Petroleum Refining: Lab Tests & ASTM Procedures Ch 3

• Chapter 3 explores the significance of lab tests in petroleum refining.

Laboratory Standard Test Procedures (ASTM)

• ASTM procedures are crucial in petroleum refining.
• They cover significance of lab tests, product specifications, and the process of product quality upgrading.

The Most Important ASTM Tests in Petroleum Refining

• ASTM Distillation (D86) is used for crude oil and lighter fractions.
• Vacuum Distillation (D1160) is for atmospheric residue and heavier fractions.
• API & Specific Gravity (D287-92) applies to all.
• BS&W (D96-88) is used for crude oil feed.
• Octane Number (Motor/Research) (D357/D908) is for gasoline.
• Molecular Weight (D2503) applies to all.
• RVP (D323-94) is for light fractions.
• Lamp Sulfur (D1266) applies to all.
• Doctor Test (D325) applies to all.
• Flash Point (D56-97A) is for naphtha & gasoline.
• Freezing Point (D2386) is for kerosene.
• Smoke Point (D1322) is for kerosene (ATK).
• Viscosity (Saybolt universal) (D88) is for heavy fractions.
• Viscosity (Kinematic) (D445) is for heavy fractions.
• Pour Point (D97-96a) is for diesel & heavier fractions.
• Cloud Point (D2500) is for diesel & lighter fractions.
• Color (clear liquids) (D1209-93) pertains to diesel & lighter fractions.
• PNA/PINA/PONA/PIONA (D5443-93) is for naphtha & kerosene.
• Refractive Index (RI) (D1218-92) applies to all.
• Aniline Point (D611) applies to all.
• Cetane Index (D976) is for diesel.
• Cetane Number (D613) is for diesel.
• Conradson Carbon (D189-97) is for heavy fractions.
• Ramsbottom Carbon (D524) is for heavy fractions.
• H/C Ratio (D5291) applies to all.
• Heating Value (D240/D4809) applies to all.
• Flammability Limits (E681) applies to all.
• Salt, PTB (D3230/D6470) is for crude oil.
• Penetration (D5/D5M-19) is for asphalt & bitumen.
• Corrosion (D130) is for transportation fuels.
• Gum (D381) is for transportation fuels.
• ORSAT analysis is for gases.
• GC analysis is for gases.

API (Specific) Gravity

• API gravity determination applies to crude oil and petroleum products.
• Standard test number: ASTM D287-92.
• The principle is buoyancy.

API Gravity - Objective

• Determines API gravity of crude petroleum and petroleum products handled as liquids.
• These have a Reid vapor pressure of 26 psi or less.
• Measurement is at a constant temperature of 60 °F.

API Gravity - Procedure

• Temperature is adjusted based on sample type.
• Transfer the sample to a clean hydrometer cylinder.
• Gently lower the hydrometer and depress it about two scale divisions into the liquid, then release.
• When the hydrometer rests freely and the temperature stabilizes, record the hydrometer reading.

ASTM Distillation

• Distillation covers natural gasoline, motor gasoline, aviation gasoline/turbine fuels, special boiling point spirits, naphtha, white spirit kerosene, gas oils, distillate fuel oils, and similar petroleum products.
• It utilizes manual or automated equipment.
• The sample is all.
• Standard test number: ASTM D86-96, D1160.
• The principle is physical separation (vaporization).

ASTM Distillation - Procedure

• Heat a 100 ml sample in a flask at a regulated rate to maintain a uniform condensation rate.
• The rate varies, starting from zero to 5V% recovered, then 5 to 10 V% recovered, and so on.
• Record the thermometer reading (vapor temperature) as the initial boiling point (IBP) when the first drop appears.
• Temperature readings are recorded at several V% distilled up to the final boiling point (FBP).
• Heating is paused, and the volume of remaining liquid is measured and recorded as recovery after cooling.

ASTM Distillation - Heavy Fractions

• For heavy fractions, heating stops when the decomposition point is observed.
• Occurs when the vapor reaches a maximum temperature and then starts declining before the endpoint.

