PETROCHEMICALS

BYNibir Pawan Das

What are “Petrochemicals”?

Petrochemicals are:Chemicals products.Derived from Petroleum.Also from Fossil Fuels and Renewable

sources.

Major petrochemical products

Primary polymer resins and plasticisers:PVC.LDPE/HDPE.POLYSTYRENE.

Fibers:Acrylic fiber.Nylon.Polyester.

Major petrochemical productsChemicals:Dye stuff and chemical intermediates.Pharmaceuticals.Detergents.

Requirements of Petrochemical Industry

To meet the increasing demand.Vital for economic growth.Self-sufficiency by decreasing imports.

Structure of Petrochemical industry:Feedstock

Building blocks

Intermediates

Final Products

Processes InvolvedCracking:Thermal cracking.Catalytic cracking.

Reforming:Catalytic reforming.Steam reforming.

Naphtha Cracking

Steam cracking.Catalytic cracking.

The back-bone of petrochemical industry

Naphtha

Aromatic Olefins

Crac

kin

g

Crackin

g

Steam cracking.Steam cracking is a Pyrolysis process ,

involving cracking and de-hydrogenation.

Heating of hydrocarbons in the presence of steam.

Endothermic.Less residence time.

Motivation for steam cracking

The worldwide demand and production of olefins…

Currently, production through steam cracking

1. 94% of the world propylene.

2. In Western Europe, 95% of

ethylene and 70–75% of propylene.3. In Asia, 61% of ethylene.

Process of steam cracking of naphtha

Pyrolysis section

Fractionation andCompression Section

Product recovery and Separation Section

Naphtha

Pyrolysis section

Pyrolysis furnace

Transfer line exchange

(producing steam)

Cracked gas

Naphtha 650 - 750

300

Separation

section

Ethylene (24%)

Propylene(20%)

Butadiene(3%)

BTX(1%)

Petroleum ether(25%)

Products from separation section

Process conditions:Pressure 2-3 bar.

Temperature 800 -850 0C.

Residence time 0.1 – 0.5 seconds.

Dilution steam ratio 0.3 – 0.8 kg/kg

Chemistry of steam cracking

Propagation

Initiation

+ =C +

Terminatio

n

Severity vs Product yield

Energy analysis in steam cracking sections

Section Energy required

Energy loss

Pyrolysis 65% 75%Fractionation and Compression

15% 25%

Recovery section

20% 15%

Latest Development in steam cracking of naphtha

Advanced furnace materials

Advanced distillation column

Membranes

zeolite

Alternative technologies

Catalytic cracking of naphtha

Hydro-pyrolysis of naphtha

Use of products of steam cracking of naphtha

References• Olefins from conventional and heavy feedstock's:

Energy use in steam cracking and alternative processes. Energy 31 (2006) 425-251.. By Tao Ren, Martin Patel, Kornelis Blok.

• www.ihs.com• www.afpm.com• www.petrochem.net• www.ficci.com

Thank you