RU2451718C2 - Additive for increasing cetane number of diesel fuel - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to diesel fuel containing additives which increase cetane number. The additive for increasing cetane number of diesel fuel consists of premixed cyclohexyl nitrate or 2-ethylhexyl nitrate and peroxides selected from: ditertbutyl peroxide, dicumyl peroxide, cumyl hydroperoxide, with said components in ratio from 3:1 to 1:3. The additive is added to the diesel fuel in amount of 0.1-0.5 wt %.

EFFECT: high cetane number of the diesel fuel and low content of nitrogen oxides in exhaust gases.

2 cl, 1 tbl

Description

The invention relates to the field of oil refining and petrochemistry, in this case, to the composition of additives that increase the cetane number, which determines the flammability of diesel fuel (DT): at its optimum value, the engine is most economical and environmental performance is improved (exhaust smoke is reduced, emissions of incomplete products are reduced combustion, СО, soot, etc.).

It is known that organic compounds of various classes can be used as cetane enhancing additives - ignition promoters (CIP): aldehydes, ethers and esters, nitro compounds, peroxides, mono- and polynitrates of aliphatic and cyclic alcohols [Lerner M.O. M .: Chemistry, 1979, 222 p.]. For several reasons, nitrates of aliphatic and alicyclic alcohols and, to a lesser extent, some alkyl peroxides have found practical application [Danilov A.M. Directory. The use of additives in fuels for automobiles. M., Chemistry, 2000, 227 pp.]. From the class of organic nitrates, it is known to use ignition of cyclohexyl nitrate (CGN) and 2-ethylhexyl nitrate (2-EGN) as promoters, while the CGN is superior to 2-EGN in efficiency and a number of operational properties [Danilov A.M. Directory. The use of additives in fuels. M. Mir, 2005, 288 pp.] From the class of alkyl peroxides are di-tert-butyl peroxide (DTBP), dicumyl peroxide (DCT) and cumyl hydroperoxide (CGP). The effectiveness of peroxides compared with alkyl nitrates is much lower, for example, the promoting effectiveness of DTBP is about 85% of the effectiveness of 2-EGN [Danilov A.M. Domestic additives to modern diesel fuels. Sat Proceedings of the 5th International Forum "Fuel and Energy Complex of Russia: Regional Aspects. 2005, 182 pp.] and, according to our data, less than 70% of the efficiency of CTG.

Also known is an additive for increasing the central temperature of the diesel fuel, consisting of pre-mixed CTG and a fraction of normal structure paraffinic hydrocarbons from C ₉ -C ₂₀ with a mass ratio of these components from 4: 1 to 1: 4 added to the diesel fuel in an amount of 0.05-0, 75 wt.% (Patent No. 2309975, RF, 2007). The additive has a synergistic effect and, due to its greater solubility, facilitates the process of mixing with fuel.

The aim of the invention is the development of a composite additive that effectively increases the HR, reducing its cost and further reducing the exhaust gas nitrogen oxides.

The problem is solved by introducing into the composition of the diesel fuel a composite CPP containing TsGN and / or 2-EGN and peroxides from the group: cumyl hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide with a mass ratio of components from 3: 1 to 1: 3, respectively.

Replacing part of the CNG with peroxides, in addition, reduces the content of nitrogen oxides in the exhaust gases, and the introduction of an additive, for example, cumyl hydroperoxide, which is a semi-industrial product in the production of phenol and acetone, allows expanding the raw material base and reducing the cost of CPP at a given value of the increase in CC . A composite CPP additive according to this invention is prepared by pre-mixing alcohol nitrates with alkyl peroxides. The proposed composition can be introduced into diesel fuel of any grades in concentrations of 0.1-0.5 wt.% Without compromising the basic operational properties of fuels.

The combined use of alcohol nitrates and alkyl peroxides as CPP is not known to us. Therefore, the prototype in the application is taken nitrates of alcohols and the corresponding alkyl peroxides in pure form.

Table 1 presents the test results of the proposed CPP, while for the base diesel fuel they took L-02-40 grade fuel according to GOST 305-82 manufactured by Kirishinefteorgsintez LLC and Slavneft Yaroslavlnefteor gsintez OJSC.