Related standards for distillation of petroleum products

• D86-96 is for light petroleum fractions like naphtha, kerosene, and diesel.
• D1160 is for heavy petroleum fractions such as VGO, atm residue, and vac residue.
• D2887 is for simulated distillation (GC method); TBP of petroleum fractions other than gasoline.
• D3710 is for simulated distillation (GC method); TBP of gasoline.
• D5307 is for simulated distillation (GC method); TBP of crude oil.
• D6352-98 is for simulated distillation (GC method); TBP of distillates (BP range 174 to 700°C).
• D2892 is for 15/5 distillation using a 15 theoretical plate column (simulated TBP).
• D5236 is for the distillation of heavy HC mixtures (Vacuum Pot-still Method).
• Tests 1 & 2 may be combined for wide boiling range materials.
• Test 2 is used for fractions heavier than diesel.
• Test 3 can replace test 1 for white products (gasoline, Naphtha, kerosene).

BS&W (Bottom Sediments and Water)

• Crude oil sample
• Standard Test Number: ASTM D96-88
• Principle: Centrifuge

BS&W - Objective

• Determines sediment & water in crude oil using the centrifuge method.
• It is practical for field determination, although not the most accurate.

BS&W - Procedure

• Place two 50 ml samples in 100 ml cone-shaped centrifuge tubes.
• Add 50 ml of solvent to mixture, then plugged with a stopper.
• Heat tubes to 60 °C and invert a minimum of 10 times.
• Place the tubes in centrifuge and spin for 5min.
• Combined volume is recorded.
• Reheat to 60°C and return without agitation to the centrifuge, and spun for 5 min.
• Repeat until two values are consistent

Related standards

• D95 (Water in petroleum products and bituminous products by azeotropic distillation).
• D473 (Sediment in crude oil and fuel oil by extraction).
• D1744 (Water by Karl Fischer Method – electrometric, after the addition of KF reagent).
• D1796 (Water and sediment in fuel oils, mix with toluene and centrifuge).
• D2709 (Water and Sediment in Distillate Fuels by Centrifuge).

Octane Number

• Measures the gasoline's antiknock
• Sample: gasoline
• Numbers: ASTM D357 (Motor) & ASTM D908 (Research)
• Principle: Combustion in a variable compression ratio motor.

Octane Number Facts

• Octane number compares gasoline fuel to the ratio of n-heptane and isooctane.
• Isooctane is expressed as vol% isooctane (2,2,4-trimethylpentane).
• Octane number depends on the compound's activation energy.

Motor Octane

• Lab tests determine both motor octane number (MON) and research octane number (RON).
• Both use the same engine but work under different conditions.
• Motor method (MON) is determined at high engine speed.
• It represents performance on the highway or heavy load conditions.
• Research method (RON) is determined at low engine speed.
• Performance during driving where low speed and acceleration is frequent.
• The RON is usually slightly higher than MON, but sometimes it's less.
• Posted octane number (PON) represents the average of the RON and MON.
• This number is posted on gas pumps in US gas stations.
• Sensitivity of the performance fuel relates to RON & MON.
• Low Sensitivity is desirable because the fuel gives equal performance for all driving conditions.

Compression Ratio

• Ratio is the maximum to minimum volume in the cylinder for an internal-combustion engine.
• Compression Ratio = Max cylinder vol./min cylinder vol. = BDC (Bottom dead center)/TDC (Top dead center)

Definition of Octane Rating

• The measurement of the resistance of gasoline and other fuels to detonation.
• Fuels are subjected to high pressure/compression in spark-ignition engines.
• The measure is compared to a ratio of isooctane and n-heptane.
• Gasoline with the same knocking traits as 90% isooctane/10% n-heptane has an octane rating of 90.
• Octane doesn't add any more hydrocarbon content or oxygen, the engine cannot produce more power.

Octane Ratings

• The measure is determined by comparing with the a mix of isooctane and normal heptane.
• Fuels go through a comparison under test.
• Higher-performance engines have higher compression ratios.
• Octane does not correlate with energy content or combustion.
• The most common type is Research Octane Number (RON)

Octane - Regional Variations

• Octane ratings are higher in Europe than in North America.
• Most countries (Europe and Australia) show the RON on the pump.

Octane - Possible Fuel Ratings

• The value can have a RON greater than 100
• Occurs because isooctane is not resistant substance available.
• Fuels like racing fuels, AvGas, LPG, and alcohol fuels like methanol have greater ratings.

Octane Boosters

• The gasoline additives consist of TEL, MTBE, and Toluene.
• Tetra-ethyl lead is easily decomposed to its component radicals
• TEL discontinued due to concerns on the environment and human health.

Low Octane Fuels

• Fuels have lower activation energies, and when compressed overcome activation energy.
• The process has enough time to explode spontaneously before exposing to a spark.

Effects of Lower Octane Fuel

• Explosion not desired because the explosion will cause pressure before expanding gases.
• Burning fuel with a lower octane rating reduces output.
• Many engines use a knock sensor, which detects a knock and retards the timing.

