By Gerard B. Hawkins Managing Director, CEO

Refinery Operations Naphtha Characterization Syn Gas Production needs Characterization methodology GBHE VULCAN software Impurities in crude HDS Report HDS Design method HDS Design guide

Crude Oil and Petroleum Products can characterized two ways

Physical Chemical

Don’t need to know exact chemical composition Products largely go into fuel industry Need to know how easily it can be handled ◦ Viscosity, density

How much heating or energy value it has ◦ Calorific Value

Cut points are approximate

Distillation defines quality of crude ◦ Hence quality of

fractions

Quality = Octane # = Profit

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Heavy Naphtha

Light Naphtha Light Ends

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Boiling Range Density (Specific Gravity) Viscosity Refractive Index Calorific Value

Only Physical characteristics

Summary Report is approximate

Target is octane value of feedstock as inferred by Gasoline, Naphtha and Gas Oil content

Crude Oil and Petroleum Products contain multitude of chemical species

Typically categorised as hydrocarbons i.e. compounds solely comprised of carbon & hydrogen atoms Can be ◦ simple e.g. Propane C3H8 ◦ complex e.g. ‘chicken wire’ compounds .. multiple ring stuctures

Chemical composition ◦ PONA Paraffins Olefins Naphthenes Aromatics

Average Molecular Weight Carbon: Hydrogen ratio

Sulfur species Chloride species Nitrogenous species Arsenic Heavy Metals ◦ Mercury, Nickel, Vanadium, Copper

Salt

Its in the feed, where does it end up?

Depends on boiling point

B Pt depends on species

Need to understand speciation!

So looking at sulfur compounds…………

Boiling Point at atm Pressure

Thermal decomposition temperature

degC degC Methyl mercaptan CH3SH 6 150 Ethyl mercaptan C2H5SH 35 150 Propyl mercaptan C3H7SH 67 150 n-butyl mercaptan C4H9SH 99 150 i-butyl mercaptan C4H9SH 89 225-250 phenyl mercaptan C6H5SH 169 200 cyclohexyl mercaptan C6H11SH 159 200 phenyl benzyl sulphide C6H5SC6H4CH3 197 300 diethyl sulphide C2H5SC2H5 92 400 diphenyl sulphide C6H5SC6H5 296 450 dimethyl disulfide CH3SSCH3 110 ~150 2,5-dimethylthiophene (CH3)2C4H2S 137 475 benzothiophene C6H5C4H2S 221 800 dibenzothiophene C6H5C4SC6H5 332 800 thiophene C4H4S 84 900 tetrahydrothiophene C4H8S 121

Boiling Point at atm Pressure

Thermal decomposition temperature

degC degC thiophene C4H4S 84 900 diethyl sulphide C2H5SC2H5 92 400 dimethyl disulphide CH3SSCH3 110 ~150 tetrahydrothiophene C4H8S 121 640 phenyl mercaptan C6H5SH 169 200

Straight run Naphtha

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Boiling CurveThiopheneDiethyl SulfideDimethyl DisulfideTetrahydrothiophenePhenyl Mercaptan

PONA Analysis (w/w)Paraffins = 84.3%Olefins = 2.3%Naphthenes = 11.4%Aromatics = 2.0%

Space Velocity ◦ SV is defined as Liquid Hourly Space Velocity, LHSV

◦ LHSV because

Naphtha is a liquid as supplied to plant battery limits

Naphtha pumped into plant

Flow measurement easier as liquid rather than vapor

Naphtha Flow (1) ◦ Vapor flow calculated from mass flow and Naphtha

average M Wt ◦ Vapor flow = 22.414 * Naphtha mass flow / M Wt

Nm3/hr kg/hr Naphtha Flow (2) ◦ Volumetric liquid flow calculated from liquid density ◦ Liquid flow = Naphtha mass flow / Liquid density m3/hr kg/hr kg/m3

LHSV = Liquid flow / Catalyst Volume

GBHE Mediterranean Client - Naphtha/LPG feed VULCAN DSMAKE Ver 2.0 NAPHTHA RATE 342.8 kgmol/hr NAPHTHA MOLECULAR WEIGHT 56.8 NAPHTHA DENSITY 600.0 kg/m3 HYDROGEN RECYCLE MOLAR RATIO 0.270 TEMPERATURE 360.0 C PRESSURE 33.3 atma = 33.4 kg/cm2g INLET H2S 1.0 ppm w/w = 1 ppm w/w S INLET disulphides(DMDS) 0.0 ppm w/w INLET mercaptans (Phenyl mercaptan) 151.3 ppm w/w = 44 ppm w/w S INLET sulphides (DES) 0.0 ppm w/w INLET tetrahydrothiophene 14.2 ppm w/w = 5 ppm w/w S INLET thiophene 0.0 ppm w/w EXIT NON-REACTED SULPHUR 0.2 ppm w/w S CATALYST DENSITY 710.0 kg/m3 Reduced thiophene rates used, see CFR 127662 NUMBER OF BEDS OF ZNO 2.0 LIFE REQUIRED PER BED 200.0 days CATALYST VHT-S101/VHT-N101 VOLUME 4.85 m3 LIQUID HOURLY SPACE VELOCITY 6.695 /hr – should be max 2.0 /hr Therefore increase volume to 4.85 * 6.695 / 2 = 16.25 m3

How does it work? Calculates catalyst volume for each species based

on kinetics Allows for equilibrium effects of H2S Has inbuilt catalyst activity factor based on VHT-S101 and VHT-N101 Adds volumes together to give answer.