OBJECTIVES: 1. To be able to determine the carbon residue of sample lub o ils.
THEORY/HYPOTHESIS:
If lubricating lubricating oil is heated to a high temperatur temperaturee in an enclosure where there is a limited supply of air, the greater part of the oil will be distilled distilled and there will remain remain a residue of carbon. The amount of this carbon residue in lubricating oil is an indication of the extent of its decomposition when used for high-temperature lubrication.
Carbon residue determinations are generally made by the method introduced by Conradson and the apparatus being used consists of the following equipment:
1.
orce orcela lain in cruc crucib ible le gla! gla!ed ed thro throug ughou hout, t, "# to to "$ cubic cubic cent centim imet eter er capa capaci city ty,, %$ mil milli lime mete ters rs in diameter.
".
&'idm &'idmor oree iron iron cruci crucibl ble, e, %# cubi cubicc centi centime mete ters rs capa capaci city ty,, $# mill millim imet eter erss in diam diamet eter er,, () to (* millimeters high with co+er, without deli+ery tubes and one opening closed.
(.
rough ught iron crucib cible formed from spun pun sheet iron wit with co+e o+er, about 1 cubic bic centimetres capacity, millimeters in diameter, # to $ millimeters high. /t the bottom of this crucible a layer of sand is placed about 1 millimeters deep or sufficient to bring the &'idmore crucible with co+er on, nearly n early to the top of the wrought wrough t iron crucible.
%.
Trian riangl gle, e, pipe pipe stem stem co+e co+ere red, d, with with a pro0 pro0ec ecti tion on so as as to foll follow ow the the flam flamee to reac reach h the crucible on all sides.
#.
&heet &heet iro iron n or asb asbes esto toss hood hood pro pro+i +ide ded d with with a chim chimney ney about about " to " inche inchess high high,, " 12 12 to to " inches in diameter, to distribute the heat uniformly during the process.
$.
/sbe /sbest stos os or or holl hollow ow shee sheett iron iron blo bloc' c' 3in 3insu sula lato tor4 r4,, $ to ) inch inches es squ squar are, e, 1 to to 1 inch inches es hig high, h, pro+ided with opening in the center, ( inches in diameter at the bottom, and ( inches in diameter at the top.
To determine carbon residue by Conradson apparatus, the oil sample, in the crucible, is heated at a state rate and caused to +apori!e. /fter ignition and further heating for a specified time, the residue is cooled and weighed. 5uplicate tests should agree within 1 per cent if the carbon residue is about " per cent or within " per cent if the residue is abo+e .# per cent 3see /&T6 5-1*4.
7or oils without detergency detergency additi+es, additi+es, carbon residue residue by the Conradson Conradson test is a rough index of the tendency of the oil to decompose in ser+ice and to lea+e carbon residue on hot surfaces.
In order to get accurate results, the dimensions of the apparatus used must be as nearly as possible the same as those specified in this description. &pecial precautions must be ta'en to obser+e the first appearance of +apors. In order to ma'e this obser+ation as accurate as possible the gas burner may occasionally be momentarily remo+ed to facilitate this obser+ation. If, at any time during the test the +apors from the oil exceeds ex ceeds the ( inch specification abo+e the chimney of the hood, the gas burner may be remo+ed for a short inter+al inter+al until the si!e of the gas flame can be reduced sufficiently to 'eep the +apour flame about " inches abo+e the top of the chimney.
LIST OF APPARATUS: APPARATUS:
1. 6e'er 8as 9urner
". Conradson /pparatus
(. Tripod
*. &'idmore crucible
%. ire mesh
1. ichrome wire triangle
#. Chimney
11. /sbestos cylindrical bloc' 3insulator4
$. 5igital 9alance
1". &/;1
). Crucible tong
1(. &/; (
. Iron crucible
PROCEDURE:
1 " (
eigh igh the the por porce cela lain in cruc crucib ible le.. 7ill 7ill the the porc porcela elain in crucib crucible le with with 1g of &/;1 &/;1 &et-up the apparatu apparatuss by placing placing the wire wire triangle triangle on top of the the tripod tripod and then the the
%
refractory bloc' insulator ring on top of the wire triangle. lace the porcela porcelain in crucibl cruciblee inside inside the the s'idmore s'idmore crucible crucible and and then then place place the s'idmore crucible inside the nic'el crucible. Co+er the s'idmore crucible and then
co+er the nic'el crucible. # lace lace the the nic'el nic'el cruc crucibl iblee insid insidee the insu insulat lator or ring ring.. $ lace lace the carbo carbon n residue residue appara apparatus tus hood hood on top top of the insul insulato atorr ring. ring. )
T=<;>/C;&: eights of oil sample should be accurate to within # mg. Tests should be run in duplicate and repeated if necessary until the percentages of carbon residue differ by not more than 1 per cent ce nt from an a+erage.
