Fuel composition comprising a heavy fuel oil and biomass product

FUEL COMPOSITION COMPRISING A HEAVY FUEL AND A PRODUCT DERIVED FROM THE BIOMASS

The present invention provides a fuel composition comprising a heavy fuel and a product derived from the biomass.

Residual fuel oils are hydrocarbon commercial high-boiling, relatively rich in heteroatoms such as sulfur or nitrogen and metals. Residual fuel oils require, for most of them, be stored heat in order to prevent solidification and for ease of pumping and flow for carrying out said method. Commercial fuel oils are to be according to ASTM d396 - 98.

Typically, residual fuel oils are formulated by assembling different bases derived from petroleum refining. In some cases, when trade specifications are difficult to reach with the bases used usually for the formulation, heavy oil is mixed logged lighter distillates as sections or desulfurized, e.g. a residue of ARDS ("for Atmospheric pyrolysis residue upset"), which have a greater added value, that the formulator seeks to avoid. In addition, residual fuel oils resulting from the assembly of different bases must be sufficiently stable in time. The jitter can be materialized as by an increase in the viscosity or by sedimentation of certain products. It is therefore necessary to conduct stability tests upon any new formulation of heavy fuel oil. Tall oil, tall oil is also known as or or tall oil, is a by - product liquid kraft pulping of wood processing for isolating one side of the wood pulp useful for the paper industry, and other tall oil. Tall oil is essentially obtained when using conifers in the kraft process. After processing of the wood chips by sodium sulfide in aqueous solution, tall oil isolated is alkaline. The latter is then acidified by sulfuric acid to produce the crude tall oil.

Acidification may lead to insufficient crude tall oil containing metal salts, typically sodium. This feature arises because tall oil predominantly comprises hydrocarbon compounds functionalized by organic acids, essentially carboxylic acids, sometimes phenols. Tall oil also includes non-saponifiable sterols, fatty alcohols and other derivatives of alkylated hydrocarbons. Tall oil means has a tan (the total of Acid a number, in mg of KOH per mg of product) of between 100 and 200, more typically between about 125 and 165.

To tall the fuels are generally useful as bases in the chemical industry and for the production of adhesives and adhesives.

In addition, the oils of neutralization are derived from the acidification of soapstocks. The soapstocks comprise essentially neutralized fatty acids by a base, and originate directly in the saponification of a vegetable or animal oil. In addition to the fatty acids having their free carboxylic acid function, neutralizing oils may contain, according to their origin and quality of the saponification, traces of phospholipids or mono -, a di - or tri-glycerides unreacted.

Neutralizing oils are often used for animal feed.

The refining industry, at least in Western, tends to decrease production of heavy fuel oil, due to the lowering of demand. This decrease is related to passage of alternative energy sources by the customers, especially natural gas, as well as to environmental stress which tend to limit the amount of sulfur in heavy fuels, the sulfur is almost absent from the natural gas business. The decrease in the amount of sulfur in heavy fuels requires investments in refining and operational overhead which make this purification step often not economically viable. In addition, heavy oil generally requires to be stored at a temperature of around 50 °c to make it pumpable. A decrease in the storage temperature would improve the overall energy efficiency.

There is thus a need for obtaining fuel oils best suited to the environmental stresses.

To this end, the invention concerns a use of a liquid fuel derived from biomass as an additive for stabilizing a fuel composition comprising a heavy fuel oil, heavy oil being defined ASTM d396 - 98.

Thus, the applicant has shown that the use of such an additive in a composition comprising a heavy oil, unpredictably stabilizing the composition resulting combustible mixture or composition total fuel (liquid fuel derived from biomass and fuel composition comprising a heavy fuel), i.e. maintain substantially constant viscosity during storage, to say whose change is preferably at most 10%, of the composition total fuel for storage lifetimes greater than 3 months, preferably 3 to 6 months. This provides a gain sensitive storage temperature of said blended composition, which therefore can be decreased, and suppress the necessity of reheating of such mixture. Also, the gain in stability is measured by the acid number, determined by measuring the "of tan" ("the total of Acid a number"). Although embodiments of the invention, the acid value of the mixture composition can be raised, the acid corrosion is limited.

Further, the stability of the composition total fuel is determined by monitoring the evolution of peptizing parameters, measured in accordance with ASTM standard , and the homogeneity of the mixture by measuring the sulfur content.

The liquid fuel derived from biomass is advantageously selected from the group consisting of an oil neutralization and tall.

