HiTEC® 4678

HiTEC® 4678
HiTEC® 4678
Multifunctional detergent
For diesel fuel
Report Number: Fuels 01/2008
Version 1
Date: May 2008
__________________
Chemist
CONTENTS
Page
INTRODUCTION
2
INJECTOR DETERGENCY - THE MECHANISM
4
ENGINE TEST POLICY
6
INJECTOR DETERGENCY - TESTING
8
FUEL ECONOMY & EMISSIONS REDUCTION
11
FOAM CONTROL
13
CORROSION CONTROL
16
WATER DEMULSIFICATION
18
BIO-DIESEL COMPATIBILITY
19
PHYSICAL PROPERTIES
22
HiTEC® 4678
Page 1
INTRODUCTION
Afton is the largest fuel additive
addi
producer worldwide and has been marketing a
wide range of gasoline and diesel performance additives for a number of
decades.
Afton have a well established value proposition of adding value to fuels by
harnessing technical innovation and global marketing expertise which allows oil
companies to offer their customers a differentiated diesel quality. We strongly
believe in:
Working together. Delivering more.TM
During the last few decades we have seen tremendous advances in the design of
diesel engine technology as vehicle manufacturers strive to meet the more
demanding government vehicle emissions regulations. This has also required oil
companies to make available fuels which will allow new vehicle hardware to
continue operating to the latest design
design specifications. These changes are
captured schematically below:
In addition we are seeing changes to fuel quality driven by environmental
concerns. The introduction of bio-fuels
bio fuels is now a well established fact with fatty
acid methyl ester (FAME) being permitted in EN590 diesel as a blend component
at a level of 5% and there are currently discussions aimed at increasing this level
to 10% in the near future. These fuels offer different challenges to additive
companies who have to give re-assurance
re
that
at the appropriate chemistry is
available to maintain engine
en
performance with Bio-diesel use.
You will see later in this report that Afton Chemical has conducted an extensive
investigation into the impact of Bio-diesel
Bio
on products such as HiTEC® 4678.
HiTEC® 4678
Page 2
HiTEC® 4678 is multifunctional by design and is the result of extensive research
and development designed to achieve a high level of performance coupled with
the reassurance of complete compatibility with modern diesel engine technology
& evolving diesel specifications. The use of a product such as HiTEC® 4678 allows
oil companies to market a premium quality diesel fuel.
The recommended treat-rate of HiTEC® 4678 is 190ppmv. If used at the higher
treat-rate of 256ppmv HiTEC® 4678 will deliver a demonstrable reduction in
emissions and improved fuel economy. Engine protection will be provided at a
treat-rate as low as 106ppmv.
Initial additive development, performance and no harm testing is conducted in
our state of the art engine test facilities based in Richmond, Virginia. This is
complimented by more specific industry engine tests which are performed at
local independent ISO accredited test facilities.
HiTEC® 4678 will improve the performance of treated diesel by preventing the
build up of deposits in the critical region of the engine and, at slightly higher
treat-rates, will result in clean up and removal of existing deposits. The most
critical part of the engine is the injectors.
HiTEC® 4678 is a well established diesel performance additive with the following
features:
Excellent injector deposit control
Significant reduction of injector flow loss
Almost completely eliminates foam
Fully compatible with Bio-diesel
Low viscosity for easy handling
Chlorine free
HiTEC® 4678, used at the recommended treat-rate, will give up to 5 times more
fuel flow in both older and modern types of diesel engine leading to the following
performance benefits:
Improvement in fuel economy & reduction in carbon dioxide emissions
Significant reduction in undesirable emissions from the exhaust
Reduced foaming during tank filling leading to quicker & cleaner filling
Excellent corrosion control preventing filter blockage
Prevent emulsion formation & improve water separation
HiTEC® 4678
Page 3
INJECTOR DETERGENCY-THE MECHANISM
All diesel fuels have a tendency to form small amounts of hard, carbonaceous
deposits on the fuel injector nozzles of both direct injection and indirect injection
diesel engines. This process is known to occur during the first few hours of
operation, and then generally to persist throughout the lifetime of the nozzles.
