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English version based on the presentation of

Szalmásné Dr. Pécsvári Gabriella held in 2014

Hydrocarbon processing Utility units

Feedstock: vacuum residue

Compounds determining the bitumen behaviour:

• Asphaltenes – give the structure of bitumens (heat sensitivity)

• Resin like compounds (elasticity, adhesion)

• Oily parts (aromatic/paraffinic)

Specification of bitumens:

• Softening point

• Penetration

Bitumen production

Goal of bitumen production is to produce different grades bitumens from vacuum

residue. There are two main processes:

1. Mild oxidation with air blowing (temperature: 280-290 °C)

Bitumen production

• Blowing temperature:

– Higher – construction/building bitumen.

– Lower – road bitumen.

• Duration of blowing (residence time):

– Similar effect may be reached at lower temperature.

• Blowing air quantity

• Production of special bitumens:

– Road construction

– Shingle sheet production (Zsindely lemez)

– Insulating plate production

• Modification:

– Blending with special additives (polimers)

– Properties adjustment

2. Modification with special addivives (polimers)

Rubber bitumen

First road fully built from rubber bitumen at Villány

Idea: mixing rubber grist from used vehicle tyres into road bitumen

Innovation: technology was developed jointly at Pannon University and MOL

Advantages: longer lifecycle, lower operating cost

better usage behaviour (higher load capacity, better fatigue properties

/less rapture/)

better adhesion, reduced pot-hole formation

lower traffic noise

lower braking distance

Bitumen production process

117 121

104-A,B,C

103-A,B,C

113

106-C106-A

107

108-A,B

Fúvató levegő

Gudron

Biztonsági gőz

Fúvatott bitumen

Fúvatási gáz

Melegítő olaj

Olajos mosó Vizes mosó

140-150 °C

280-290 °C

Vacuum residue

Safety steam

Blowing air

Oil washer Water washer

Air blowed

bitumen

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Utility units – Hydrogen production

Steam Methane Reforming (SMR) Task: Hydrogen production for

hydrotreaters

Feedstock: methane + water

Product: hydrogen (99,9% purity)

Temperature: 800 – 850 °C

Catalyst: Ni/Al2O3

Steam Methane Reforming

Methane reforming

simple stochiometry

shift reaction is taking place rapidly, paralelly

the whole process is strongly endothermic

CH4 + H2O ↔ CO + 3H2 (steam reforming)

CO + H2O ↔ CO2 + H2 (water shift reaction)

Reforming of heavier hydrocarbons

stochiometry depends on hydrocarbon

cracking may happen as side reaction

endotherm process

CnHm + nH2O ↔ nCO + (n+m/2)H2

CnHm ↔ xC + C(n-x)Hy + (m-y)/2H2

Steam Methane Reforming – Catalyst

Industrial catalysts:

• Prereforming NiO / MgAl2O4

• Steam reforming NiO

• Shift reactions Fe/Cr or Cu/Cr

Ni: Robust, high activity, less sensitive to potential catalyst poisons

most widely used

Catalyst support:

Requirements: good heat resistance, pressure resistance, acidic sites are not

allowed due to cracking

Materials: a-aluminium-oxide, calcium-aluminium-oxide, magnesium-

aluminium-oxide

Steam Methane Reforming – Feed preparation

Task of desulphurisation unit: removal of sulphur and chloride content of feed natural gas, in order

to avoid deactivation and poisoning of reforming catalyst.

Transformation of all sulphur and chloride compounds to hydrogen-sulphde (H2S) and hydrochlorid

acid (HCl)

Catalysts:

Desulphurisation: Co/Mo

H2S and chloride removal: ZnO / CaO

Steam Methane Reforming – Processing Scheme

Prereformer

Fuel gas

Hydrotreater

Export steam

Hydrotreater

Air

Boiler feed water

Hydrogen

Product gas cooler

Steam drum

Steam

reformer

Adiabatic prereforming

Main task of the prereformer is to react all higher hydrocarbons to methane. Advantages:

– No need to fill catalyst to the reformer, oriented to reaction of higher hydrocarbons

– Lower steam/hydrocarbon ratio is possible

– Increased reformer catalyst life time, since the prereformer is provides sulphur defense too

Typical operational temperature is 400-520°C. Desulphurised feed (natural gas/hydrogen) is mixed with high pressure steam upstream of entering the prereformer (45 barg, 450 °C).

Reforming In the reforming part the hydrocarbon feed is converted to synthesis gas, which is mainly comprised of

hydrogen, carbon-monoxide and carbon dioxide, and in small parts unreacted methane

– temperature (800 – 890 °C)

– pressure (25 - 30 barg)

– steam/hydrocarbon ratio (2 - 4.5)

Reforming reactions are always endothermic.

Steam Methane Reforming – Subunits

Shift reactor

• In the shift reactor the carbon-monoxide is transformed to carbon-dioxide

• Operational temperatures of Shift catalysts at start of life cycle is around ~195°C (inlet)

and 313°C (outlet).

Waste heat removal of flue gas

• Flue gas, leaving the radiation section of reformer takes significant amount of heat.

Major part of this heat may be regained with the heat exchanger bundles placed in the

convection zone of the reformer. With this reuse together with the heat absorbed in the

reformer bundles, 90% of the heating value of the fuel gas may be utilised.

Hydrogen purification

• The reaction gas consits hydrogen and carbon-dioxide, together with some carbon-

monoxide, nitrogen and methane. The hydrogen content may be purified up to more

than 99,9% in the PSA unit.

Steam Methane Reforming – Subunits

Hydrogen Purification – PSA

Pressure Swing Adsorption

• High purity >99.9 vol.%

• Simple system

• Fully automated

Impurities may be desorbed via the depressurisation and the adsorber beds can be

regenerated.

The cycles of the adsorbers are delayed compared to each others, in order to provide

continuous product and waste gas flow

Hydrogen Purification – Hydrogen recovery

PSA Cryogenic Membrane

Big unit footstep Small unit footstep Small unit footstep

Medium CAPEX High CAPEX Low CAPEX

Very low OPEX High OPEX Low OPEX

H2 >99 mol % H2 ~ 93 mol % H2 ~ 98 mol %

High H2 loss Low H2 loss Medium H2 loss

No perssure loss Low perssure loss High perssure loss

Goal: Transforming the H2S containing

gases into liquid or solid sulphur

product.

Sulphur removal efficiency 99,5-99,9 %

• Thermal reaction (1000 - 1400 °C)

3H2S + 1,5O2 2H2S + SO2 + H2O

• Catalytic reaction (200 - 340 °C)

2H2S + SO2 3S + 2H2O

Utility units – Claus process

Claus process – Process scheme

The newest catalysts design:

• Fe2O3 and Fe3PO4 on amorph or alpha-aluminium-oxide support

• Na2O/Zn promotors (reducing the SO2 formstion, thus increasing the

sulphur removal efficiency

Claus process – Process chemistry