supplies.

Transportation and storage of biomass pose considerably smaller risks for the environment in case of accidents than is the case with fossil energy carriers. With biomass there are no disasters comparable to leaking gas pipelines, damaged oil tankers or bursting oil pipelines.

The energy balance of biomass is positive: the amount of energy used for extracting biomass energy carriers is smaller than the amount of energy set free during its energetic utilization.

Renewable raw materials usually come from the region where they are used, which means that hauling distances are short.

Being a country with very few resources, Germany is highly dependent on the import of fossil energy carriers. The import industy, however, is controlled by a small number of large combines. So money from the region boosts their finances or disappears abroad. But through the energetic utilization of biomass, the profits stays in the region.

In many cases Germany imports fossil raw materials from crisis areas (the Middle East, Russia). Increasing the usage of locally available energy carriers like wood reduces the dependency on fossil energy carriers and will in the long run result in higher flexibility in times of energy crises and price increases.

Agriculture and forestry are carried on by people who have their roots in that particular region. Almost all costs for fuel, the process of obtaining it and the operation of the biomass heating station stay in the region and will be of benefit to it. The decentralized production of energy from biomass does not just make sense ecologically but also economically.

The improvement of the already highly-developed combustion technology calls for innovation. Mostly innovative ideas come from small and medium-sized companies. Innovations are also necessary in the sector of the production of biomass. For companies both in Germany and on an international level new markets with a promising future can be found in this field.

Farmers both in agriculture and forestry often do more than provide biomass. They also operate biomass heating stations. This combined with an increase in sales of hitherto unused residue from the wood industry creates new areas for employment and new sources of income. In this way jobs are being preserved and rural structures are being strengthened.

2.3. Solid fuels

Solid fuels are the biogenous fuels that are employed most often. Wood is the material which is used most, in various forms, such as billet wood, wood chip, wood shavings, and sawdust. Additionally, straw and especially-grown annual plants are used for energetic purposes in the form of shredding, bale or pellets.

2.3.1. Wood

Wood is available in large amounts (not only) in Bavaria. The annual, unused growth of wood of approximately 6 million m³ could cover 2.7 % of the primary energy demand in Bavaria. In the past 20 years, however, only about 70 % of the real growth actually was used.

There are several production methods:

• Producing billet wood requires working with saws and axes; which is labour-intensive and results in high costs.
• Sawing residue is the left-overs from wood-processing industrial companies. It consists of large bulk as well as of smaller material (e.g. saw dust). The bulk material is processed to wood chip.
• Hackers are used to take wood directly from the forests. The wood used is usually residue from forest conservation measures, which cannot be used for other purposes, but should not be left in the forests because it diminishes the growth and health of better trees. This kind of wood is an energy carrier that is ready without further processing; if it were not put to use, it would simply decompose.
  Even the increased exploitation of wood for energetic purposes has no negative effects on the strict law of sustainability which is employed in forestry.
• If energy prices rise, energy wood plantations with fast-growing tree populations like poplar and willow might be a realistic option.

2.3.2. Energy crops

So far agricultural plants have usually come in the form of residue. Straw is the most widely known of these materials; it is a relatively inexpensive fuel, which only causes recovery costs. Annual energy crops require comparable technological processes (bales, pellets). Their cultivation, however, is hindered by low yields and by the low prices for other energy carriers; the same is true for energy crops of several years, e.g. miscanthus.

2.3.3. Wood combustion

The combustion process is split up into three different phases: drying, pyrolysis and oxidation. As a rule, it can be said that the smaller the water content of the wood, the higher the usable energy content.

Only in the last stage of combustion, the phase of oxidation, is the usable energy set free. Approximately 1 % of the original amount of wood is left over as ash.

The combustion of wood sets free steam, carbon dioxide, nitrogen oxide and ash particles. Nitrogen oxides can be minimized through the usage of untreated wood or reduced by burning. The emission of ash particles can also be reduced to an amount far below the legal limits.

Avoidable emissions like carbon dioxide, carbon monoxide or particles which do not get burnt (soot) can be minimized through optimal furnaces, which at the same time increases efficiency.