SET-UP OF APPARATUS
Figure 1. Weighing Weighing of crucible crucible
Figure 2. 2. Applying heat from from a gas burner
Figure 3. Empty Empty crucible (no carbon residue)
VI. Final Data Sheet
Test =il
eight of Crucible
eight of
3=il &pecification4
1
"
1
&/;1
"1."g
1g
"
&/; (
"1."g
1g
Trials
eight of Carbon >esidue
ercent of Carbon >esidue
Time
g
?
) min, #%sec
().mg
.()?
1# min, $sec
(
VII. Sa!le C"!#tati"n
! . .? =
W ( W "
× 1?
W (
=
weight of the crucible and carbon residue − weight of crucible
W "
=
weight of the crucible and oil − weight of crucible
Trial " 3&/;1@(4 C.R.=
C.R.=
W 3 W 2
× 100
37.8 10
× 100 =0.378
TEST DATA A$ALYSIS
The third experiment concerns with the determination and analysis of the carbon residue that will be formed after the combustion of certain carbon-rich materials 3fuel, oil or lubricant4 lubricant4 on an enclosed enclosed space or +essel. +essel. The experiment experiment is di+ided into three trials, trials, trials trials for the &/; ( and &/;1 lubricants lubricants respecti+ely respecti+ely..
/ special special characteris characteristic tic of
lubricating oils is that they contain high percentage of carbon in combined form. =n heating heating the decompose deposits deposits a certain certain amount of carbon, the deposits deposits of such carbon in the machine is intolerable. They are particular in particularly in internal combustion engines and air compressors. The basis for a good lubricant is that upon the combustion for example in the internal combustion engine, a lubricating oil present upon the addition of heat shall not lea+e any carbon residue. / good lubricant should deposit least amount of
carbon
inuse.
The percent of co'ed material remaining after the sample of the lubricating oil has been exposed to high temperature is called the carbon residue. /s far as the effect of residue on performance, one option is that the type of carbon that is more important than it quantity. &ince compounded oils contain metallic additi+es that generally lea+e a residue, other testing should be done to identify the type of residue rather than 0ust the amount. / higher carbon residue is the one responsible for the hea+y smo'e emission from the engine. The o+erall relationship between actual diesel engine performance and carbon residue is poor, howe+er, the carbon residue +alue is considered by some to gi+e an indication of the combustibility and carbonaceous deposit forming tendencies of a fuel. The carbon residue residue pro+ides pro+ides information information on the carbona carbonaceo ceous us deposit depositss which which will will result result from from combustion of the fuel. 7or fuels with a high carbon- high carbon2hydrogen ratio, it is pro+ed more difficult to burn them fully, which results in incr increas eased ed depo deposi sits ts in the the combus combusti tion on and exhaust spaces. 7uels with a high carbon residue +alue +alue may caus causee prob proble lems ms in older older engi engines nes
when they are operating under part load conditions. The carbon residue +alue of a fuel depends on the refinery processes employed in its manufacture. &/;1 has a !ero percent of car carbon bon res residue idue whi while &/;( &/;( has has a .() .()? ? resi residu due. e. Thi This impl implie iess that hat aft after burning2combusting, different lubricants will yield different percentage carbon residue resultA there are some which has and other which has no residue.
The The carb carbon on resi residu duee +alu +aluee of a fuel fuel depe depend ndss on the the refi refine nery ry proce process sses es empl employ oyed ed in its its manuf manufact actur ure. e. 7or straight run fuels, the +alue is typically 1 - 1"? m2m, while for fuels from secondary refining processing the +alue depends on the se+erity of the processes applied. In some areas it can be as high as "? m2m.