The build up of excessive amounts of these deposits will disrupt the spray
pattern of the fuel from the nozzle, which can lead to serious drivability
problems. Increased fuel consumption, high noise levels and increased
emissions are some of the other problems attributed to excessive nozzle coking.
The schematic below shows the design of an indirect injection pintle nozzle and
the area where deposit build up is most likely to occur.
The use of detergents will dramatically reduce the build up of deposits so that
the flow of fuel through the injector is not impeded, resulting in a robust spray
pattern. The stronger the spray pattern the better the fuel will mix with excess
air leading to more complete combustion, improved fuel economy & lower
emissions.
Fuel detergents are generally associated with a range of amine type chemistries
in which a polar amine group is reacted on to a hydrocarbon soluble backbone.
The detergents function by surface active attachment of the polar head group to
form a barrier film on the critical surfaces. There is also a dispersant action
whereby the additive prevents agglomeration of particulate matter and keep it
dispersed so that it is less likely to accumulate on the injector surfaces.
Detergents have a solvent activity whereby the additive can dissolve pre-formed
deposits.
HiTEC® 4678
Page 4
Afton Chemical has a history of continued improvement in the potency of their
diesel detergent additive
dditive chemistry. The current product used in HiTEC® 4678 is
based upon succinimide chemistry which has been
be
optimised to give state of the
art performance both in keeping injectors clean and also to clean up dirty
injectors. An indication of the chemistry
chemistry of the Afton Chemical diesel detergent is
shown below:
A very similar mechanism occurs for the modern direct injection diesel engines
except, due to the design of the injectors, it is not possible to quantify the effect
of deposits of the fuel flow through the injectors. In this case the impact of
deposit build up is measured indirectly by quantifying the loss of power
power.
HiTEC® 4678
Page 5
AFTON’S ENGINE TEST POLICY
For a number of years it has been the policy of Afton to use internal engine
testing only for research and development of new additive formulations. Afton
has a state of the art research centre situated in Richmond, Virginia which is
fitted with a number off engine tests including the standard Peugeot XUD
XUD-9 and
recently introduced Peugeot
ugeot DW-10,
DW
and these engines are operated according to
current CEC procedures.
In most countries, including the European Union, the engine tests for evaluating
detergent packages
ges are agreed and formalised by the Coordinating European
council (CEC). Representatives of the CEC working groups are from oil
companies, equipment manufacturers and additive companies.
The CEC protocol previously used for test development is summarised below:
When generating data to support the performance of commercialised fuel
additives, where possible, all testing is conducted in ISO accredited and
independent engine test laboratories which are mostly situated in Europe. The
engine laboratories used run the engine tests strictly according to the
appropriate CEC test procedures and they also participate in regular round robin
testing to ensure the engine severity is in-line
in line with the industry standard.
HiTEC® 4678
Page 6
The traditional performance test in terms of defining additive treat-rates is the
Peugeot XUD-9, CEC-F-023, and particular care is taken to ensure this test is
conducted correctly. Changes in engine technology and the increased use of
bio-derived components is expected to see greater focus on the DW-10 test for
future benchmarking.
The repeatability and reproducibility of the XUD-9 test is re-established after
every round robin but the current values are shown below:
Peugeot XUD-9
The precision of the test has been assessed in round robin exercises in which
CEC reference fuels were tested at a number of laboratories. The precision
statistics for the Air Flow Loss for each fuel were as follows, where r refers to
repeatability and R refers to reproducibility.
The information in this bulletin is, to our best knowledge, sure and accurate, but
all recommendations or suggestions are made without guarantee since the
conditions of use are beyond our control. Afton Chemical Corporation and its
affiliates disclaim any liability incurred in connection with the use of these data or
suggestions. Furthermore, nothing contained herein shall be construed as a
recommendation to use any product in conflict with existing patents covering any
material or its use.
HiTEC® 4678
Page 7
INJECTOR DETERGENCY - ENGINE TEST DATA
There are two basic engine designs for diesel passenger cars in the current
European car parc. Older designs of passenger diesel engines are based upon
indirect injection technology where the fuel is sprayed through a pintle injector
into a pre-combustion chamber. The purpose of the prechamber is to improve
the efficiency of combustion by providing better fuel/air mixing prior to the fuel
passing into the main combustion chamber.
