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Introducing CATS - Central
Area Transmission System
C.A.T.S.
Jon Wagner, CATS
Margaret H. Barrass, Driffield School
Fuels
Date 11.07.12
Introducing CATS
Day in the life of an engineer…….
My name is Jon Wagner, and I am a
Chemical Engineer working at
the CATS Natural Gas Processing
facility on Teesside. Today is a
slightly different day to my normal routine in that I am
going to support the site on starting up part of the
facility following a shutdown for several weeks to do
critical maintenance.
Fuels
Date 11.07.12
Introducing CATS
CATS – Central Area Transmission System
CATS is designed to bring natural gas from 250 miles
away, in the middle of the North Sea where it is extracted
from several miles underneath the sea bed along with oil
and water. About 10-15% of the UKs gas supply comes
along this facility, enough to heat and power over 3
million homes in the UK.
Fuels
Date 11.07.12
Introducing CATS
CATS
At CATS we remove several contaminants out of the gas
(H2S, mercury) which can be toxic and harmful to the
end user. We also condense out as much Propane (used
in plastic manufacture, camping gas/barbecues,
refrigerant coolant and now as an alternative fuel for
cars) and Butane (fuel, aerosols) from the natural gas
(mixture of alkanes from CH4 to C6H14 typically).
Fuels
Date 11.07.12
Introducing CATS
CATS
To remove the Propane and Butane from the Natural Gas
we drop the gas temperature to -33 oC at which point
Propane and Butane want to exist in the liquid phase at
that pressure, which makes it easier for us to separate
the liquid and the remaining gas.
Fuels
Date 11.07.12
Introducing CATS
CATS
For CATS then to sell the remaining gas which will either
go to gas fired power stations or to people’s homes for
their central heating system, we must heat the gas from
-33 oC to around 5 oC.
To do this we have a huge gas fired heater which heats
oil in a circulating oil system.
This oil system then heats the gas in the vessel (similar
principle to central heating boiler and radiator).
Fuels
Date 11.07.12
Introducing CATS
CATS
We have to heat the oil to 240 oC via
burners which operate at 1400 oC. We
have 8 large burners (big Bunsen
burners) in each heater which on a
given day can consume 300 tonnes of
natural gas (typically CH4). Inside the
heater, the flames are burning so
hard that the flames can reach 25
metres in length
The Hot Oil Heater
Combustion of alcohols
Lesson 1
Margaret H. Barrass
Extension
Foundation
Heat of combustion
Method
Small beaker
with 100cm3
water
10 cm
Fuel
Record the mass
of the fuel in the
spirit burner.
Record the
temperature of the
water.
Burn the fuel for 2
minutes.
Record the final
temperature.
Record the final
mass.
Heat of combustion
Small beaker
with 100cm3
water
10 cm
Fuel
Record the mass
of the fuel in the
spirit burner.
Record the
temperature of the
water.
Burn the fuel for 2
minutes.
Record the final
temperature.
Record the final
mass.
Energies of combustion
Calculations
1. What does the data show?
Calculate the mass of fuel burned in 2 minutes.
Calculate the temperature rise of the water.
2. Temperature rise per gram of fuel
Temperature rise per gram of fuel =
measured temperature rise (oC)
mass of fuel burned (g)
Which fuel releases the most heat per
gram?
3. How much energy was released by
the burning fuel in one minute?
Here we use the equation:
Q = mCΔT
where Q = energy (j)
m = mass of water (g)
C = the specific heat capacity
of the water (4.2 jg-1oC-1)
ΔT = the temperature change
of the water (oC)
Extension
The formulae of the alcohols
methanol
1 carbon atom
ethanol
2 carbon atoms
propanol
3 carbon atoms
butanol
4 carbon atoms
4. How many moles of fuel were burnt in 2
minutes?
Number of moles =
mass of fuel burnt (g)
relative molecular mass (g/mol)
5. Energy released per mole of fuel
The energy which one mole of burning fuel
would release (jmol-1)
=
=
energy released in 2 minutes (j)
number of moles burned in 2 minutes
answer to part 3
answer to part 4
Plenary
Look at your plenary triangle:
Evaluate the Learning Objectives
Extension
Foundation
Enthalpies of Combustion
Lesson 2
Margaret H Barrass
Enthalpies of combustion
Date 12.07.12
Enthalpies of Combustion
First you need a balanced symbol equation for the
combustion of your alcohol.