The applicant has found that the selection of these two liquid fuels derived from biomass responded particularly advantageously to the desired objectives. Oil neutralization is defined as fatty acid compositions neutralized by a base, which has been acidified, the fatty acids from advantageously directly from the saponification of a vegetable or animal oil, such as, though not exclusively, sunflower, soybean, canola and olive, and comprising conventionally as overwhelming majority carbon chains in c16-to-c18, saturated or unsaturated, among which preferably unsaturated carbon chains c18. Vegetable oils typically include palmitic acid, oleic and linoleic acid and other in lower amounts. Fatty acid compositions are typically neutralized by a base soapstocks. In the context of the invention, alternatively it may be byproducts or precursors of neutralizing oil. Neutralizing oil is advantageously present in the composition total fuel in an amount ranging from 1 to 80% by weight, preferably from 10 to 50% by weight, more preferably from 20 to 40% by weight relative to the total weight of the composition total fuel, best results being observed for the last range of proportion (20 - 40% by weight).

Oil neutralization can therefore advantageously be used as a fluxing for the preparation of a composition of fuel mixture comprising a heavy oil. In effect, the lowering of the viscosity obtained by addition of the neutralizing oil is a distinct advantage, because the storage temperatures can be significantly reduced.

Neutralizing oil is advantageously used for the preparation of a composition of fuel mixture comprising a heavy oil for improving the pour point and/or to reduce the sulfur content of the fuel blend composition.

Neutralizing oil is also used as an additive for the preparation of a composition of fuel mixture comprising a heavy oil, for reducing the temperature of storage with respect to the storage temperature in the absence of said additive, namely oil neutralization.

In other embodiments, the liquid fuel derived from biomass is advantageously tall oil (tall) or optionally a by-products thereof or precursors.

Tall oil is present in the composition total fuel in an amount ranging from 1 to 80% by weight, preferably from 5 to 50% by weight, more preferably from 10 to 30% by weight relative to the total weight of the composition of combustible mixture, the best results being observed for the last range of proportion (10 - 30% by weight).

Tall oil is advantageously used as an additive for the preparation of a fuel composition containing total a heavy fuel to decrease the storage temperature relative to the storage temperature in the absence of said additive, i.e. the tall oil.

The total fuel composition advantageously includes a supporter of combustion. Such a supporter of combustion is not limited and may be selected from the group consisting of a combustion catalyst, such as noble metal, organic derivatives of noble metals and non-metallic, in a broad sense, a combustion additive comprising surfactants. Such compounds are known and commercially available. A combustion additive comprising a mixture of oxides of Fe, CA and/or Ce in a hydrocarbon solvent, such as apolar hydrocarbon solvents, is most preferred. Such an additive is preferably present in an amount between 0,020 and 0,030%. One example is the product ca2200 provided by the Company.

The fuel derived from biomass used as additive comprises advantageously proportionally less sulfur than heavy oil.

The composition of fuel mixture according to the invention can advantageously be used for supply of a furnace or a boiler.

Thus, another object of the present invention is the use of a fuel composition comprising a liquid fuel total biomass and a fuel composition comprising a heavy fuel oil, heavy oil being defined ASTM d396 and 98, such defined previously, for the supply of a furnace or boiler.

Description of the drawings

Figures 1 and 2 graphically represents the evolution of the viscosity of the mixture fuel oil and TaN/oil neutralization during storage, for the example 1, below.

Figure 3 represents the evolution of the viscosity during storage at 80 °c, for tall oil alone or mixed with a fuel oil, compared to fuel oil alone. Figure 4 represents the evolution of s value over storage for the products identified in Figure 3. Figures 3 and 4 are related to the example 2.

Figure 5 shows the circuit diagram of homogenizing a mixture of tall oil/heavy fuel (weight/weight) 30/70 tests (example 3) combustion.

Figure 6 shows the circuit diagram of storage up to the burners, including the circuit homogenization of Figure 5.

Figure 7 represents the evolution of the temperature of the exhaust based on the oxygen supply in the context of the example 3.

EXAMPLES

Example 1: oil neutralization

Physico-chemical features of products and the mixture of fuel oil and characterization of oil

The characteristics of the products and of the mixture are presented in Table I.

Oil neutralization is much less viscous than a heavy fuel oil or tall oil. Its acid value itself is much higher; generally, the TAN to tall of fuels is of the order of 50 to 60^{" 1} whereas that in oil neutralization characterized in this study is 120^{" 1} .

Its low content of sulfur and nitrogen it impart advantageous properties in terms of regulated pollutants.

A PCB is somewhat shorter than the fuels to a tall (of 1 5mJ or greater. kilograms.^{" 1} on average).