The industry standard engine test for indirect injection passenger technology is
based upon the Peugeot XUD-9 engine. This test procedure was first developed
in the mid 1980,s by a working group affiliated to the CEC. The initial test was
published as the CEC-F-23-X-95 and this test was under development for up to
10 years. The test began as a 6 hour steady state test but after the 1997 CEC
round robin it was declared that this test did not meet the statistical
requirements of the CEC.
In 1998 an alternative test procedure, using the same engine, was presented to
the CEC working group. This test was based upon a 10 hour cyclic procedure and
it was felt that this procedure was more likely to meet the CEC statistics
requirement. After a very thorough investigation it was decided that the 10 hour
test had significant improvements over the 6 hour test. Armed with strong
repeatability & reproducibility data an application was made to move the
procedure from ‘’X’’ status to ‘’T’’ status and this was granted in January 2000.
The graph below indicates the level of performance that can be obtained with
HiTEC® 4678 in the current European reference diesel.
Remaining Flow @ 0.1mm
60
46
50
32
40
30
24.25
20
8
10
0
0
HiTEC® 4678
106
190
285
HiTEC 4678 Treat rate (ul/l)
Page 8
More recently, direct injection common rail engines have been introduced to the
European market by major car manufacturers as a means to meet the stringent
emission limits of current European legislation. These modern diesel engines are
fitted with very precise injection technology designed to help deliver better
combustion efficiency with a consequent reduction in tailpipe emissions.
However, over time deposits will build up on the critical parts of the diesel fuel
injection equipment and these will not allow the engine to operate to its design
specification. To maintain the performance levels attributed to modern engine
designs it is important to keep the injectors clean and free of deposits.
As a consequence, the current industry standard coking test, CEC F-23-01 (XUD9) originating from 1993 no longer meets the needs of the modern diesel car
parc. A new test has recently been developed to monitor the performance of
premium quality fuels to ensure that modern diesel engines are protected against
the power loss and spray pattern degradation that can result from deposit build
up on injectors.
The new test is based upon the Peugeot DW10 2.0litre HDi engine operated with
multi hole ‘sensitive’ injectors indicative of EURO V applications and supplied by
Siemens. Engine power loss is evaluated during a 72 hour test cycle which
consists of a total running time of 32hours. Vehicle manufacturers are indicating
that 2% power loss could be considered as an acceptable performance limit for
this test. The test now has official status and has been allocated the CEC F-9808(DW-10) nomenclature.
There are two mechanisms that can be used to produce deposits in this test, one
is based on the addition of zinc and the second requires the addition of 10%
FAME. The use of zinc will lead to more acceptable reproducibility than FAME but
FAME is seen as being more representative of current EN590 diesel fuel quality.
HiTEC® 4678 has been evaluated using both these mechanisms and the results
are shown graphically below:
Power loss since SOT (%)
HiTEC® 4678 performance in the direct injection Peugeot DW10 test
Fuel treated with 1 ppm Zinc
HiTEC® 4678
0
-1 0
-2
-3
-4
-5
-6
-7
-8
-9
-10
Engine run time (hrs)
8
16
24
32
Base + Zn
Base + Zn + H4678 @ 380ppmw
Page 9
HiTEC® 4678 performance in the direct injection Peugeot DW10 test
Fuel blended with 10% FAME
Power Loss [%]
4
2
0
-2
-4
-6
-8
-10
-12
-14
-16
-18
-20
-22
B10 + H4678 @ 190ppm
B10 + H4678 @ 380ppm
B10
0
4
8
12
16
20
24
28
32
36
40
44
48
Engine Run Time with Test Fuel [h]
The data shown above demonstrates that HiTEC® 4678 gives good protection
against power loss resulting from deposit build up in direct injection engines. At a
treat-rate of 380ppm HiTEC® 4678 has given complete protection against power
loss irrespective of the mechanism used to promote power loss.