The carbon residue +alue of burner fuels ser+es as a rough approximation of the tendency of the fuel to form deposits in +apori!ing pot Btype and slee+e- type burners. &imilarly, pro+ided al'yl nitrates are absent, the carbon residue of diesel fuel correlates approximately with combustion chamber deposits. The carbon residue +alue of gas oil is useful as a guide in the manufacture of gas from gas oil. In a gas turbine it can be an indication of the tendency to form carbon deposits in the combustion chamber.
%UESTIO$S A$D A$S&ERS
1.
hat is pyrolysis of petroleum materials yrolysis is a form of treatment that chemically decomposes organic organic materials materials by heat in the absence of oxygen. yrolysis typically occurs under pressure and at operating temperatures abo+e %( C 3 74. In practice, it is not possible to achie+e a comple completel tely y oxygenoxygen-fre freee atmosp atmospher here. e. 9ecause 9ecause some some oxygen oxygen is presen presentt in any pyrolysis system, a small amount of oxidation occurs. If +olatile +olatile or semi-+olatile materials are present in the waste, thermal desorption desorption will will also occur. yrolysis transforms ha!ardous organic materials into gaseous components, small quantities of liquid, and a solid residue 3co'e4 containing fixed carbon and ash. yroly yrolysis sis of organi organicc materi materials als produce producess combus combustib tible le gases, gases, includ including ing carbon carbon monoxi monoxide, de, hydrogen hydrogen and methane methane,, and other other hydroca hydrocarbo rbons. ns. If the off-ga off-gases ses are cooled, liquids condense producing an oil2tar residue and contaminated water.
'.
hat are the two types of carbon residue produced by pyrolysis Char Char 3or 3or bioc biochar har and2 and2or or co'e4 co'e4 and and ashes ashes are are the the two two carb carbon on resi residu duee of pyrolysis. 9iochar is one of the solid residues of pyrolysis of +arious materials, mostly organic waste. 9iochar impro+es the soil texture and ecology ecology,, increasing its ability to retain fertili!ers and release them slowly. It naturally contains many of the micronutrients needed micronutrients needed by plants, such as selenium selenium.. It is also safer than other DnaturalD fert fertil ili! i!er erss such such as manure or sewage sewage,, since it has been disinfected at high high temperature. /shes, meanwhile, are powdered grayish residue of combustion of the pyrolysis of organic material such as wood scraps. scraps.
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hat is fixed carbon >ams bottom Carbon >esidue, which abbre+iation is >C>, is well 'nown in the petroleum the petroleum industry industry as as a method to calculate the carbon residue of a fuel. The
carbon residue residue +alue is considered considered by some to gi+e an approximate approximate indication of the combustibility and deposit forming tendencies of the fuel. 7or the test % grams of the sample are put into a weighted glass bulb. The sample in the bulb is heated in a bath at ##(EC for " minutes. /fter cooling the bulb is weight again and the difference noted. >ams bottom Carbon >esidue test method is limited to those samples that are mobile below *EC.
).
hat is incomplete combustion Fow does it occur Incom Incompl plet etee comb combus usti tion on is a pheno phenome meno non n in whic which h oxidat oxidatio ion n of the the fuel fuel is incomplete, meaning there is insufficient amount of oxygen for the fuel to completely burn. Incomplete combustion occurs when a substance is burned with limited oxygen, producing a more di+erse range of products than that of complete combustion or when there isnGt enough oxygen to allow the fuel to react completely to produce carbon dioxide and water. It also happens when the combustion is quenched by a heat sin' such as a solid surface or flame trap. 7or most fuels, such as diesel oil, coal or wood wood,, pyrolysis pyrolysis occurs occurs before combustion. In incomplete combustion, products of pyrolysis remain unburnt and contaminate the smo'e with noxious particulate matter and gases.
*.
hat is the ignition quality in smaller engines Ignition quality is the property of a fuel that ignites when in0ected into the compressed-air charge in a diesel engine cylinderA measurement is gi+en in terms of cetane number. 5iesel, as we all 'now, is a compression-ignited fuel. The higher the compre compress ssion ion ratio ratio of the diesel diesel fuel, fuel, the better better the engine engine effici efficiency ency.. This This high high compression ratio can only be achie+ed by using a high cetane-rating diesel fuel. Figh cetane diesel fuel mean that the pre-ignition time of the fuel is less, thus the fuel ignites faster and produces more energy at faster rate.