CC was determined according to GOST 3122-67 (with amendment 1-4). The effectiveness of CTG is 4-5 points higher than the effectiveness of peroxides and 2-3 points higher than the efficiency of 2-EGN. When replacing part of the alcohol nitrate with less effective peroxides, one would expect a decrease in the effectiveness of the mixed additive as compared to pure nitrate. However, tests have shown that the use of a mixture of alcohol nitrates and alkyl peroxides as a composite additive does not lead to a decrease in efficiency. The increase in CC of the composite additive is equal to or close to pure alcohol nitrate. The data are presented in table 1.

Depending on the ratio of components (table 1):

for cumyl hydroperoxide

examples 1, 2, 7, 8, 25, 26 with an additive content of 0.1 wt.%

examples 3, 4, 9, 10, 27, 28 with an additive content of 0.2 wt.%,

examples 5, 6, 11, 12, 29, 30 with an additive content of 0.5 wt.%

for di-tert-butyl peroxide

examples 13, 14, 31, 32 with an additive content of 0.1 wt.%,

examples 15, 16, 33, 34 with an additive content of 0.2 wt.%,

examples 17, 18, 35, 36 with an additive content of 0.5 wt.%,

for dicumyl peroxide

examples 19, 20, 37, 38 with an additive content of 0.1 wt.%,

examples 21, 22, 39, 40 with an additive content of 0.2 wt.%,

examples 23, 24, 41, 42 with an additive content of 0.5 wt.%.

This synergistic effect can probably be explained by the effect of the products of the initial decomposition of peroxides, which occurs at a constant rate already at 110-120 ° C in the conditions of the combustion chamber, on the initiation of the decomposition of alcohol nitrate, which begins at higher temperatures. In this case, the formation of the necessary concentration of radicals due to the decomposition of alcohol nitrate for the implementation of the chain reaction of combustion occurs in a shorter period of time than when using the components separately. As a result, the delay period of ignition of DT is reduced and the promoting effect remains at the level of pure alcohol. The use of alkyl peroxides in the composition of the proposed additive additionally reduces the nitrogen content in diesel fuel, and the use of cumyl hydroperoxide can reduce consumer costs per 1 point of increase in cetane number. For example, if we take the unit cost of 1 point increase in the cetane number when using only a nitrate additive, then for a composite additive containing cumyl hydroperoxide, this value will be 0.7 for a ratio of components 1: 1 and 0.5 at a ratio of 1: 3.

Table 1 Example No. Component Name The ratio of the component wt.% Concentration additives wt.% Cetane number CC gain Relates. the cost of 1 point of the Central Committee one 2 3 four 5 6 7 8 Base fuel - - - - 48 - - Comp. example CTG - - 0.1 52-53 4-5 1,0 CTG 0.2 54-55 6-7 1,0 Comp. example - KGP - 0.1 49 one 0.25-0.30 KGP - 0.2 fifty 2 0.25-0.30 one CTG KGP 3: 1 0.1 52 four 0.8 2 CTG KGP 1: 3 0.1 51 3 0.5 CTG KGP 3: 1 0.2 54 6 0.8 four CTG KGP 1: 3 0.2 52-53 4-5 0.5 5 CTG KGP 1: 3 0.5 53-54 5-6 0.5 6 CTG KGP 3: 1 0.5 54-55 6-7 0.8 Base fuel - - - - 51 - - Comp. example CTG - - 0.1 57-58 6-7 1,0 CTG - - 0.2 58-59 7-8 1,0 Comp. example - KGP 0.1 52 one 0.25-0.30 - KGP - 0.2 53 2 0.25-0.30 7 CTG KGP 3: 1 0.1 57-58 6-7 0.8 8 CTG KGP 1: 3 0.1 56-5.7 5-6 0.5 9 CTG KGP 3: 1 0.2 58-59 7: 8 0.8 10 CTG KGP 1: 3 0.2 57-58 6-7 0.5 eleven CTG KGP 1: 3 0.5 58 7 0.5 12 CTG KGP 3: 1 0.5 57-58 6-7 0.8 Base fuel - - - - 45 - - Comp. example CTG - - 0.1 51 6 1,0 CTG - - 0.2 54 9 1,0 Comp. example - Road accident - 0.1 47 2 1.5-2.0 - Road accident - 0.2 48 3 1.5-2.0 13 CTG Road accident 3: 1 0.1 51 6 1.5-1.8 fourteen CTG Road accident 1: 3 0.1 fifty 5 1.5-1.8 fifteen CTG Road accident 3: 1 0.2 53-54 8-9 1.5-1.8 16 CTG Road accident 1: 3 0.2 52-53 7-8 1.5-1.8 17 CTG Road accident 1: 3 0.5 53-54 8-9 1.5-1.8 eighteen CTG Road accident 3: 1 0.5 54 9 1.5-1.8 Base fuel - - - - 48 - - Comp. example CTG - - 0.1 53 5 1,0 CTG - - 0.2 55 7 1,0 Comp. example - DCT - 0.1 49 one 1.5-2.0 - DCT - 0.2 fifty 2 1.5-2.0 19 CTG DCT 3: 1 0.1 53 5 1.3-1.8