Open fire places, open chimneys, log wood boilers and wood chip boilers are common kinds of furnaces. The combustion of log wood, and especially of wood chip, is technically developed to such a high degree that very good combustion, high efficiency and low emission levels are combined.

2.3.4. Standard: District heat from biomass

A typical case is district heating by central biomass heating stations.

A biomass heating station provides ready-for-use heat in the form of hot water which is pumped to the consumer through insulated pipes underground (flow pipe). When it reaches its goal, the heat is transmitted to the heating circuit of the building by a heat exchanger. The cooled-down water is fed back to the heating station (return pipe).

For economical operation the heating station is usually designed so that the energy from biomass covers the constant load of heat needed. The peak load is only reached during a few cold days of the year and is usually covered by a peak load boiler that is run on fossil energy carriers. This combination guarantees a highly secure supply. An advantage for the consumer is that no furnace or storage rooms are necessary. The interconnecting stations can be put into small wall panels. Servicing and reparations are usually conducted by the heating station's operating authority.

2.4. Liquid fuels

Native vegetable oils (in Germany mainly rape seed and sunflower oil) can be used both in the technical and the energy sector: as motor fuel and for stationary use as fuel in block-type heat and power stations.

2.4.1. Two alternatives

There are two kinds of biogenous, and therefore renewable fuels: untreated, cold-pressed vegetable oil (natural diesel) and chemically transformed vegetable oil (biodiesel).

In the case of natural diesel, the engine (an Elsbett engine) is converted to fit the fuel, in the case of biodiesel the fuel is converted to fit the engine. Even if used to exhaustion point, biodiesel could only cover about one tenth of the overall need for fossil diesel. Realistic estimations reckon that biodiesel, the "agricultural diesel" will reach no more than a 3 % share of the market, while today it still lies at less than 1 %.

Biogenous fuels are only usable for diesel engines. Converting series production engines to vegetable oil engines is only possible for a small number of engines.

Unlike natural diesel, biodiesel can be used in all conventional diesel engines because of its combustability. In order to produce biodiesel from vegetable oil, chemical treatment with the aid of alcohol is necessary. The by-products of this process are glycerine and whole-rape meal, the latter also being a by-product of natural diesel.

2.4.2. Usable biodiesel

Since biodiesel reacts different from fossil diesel fuel in combination with synthetic materials, the elastomers (pipes, gaskets) used in the particular engine need to be made from materials that are resistant to biodiesel. For troublefree operation of the engine, it is necessary that the biogenous fuel is of at least minimum quality of DIN E 51 606. It is possible to switch between fossil and biogenous fuels without further problems.

The chemical structure of biodiesel allows a combustion with comparably low emissions, especially low emission of particles. The installation of an oxydation-type catalytic converter results in a further improvement of emission levels.

Biodiesel is 100 % biodegradable and hardly a risk for our water supplies. Typical areas for the utilization of biodiesel are therefore city traffic (taxi, buses) and water reserve areas. Biodiesel is a competitive alternative to conventional fuels, because it is not liable to tax on oil.

2.5. Gaseous fuels

Biogas is another renewable energy carrier. It is produced through the microbial process of decomposing organic material under the exclusion of oxygen. Biogas is a gas compound that is saturated with steam. Its main component, methane, which makes up 40 to 80 % of the total volume, is the part that is usable for the generation of energy.

Agricultural biogas plants use the excrements of their animal stock. Organic material with a high water content is the most suitable. Biogas is produced in a septic tank in a microbial process and is energetically utilizable after temporary storage. The usage of biogas is especially effective in decentralized block-type engine heating stations. Biogas can also be produced in the agricultural industry and communal disposal industry. However, in these areas, waste management is put before the production of energy.

The technically usable potential of organic materials equals about 1 % of the total demand of primary energy in Germany. Organic residue from the agricultural sector alone make up about half of this amount. German legislation basically excludes the possibility of direct disposal of organic waste. Approximately one third of the organic waste that is produced every year is extremely suitable for usage in biogas plants because of its high water content.

