Introduction:

Acrylonitrile, first synthesized in 1893 by Charles Moureu, did not become important until

the 1930s, when industry began using it in new applications such as acrylic fibers for textiles

and synthetic rubber. Although by the late 1940s the utility of acrylonitrile was

unquestioned, existing manufacturing methods were expensive, multistep processes. They

seemed reserved for the world's largest and wealthiest principal manufacturers: American

Cyanamid, Union Carbide, DuPont, and Monsanto. At such high production costs,

acrylonitrile could well have remained little more than an interesting, low-volume specialty

chemical with limited applications. In the late 1950s, however, Sohio's research into

selective catalytic oxidation led to a breakthrough in acrylonitrile manufacture.

Overcapacity had been a problem for ACN markets but they are now much better balanced

due to plant closures brought about by poor demand and surging feedstock costs. In

general, plant closures have exceeded capacity additions with ACN supply becoming tight to

balance. There has also been a shift in capacity from North America to Asia.

As far as the demand is concerned, global demand for ACN is only expected to grow by 1-

2%/year, with strongest demand in Asia pulled by the growth in ABS.

World annual production of Acrylonitrile in 2001 was 4 million tonnes and in 2008, 6.2

million tonnes, with just under half of that coming from the United States.

The present plant under operation in India is Indian Petrochemical Corp. Ltd, Gujarat.

Problem Statement:

In examining the steps commonly practiced in designing a chemical product or process, it is

important to keep in mind that design problems are open ended and may have many

solutions that are attractive and near optimal.

The design team needs to design a process for production of 50000 Tonnes per annum of

Acrylonitrile as the product.

Choose the optimal pathway for your process (appendix) considering techno economic

feasibility and environmental factors. You are provided with information of availability and

cost of raw materials and three sites for construction of plant (appendix). Using different

parameters like prosperity, profitability and productivity (appendix) select your plant

location. Come up with a legitimate Process Flow Diagram (PFD) of the process chosen and

perform “design and sizing of reactor”.

Rules:

Submission format:

Process selection: Explain using “Techno economic feasibility sheet”

Document explaining site selection

PFD of the selected process using software like Microsoft visio with proper

labeling of temperature and pressure.

Explanation of the Process flow diagram (PFD)

Explain the type of reactor used and Sizing of the reactor for the process.

Submission deadline for stage 1 is 25th February, 2013

Appendix:

Reaction Pathways

1. From Acetylene and Hydrogen Cyanide:

N

Hydrogen CyanideAcetyleneN

Acrylonitrile

+

Temperature: About 80 degC.

Pressure: 2-3 psig

Catalyst: CuCl in HCl

2. From Acetaldehyde via Lactonitrile:

N

Hydrogen Cyanide

OAcetaldehyde

OH

N

Lactonitrile

N

Acrylonitrile

Phosphoric acid

+

Temperature: 650 for dehydration

Pressure: 1 atm

Catalyst: 10% NaOH for 1st step & H3PO4 for dehydration

3. From Ethylene Oxide:

Lactonitrile

NHydrogen Cyanide

O

Ethylene Oxide

+N

OH

Ethylene CyanohydrinN

Acrylonitrile

Temperature: 55 – 60 for the 1st step and 200 for dehydration

Pressure: 1 atm

Catalyst: Diethylamine for the 1st step and alumina for liquid phase dehydration

4. From Propylene and Nitric Oxide:

+4 6 6N

Acrylonitrile

+ H

O

H

WaterPropyleneNO

Temperature: 450 – 550

Pressure: 1 atm (higher pressures give better yield )

Catalyst: Silica based or Lead and Thallium based

5. From Acrolein:

Temperature: 350-550

Pressure: 1 atm

Catalyst: Mixture of oxides of Sn and Sb, they being in a ratio of 0.1 – 10

6. Ammoxidation of Propylene:

N

Acrylonitrile

H

O

H

WaterPropylene

NH3+ 1/2 O2+ 3+

Temperature: 400-500

Pressure: 0.3-2 bar (gauge)

Catalyst: Several possibilities

7. From Propane:

Temperature: 485 – 580

Catalyst: Sb based

Appendix 2

The entire site selection exercise can be divided into three main factors:

Profitability factors

o Land

o Climatic Conditions

o Raw Material Source and Product Market

o Utilities

o Environmental Aspects

o Housing

o Transport to Staff

o Equipment Transportation

o Statutory Duties and Taxation

Productivity factors

o Communication

o Industrial Infrastructure

o Housing/Hotels

o Civic Amenities

o Labor

o Transport