Energianalys av etanolproduktion
en fallstudie av Lantmännen Agroetanols produktionssystem i Norrköping
In this thesis an energy analysis of ethanol production at the ethanol plant of
Lantmännen Agroetanol in Norrköping has been performed. The ethanol plant has
been studied in combination with Händelöverket, the combined heat and power
plant which provides the ethanol process with steam. The purpose of this study
was to determine the energy consumption for the whole production chain from
grain to ethanol. The analysis has included the energy consumption for cultivation
of grain, production of chemicals, the production chain for wood chips, the steam
production and the ethanol plant. The grain and wood chips are both considered
raw materials there for the energy content in these are not included as energy input
in the system. Instead the help energy to produce these two raw materials have
been included as input of energy.
The result from the study is presented as an energy balance, defined as the energy
content for the ethanol divided by the total energy input for production of the
ethanol. The energy balance has shown to be 2,6 if economic allocation is used.
This means that there is more energy produced in form of ethanol than has been
used to produce the ethanol. It is possible to make the production of ethanol more
energy efficient by producing electricity with a steam turbine before the steam is
used in the ethanol plant. If this is done the energy balance will increase to 3,1.
An alternative production system for ethanol has also been studied, in which
DDGS (distillers dried grains with solubles) and DWG (distillers wet grain) is used
as fuel for steam and electricity production. This system has less quantity of byproducts
since most of the DDGS is used as fuel instead of animal feed as in the
earlier studied system. The energy balance for this system showed to be 2,9 or 3,1
for economic allocation depending on if DWG or DDGS is used as fuel.