For example the reaction that Jon Wagner at C.A.T.S. is
most interested in is the combustion of methane :
CH4 + 2O2  CO2 + 2H2O
Next you need to work out how many INDIVIDUAL bonds
are involved
Enthalpies of combustion
12.07.12
Enthalpy of combustion of
methane
How many bonds are there?
CH4 + 2O2  CO2 + 2H2O
C-H
C-H
C-H
C-H
O=O
O=O
C=O
C=O
O-H
O-H
O-H
O-H
Enthalpies of combustion
12.07.12
Bond energies
Each type of bond has its own energy which has to be
put in to break it or is given out when it is made.
Bond energies
C-H
O=O
C=O
O-H
413 kJ mol-1498 kJ mol-1
805 kJ mol-1
463 kJ mol-1
Enthalpies of combustion
12.07.12
Bond energies
•
First we need to calculate how much energy has to go in
to break the bonds of the reactants:
CH4 + 2O2
C-H
C-H
C-H
C-H
413
413
413
413
1652 kj
Total:
2648 kj
O=O
O=O
498
498
996 kj
A table of
bond
energies (kj)
Enthalpies of combustion
12.07.12
Bond energies
How much energy is released when the products bonds are
made?
CO2 + 2H2O
C=O
C=O
805
805
1610 kj
Total
3462 kj
H-O
H-O
H-O
H-O
463
463
463
463
1852 kj
Enthalpies of combustion
Enthalpy of combustion
12.07.12
Enthalpies of combustion
12.07.12
Energy level diagram
x = +2648 kjmol -1
y = -3462 kjmol -1
Z = -814 kjmol -1
Enthalpies of combustion
Enthalpy of combustion of
alcohols
Now try to calculate the enthalpy of combustion of the
alcohol you burned last lesson.
12.07.12
Enthalpies of combustion
12.07.12
Enthalpy of combustion of
alcohols
Bond energies:
C-C
C-H
C-O
O-H
O=O
C=O
348 kJ mol-1
413 kJ mol-1358 kJ mol-1
463 kJ mol-1
498 kJ mol-1
805 kJ mol-1
methanol
1 carbon atom
ethanol
2 carbon atoms
propanol
3 carbon atoms
butanol
4 carbon atoms
Enthalpies of combustion
12.07.12
Enthalpy of combustion of
alcohols
Questions
• Compare the enthalpies of combustion of the four alcohols.
Plot a bar chart of the number of carbon atoms in each
alcohol against the enthalpy of combustion.
• Which from the four alcohols and methane releases the
most heat per mole of fuel?
Enthalpies of combustion
12.07.12
Enthalpy of combustion of
alcohols
Extension Questions
• Draw an energy level diagram for the combustion of your
alcohol – label it with your calculated energy values.
• How does the theoretical enthalpy of combustion compare
with your practical value?
• What were the sources of error in your practical?
Environmental Consequences of
Combustion of Fossil Fuels
Lesson 3
Margaret H. Barrass
Environmental Consequences of
Combustion of Fossil Fuels
C.A.T.S.
C.A.T.S. takes its environmental
responsibilities very seriously.
The combustion of CH4 in the Hot
Oil Heater requires sufficient
oxygen for complete combustion
The Hot Oil Heater at
C.A.T.S
15.07.12
Environmental Consequences of
Combustion of Fossil Fuels
15.07.12
C.A.T.S
Complete combustion of methane produces carbon dioxide
and water – both greenhouse gasses.
However as Jon Wagner explains:
“If we do not provide sufficient oxygen to the burners, the
flames will burn with incomplete combustion (typically
observed by a yellowish flame rather than blue and may
generate soot), this chemically is represented as follows:
CH4 + 1 1/2 O2 = CO + 2H2O
Environmental Consequences of
Combustion of Fossil Fuels
15.07.12
C.A.T.S.
“CO generation or even worse un-combusted CH4
released to the atmosphere rather than CO2 via the
heater exhaust stack (chimney) can cause significantly
more damage to the environment including greenhouse
effect (CH4 has 100 times greater impact on greenhouse
effect than CO2)”.
Jon Wagner
Environmental Consequences of
Combustion of Fossil Fuels
15.07.12
C.A.T.S.
