rb bertomeu, S.L.
Technical Services Dept.  / January 2004. Updated November 2015



It is not easy to calculate the fuel savings provided by a specific treatment of fuel oil in power plants with Diesel engines, or in other combustion installations.  In order to obtain reliable values it is necessary to monitor comparative consumption data (WITH and WITHOUT additive treatment) over a prolonged period, along with further operating conditions which influence overall fuel consumption (fuel oil sludge, net calorific value, operational schedules, comparisons of data from homogeneous annual periods, analysis of the fuel and its origin, etc.).


Many of our customers recognise that the use of the additive “rb bertomeu” beco F1/ASF in their cogeneration [power] plants not only provides significant benefits in operational and financial terms, but also saves fuel oil.  However, in general, they have difficulty in quantifying these savings accurately, estimated at between 1% and 3% in certain plants with 5-7 years experience using this particular additive.


Some   customers   have   collected   sufficient   data   to   be   able   to analyze   the   effects   of   the additive  “rb bertomeu” beco F1/ASF and   quantify the saving in   fuel oil obtained.  Obviously, one of the factors that determine the scale of the saving in fuel oil is the state of repair and efficiency of the engines prior to commencing additive treatment of the fuel oil.


In this respect, we may quote a highly illustrative real example, as we have received data from an individual customer who has two cogeneration plants equipped with the same type of engines from the same manufacturer.  The engines were adjusted differently in both plants, producing different overall consumption figures prior to commencing the additive treatment of the fuel oil with “rb bertomeu” beco F1/ASF.


With over two years of experience and of monitoring data in both plants, the following results have been obtained and forwarded to us:


Plants :             COOSUR, located in Vilches, Jaén province, Spain; OLCESA, in Tarancón, Cuenca province, Spain.


Engines :          Each plant has 2 Wärtsilä engines (running on heavy fuel oil) type 12V 46B,

with a power output of 10.5 MWhe per engine.


Fuel :                Fuel oil No. 1 (Spanish specification) used in both plants


Period monitored without the use of additives for fuel oil :     between 18 months and 2 years


Period monitored with the use of additives for fuel oil :          2 years and 6 months


Additive used :              “rb bertomeu” beco F1/ASF   in both plants


State of engines prior to commencement of additive treatment with “rb bertomeu” beco F1/ASF:


-          COOSUR Plant: very well adjusted overall, with fuel oil consumption levels considered low, at 201.5 g / KWhe produced.


-          OLCESA Plant: engines less well adjusted overall than those of COOSUR, with fuel oil consumption levels considered somewhat excessive, at 208.5g / KWhe produced.



Levels of fuel oil consumption recorded:


Plant                            Period             Additive treatment of fuel oil     Consumption (g/kWhe)


COOSUR                   2000-2001       no additive used                                   201.55

                                              2002      beco F1/ASF                                       199.8

                                              2003      beco F1/ASF                                       198.3


OLCESA                    2000-2001       no additive used                                   208.5

                                              2002      beco F1/ASF                                      201.8

                                              2003      beco F1/ASF                                      198.9



Reduction in fuel oil consumption due to additive treatment:


                                                                                          g/KWhe                  Percentage  


COOSUR Plant  :                    201.55 – 198.3  =                     3.25                        1.61 %


OLCESA Plant   :                   208.50 – 198.9  =                      9.60                        4.60 %


Average saving in both plants:                                               6.40                        3.10 %



The saving in fuel oil detected in the COOSUR Cogeneration Plant coincides with the saving of 1.56% calculated in our study "RB6- Tests of fuel oil additive performed in the power plant of 'Gallega de Cogen'", tests carried out over 6 months, in a plant equipped with Wärtsilä engines of 6.3 MWhe. This confirms our claim of attaining a minimum saving in fuel oil of 1.5%, even in well-adjusted plants.






One of the reasons for the reduction in consumption is the increased utilisation of organic fuel oil sludge, that is, lower production of sludge to be removed from the system, given that it is utilised by the engine as fuel.


In the majority of Plants using the additive “rb bertomeu” beco F1/ASF, the reduction in fuel oil sludge is calculated in the order of 50-70%, depending on the type of fuel oil, the impurities it contains, efficiency of filters, etc. We hold specific data supplied by the plant of COOSUR and MSM, where low levels of residual sludge were generated, and where the following reductions were obtained:



                                                                      COOSUR        MSM               Average

                                                                       Plant                Plant                  Value


Power rating, MW                                           21.0                 18.9                 19.95

Fuel                                                                 fuel oil  no.1      fuel oil no.1       fuel oil no.1


Fuel sludge extracted:

   Kg sludge/mT of fuel, without additive            7.75                 8.04                 7.90

   Kg sludge/Tm fuel, with additive                    3.50                 3.31                 3.40


Reduction in sludge when using additive:

   Kg sludge/mT of fuel                                     - 4.25               - 4.73               - 4.50

   Percentage                                                   - 54.8%             - 58.8 %           - 57.0 %



Applying the average value of reduction in residual sludge (- 4,5 Kg/Tm of fuel-oil) to the overall AVERAGE reduction in fuel oil consumption as monitored in the Plants of COOSUR and OLCESA, we are able to calculate the percentage of reduction in consumption due to the reduction in residual sludge:


COOSUR Plant   :   201.55 x 4.50/1000 = 0.907 g/KWhe         =    0.45 % of the total saving

OLCESA   Plant  :   208.50 x 4.50/1000 = 0.938 g/KWhe          =    0.45 % of the total saving

Average value :         0.45 % of the total saving in fuel oil



Considering the average value given above (0.45%) and the overall average saving in the two plants together (3.10 %), we can extrapolate the following breakdown of the causes of the saving in fuel oil:



Saving in fuel oil due to reduced residual sludge  :                                     0.45 %

Saving in fuel oil due to improved combustion :                                          1.56 %

Saving in fuel oil due to less waste accumulation in turbo compressors:   0.19 %

Saving due to less wear in the injection system :                                        1.50 %

Total :                                        3.10 %



© 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
 www.rbbertomeu.es - rbbertomeu@rbbertomeu.es