Chapter 1
Fundamental Biochemical and Biotechnological Principles of Biomass Growth and Use

Manfred Kircher

KADIB-Kircher Advice in Bioeconomy Kurhessenstr, Frankfurt am Main, Germany

Jared Diamond, [2005]

1.1 Learning Objectives

This chapter discusses about vegetable biomass and its future role as industrial feedstock to provide fuel and chemicals. In the transition phase from the current fossil-based into the bio-based economy, vegetable biomass needs to face up to competition against the fossil benchmark, which is at mineral oil. Therefore, this chapter starts with an analysis of the fossil economy, especially in the chemical sector.

In future, when fossil feedstock inevitably becomes scarce and the bio-economy increasingly unfolds, vegetable biomass must meet the industrial feedstock demand for a growing global population. While further serving the traditional food, feed, and fiber markets, this is no easy challenge. More sustainable carbon sources and applications are another topic of this chapter.

Turning the bio-economy into reality is more than a technical issue. From an abstract point of view, it needs scientific and technical push as well as market pull to make the bio-innovation leap. But first and foremost, it needs people with visionary: devoted scientists, future-oriented entrepreneurs, a supportive political framework, and last but not least a willing general public. These so-called pillars of competitiveness are presented as well.

The learning objectives of this chapter are

1. 1. the significance of carbon in our economy;
2. 2. the fundamental biochemical and biotechnological principles of fossil- and bio-based carbon sources concerning nature, production, and processing; and
3. 3. the complex challenges in making vegetable biomass the dominant sustainable feedstock.

1.2 Comparison of Fossil-Based versus Bio-Based Raw Materials

1.2.1 The Nature of Fossil Raw Materials

The current global economy is very much based on fossil resources to produce energy (electricity, fuel, heat) and organic chemicals. The initial source of these feedstock has been biomass transformed through geological processes into crude oil, natural gas, black coal as well as lignite and peat. What makes these materials valuable for use in energy and chemistry processes is their high energy as well as carbon content (Table 1.1). The most valuable fossil resources are the hydrocarbons that consist only of carbon and hydrogen. Subgroups are, for example, alkanes (saturated hydrocarbons; CnH2n+2), cycloalkanes (CnH2n), alkenes (unsaturated hydrocarbons; CnH2n), and aromatics (ring-shaped molecules) differing in the number of carbon and hydrogen and molecular structure.

Table 1.1 Composition (%) and heat value (MJ kg-1) (Herrmann and Weber, [2011]) of fossil feedstock

Coal, especially black coal, is the oldest fossil resource. Formed from terrestrial plant biomass, it has been consolidated between other rock strata and altered to form coal seams by the combined impact of pressure and heat under low-oxygen conditions over about 300 million years. Black coal is extracted by open-cast mining as well as deep mining (up to a depth of 1500 m). It is composed primarily of carbon.

Fossil oil has been formed over a time period of about 100 million years by the exposure to similar conditions on sedimentation layers of marine organisms such as algae and plankton. Under such conditions, the long-chain organic molecules of the vegetable biomass are split into short-chain compounds forming liquid oil. It accumulates in specific geological formations called crude oil reservoirs.

Some fractions even split down to molecules with only one carbon and become gaseous methane (CH4). Therefore, oil deposits (and coal mines) always contain methane of more or less similar age. Methane sources covered by nonpermeable geological layers lead to real methane deposits. From such geological formations, the gas can be extracted in the form of natural gas. Natural gas can also be the result of biological catabolic processes degrading biomass. These deposits are also found under nonpermeable geological formations but have been formed over a period of about 20 million years.

As oil and gas generation needs high-pressure conditions the corresponding deposits are highly pressurized. If such sites are drilled, oil and gas escape through the well - a process called primary recovery allowing to exploit 5-10% of the total oil and gas. By pumping (secondary recovery) and more sophisticated methods (tertiary recovery) more oil and gas can be extracted. Obviously exploiting an oil and gas deposit is easy in the beginning but becomes more and more technically complex and costly with time.

Lignite has a similar origin as black coal. It has been exposed to the harsh geological conditions for up to 65 million years and can be extracted by open-cast mining. The carbon content is lower than that in black coal, but extraction costs are in average more beneficial.

Peat is another fossil resource. It is as well formed from terrestrial plants under aplent moor conditions when the biomass decays for several 1000 years under low-oxygen conditions. Peat contains the lowest carbon and highest water share under fossil resources. It is recovered from ground.

All fossil resources have the following common characteristics: (i) they are rich in carbon and energy; (ii) their composition is not very complex and quite homogeneous; (iii) they can be produced at moderate, though growing cost; and (iv) fossil resources can be shipped easily by railway, tankers, and pipelines.

1.2.2 Industrial Use

1.2.2.1 Energy

All fossil feedstocks are characterized by high energy content. By oxidation (adding oxygen) the chemical energy stored in the molecules is released in the form of heat - a process called burning in everyday language. Therefore, fossil feedstock is an efficient and easy material to produce energy. In 1709, it was used for the first time in England for industrial purposes when black coal instead of wood-based charcoal was used for iron melting in a coke blast furnace. Discovering this energy source came just in time to start metal-based industrialization because charcoal production had significantly decimated the area under forests. Since then black coal is one of the most relevant primary energy carriers. In 1859, the Pennsylvania Rock Oil Company drilled the first oil well in Titusville (Pennsylvania, USA). Only 10 years later, John. D. Rockefeller founded the Standard Oil Company in 1870, thus starting the era of multinational companies serving the global energy markets. Gas exploitation followed in 1920 in the United States and in 1960 in Europe. Table 1.2 shows the share of fossil material use in different global regions.

Table 1.2 Use of fossil feedstock in different global regions (%) (EKT Interactive Oil and Gas Training, [2014])

In summary, production of heat, fuel, and electrical power from fossil resources has been the starting point of industrialization and is still today by far the dominant application. Ninety-three percent of oil, 98% of gas and coal, and 100% of peat are going into energy markets (Höfer, [2009a]; Ulber et al., [2011b]). It is estimated that even in 2040 mineral oil, natural gas, and coal will serve more than three-fourths of total world energy supply (US Energy Information Administration, 2013). The mix of fossil feedstock differs among global regions dependent on regional resources and trade routes.

1.2.2.2 Chemicals

The cheap and seemingly unlimited availability of fossil resources not only triggered an energy-hungry industrialization but also the innovation leap into today's chemical industry. High carbon content in combination with easy logistics through pipelines and tankers made especially oil and gas an ideal industrial feedstock. Seven percent of the global oil and about 2% of world natural gas consumption go into chemicals...