“CATS is very lucky in that the gas we burn is relatively
clean, however we still need to do close monitoring to
check whether any NOx and SOx gases are being
generated from our heater. These gases when in
sufficient volumes will mix with the moisture in the air
(namely clouds) and could cause “acid rain” which can
be harmful to plants and wildlife.”
Jon Wagner
Environmental Consequences of
Combustion of Fossil Fuels
15.07.12
Student Activity
Use the internet to research one of the following:
The causes and environmental consequences of the
release of:
NOx
SOx
CH4
CO
Or summarise the causes and possible effects of:
Global warming
Global dimming
Produce a 2 minute PowerPoint to explain your findings
Environmental Consequences of
Combustion of Fossil Fuels
15.07.12
Student Activity
Possible internet sites:
http://environment.nationalgeographic.com/environment/global-warming/acidrain-overview/
http://www.epa.gov/iaq/co.html
http://library.thinkquest.org/CR0215471/global_warming.htm
http://environment.nationalgeographic.com/environment/global-warming/
http://www.webschool.org.uk/modules.php?op=modload&name=News&file=articl
e&sid=175
http://www.globalissues.org/article/529/globaldimming#Burningoffossilfuelsiscreatingtwoeffects
Environmental Chemistry
Alternative Lesson 3
Nicky-Jo Cooper
Green Chemistry in the
Natural Gas industry
CATS is the Central Area Transmission
System, which delivers 12% of the
UK's gas demand through a 404
kilometre (223 mile) pipeline from the
Central North Sea to the CATS
processing terminal in Teesside on the
north east coast of England. CATS is a
Joint Venture operated by BP.
The sustainability of a chemical process
depends on:
American scientists Paul Anastas and John Warner formulated the Twelve Principles of Green
Chemistry in 1998. These guidelines help chemists to reduce the ecological footprint of the
chemicals they produce and the processes which they use.
• Prevention of waste: use of other products/impurities
• Higher atom economy
• Less hazardous chemical syntheses
• Designing safer chemicals
• Safer solvents
• Design for energy efficiency
• Use of renewable feedstocks
• Reduce chemical derivatives
• Catalysis
• Design for degradation
• Real-time analysis for pollution prevention
• Inherently safer chemistry for accident prevention
Task:
Over the next few slides you will learn about the
chemical processes at the CATS terminal. Mark down on
your sheet points where they take steps to reduce the
environmental impact of the process.
My name is Jon Wagner, and I am a Chemical Engineer
working at the CATS Natural Gas Processing facility on
Teesside. Today is a slightly different day to my normal
routine in that I am going to support the site on starting
up part of the facility following a shutdown for several
weeks to do critical maintenance.
CATS is designed to bring natural gas from 250 miles
away, in the middle of the North Sea where it is extracted
from several miles underneath the sea bed along with oil
and water. About 10-15% of the UKs gas supply comes
along this facility, enough to heat and power over 3
million homes in the UK.
At CATS we remove several contaminants out of the gas
(H2S, mercury) which can be toxic and harmful to the end
user. We also condense out as much Propane (used in
plastic manufacture, camping gas/barbecues, refrigerant
coolant and now as an alternative fuel for cars) and
Butane (fuel, aerosols) from the natural gas (mixture of
alkanes from C1H4 to C6H14 typically).
•We remove the toxic materials using a catalytic
reaction with a substance called Puraspec (consists
of mainly ZnO). It is a direct substitution reaction
with H2S in the gas to produce ZnS + H2O.
ZnO + H2S
ZnS + H2O
Once ZnS is produced, it is classed as being nearly
pyrophoric (when in contact with oxygen, it selfheats and can eventually combust!!!) – therefore
very special controls are required to ensure the
material is removed and then kept in air-tight
containers once it’s changed out for new.
To remove the Propane and Butane from the Natural
Gas we use a phenomenon known as the JouleThomson (J-T) effect where by dropping the pressure
of the gas we can significantly reduce its
temperature, we drop the gas temperature to -33
degC at which point Propane and Butane want to
exist in the liquid phase at that pressure, which
makes it then easier for us to separate the liquid and
the remaining gas.
For CATS then to sell the remaining gas which will
either go to gas fired power stations or to people’s
homes for their central heating system we must heat
the gas from -33degC to around 5 degC.
