298 94 307/02 Untersuchungen zum Stand der Umsetzung des ...

Investition
Re-Invest
©
150
TDM
50
0
-50
-100
40
Monate
20
10
0
370-01-00
12 Monate
6 Monate
Teil 3 Seite 10-4
2 4 6 DM/kg
Esterpreis
zusätzliche
Investition
Einsparung pro Jahr
4,30 DM/kg
3,40 DM/kg
Figure 10-2 Mineral oil-ester cost comparison (example)
In comparison to mineral oil costs of approx. € 1/kg, additional costs of approx. € 75.000
must be expected in the illustrated example of a central cooling lubricant supply when
switching to ester at a purchase price of € 3,5-4/kg. With an annual savings potential of
approx. € 17.500 to 20.000 through, amongst others, lower drag-out through grits and
grinds and extended grinding disk life-span a replacement investment only occurs after 4
years. Due to economic reasons, this is too long for most investors, causing such a con-
version towards an environmentally friendly product not to be carried out. Only when suc-
cesses are achieved to lower cooling lubricant costs to approx. € 2 would it be possible to
reduce replacement investment to below 1 year. In this event, the willingness of many
users to convert would tend to increase.
One possibility to lower the raw material costs would be on the basis of fats derived from
animal carcass disposal plants. These animal fats are manufactured by means of the so-
called dry melting process from slaughtering waste, unsuitable meat and animal car-
casses. By means of suitable types of alcohol, a transesterification into cooling lubricants
is certainly possible after purification of the raw fats. Due to the low price of the raw mate-
rial of approx. € 200/t (as at 6/2000), despite these purification and transesterification
steps, a cooling lubricant price falling into the above range is definitely possible.
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