The centre of biogas utilization is in the South of Germany (Bavaria, Baden-Württemberg).

Biogas is a renewable energy carrier that saves fossil resources and counteracts the greenhouse effect. The cycle of CO₂ is almost closed. An ecological assessment is still to come. A clearly positive evaluation can be given for the manure after the process of gas evolution, which used as fertilizer has many advantages for the soil and the plants.

3. Industrial utilization

Unlike in the field of energetic utilization, the material utilization of renewable raw materials for industrial purposes offers a great number of basic substances and lines of products.

It is advisable to use the groups of oils/fats, starch/sugar and crude fibres as guidelines.

In the field of the material utilization of renewable raw materials a lot of lost time has to be made up for, which is an impediment to the penetration of the market both by single products and whole lines of products. The ready availability and low prices of fuel oil have encouraged the neglection of research into natural materials for decades. This disadvantage can only be made up for gradually.

3.1. Wood

Wood has always been the most important renewable raw material both in terms of quantity and value. Trees absorb carbon dioxide, and the wood that grows in forests throughout Germany stores approximately 9 billion tons of this gas which is responsible for the greenhouse effect. Every year the German forests take up another 15 million tons of CO2 from the atmosphere.

Through the use of products made from wood, the storage potential of the forest is expanded beyond the life span of the individual tree. Increased usage of wood in no way poses a threat to the forest land. In Bavaria, which is the German Land with the largest amount of forests, over the next 30 years up to 18 mio. m³ solid measure of timber could be used annually on 2.5 mio. ha of forest. In comparison there is an estimated felling of just under 12 mio. m³ solid measure of timber.

3.1.1. Areas of usage

Wood can be used in a variety of ways and areas: in the construction and furniture trade, the packaging and insulating industry; as cellulose it is used in the paper and cardboard industry. Wood is a universal building and industrial material, which we simply cannot do without.

Nevertheless initiatives by the state are necessary to make people aware of the advantages of the renewable raw material wood. The sector of building in timber is one example of this. Ecologically aware experts in the field of construction value timber as an excellent material that is stable in value and has a superb LCA. The advantage of building in timber as compared to conventional masonry lies in low energy buildings without additional costs.

The chip board industry is the second biggest user of wood, which is a good material for heat insulation. Timber is especially suitable as insulation material.

3.1.2. Wood as part of the natural cycle

Wood is an exemplary raw material, which can be used and re-used in a variety of ways. Packaging made from wood, for example, can be used more than once, and afterwards the material can still be used in the chip wood industry. Once this is no longer possible, use as a substitute for peat, composting or energetic utilization are further options.

The consumption of wood and its products has been rising for years, which is mainly caused by the increasing demand for paper. Venturing a prognosis for sales opportunities for wood from local production is difficult. Because of its excellent ecological quality, however, wood will become more important in the future again.

3.2. Flax and hemp

Cotton and synthetic fibres almost made us forget about flax, a traditionally-grown, blue-flowered plant. Over the years there has been an attempt to re-establish flax on the market again, and good results seem to have been made, at least on a smaller scale.

Although the plant is undemanding, harvesting it is complicated and full of risks. In order to obtain fibres of good quality, optimal weather conditions are necessary during the harvest. No new methods of harvesting flax are available yet. Furthermore a number of costly processing steps make the harvest even more expensive. Economic and technological difficulties have so far prevented the development of alternatives.

The harvested flax straw is processed and broken in an oscillating crank into long fibres for the production of yarn. Shives and short fibres are what is left over. The market still needs to be opened up more for these parts, since they make up the main part of the plant (60%). They could be used for paper, vegetation mats, and technical fleece, for example for car interiors and insulating materials.

Hemp, another useful plant that had traditionally been cultivated, was, like flax, put out of competition by petrochemical products. After 1982 the cultivation of hemp became illegal in Germany. For about three years, however, the media have been celebrating its resurrection. Since 1996 hemp can be grown again as long as certain requirements are adhered to.

