Petrochemistry

SCES 2324

Overview

• Code: SCES 2324

• Pre-requisition: pass SCES 1220

• 2 credits

• Lectures: Tuesday and Thursday (12 - 1 pm), DK 2

• Evaluation:

• 30% continuous assessment

• 70% final examination

• e-mail: hairul_tajuddin@yahoo.com

Content

Production of petrochemicals based on gaseous feedstocks - methane, hydrogen, carbon monoxide, ammonia, methanol, ethane, ethyne, propene, and butadiene

Production of petrochemicals based on liquid feedstocks - benzene, toluene, ethylbenzene, xylene and other feedstocks

Objectives

• Acquire knowledge of various petrochemical processes

• Acquire knowledge how selected petrochemicals are produced in industry

• Understand the relationship between theoretical chemistry with its application in industry

Reference

P. Wiseman, Petrochemicals, Ellis Horwood Limited, 1986 M. J. Astle, The Chemistry of Petrochemicals, Reinhold

Publishing Corporation, 1960 R. F. Goldstein, A. L. Waddams, The Petroleum Chemicals

Industry, E. & F. N. Spon Ltd. 1967 A. L. Waddams, Chemicals from Petroleum: An Introductory

Survey, Butler and Tanner Ltd, 1968 A. V. Hahn, The Petrochemical Industry: Market and

Economics, McGraw-Hill, 1970

Introduction

Petroleum and Natural Gas

The Raw Materials Crude oil recovered from flows

out (reservoir pressure) or pumped out

Different source of location, different character and quality (colour, smell, viscosity etc.)

Depends on the composition and types of hydrocarbons, alkanes, cycloalkanes and aromatics

Composition by weight

Element Percent range

Carbon 83 to 87%

Hydrogen 10 to 14%

Nitrogen 0.1 to 2%

Oxygen 0.1 to 1.5%

Sulfur 0.5 to 6%

Metals less than 1000 ppm

Distribution of oil and natural gas reserves (%)

Oil Natural gas

Africa 9.8 5.9

Asia and Australasia 6.3 5.8

Middle East 54 24.2

Latin America 9.5 5.8

North America 7.3 9.1

USSR and Eastern Europe 10.3 44.3

Western Europe 2.8 4.9

* P. Wiseman, Petrochemical, Ellis Horwood Limited, 1986, page 15

Behind the Scenes

What a chemist can do to petroleum raw products?

General Process

Chemical products from petroleum Two ways of production: 1. Physical processes 2. Chemical reactions and modification Physical – distillation, extraction, crystallization, absorption,

adsorption Chemical – cracking, reforming, alkylation, isomerization,

polymerization

Physical Process

Distillation Separation by the difference of volatility or

boiling point Most volatile goes on the top Requires more than one column Usually at atmospheric pressure, high

vacuum or at elevated pressure

Physical Process

Solvent extraction Using of a liquid with selective characterization Example: aromatics from paraffins

Crystallization To form crystal in a solvent or a molten mixture Further separation: filtration or centrifugal

Physical Process

Absorption Solvent extraction A component of a gas or vaporized mixture in

a liquid

Adsorption Using of highly porous materials e.g. activated

charcoal, silica gel Condensing on their surface

Chemical ProcessCracking Breaking down of the large molecule into a lower

molecular weight Thermal cracking (pyrolysis): without air, very high

temperature OR high temperature and catalyst

Reformation Processes designed to upgrade gasoline quality Thermal or catalytic reforming, modify molecule

structure, higher anti-knocking rating Condition: catalyst/H2

Alkylation Alkyl group attached to an aromatic or an unsaturated

hydrocarbon Product: alkylated aromatic compounds

Isomerization Rearrangement of atoms in a molecule Normal paraffin to isoparaffin Methyl cyclopentane to cyclohexane

Polymerization Molecules of single reactant (monomer) linked together Copolymerization: two or more monomers involved

Chemical Process

Summary

Physical processes – distillation, extraction, crystallization, absorption, adsorption

Chemical processes – cracking, reforming, alkylation, isomerization, polymerization

Additional information: focus on feedstock in liquid form