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RB-4 ANALYSIS OF THE DECREASE OF SLUDGE DEPOSITED IN THE FUEL OIL FILTRATION SYSTEM IN A POWER PLANT
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rb
bertomeu, S.L. |
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1 - INTRODUCTION
In order to quantify the effect that the additive for fuel oil “rb
bertomeu” has on the formation of sludge in the fuel filter of a
cogeneration plant, we reviewed the data contained in our archives, and
eventually chose data from the cogeneration plant at the company Minera de
Santa Marta located in Belorado, Burgos province, Spain. Only this plant
provides sufficient data to form comparisons between the use and non-use
of additive treatment.
The effects of our additives in this respect are produced by the dispersal of
carbon solids contained in the fuel oil, in such a way that they are
homogenised within the fuel, while preventing further sedimentation (a common
occurrence due to ageing of the fuel). In practice, both effects have
the following results: a) Reduced sedimentation of sludge occurs in the
fuel oil storage tanks. b) Reduced quantities of sludge are deposited in
the fuel oil filtration system. This sludge is composed mainly of
insoluble carbon and asphalt residues, but can be utilised in combustion and
improve the energy yield of the fuel. c) Because comparatively lesser quantities of
sludge are produced, the costs of treating and removing them are reduced. This
analysis aims to quantify the result in (c) on the basis of data recorded in
the plant detailed above, which is equipped with three Deutz engines and has
run on fuel oil No. 1 BIA since it was brought into service in March/April
1995. 2 - AVERAGE COMPOSITION OF THE
FUEL OIL USED
Although this is not absolutely essential for this study, as the data are
comparative, it may be of interest to provide the average composition of the
fuel oil No.1 BIA used, including the components that are mainly responsible
for the formation of sludge.
Conradson Carbon
9.40 %
Asphaltenes
4.20 %
Heavy Metals
120 ppm
Water and sediment
0.30 %
Ash
0.046 % 3 – SLDUGE DEPOSITED IN THE
DEPURATION SYSTEM
The quantities of sludge produced are quoted in dry Kg (excluding the water
contained in the sludge) per Ton (T) of fuel oil consumed.
Period monitored
Additive utilised
Kg. sludge / T fuel Order
May – July
1995
None
8.87
1 August – October
’95
“rb bertomeu” beco
FB
4.97
2 Nov. ’95 – Jan.
’96
None
8.04
3 Feb. - Dec.
’96
“rb bertomeu” beco
F1/ASF
3.31
4 * Reduction attained in the first
test period (2 - 1):
8.87 – 4.97 = 4.97 Kg of sludge per T of fuel
Reduction = 44 % * Reduction attained in the second
test period (4 - 3):
8.04 – 3.31 = 4.73 Kg of sludge per T of fuel
Reduction = 59 % * Average overall reduction:
(8.87+8.04) - (4.97+3.31) = 4.32 Kg of sludge per T of
fuel
2
2
Reduction = 51 % 4 - EVALUATION OF THE RESULT
4-1 The improved utilisation of the combustible solids contained in
the fuel oil, assuming that these solids have the same N.C.V. as the
fuel as a whole, would produce a an energy saving equivalent to:
Average reduction in combustible sludge = 4.32 Kg per T of fuel
Energy saving = 0.432 %
Average fuel consumption = 216.5g fuel per KWhe produced
Fuel saving = 216.5 x 0.432 % = 0.94 Kg fuel per Kwhe produced
Savings per MWhe produced = 0.94 Kg fuel oil /MWhe x 0.195 €/Kgr fuel oil = 0.1833 €/MWhe
4-2 The reduction in sludge deposits means that the total costs of
removing them for off-site treatment in an authorised plant are reduced
proportionately. Currently, the cost of the sludge removal is calculated at an
average 110 €/T. Thus, by taking into
account the reduction attained along with this cost, the saving is:
Average reduction in combustible sludge = 4.32 Kg / T of fuel
Saving per T of fuel oil = 4.32 Kg sludge/Tm fuel x '.11' €/kg sludge removal = 0.4752 €/T
Savings per MWhe produced = (216.5 x 0.4752) / 1,000 = 0.1029 €/MWhe
5 - SAVINGS
After adding the results from the sections 4.1 and 4.2, we will obtain the total savings due to sludge reduction.
Savings due to sludge leverage = 0.1833 €/MWhe
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©
rb bertomeu, S.L. - Pol. Ind. Fondo de Llitera, Par. 82-83 - E-22520 Fraga,
Huesca (Spain) Tel.: +34 974 47 48 04 /
+34 630 43 08 43 |