20 Introduction to Renewable Biomaterials
Ethanol is made bySaccharomyces cerevisiae(baker’s yeast) fermentation using sugar
as carbon source. First-generation ethanol is made from sugar or starch (plant-derived
sugar), whereas second-generation ethanol results from woody raw materials after
releasing the lignocellulosic sugars. The United States (50 billion liters) and Brazil
(25.5 billion liters) are leading in the production of ethanol.
Recently,Clostridiumhas been tested on pilot scale. These anaerobic bacteria are able
to produce ethanol from gaseous CO that comes with industrial off-gases (e.g., from
a steel mill) or with synthesis gas (CO, H 2 )fromgasifiedbiomassorotherorganic
materials.
Power Generation of bio-based power uses wood pellets and chips as well as biogas. In
Germany (leading in biogas), 6000 plants produce biogas from specially grown energy
crop (corn) and animal dung (e.g., from poultry production). However, the future is seen
in biogas from industrial and municipal residues (e.g., food processing). Another option
currently under evaluation is gasifying biomass (directly or in the form of municipal
waste) and generating power from the resulting synthesis gas. Most of the gas is used
to generate power, some goes into heat production, and there is also an option to feed
biogasintothenaturalgasgridasmethaneisthemaincomponentofbiogasaswellas
natural gas.
Wood-based power generation is already an established global market. The high
demand in Europe is met by importing feedstock especially from North America (75%),
Russia, and Eastern Europe.
Heat Solid biomass is by 90% the most important energy source in bio-based heating
(housing, cooking). Europe is leading and burns 15 million tons of wood pellets (2013).
North America is also an expanding market. Though most of biogas is used to generate
power its role in heating should not be underestimated especially in rural areas with less
developed infrastructure.
1.3.9.2 Chemicals
In many industries, bio-based feedstocks are already established, either because of
(i) special feedstock suitability (pulp and paper), (ii) missing alternatives (proteins,
drugs), (iii) unique characteristics (special polymers, tensides, lubricants), or
(iv) customer demand (cosmetics). All the following chapters demonstrates that
modern bio-based feedstocks conquer chemical markets according to similar rules
of the fossil-based chemicals that emerged 150 years ago: Starting from high-value
adding pharmaceutical markets where bio-based materials provide the only alternative,
the growing knowledge encourages first to enter fine and bulk chemistry markets and
finally to compete directly with fossil-based processes. One of the striking differences
to the early chemical industry times is the fact, that science and knowledge are key
from the very beginning.
Bio-based raw materials like rubber, wood, starch, and vegetable oils are established
in various industrial applications. Figure 1.2 presents an overview about the current
material use of biomass.
Natural rubber goes into high-performance tires, for example, for heavy-duty vehicles
and special applications like medical products. It is a long-chain polyterpene, which
is more uniform than its fossil-based synthetic alternative. About 50% of the global