New and exotic hemp products are continually introduced onto the market. However, experiences gained in the flax production advise caution. The time is not yet ready for the cultivation of hemp on a large scale.

Hemp is suited for the production of textile fibres, paper, construction materials, salad oil, paints and cosmetics. In Germany, however, the lack of experience and expertise can be seen in the areas of both cultivation/harvest and processing technology. Most of the areas for the utilization of hemp mentioned above are developments taken from the flax industry, which cannot simply be straightforwardly applied to hemp, in so far as the industrial utilization of flax has not yet been fully developed.

3.3. Insulating materials

The demand for insulating materials made from renewable raw materials has increased continually over the last years because of its ecological advantages. Biological insulating materials have qualities comparable to those of conventional materials. They are made from cellulose, wood, reed, hemp, flax, and sheep wool.

3.4. Oils and fats

Vegetable oils are becoming very popular for a wide variety of technical and chemical uses. The most important providers of oil are rape seed, sunflowers and flax.

The deciding factors for each particular area of utilization in the non-food industry are the different components of the vegetable oils, i.e. their fatty acids. The different patterns of fatty acids that are found in oil plants decide what the plants can be used for.

For industrial utilization one distinguishes between "direct" and "indirect" forms of utilization.

The production of lubricants is a direct form of utilization. Vegetable oils or modified vegetable oils are in many ways adequate as replacements for conventional lubricants which are based on mineral oil. The most suitable is rape seed oil. Lubricants are chain saw oils, point mechanism oils, lubricating greases and forming oils.

It is more than reasonable in terms of ecology to replace these with lubricants based on vegetable oil. Hydraulic oils and cooling lubricants can be substituted, too; rape seed and sunflower oil hydraulic oils make up 5 % of market sales today, and the demand is getting stronger. They are biodegradable and relatively easy to dispose of, which makes lubricants from renewable raw materials an ecologically-sound alternative to conventional lubricants.

Vegetable oils are also being used for the production of cosmetics, pharmaceutical products, leather care products, paints and varnishes. Linseed oil is used for the production of linoleum.

3.5. Starch and sugar

Apart from cellulose, starch is the most important organic-chemical raw material. It is available in large amounts and with high chemical purity at low prices. Today there are more than 600 different products made from starch for a wide range of usage.

In Germany the plants that are cultivated for providing starch are corn, wheat and potatoes. Besides the traditional ways of utilization in the paper and cardboard industry, there is a large number of new products which are now on the market: detergents, basic materials for the cosmetic and pharmaceutical industry, raw materials for fermentation purposes and biodegradable industrial materials which can replace petrochemical synthetic materials. The overall trend points toward utilization in the chemical and technical industries.

Biodegradable industrial materials that have qualities similar to those of synthetic materials could open up the market for starch products to a considerable amount. The need for this development is further reinforced by the alarming increase of waste we produce. Both in Germany and in the West of Europe large amounts of solid waste are produced every year, and dumping space is becoming more and more of a problem. Almost one third of the waste volume is made up by long-lasting packaging which has been made for short-term use. The call for production within the cycle of nature is getting louder. Biorecycling is becoming more popular.

Quickly degradable biological starch materials can be processed into hollow parts, mouldings, foams or sheetings by methods used for synthetic materials, too. They are a sensibel alternative for short-lived products (packaging, hygiene products, fast-food packaging and throw-away cutlery). The fact that they are biodegradable is also an advantage for their use as gardening products like plant pots, soil sheeting or bags for rubbish disposal).

4. Prospects

Products made from renewable raw materials must be understood as an integral component of an economy that tries to save natural resources and our environment by staying within the cycle of nature. Specialists regard natural materials as a main component of future-oriented forms of economy.

Already biomass is the most important renewable energy carrier, covering 3 % of the demand of primary energy in Bavaria. That means a reduction of the total amount of carbon dioxide emissions by 4.5 t in Bavaria.

The Bavarian government wants to raise this share to 5 %. Specialists think biomass could reach a maximum market share of 12%. A slow but steady increase in prices for fossil energy carriers would be enough to establish renewable raw materials on the market.