Carbon Residue

University of Zakho School of Engineering Petroleum Eng. Dep.

 Standard Test Method for Caron !esidue

"ame# Saman "ame# Saman Hassan Rasul Stage# 2 E$. "%.# 2 "%.# 2 Date of E$periment# 2-11-2014 Date of Sumitting# 9-11-2014 Sumitting# 9-11-2014

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&.' %(ective# To determine the amount of carbon residue left after evaporation and pyrolysis of crude oil.

&.& )ntroduction#  !ei"hed #uantity of sample is placed in a crucible and sub$ected to destructive distillation. The residue under"oes crac%in" and co%in" reactions durin" an a&ed period of severe heatin". t the end of the speci'ed heatin" period( the test crucible containin" the carbonaceous residue is cooled in a desiccator and  !ei"hed. The residue remainin" is calculated as a percenta"e of the ori"inal sample( and reported as )onradson carbon residue. The carbon residue of a fuel is the tendency to form carbon deposits under hi"h temperature conditions in an inert atmosphere. *t may be e&pressed as Ramsbottom )arbon Residue +R)R,( )onradson )arbon Residue +))R, or icro )arbon Residue +)R,.umerically( the ))R value is the same as that of )R. The carbon residue value is considered by some to "ive an appro&imate indication of the combustibility and deposit formin" tendencies of the fuel. The carbon residue of a fuel is the tendency to form carbon deposits under hi"h temperature conditions in an inert atmosphere( and may be e&pressed commonly as icro )arbon Residue +)R, or alternatively )onradson )arbon Residue +))R,. *t should be noted that numerically )R is effectively the same as ))R

&.* )nstruments# )onradson carbon residue apparatus includes the follo!in"/ 1243-

porcelain )rucible *ron )rucible- S%idmore iron crucible *ron crucible ire Support Hood *nsulator-sbestos bloc%( refractory rin"( or hollo! sheet-metal bo&. 5urner. Page

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&.+ Procedure# 1- ei"h accurately the empty dry and clean crucible on the analytical balance( m1( "m. 2- Sha%e thorou"hly the sample to be tested( first heatin" to 0  o) !hen necessary to reduce its viscosity. *mmediately follo!in" the heatin" and sha%in"( filter test portion throu"h a 100 mesh screen. -  10 " sample is !ei"hed into a tarred porcelain or silica crucible containin" 2 "lass beads 2. mm in diameter. 4- The crucible is placed in the center of s%idmore crucible !hich is set at the center of the iron crucible and covers are applied to both of s%idmore and iron crucible. -  stron" flame is applied from the "as burner to have hi"h heat for a period of 10 min. 3- hen smo%e appears from the chimney the burner is moved or tilted to i"nite the vapor then removed temporarily. - hen the vapor cease to burn the heat is reapplied until the bottom of the sheet iron crucible is cherry red. 6- The burner is removed and the apparatus is cooled until no smo%e appears then the cover of the s%idmore crucible is removed +about 1 min,. 9- The porcelain or silica crucible is removed and placed in the desiccators( cooled and !ei"hed a"ain accurately( m( "m and 7 of carbon residue is calculated based on the ori"inal sample.

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&., Calculations# )alculate the carbon residue of the sample( from the e#uation/ 1 +mass of empty crucible, 82. " 2 +mass of crucible  sample, 8.3 "  +mass of residue  crucible, 824. " carbonresidue present  ∈the sample =

 M 3 − M 1  M 2− M 1

∗1 00 =

24.3 −23.3 33.6 −23.3

∗100 =9.7

&.- Discussion# Page

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Here !e have a standard test method to determine the amount of carbon residue e&ist in a sample of petroleum( the conradson test is used to measure carbon residues of oil. *n brief( the carbon residue of a fuel is the tendency to form carbon deposits under hi"h temperature conditions in an inert atmosphere. This is an important value for the crude oil refinery( and usually one of the measurements in a crude oil assay. )arbon residue is an important measurement for the feed to the refinery process fluid catalytic crac%in" and delayed co%in". )arbon residue for a fossil fuel can be defined as the tendency of that fuel to form carbon deposits at hi"h temperature in an inert atmosphere. )arbon residue for a fuel is measured in !ei"ht percenta"e +!t 7, or parts per million by !ei"ht +ppm !t,. Hi"h carbon residue value is undesirable for a fuel( so carbon residue is an important value for oil products price.

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