twenty CTG DCT 1: 3 0.1 51-53 3-5 1.5-2.0 21 CTG DCT 3: 1 0.2 55 7 1.3-1.8 22 CTG DCT 1: 3 0.2 54-55 6-7 1.5-2.0 23 CTG DCT 1: 3 0.5 54-55 6-7 1.5-2.0 24 CTG DCT 3: 1 0.5 56-57 7-8 1.5-2.0 Base fuel - - - - 48 - - Comp. example 2-EGN - - 0.1 50-51 2-3 1,0 2-EGN - - 0.2 51-52 3-4 1,0 Comp. example - KGP - 0.1 49 one 0.3 - KGP - 0.2 fifty 2 0.3 25 2-EGN KGP 3: 1 0.1 fifty 2 0.8 26 2-EGN KGP 1: 3 0.1 49 one 0.5 27 2-EGN KGP 3: 1 0.2 51 3 0.8 28 2-EGN KGP 1: 3 0.2 51 3 0.5 29th 2-EGN KGP 1: 3 0.5 51-53 3-4 0.7 thirty 2-EGN KGP 3: 1 0.5 52 four 0.8 Base fuel - - - - 45 - - Comp. example 2-EGN - - 0.1 49 four 1,0 2-EGN - - 0.2 51 6 1,0 Comp. example - Road accident - 0.1 47 2 1.5-2.0 - Road accident - 0.2 48 3 1.5-2.0 31 2-EGN Road accident 3: 1 0.1 49 four 1.5-1.8 32 2-EGN Road accident 1: 3 0.1 48 3 1.5-1.8 33 2-EGN Road accident 3: 1 0.2 50-51 5-6 1.5-1.8 34 2-EGN Road accident 1: 3 0.2 49 four 1.5-1.8 35 2-EGN Road accident 1: 3 0.5 fifty 5 1.5-1.8 36 2-EGN Road accident 3: 1 0.5 51 6 1.5-1.8 Base fuel - - - - 48 - - Comp. example 2-EGN - - 0.1 51 3 1,0 2-EGN - - 0.2 52 four 1,0 Comp. example - DCT - 0.1 49 one 1.5-2.0 - DCT - 0.2 fifty 2 1.5-2.0 37 2-EGN DCT 3: 1 0.1 51 3 1.5-2.0 38 2-EGN DCT 1: 3 0.1 fifty 2 1.5-2.0 39 2-EGN DCT 3: 1 0.2 52 four 1.5-2.0 40 2-EGN DCT 1: 3 0.2 51 3 1.5-2.0 41 2-EGN DCT 1: 3 0.5 52 four 1.5-2.0 42 2-EGN DCT 3: 1 0.5 53 5 1.5-2.0 Designations in the table:
CC - cetane number,
TsGN - cyclohexyl nitrate,
2-EGN - 2-ethylhexyl nitrate,
KGP - cumyl hydroperoxide,
DTBP - di-tert-butyl peroxide.
DCT - dicumyl peroxide

Claims (2)

1. Additive to increase the cetane number of diesel fuel, consisting of pre-mixed cyclohexyl nitrate or 2-ethylhexyl nitrate and peroxides selected from the group: di-tert-butyl peroxide, dicumyl peroxide, cumyl hydroperoxide with a mass ratio of these components from 3: 1 to 1: 3. 2. A fuel composition based on diesel fuel containing an additive from pre-mixed cyclohexyl nitrate or 2-ethylhexyl nitrate and peroxides selected from the group: ditretbutyl peroxide, dicumyl peroxide, cumyl hydroperoxide with a mass ratio of these components from 3: 1 to 1: 3, in the amount of additive 0, 1-0.5 wt.%.