ISSN 1070-4280, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 7, pp. 1225–1234. © Pleiades Publishing, Ltd., 2007.
Original Russian Text © V.N. Skobelev, V.M. Yablokov, V.V. Serdyuk, L.A. Ashkinazi, 2007, published in Khimicheskaya Promyshlennost, 2007, Vol. 84,
No. 2, pp. 79–91.
Amines as Antiknock Compounds.
V. N. Skobelev
, V. M. Yablokov
, V. V. Serdyuk
, and L. A. Ashkinazi
St. Petersburg State Technological Institute, St. Petersburg, Russia
Academy of Apply Research, St. Petersburg, Russia
Received March 14 , 2007
Abstract—For enhancing octane number and improving ecological characteristics of internal combustion engines
nitrogen-containing compounds of amine class are applied. Although these additives are inferior to the additives
based on iron and manganese organoelement compounds (iron dicuyclopentadienyl, manganese methylcyclopenta-
dienyltricarbonyl and others), but superior to oxygen-containing additives (low alcohols, methyl tert.-butyl ether and
alone and mixed with tert-butanol and others). The nitrogen-containing compounds are ashess addition agents, thus
they are advantageous over the addition agents based on organometallic compounds. A significant advantage of
these additives is polyfunctionality. Being effective enough antiknock agents, they also possess antioxidant, stabiliz-
ing and anticorrosive properties.
TECHNOLOGY OF ORGANIC
AND INORGANIC SUBSTANCES
This work is denoted to:
–Elucidation of mechanism of amine action with
various fuels in the combustion chamber,
–Comparative analysis of efficiency of different
amines in dependence of their molecular struc-
–Revealing the possibility of prognosis of most
effective compounds for application, not inferior
and even superior to the well known antiknock
agents as aniline and monomethylaniline.
The initial position proceeds from the statement
proceeding from the theory of chain reactions that over
the pistion the preflame reactions on the frontier in
going from combustion to explosion and detonation of
the combustion products develop too vigorously. This
leads to accumulation of many radicals developing and
branching the chain reaction.
Development of chains  in time n(t) depends on
the probability ratio of interrupting (b) and continuing
(a) the chain. It is therefore naturally that in the fuel
charge the process of increase in the reaction rate be-
low the critical value is closely connected with the ra-
tio of these probabilities:
is initial rate of generation of radicals.
It is naturally that in each group of fuel the proc-
ess of growing of reaction rate to critical value is con-
nected with own probability ratio.
For increasing detonation resistance of fuel it is
necessary to introduce the additives trapping radicals,
thus increasing probability of chain interruption, which
leads to smooth process of combustion the fuel charge.
That is, efficiency of an additive is defined completely
by the value of probability (b).
Due to fast exponential accelerating and, respec-
tively, decelerating reaction in cylinder, even small
increase in probability (b) leads to sharp deceleration
of the process and respectively to increase in duration
of growing number of radicals n(t) in (1) to critical
value (Fig. 1).
From relation (1) follows and in Fig. 1 is seen that
in very beginning of the chain process of chain propa-
gation the concentration of active radicals n(t) is pro-
portional to time and rate of increase in reaction rate to
critical value depends significantly on the initial, start-
up concentration of radicals n
. Start-up radicals ap-
pear in the fuel charge spontaneously as a small por-
tion of active high-energy particles in Maxwell distri-
bution, or are created artificially, e.g. at illumination in
The authors of out-of-engine express-method of
estimation of octane number [6, 7] established experi-
mentally that induction period of spontaneous ignition
well correlates with octane number and symbasic cor-