The viscosities to 50 and 100 °c and the density have been computed from the laws of mixture and are given in table I as indicative.

The viscosity at 100 °c of the mixture could not be measured because the sample evaporates in the tube of the viscometer. The value is illustrative, however it is close to the theoretical viscosity obtained by application of the law mixture viscosity.

Table I: the method for transmitting the copied and of melan AE

" Value calculated from the law of variation of viscosity with temperature.

^** value calculated based on the relationship between PE and PE Martens on (FS. T-FD and 60 - 145) characterization of the mixture

This study has been to follow the evolution in time of a mixture of 30% / 70% heavy fuel oil neutralization brought to 80 °c in terms of viscosity and acid number (the total of tan - cyclopentan a number).

Table II shows the evolution of the TAN and viscosity during storage in an oven at 80 °c, opened vials.

The viscosities to t=0, 1 and 4 days could not be measured due to the evaporation of a fraction of the sample in the viscometer; these values are given as a guide.

Table II: TaN progression and the viscosity of the mixture of 100 @ °C during storage to 80 °c

Figures 1 and 2 graphically represents the evolution of the viscosity of the mixture fuel oil and TaN/oil neutralization during storage.

By contrast behaviors/biomass fuel oil mixtures, the results obtained with the mixture fuel oil/tall oil and were also carried on these graphs. Heavy oil used is the same.

The viscosity of the mixture heavy fuel/oil neutralization little change during storage. In contrast, a thermal evaporation of the light fraction when viscosity measurements at the beginning of storage that prevents the viscosity measurement. After 6 days this phenomenon disappears, the viscosity measurement becomes possible but not observed any significant increase viscosity as in the case of mixture heavy fuel/tall oil and HCL.

The acid value of the mixture heavy fuel/oil neutralization is quite high (of the order of 35 mg KOH/g oil) and corresponds to the value calculated from the law of mixture. By against the evolution during storage appears to be substantially different from that in the case of mixture with tall oil HCL. Indeed, if observed, just like with tall oil HCL a slight increase followed by a decrease of the TAN at the beginning of the storage thereof increases again in the case of mixture with the oil neutralization. However, the TAN after 30 days of storage is of the same order of magnitude as the TAN calculated of the mixture.

On the other hand the corrosion test (test to the copper strip) shows an absence of corrosive action of the mixture (quotation of the blade: 1 has). Briefly and not limitation, although having a high acid value and a PCI less than a heavy fuel oil or tall oil, oil of neutralization is from biomass fuel a potentially interesting to incorporate in heavy oil. Its good flux leads to a significant decrease in the viscosity of the mixture which would decrease the storage temperature and heating of such fuel.

The mixture is storage stable, more so as, in conjunction with the low viscosity of the mixture, the storage temperature can be lowered dramatically.

In case of using such a product of particular precautions have to be taken as a result of the strong acid value; however, the risk of corrosion acid is very low based on the results of such test to the copper strip.

Example 2: the tall oil

Evaluation of the stability of the mixture

Conditions of implementation

The degree of incorporation of tall oil to heavy fuel was targeted to 10% by volume, for a storage period of one month. The storage temperature is of the order of 65 °c.

Program analysis

The aim of these measures is to verify the stability of the mixture by monitoring the evolution of the viscosity and peptizing parameters, and the homogeneity of the mixture by measuring the sulfur content in two taps (high and low) in the vial.

Heavy oil used for testing is a fuel oil . The degree of incorporation of tall oil is 10% by volume.

Peptization parameters are measured following ASTM d7157: a precise sample amount is filled accurately toluene. This mixture is then added a quantity of heptane until the appearance of the flocculation of asphaltenes.

The three tests at different solvent volumes are made and which calculate the following indices:

O: indicates the intrinsic stability of the product.

Its: aromatic character indicates the asphaltenes.

S0: indicates the aromatic character of the matrix.

Generally, it is considered that a fuel oil is stable if s wi appreciation is greater than 1.4 (1 .45 or).

Storage stability

To study the aging of the product in storage conditions relatively severe, the samples were placed in an oven at 80 °c, opened vials. The viscosity measurements at 100 °c and peptizing parameters were carried out on t=0, 1, 3, 7, 15 and 30 days.

The results are presented in the following table.

The evolution parameters peptizing heavy fuel mixture are presented in the following table. The parameters peptizing tall oil could not be measured because of the absence of asphaltenes.

