(Translated from original letter)

COGEMANSA                    E13300 VALDEPEÑAS – Ciudad Real – (Spain)

Valdepeñas, 10th January 2001

Dear Sir,

This letter is to certify that in our cogeneration [power] plant, equipped with two Deutz PV 16M440 engines, we have been using "rb bertomeu" additives for fuel oil since September 1996, to our full satisfaction inasmuch as ostensible improvements have been observed with respect to periods in which were not using the fuel oil with these additives.

After more than 32,000 and 34,000 operation hours respectively in each one of the engines, we are pleased to confirm, replying to your request, that we have detected operational improvements in the following aspects:

·    Notable decrease in the corrosion and blowing in the exhaust valves of the engines.

·    Absence of corrosion in the inlet valves of the engines.

·    Absence of corrosion in the turbos.

·    Residue decrease in the exhaust valves, turbos, gas collectors, etc., which reduces cleaning necessities and raises the service factor of the Plant.

·    Sharp decrease of sludge formation in tanks and fuel oil purifiers, which has been translated into a decrease of the fuel consumption per kWhe produced and a saving in management of fuel oil sludge.

·    Removal of black smoke due to incorrect combustion, which means a reduction of pollution and fuel consumption.

Though we have not quantified the savings which have been produced as a consequence of the detected improvements, we assure that overall, the use of "rb bertomeu" additives for fuel oil provide us with a positive economic balance (benefit - cost).

Also, we can also express our satisfaction with the Technical Service that has been provided for us, referring to the periodic analysis of exhaust gases of the engines, as well as to their inspection, whose technical and photographic reports have constituted an element of great help for the management of the Plant in its first operational years.

We authorise the use of this letter for reference purposes.