+.
hat will happen when fuels ha+e high cetane numbers
Cetane number is actually a measure of a fuelGs ignition delay. delay. This is the time period between the start of in0ection and start of combustion 3ignition4 for the fuel. In a particular diesel engine, higher cetane fuels will ha+e shorter ignition delay periods than lower cetane fuels. This means a better engine performance.
,.
hat is definition of cetane number Cetane umber is a measure measure of the ignition quality of a diesel fuel. It is often mista'en as a measure of fuel quality. Cetane number is actually a measure of a fuelGs ignition ignition delay. delay. This is the time period between the start of in0ection in0ection and start start of combustion combustion 3ignition4 3ignition4 for the fuel. In a particular particular diesel diesel engine, higher cetane fuels will ha+e shorter ignition delay periods than lower cetane fuels.
.
hat is definition of 5iesel index 5iesel index is a measure of the ignition quality of a diesel fuel calculated from a formula in+ol+ing the gra+ity of the fuel and its aniline point. 5iesel fuel rating2index is based on ignition qualitiesA high-quality fuel has a high index number. The higher the grade of the th e diesel fuel, the better its performance.
CO$CLUSIO$
The group group was succes successfu sfull in attain attaining ing the ob0ect ob0ecti+e i+es. s. 7irst 7irst ob+ious ob+iously ly,, by doing doing the experiment and getting the results. The other ob0ecti+e, to learn about carbon residue test was also achie+ed by performing the Conradson Carbon >esidue Test and by explaining the importance of 'nowing a lubeHs carbon residue.
9y measuring the weight of the porcelain crucible, the amount of the carbon residue can be determined, setting it as reference weight 3to simplify calculations4, pouring 1g of test oil, and measuring of weight before and after the experiment. The 6e'er burner can +apori!e lubricating oil quic'ly. q uic'ly. It is +ery important to get the amount of residue since these residues may cause some failur failuree in the purpos purposee of lubric lubricati ating ng machine machine parts, parts, thus thus result resulting ing in the failur failuree or bro'erage of the engine and the machine itself. ThatHs why the cleaning and remo+ing of these residues are important matter in machine safety and maintenance. /side from these, carbon residues are life threatening to people since these substances are toxic. nowing this property of a lubricant, a machinist, engineer, or an ordinary person may choose the best oil for a specific application. Carbon residue is what remains after the combustion of a carbon rich material under high temperature. temperature. 6oreo+er, 6oreo+er, carbon residues residues ha+e a large large implication implication on the performance of an engine running on fuels and lubricants. 7inally, lubricants can be classified into grades, which are dictated by the amount of carbon residue formed after combustion. The smaller the remaining carbon residue on the test, the better the lubricant is. This pro+ides the ground in what lubricant to be used on a specific material.
I thin' there is only one thing that may ha+e caused an error in the results. The residue in the the glas glasss cruc crucib ible le was was poure poured d in the the digit digital al bala balanc ncee by usin using g a brus brush. h. 7rom 7rom this this happening, we can say that there is already a decrease in the mass of the carbon residue. =+erall, the whole experiment is successful and follows the theories applied.
REFERE$CES
•
Joung, Fugh 5. and >oger >oger /. 7reedm 7reedman. an. "). "). Kni+er Kni+ersit sity y hysic hysics. s. Califo Californi rnia: a: earson ;ducation Inc.
•
9ritannica ;ncyclopedia Lolume Lolume 11.1**%.K&/: ;ncyclopedia 9ritannica Inc.
•
9ar-6eir, 9ar-6eir, 8enic'."11. 9asic of fluid mechanics. mechan ics. Chicago: 8enic' 9ar-6eir
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ul'rabe',J. 1**). Internal Combustion ;ngine. ew Jor': Jor': earson
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www.engne11.com
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www.machinelubrication.com
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www.shxf1).com • • • • • •
http"##en.wi$ipedia.org#wi$i#%yrolysis&oil http"##www.bun$ering.co.$r#bun$er&spec#carbonresidue&1.htm http"##www.wisegee$.com#what'is'carbon'residue.htmdid'you'$now http"##www.machinerylubrication.com#ead#11 http"##www.engineeringtoolbo*.com#api'gra+ity'd&1212.html http"##www.engineeringtoolbo*.com#centrifugal'pumps'+iscosity'd&,-.html
