The Industrial Manufacture
of Chemical Compounds
Dr. Christina McEvoy
Step up Lecture
November 2010
Contents
• What factors do we need to consider
in design of a plant?
• Types of industrial processes
• What factors are important in
running a plant?
Key design factors
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What do we want to make?
In what quantities?
How will we manufacture?
How can we ensure safe production?
What environmental considerations are
there?
• What are the costs associated with the
project?
• How will we run the plant (people and
shifts)?
What and how much do we
want to make?
• Will this plant make only one product or
many products?
– Examples sulphuric acid, sodium hydroxide,
dyestuffs, perfumes
• How much will we make?
– 10g, 10kgs or 10,000T
The answers to these questions will
determine how we will manufacture
Manufacturing processes
• Batch process - A process that is not in
continuous or mass production;
operations are carried out with discrete
quantities of material or a limited number
of items (1T of X and 2T of Y)
• Continuous process -Industrial process
that continuously receives raw materials
and processes them through to
completed units (1T/h of X and 2T/h of Y)
Manufacture of Aspirin –
batch process
Examples of batch
processes
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Pharmacuticals
Agrochemicals
Dyestuffs
Food additives
Perfumes
Vitamins
Pigments
Advantages of batch processes
• Good for small amounts of speciality
chemicals
• Make a range of products using
same equipment
• Good for developing new products
• Easier to scale up from lab scale
• Generally cheaper set up costs
Disadvantages of batch
processing
• Frequent start up and shutdown of
equipment
• Cleaning time between batches
• May be batch to batch variability
• Not good for bulk chemical
production
Examples of Continuous
Processes
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Sulphuric acid production
Sodium hydroxide production
Ammonia
Petrol
Chlorine
Methanol
Advantages of Continuous
Processing
• Good for large volumes (bulk
chemicals)
• Fewer start up and shutdowns
• Potentially greater yields
• Potentially easier to maintain quality
or spot out of specification product
sooner
Disadvantages of
Continuous Processing
• Requires periodic shutdown of whole
plant for inspection and maintenance
• May rely on critical pieces of
equipment which have the potential
to stop production on whole plant
• Higher initial costs
Designing in Safety
• Sets of legal and business standards to which
plants must comply
• Process Safety Management
• What if?
• Risk assessment
Key at the design stage is to review proposed
design, identify hazards and engineer them
out. If the hazard cannot be eliminated then
the risk must be reduced using various
means.
Examples of Safety Devices
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Relief Valves
Rupture discs
Conservation vents
Failsafe logic
Process Interlocks
Alarms, monitoring of process conditions
Physical barriers
Personal Protective Equipment (PPE)
Training of personnel
Key Environmental
Considerations
• International/national laws
• Governmental conditions (licence to
operate)
• Again key is to eliminate or minimise
at design stage.
• If can’t eliminate then must look at
containment and treatment.
What will this Cost?
• Fixed Capital investment – Total
cost of the plant ready for start up.
• Working Capital investment –
additional investment required over
and above fixed capital to start the
plant up and operate it to a point
where income is generated.
Types of Costs
Fixed Capital Investment
Working Capital Investment
1.
Concrete and steel
1.
Start up
2.
Equipment
2.
Initial catalyst charges
3.
Piping
3.
Raw materials
4.
Instrumentation
4.
5.
Buildings for process and other
eg offices
Finished Product
Inventories
6.
Storage facilities
7.
Utilities provision
8.
9.
Non Capital Investment
1.
People involved in start
up
Design and engineering costs
2.
Travel
Contractors fees
3.
Training
An Oil Refinery
Photo courtesy Phillips Petroleum Company
http://science.howstuffworks.com/oil-refining.htm/printable
Fractional distillation of Crude Oil
BP America Refinery Explosion
Location: Texas City, TX
March 23, 2005
http://www.csb.gov/assets/investigation/original/CSB_Photo-Destroyed_Trailers_BP_Near_Isom_Unit.JPG
Accident Description
•
At approximately 1:20 p.m. on March 23,
2005, a series of explosions occurred at the
BP Texas City refinery during the restarting
of a hydrocarbon isomerization unit. Fifteen
workers were killed and 180 others were
injured. Many of the victims were in or
around work trailers located near an
atmospheric vent stack. The explosions
occurred when a distillation tower flooded
with hydrocarbons and was overpressurized,
causing a geyser-like release from the vent
stack.
For more details see:
http://www.csb.gov/investigations/detail.aspx?SID=20&Type=2&pg=1&F_All=y
Chlor-Alkali
HCl
Product
Hydrogen
Handling
HCl
Production
HCl
Storage
Chlorine
Compression
Chlorine
Liquefaction
Chlorine
Storage
Hypo
Production
Hypo
Storage
Hypo
Product
Caustic
Storage
Caustic
Product
Sulphuric Acid
Carbon Dioxide
NaOH
Chlorine
Drying
Salt
Demin. Water
To Hypo
Brine
Saturation
Primary
Treatment
Secondary
Treatment
Chlorine
Packing, Filling
Vaporization
Chlorine
Product
Sulphuric Acid
Sodium Sulphite
Sulphate
Removal
HCl
Electrolysis
NaOH
Brine
Dechlorination
Caustic
Concentration
Chlorate
Destruction
Demineralized Water
AC Power Supply
HCl
DC
Rectification
Hypo
Destruction
CHEMETICS
http://www.akerkvaerner.com/NR/rdonlyres/A078B10E-6369-48E5-9E2D-ECD2BFE2E628/12091/ProcessFigure1.PPT
Electrolysis
http://encarta.msn.com/media_461541587/Chloralkali_Electrolysis.html
Agrochemical Production
• Bulk chemicals production –how do
you think you would manufacture?
• Fertilisers – what hazards exist in
design and production?
The Haber Process
N2(g) + 3H2(g) → 2NH3(g) ΔHo = -92.4 kJ/mol
•Reversible Reaction
• Exothermic reaction – best
yield obtained at lower
temperatures but rate of
reaction is too slow so
increased temperature is used.
• Catalyst is used to help speed
up the reaction rate
• Increased pressure increases
yield
What do you think are the key variables to control during production?
Recent Incident
Explosion at Terra Nitrogen (UK) Ltd, Billingham
01.06.2006
Terra Nitrogen is the UK's largest manufacturer of nitrogen products used
extensively in the chemical industry and agriculture and employs around
250 people on Teesside.
The incident happened on a pipe at the plant and led to a fire involving
mixed gases including hydrogen, nitrogen and a small amount of ammonia
which was extinguished automatically as the pipe depressurised. The exact
cause of the blast is not yet clear.
The HSE are currently investigating with the Environment Agency (EA).
How will we run the plant?
• Will it be 24/7 operation?
• How many people?
• What skills do they require
(operating technicians, maintenance
technicians, engineers)?
• What support staff (HR,
admin,finance, IT)?
Aim of Production
To make first time, first
quality product, safely, with
maximum yield
Key monitoring conditions
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Pressures
Temperatures
Flows
pH
Concentrations
Mixing rates
Running Costs
Fixed costs – Costs which are
paid regardless of production rate
Variable Costs – Costs
related to production
• Labour costs
• Raw materials
• Maintenance costs
• Utilities
• Admin costs (insurances, rates,
taxes)
• Packaging
• Storage and distribution
Questions?