Other Relevant Standards

• D909 is for knock characteristics for Aviation fuels
• D2699 is used for knock characteristics of motor fuels by research method.
• D2700 is for knock characteristics of motor and aviation fuels by motor method.
• D2623 is for knock characteristics of LPG by the motor (LP) method.
• D2885 is for Research and Motor Method Octane Ratings Using Online Analyzers.

Cetane Number

• Sample: Diesel
• Uses: ASTM D613-01.
• Principle: Ignition number
• Scale: Arbitrary

The Cetane Number Provides

• Measure: the measure of fuel oil in engines
• Standard: Arbitrary

Higher Cetane Fuels

• Benefit: Fuels feature have shorter ignition.
• Result: Fuel combusts fast when compressed and is not desired in gasoline, but desirable in diesel fuel.

Diesel Engines

• Run: The fuels run well with a CN from 40 to 55.
• Benefit: A higher CN means shorter delays and greater performance.
• CN is raised past 55; after this point, the fuel's performance plateaus.
• Testing: A CFR engine uses a hand-wheel to test under standard.

Chemical Relevance Value

• Assigned: Cetane has a value that is easy to ignite, and is assigned a CN of 100
• How: Hydrocarbons in oil are all indexed
• Testing: Test happens under the measure of quick starts.

Measuring Cetane Number

• Rather: The reading properly is difficult.
• What: The value is tested when burning.

Other Relevant Readings

• ASTM D6890 – 13 is to determine ignition.
• Method: The reading is completed when using a constant volume under pressure.

Cetane Index

• Calculation: Index represents estimation of the value of the oil API and Midpoint
• Versions: The test depends on the use if metric is being valued.
• Desired: Numbers calculated are specific to the numbers for the point of extraction.
• Value: The test is high, but requires the use of a limited number of aromatics

Cetane Index Formulas

• CI = - 420.34 + 0.016G2 + 0.192G log M + 65.01(log M)2 – 0.0001809 M² (British units)
• CI = 454.74–1641.416 D + 774.74 D2 – 0.554 B + 97.803(log B)² (SI units)
• G = API gravity.
• D = Density at 15 °C, g/ml.
• M = MiDboiling temperature, °F.
• B = MiDboiling temperature, °C

Cetane Index - Limitations

• Not to be applied for mixing additives when raising cetane number.
• Not be to be applied for hydrocarbons

Reid Vapor Pressure (RVP)

• Sample: Naphtha, Gasoline, and others
• Standard Test Number: D323-94
• The pressure in a sample held at 100 °F

Reid Vapor Value - Other standards related

• D1267 (LPG - Bomb Method value)
• D2551 (Vapor pressure by micromethod)
• D5191 (Standard Test Method for Vapor Pressure Petroleum (Mini Method)

Sulfur Content (wt%)

• Sample: All
• Standard Test Number: ASTM D1266
• Undesirable pollutant and corrosive substance.
• "Sour crude" refers to any crude oil > 0.5 wt% content.
• Content ranges from 0.1 to 5% or more.

High Sulfur Units in Refinery

• Examples The ARDS, HTU, Merox, sulfur recovery and the Amine all are added due to the high S content. S content is high in crude.
• Crude: An amount >0.5 w% requires more extensive processing than those with lower content.

Sulfur Standards

• D129 (Bomb for fractions)
• D325 (Doctor Test – Sodium coloration of interface).
• D1552 (combustion at high temperature)
• D1072 (Total Sulfur in Fuel Gases)

Flash Point Definition

• Lowest temperature where vapors ignite when exposed to ignition
• Can increase during the transfer and storage, and ignition of fuel.
• High values mean more temperature required.
• Two types of flash point: Open and closed-cup
• ASTM closed are Tag (D56-01)
• ASTM Tag (D1310)

Freezing Pt. - Temp.

• Fuels: aviation fuels (kerosene, ATK)
• Standard: ASTM D2386
• Disappearance of crystals on reheating is the principle.
• This test method covers determining the temperature below which solid hydrocarbon crystals form.

Significance of Freezing Pt.

• Temp: In aircraft, the fuel tank falls.
• So: The minimum operational tank level should remain lower.
• Apparatus: apparatus consists of a jacketed sample tube, vessel.

Cloud Point Temperature, °C (°F)

• The sample used is diesel.
• ASTM D2500 is the standard, a sample cooled under defined.
• The test helps to determine the point of the specimen where the wax is presented.