HiTEC® 4678
Page 10
FUEL ECONOMY & EMISSIONS REDUCTION
It is a proven fact that when the injectors of a diesel vehicle suffer from flow loss
as a consequence of deposit build up there will be a direct impact on the
combustion efficiency of the vehicle. This loss of efficiency can be measured as a
reduction in fuel economy and an increase in emissions. A number of different
test cycles exist to quantify this impact.
In 1990 a test program was conducted in the well established engine test
laboratory of APL in Austria. The objective of the test was to measure the
immediate and longer term advantages of using detergent to keep diesel
injectors clean.
The first test program was carried out in a Mercedes 200D taxi with a 2 litre
naturally aspirated indirect injection engine. At the time of testing the vehicle
had done 138000 kilometers on its original injectors. The effect of detergent in
this vehicle was evaluated immediately and after 1000 kilometers of city, urban
and high speed cruising. This test was run under a number of different test
cycles but here we have focused on the European, ECE-15 test cycle results.
The second test was conducted with a Volvo truck, which represents a direct
injection heavy duty vehicle, and readings were taken immediately and after
60hours of operation. The test was run on a European ECE R49 test cycle
The actual tests were conducted with 100ppm of an older generation diesel
detergent. Based upon the nitrogen content of the detergents we can relate the
performance measured in this test with the more potent detergent used in
HiTEC® 4678. 100ppm of the old generation of detergent is equivalent to 54ppm
of the current commercial diesel detergent and this is equivalent to 253ul/l of
HiTEC® 4678.
In conclusion the use of 253ppm HiTEC® 4678 will give the following performance
benefits based upon the data generated from the AVL field trial reported above.
The benefits are shown as percentage improvement.
HiTEC® 4678
Page 11
Mercedes
passenger car
Volvo truck
Volvo truck
HiTEC® 4678
Fuel economy
(ECE-15
cycle)
Hydrocarbons
(ECE-15
cycle)
2.2%
13%
Fuel economy
(Immediate)
Hydrocarbons
(Immediate)
1.3%
11.3%
Fuel economy
(After 60
hours)
Hydrocarbons
(After 60
hours)
1.6%
21%
Carbon
monoxide
(ECE-15
cycle)
6%
Carbon
monoxide
(Immediate)
8.6%
Carbon
monoxide
(After 60
hours)
28%
Particulates
(ECE-15
cycle)
4.8%
Particulates
(Immediate)
8.3%
Particulates
(After 60
hours)
21%
Page 12
FOAM CONTROL
All diesel fuels have a natural tendency to produce foam when pumped into the
tank of a diesel vehicle. Excessive foaming can cause motorists problems by
"splashing-back" on them and increase re-fuelling times by prematurely
activating the automatic fuel cut-off in service pump nozzles. Fuel spilling onto
the service station forecourt also gives rise to environmental concerns.
A small amount of anti-foam added to the fuel can significantly reduce the above
problems. In addition, fuel marketers have seen the commercial advantages of
using anti-foam additives in terms of the greater volume of fuel that can be
added to a vehicle tank before the pump cuts-off.
There are various methods for evaluating the performance of anti-foam. Methods
range from simple handshake tests to vehicle tank filling tests. However, the
industry recognised fuel foam test is based upon the BNPe rig using the NFM 07075 test procedure. Fuel is injected under pressure into a measuring cylinder
and the initial height of the foam and the time taken for the foam to collapse are
measured. The design of the test is shown below:
HiTEC® 4678
Page 13
The effectiveness of HiTEC® 4678 in reducing fuel foaming was assessed using
the BNPe (NFM 07-075) test. Fuel is injected under pressure into a measuring
cylinder and the initial height of the foam and the time taken for the foam to
collapse are measured. The fuel used for this test was the CEC RF93-T-95
reference fuel.
European reference diesel
Test No.
1
2
3
Additive
None
HiTEC® 4678
HiTEC® 4678
0
106
190
105
75
48
32
9.1
2
Treat-rate µl/l
Foam Height (mm)
Foam Decay Time (s)
Testing has also been conducted in a European ultra low sulphur diesel fuel and
excellent performance has been seen at the recommended treat-rate of 190ppm
as tabulated below:
Ultra low sulphur diesel fuel
Test No.
