Potentiale zur energetischen Nutzung von Biomasse in der ... - EPFL

Anhang 41
Bundesamt für Energie BFE
ethanol. In Europe, however, starch containing feedstocks are often too expensive, i.e. generate too
little return, to produce ethanol for fuel purposes (Mansson, 1998).
� Lignocellulosic feedstocks (e.g. wood, grass, bagasse)
There are substantial supplies of lignocellulosic materials such as agricultural and forestry residues,
waste paper, municipal solid waste and various industrial wastes which are not well utilised and which
often present disposal problems. It is also possible to grow woody and herbaceous energy crops and
employ under-utilised land to support the indigenous production of such forms of biomass.
These raw materials are generally less expensive, but on the other hand, the process is more complex,
as the material is solid and the pulp is protected by hemicellulose and lignin. Lignocellulosic raw
materials have the additional problems of proportional variability within the mixture of its three major
components (namely cellulose, hemicellulose and lignin) and natural variability in the monomeric
sugars that make up the hemicellulose content. Also, the hydrolysis of cellulose is more difficult than
that of starch.
The use of feedstocks such as sugar cane, corn or wheat for fuel production may compete with other
high value uses such as food production. On a general basis, the choice of the most suitable crops to
be cultivated for liquid biofuels production depends on many factors, the most important of all being
the economic and strategic convenience for farmers to cultivate the new energy crop in place of the
traditional ones.
At present, the production of ethanol from lignocellulosic biomass at an industrial scale is still very
limited. However, extensive development work has been carried out (mainly in the United States) with
the aim of finding effective production methods involving enzymatic hydrolysis.
The case of Switzerland
The present section gives a brief description of the situation of fuel-ethanol in Switzerland with a first
paragraph on the present situation and a second one about the perspectives in the short to medium
term.
The present situation
In Switzerland, the Swiss Alcohol Board sells about 40 millions litres of ethanol, more than three
quarters of which are used for chemical and technical purposes. Drinking alcohol and brandies of pip
fruits do not represent more than 10% of the sales. Apart from a few test experiences, the use of
ethanol as a fuel does not yet exist on a large scale in Switzerland.
With a production of 11 millions litres of ethanol per year, Borregaard Schweiz AG (formerly Atisholz
SA, before acquisition by the Norwegian company Borregaard) is by far the largest producer of
ethanol in Switzerland, the remaining being currently imported. Initially, Borregaard Schweiz AG is
commercialising paper pulp as well as hygienic papers. Paper pulp manufacturing gives rise, besides
pulp itself, to a variety of derived products such as ethanol or lingo-sulphates (28% of the company’s
turnover in 1998). Bioethanol is thus extracted from paper pulp production wastes by acid hydrolysis,
and therefore produced from lignocellulosic feedstocks.
Short to medium term perspectives
A couple of years ago, Alcosuisse (the profit centre of the Swiss Alcohol board) launched a large-scale
project, with the objective of introducing bioethanol on the Swiss vehicle fuels market. After two
years of active research and maturation of the project, Alcosuisse is today hoping to introduce, as
soon as this year, the first litres of fuel-ethanol on the Swiss market (ethanol would be delivered by
Borregaard) and to have a 47.5 Ml/yr production plant constructed by 2007. With a second