Cloud Point Temperature, °C (°F) - Procedure

• A sample is filtered at 14°C until clear
• Sample poured to level indicator
• The result is compared to temperature reading increments.
• Check is for visible sample results

Significance of Pour Point

• Point is the amount of wax
• High Pt points indicate low paraffin and high aromatic content.

Pour Point Temp, °C (°F) Procedure

• the specimen is poured into a test jar having a cork holding a thermometer
• The specimen is then tilted to check for movement of the specimen to a point below the measurement.

Cold Filter Plugging Point (CFPP)

• The test measures quick testing of the quality.
• The point to bracket the temperature at which the fuel will start to fail is measured.
• The result determines the values of tests for the point of failure.

Smoke Point (mm):

• Sample used: kerosene (Illuminating and ATK)
• ASTM D1322 defines the standard.
• It gives the maximum height of smokeless fame.
• The higher the testing, the better.

Smoke Point Relevance

• The value is related to the hydrocarbon composition.
• The value more aromatic shows the higher smoking
• The wick test gives smoking and burning.

Viscosity

• Requires: All.
• Number: D445.
• ASTM D445: Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids
• Time Requirement: The principle is in the speed of flowing.
• The kinematic is the resistance of a fluid flowing under gravity.
• Dynamic viscosity is the ratio.

Color

• Sample: Clear liquid fuels, mostly diesel.
• Number: D1209-93 test.
• D1209-93: testing liquid colors under standards.
• The presence of color means an indication.

Color - Procedure

• The 100 ml is added into a tube after filtering.
• Tube results are compared to standard number.

Aniline Point Temperature

• The test covers most.
• Standard: D611-82 test
• The mix represents a HC for separation.

Aniline Point - Test values

• Find: The test of Aniline can help determine the values with solvents
• Solution: The point represents a measure at 100 amount

Carbon Residue (wt %)

• The procedure shows the deposit results of carbonization.
• It also the result of the asphalt oil result to find what is recovered from the results of the test.

Carbon Residue - Testing

• The value happens after vaporation in testing.
• In most cases, the less amount shows the result

Conradson Carbon

• Sample test: It is crude and heavier fractions.
• The test will show the carbon result of Petroleum.

Carbon Residue (wt %) - Testing

• Determine: The level of evaporation results
• It happens against the result that are in the test.
• Results against desolation are found near atmospheric number.

Penetration Tests

• Testing Bitumen is measured.
• Standard Test Number: ASTM D5 / D5M – 13 shows level
• Tests measures are compared against consistency.

Sulfur Content (wt%) - Testing

• Crude: Amount ranges to a degree

Relevance Test

• In petroleum refining - Chapter 3 tests are performed by:
• Copper tests
• The measure of the metal
• Corrosion tests

Standards

• ASTM D130–18 for Copper, test.
• ASTM D7095 – 17 for testing using Disposable Copper Foil test. ASTM D7671 – 10 (2015)

Gum Test

• Fuel is the sample
• Number: ASTM is compared.
• It measures the non residue amount in value.

ORSAT

• Sample: Gas

Salt Content - Number

• D6470-99 Salt in crude by Potentiometric Value
• Number D3230-99 Salts in Crude Oil

Nitrogen

• High levels are seen
• Organic numbers are downstream.
• Crude contains more needs a process needs to be added.

Metal Number

• Copper are: Nickel and Vanadium.
• Few need testing
• Result: Low levels show deactivation

C/H and value tests standards

• D5291-96: (Test) Determination of Carbon in the test
• D5373: (Test) -nitrogen determination
• D1018-11:Test for Hydrogen In numbers
• D7171-05: Test Method for Hydrogen tests under value

Hydrocarbons -Type

• Used: Number.
• Principle: Involve results for oil and hydrocarbons value
• Value: Is a comparison from

Refractive Test

• Sample: All

Flammability

• Limit values: number limits from the
• standards limits for value from gas
• Test standards include

Standards for Test

• Test.

The most important ASTM tests in Naphtha

• Atm Distillation with test number D 86
• API & specific gravity with test number D 1160
• Octane Number with test number is D96-88
• RVP test number is D323
• PNA/ PONA/PIONA(PIANO) test number is D5443-93
• Sulfur, wt% - all test number is D908
• Flash point with test number D56-97
• Refractive Index (RI) test number D1218-92
• Conradson carbon test number D189-97
• Ramsbottom carbon with test number D524
• C/H ratio test number is D5291
• Heating Value (net/gross) test number D240/D4809