1
2
Additive
None
HiTEC® 4678
0
190
100
17
42
1.9
Treat-rate µl/l
Foam Height (mm)
Foam Decay Time (s)
The above results show that HiTEC® 4678 is effective at controlling the foaming
tendency of diesel fuel and this can be demonstrated visually below:
HiTEC® 4678
Page 14
HiTEC® 4678
Page 15
CORROSION CONTROL
Corrosion in the fuel system of a vehicle can lead to severe problems. Not only
can leaks develop in vehicle fuel tanks but particles of rust can block fuel lines
and filters and, in severe cases impact fuel spray efficiency.
The corrosion properties of diesel fuel are measured by using a dynamic
corrosion test coupled with a NACE rating scheme. The test is published as
ASTM D665A (using distilled water) and ASTM D665B (using synthetic seawater).
In this method a mixture of 300ml diesel fuel and 30ml water are stirred at a
temperature of 60 degrees Celsius for a period of up to 24 hours. A steel
specimen is immersed in the liquid and this specimen is visually checked and
rated according to the NACE scale shown below:
NACE Rating
A
B++
B+
B
C
D
E
%age Rust
None
Less than 0.1%
Less than 5%
5-25%
25-50%
50-75%
100%
Pass/Fail
Pass
Pass
Pass
Fail
Fail
Fail
Fail
Original equipment manufacturers recognize the benefits of protecting the key
engine parts from corrosion.
HiTEC® 4678 is effective in imparting anti-corrosion properties to diesel fuels.
The effectiveness of HiTEC® 4678 is readily demonstrated in CEC RF93-A-92
diesel fuel using the ASTM D665A (IP 135A) procedure. A rating of "B+" or
better is generally considered to be a pass. The results of the ASTM D665A
tests are as follows:
HiTEC® 4678
Page 16
NACE RATING
HiTEC® 4678
Base = C
190ppm HiTEC 4678=B+
Page 17
WATER DEMULSIFICATION
Due to the detergency action of diesel detergents there is a risk of additive
treated diesel retaining water and thus reducing the rate of separation of the
water from the fuel. Multifunctional diesel additives are formulated with
demulsifiers in order to give acceptable behaviour when in contact with water.
HITEC® 4678 has been evaluated according to the ASTM D1094 test in a number
of commercial diesel samples and meets the requirement of giving performance
similar to untreated diesel.
It can be seen that HITEC® 4678 provides good water shedding properties when
treating at 190l/l. The results are illustrated below:
Demulse Testing (ASTM D1094)
Interface rating
4
+190ul/l HITEC®
4678
1b
Separation rating
3
2
Vol.emulsion (ml)
5
0
Vol. Aqueous (ml)
15
20
BASE FUEL
HiTEC® 4678
Page 18
HiTEC® 4678 PERFORMANCE IN BIO-DIESEL
Fuels derived from renewable biological resources are known as bio-fuels. Animal
fats and virgin and recycled vegetable oils derived from crops such as soybeans,
rape seed, canola, corn and sunflowers can be used in the production of a fuel
suitable for diesel engines called biodiesel (also known as FAME). Tall oil,
produced from wood pulp waste, is another feedstock source. Biodiesel can
either be used in its pure state or can be blended with conventional diesel fuel
derived from mineral oil.
A Directive was published by the European Parliament and the Council of the
European Union in May 2003 to promote the use of bio-fuels in Europe. This
Directive established a target of 2% bio-fuel consumption for road transportation
by 2005 and then a 0.75% increase every year to achieve 5.75% by 2010. This
was encouraged by the introduction of tax incentives for certain member states
but still the targets are not being met, so now we are seeing a move towards
mandating the use of bio-fuel components in certain European countries.
The EN590 specification currently allows the use of up to 5% FAME in diesel fuel
to be marketed at the service stations. There are currently attempts to convince
the vehicle manufacturers that the level of FAME in diesel fuel could be safely
increased to a level of 10% but as of today this has not been fully agreed.
Since Afton Chemical is the market leader in diesel performance additives it was
important to consider the impact of FAME on the current additive technology
being used in the market. Since HITEC® 4678 is a well established product used
throughout Europe it was decided to use this product to evaluate the
performance impact of FAME.