Table VI: progression during storage to 80 °c peptizing parameters (e appreciation) fuel oil mixture (10% tall oil and fuel oil by 90% /) (days)T-Mycobacterium fol 270 271 Mycobacterium fol

O OS S Wi Its OS

0, 1, 80, 0.93 0.48 1, 89, 1, 00, 0.47

1, 1, 73, 0.91 0.47 1, 89, 0.99 0.48

3, 1, 68, 0.90 0.46 1, 97, 1, 09, 0.45

7, 1, 65, 0.91 0.45 1, 76, 0.94 0.47

15, 1, 75, 1, 03, 0.41 1, 95, 1, 1, 1 0.43

30, 1, 64, 0.96 0.42 1, 71, 0.94 0.45

In Figure 3, which represents the evolution of the viscosity @ storage at 80 °C, tall oil progresses very little unlike heavy fuel. The evolution of the heavy fuel oil is however not surprising in view of the test conditions particularly severe (80 °c, opened vials).

The viscosity of the mixture keeps track of the viscosity of the heavy fuel oil. If we assume the severity of the test conditions and the difference between the viscosity of the oil and the mixture, it is believed that risk of instability of the mixture is restricted under the conditions of implementation on site.

Figure 4 is the outcome of s value over storage, shows that the s-appreciation of the mixture is greater than 1.7. Thus, even if observed variations of s appreciation over time, the mixture may be considered to be stable (e > 1.4).

Homogeneity of the mixture

The difference, in terms of characteristic physicochemical, most significantly between the two products is the sulfur content.

The homogeneity of the mixture is thus evaluated by measuring the sulfur content in two taps.

The results are presented in the table below. Table V: progression during if to 80 °c @ viscosity at 100 °C (mm.² sec.)

The tall oil fuel oil mixture (10% / 90% tall oil and fuel oil)

Mycobacterium fol reference 267 270 271 Mycobacterium fol Mycobacterium fol

sample withdrawal bleed-down

Content 0,941 0,910 0,906<0.2 sulfur

Given the uncertainty on the measurement of the content of sulfur, the sulfur levels measured at the high point and low point are comparable. The mixture can be considered homogeneous.

Other characteristics of the tall oil and/or of the mixture

In order to insure the safety of the product with respect to hardware (vessel, circuitry, pump...) but also its environmental interest also the appearance incorporation of fuel from biomass, a number of features have been measured such as: corrosive, water content, ash content.

Table VI: progression during storage to 80 °c @ viscosity at 100 °C

^* calculated from corrosion

The ISO standard NF 2160 - corrosive action on the copper - prescribes a test method for determining the corrosive action of the petroleum products on the copper.

This test involves immersing a copper strip polished in a product sample to a temperature and for a time specific to the class of the product of interest (3:00 EURES to 100 °c for fuels). At the end of the heating period, the blade is removed, rinsed and the color compared to standard corrosion.

The results (quote 1 has) show that neither the product, nor the mixture does exhibit corrosion risk to hardware.

Ash content

Tall oil has a high ash content. The incorporation of 10% tall oil at heavy fuel leads to an increase of a factor of about 2 the ash content of the mixture.

However this increase is without impact in the use configuration given the presence of electrostatic precipitators. However if the implementation of such a mixture is envisaged on other facility (boiler for example) the emission impact of dust must be taken into account.

Nitrogen content

Even if the incorporation tall oil leads to a substantial decrease of the nitrogen content, the main-NOx formation path glass furnace is the thermal path. Thus, the decrease in nitrogen constituent of the fuel does not allow significant gain on NOx emissions.

Briefly and not limitation, the storage stability of the mixture/tall oil and heavy fuel oil was evaluated by monitoring the viscosity and parameters peptizing products and the mixture during aging samples placed in an oven at 80 °c, opened vials. The results show an evolution of the viscosity of the heavy fuel and to a lesser extent tall oil. The viscosity of the mixture keeps track of the viscosity of the heavy fuel oil. By against the parameters peptizing are relatively stable. In view of the severity aging conditions and the parameter analysis peptization, the mixture does not appear to exhibit instability in storage conditions considered. Example 3: combustion of a mixture/tall oil and heavy fuel oil

Combustion tests disclosed herein have been made on a boiler 1 MW of which is equipped with a mechanical pulverization. The stress with this type of burner is the need delivery fuel with a viscosity in the range of 17 mm² sec. which for a conventional heavy fuel oil to a temperature of about 130 °c.

In view of the variability of the quality tall oil HCL, new stability measurements were performed (to assess stability of the mixture storage but also under the conditions of implementation due to the reheating before burner).