HITEC® 4678 was first evaluated for the effect it would have on injector coking.
This impact was evaluated in both the indirect injection Peugeot XUD-9 engine
test and the new Peugeot DW-10 direct injection test. Since the performance of
HITEC® 4678 in diesel containing 10% FAME has already been demonstrated in
the DW-10 on page 11 of this report we will focus on the performance in the
Peugeot XUD-9 in this section.
Testing was conducted in the Peugeot XUD-9 using standard commercial diesel
fuel blending with different percentages of Soya methyl ester. The results of this
evaluation are shown graphically below:
HiTEC® 4678
Page 19
This testing shows that the addition of 5% FAME may have a slightly positive
impact on the detergency characteristics of the base fuel. However, the FAME
containing diesel will still benefit from the addition of an additive such as HITEC®
4678 both at the 5% and the 20% level of FAME addition. More testing has been
conducted with diesel fuels containing FAME at the current commercial leve
level and
significant detergency benefits have been seen from the addition of HITEC® 4678
as shown below:
An evaluation of HITEC® 4678 was conducted in a European diesel fuel which
contained 5% rapeseed methyl ester. The results are shown graphically on the
next
ext page and indicate that HITEC® 4678 gives excellent improvement in
detergency
gency in current commercial biodiesel:
bio
HiTEC® 4678
Page 20
100
Remaining Flow @ 0.1mm
90
91
80
80.9
70
60
50
54.5
40
30
20
21.2
10
0
0
190
395
990
HiTEC 4678 Treat rate (ul/litre)
The same commercial diesel fuel containing 5% FAME has been used to evaluate
foam and corrosion performance with HITEC® 4678. The addition of HITEC® 4678
to the FAME containing diesel led to a 50% reduction in foam collapse time which
is similar to the performance expected from normal fossil derived diesel fuel.
In terms of corrosion performance we have seen a slight improvement in
corrosion protection coming from the addition of FAME to fossil diesel and this
can be still further improved by the addition of HITEC® 4678. This is
demonstrated from the data tabulated below:
Diesel
%RME
HITEC®
4678
Treat-rate
ASTM D665A
ASTM D665B
RF06
0
0
E
E
RF06
0
190
A
A
RF06
5
0
B++
B+
RF06
5
190
A
A
RF06
10
0
B++
B+
RF06
10
190
A
A
HiTEC® 4678
Page 21
PHYSICAL PROPERTIES OF HITEC® 4678
Property
Result
Method
Appearance
Clear brown liquid
Visual
Odour
Aromatic
Flash point,PMCC, ○C
56 min
ASTM D93
Sulphur content, mg/kg
22
Calculated
Density at 15○C, kg/l
0.906
ASTM D4052
Nitrogen content, wt%
1.09
ASTM D5291
Chlorine content, mg/kg
<20
TBN, mg KOH/g
27.6
ASTM D2896
TAN, mg/g KOH
1.3
ASTM D664
Silicon content, ppm
3100
ASTM D4951
Pour point, ○C
-40
ASTM D97
Viscosity, cSt at 40○C
7
ASTM D445
Viscosity, cSt at -15○C
40
ASTMD445
Viscosity, cSt at -20○C
53
ASTM D445
Shelf life(Ambient)
18 months
Aged evaluation
HiTEC® 4678
Page 22
ASIA PACIFIC
Afton Chemical Asia Pacific LLC
111 Somerset Road #09-05
Singapore
238164
T: +65 6732-0822
F: +65 6737-4123
EMEAI
Afton Chemical Limited
London Road, Bracknell
Berkshire RG12 2UW
England
T: +44 1344 304-141
F: +44 1344 420-666
LATIN AMERICA
Afton Chemical
Industria de Advitivos LTDA
Avendia Rio de Janeiro 901 (Parte)
CEP-20931-670
Brazil
T: +55 21 3860-9994
F: +55 21 2580-8647 & 2589-0531
NORTH AMERICA
Afton Chemical Corporation
500 Spring Street
Richmond
VA 23219
USA
T: +1 804-788-5800
F: +1 804-788-5184
www.aftonchemical.com