Evaluation of the combustibility of a mixture heavy fuel/tall oil and HCL

The denomination from the tall oil pitch HCL designates the mixture and lead compound obtained from the distillation of crude tall oil from paper mills.

The features heavy fuel tall oil used during this study HCL mixture and from heavy fuel/tall oil and HCL are tabulated in the following table VII. It should be noted that the sulfur content of heavy fuel is RP is 0.98% of mass. The tall oil HCL has not been determined.

The study of combustibility was made from a mixture of heavy fuel/tall oil and HCL 70/30.

Combustibility

Combustion installation

The tests have been completed on the fire tube boiler of 1 MW of which is equipped with a mechanical pulverization to two courses (atomizing pressure 26 bar), without preheating combustion air. The stress on this installation is the viscosity in the nose of the burner which is to be of the order of 17cst, is about 130 °c for a heavy fuel. The mixing vessel, a capacity 500l, enables to homogenize the fuel, either during its additive mixing or the preparation of mixtures, by recirculation of product on the vessel. This vessel is maintained at 55 °c to ensure the mixture a sufficient viscosity, allowing a proper homogenisation.

Figure 5 shows the circuit diagram of homogenizing the mixture.

List of references visible in Figure 5:

Has, b., C., D., th: manual valves

1: vessel (500l)

2: flexible tank recirculation from above

3: tub heater

4: pressure gauge (p=2 bar)

5: booster pump

6: filter (filter 1 mm)

Figure 6 shows the circuit diagram of storage up to the burners, including the circuit homogenization of Figure 5.

List of references visible in Figure 6:

7: filter (filter 250 micron)

8: the HP pump

9: pressure gauge (p=26 bar)

10: the HP heater

1, 1: hP filter (filter 160 micron)

Measuring equipment

The measuring equipment used to characterize the fumes is described in the table below:

Table VIII: hardware and emissions measurement principle

Product testing

During each test series, the measurements of emissions were made to 3 excess air following: 6%, 4.5% and 3%.

Subsequent runs were performed:

Reference measurements on a heavy fuel

Measurements on the mixture fuel oil/tall oil and a 70/30 (% by volume) HCL

Measurements on the mixture fuel oil/tall oil and HCL 70/30 additivated (additive combustion)

Reference measurements on heavy oil

The additive or supporter of combustion is the ca2200 provided by . It is an additive trimetallic, the Fe/AC/this, whose rate of additivating 1/4000 is recommended.

The observations during the tests

During the whole duration of the test, the temperature of the mixing vessel has been maintained at 52/53 °c. Testing with the fuel oil of reference were done under normal conditions, either a preheating temperature fuel's 140 °c and an injection pressure of 27, 5bars.

In experiments with the mixture fuel oil/tall oil and HCL (not containing the additives), the preheating temperature was 120 °c and the injection pressure of 28bars. Has 135 °c, we observed a blocking of the HP filter and then only a hard spot on the filter by passing to 130 °c. And subsequent combustion becomes unstable when the temperature decreases to become pulsating to 96 °c.

Finally, for testing with the tall oil/fuel oil mixture HCL additived preheat temperature was 130 °c and the injection pressure of 26bars. Problems where the flame was observed in experiments to 4.5% of o2 with tendency to setback.

The combustion tall oil HCL leads to the formation of carbonaceous deposits in a relatively large amount. It is believed that these assays have ducts to sooting tubes highlighted by the elevation of the temperature (fig. 7) of smoke ten degrees between the two reference points (tests at a heavy oil before and after the testing of mixtures).

Mixtures comprising a supporter of combustion have resulted in a significant decrease in carbonaceous deposits, is observed mainly on the filters connected on the chimneys of the exhaust passage.

The study stability evaluation tall oil HCL in admixture has demonstrated the stability of the mixture. By against the acid value very high tall oil HCL may cause corrosion problems acid. Particular attention must be loaned is stored and pipes. On the other hand the processing temperature must be controlled to avoid certain dysfunctions observed, namely blocking filters, pulse combustion phenomena...

The pollutant emissions are in accordance with the desired expectations.

Noted a strong increase dust emission due to the ash content tall oil HCL far greater than that of a heavy fuel. The use tall oil HCL as fuel preferably requires only the installation of a treatment system suitable fumes (filters or electric filters) to limit atmospheric emissions. The SO emissions_{the X} and NO_{the X} are related to the sulfur content of the fuel and nitrogen. Also noted, during combustion of the mixture from the tall oil/fuel oil, the presence in significant amount of sulfates on the filters.

The analyses of different from the tall oil showed a relatively moderate variability for major physicochemical characteristics.