To do this we have a huge gas fired heater which is
needed to generate over 19 MW of thermal energy
which is transferred to a circulating oil system, this
oil system then heats the gas in the vessel (similar
principle to central heating boiler and radiator).
We have to heat the oil to 240 degC via burners
which operate at 1400 degC. We have 8 large
burners (big Bunsen burners) in each heater which
on a given day can consume 300 tonnes of natural
gas (typically C1H4). Inside the heater, the flames are
burning so hard that the flames can reach 25 metres
in length (see photo for scale).
The combustion reaction simplified is:
CH4 + 2O2
CO2 (greenhouse gas) + 2H2O
This reaction is very demanding on getting sufficient air/oxygen into
the heater to ensure we undertake complete combustion, as illustrated
above.
If we do not provide sufficient oxygen to the burners, the flames will
burn with incomplete combustion (typically observed by a yellowish
flame rather than blue and may generate soot), this chemically is
represented as follows:
CH4 + 1 1/2 O2
CO + 2H2O
CO generation or even worse un-combusted C1H4 released to the
atmosphere rather than CO2 via the heater exhaust stack (chimney)
can cause significantly more damage to the environment including
greenhouse effect (C1H4 has 100 times greater impact on greenhouse
effect than CO2).
CATS is very lucky in that the gas we burn is relatively clean, however
we still need to do close monitoring to check whether any NOx and
SOx gases are being generated from our heater. These gases when in
sufficient volumes will mix with the moisture in the air (namely clouds)
and could cause “acid rain” which can be harmful to plants and
wildlife.
Making processes as efficient as possible is really important
for energy conservation and reducing waste.
The heat in the hot oil heaters comes from the
combustion of natural gas. Since some of the energy of
the gas is lost through the walls of the heaters and by
hot gas leaving through the flue stack, the efficiency of
the heaters is only 87.5%. Therefore more heat has been
provided by the gas than is actually transferred to the
hot oil.
This heat, H, can be calculated by dividing the required
energy of 19.25MW by the heat efficiency of 87.5% =
To ensure that CATS make efforts to reduce
their carbon emissions the government charges for the
amount of CO2 produced
Under the Emissions Trading Scheme, CATS has to pay:
19€/tonne in 2014
20€/tonne in 2015
21€/tonne from 2016 onwards.
Every kg of gas burnt produces 2.71 kg of CO2.
Therefore, it is possible to calculate the carbon tax from the fuel gas
rate, the conversion factor and the carbon cost:
Carbon cost = wFG x mCO2/mgas x carbon cost
Carbon Cost per hour = 1703.2kg/hr x 2.71kg x € 19 /tonne
Calculate:
Cost per hour = €87.8/hour
Cost per year = € 768,767/year
The following slides contain information
about CATS’s work with environmental
conservation.
This information can be found on the following
websites:
CATS’s environmental
http://www.catspipeline.com/cats/content/brochure/broc
hure.asp?sectionid=19
Reedbed systems
http://www.reedbeduk.co.uk/blowing%20in%20the%20wi
nd.html
BP CATS are involved in many wildlife preservation projects
CATS is a member of INCA (Industry Nature Conservation Association).
They also work closely together with the Tees Valley Wildlife Trust and the
Education Authority to raise the environmental awareness in the community.
CATS has taken part in a number of initiatives including 'Wild flowers for the
Millennium' and 'Nature at Work'. CATS has also taken measures to improve the
environment within the area of the Teesside Terminal. Kestrel boxes have been
placed on top of some of the terminal’s tall structures to encourage nesting.
CATS has donated a birdhide to the Tees Estuary, and in partnership with other
local industries, have constructed a footpath for people with disabilities to gain
access to the birdhide.
CATS also supports INCA in their interests in the welfare of the seals
which live and breed in the Seal Sands area.
To raise awareness of the environment in the vicinity of the Terminal CATS
invites school children to plant either dune grass at Coatham Sands or
wildflowers around the terminal's firewater pond in the dedicated 'wildflower
meadow' or in and around the reedbed.
CATS, working with the University of Durham, Industry and Nature Conservation
Association (INCA) and English Nature, have designed, built and are monitoring
a reedbed system for the treatment of waste water
CATS is proof that economic growth and environmental protection work hand in hand in
Teesside. CATS is set to contribute to the economic and natural well-being of Teesside
in the 21st Century. The reedbed project is evidence of the success that can come from
co-operation between industry and those whose business it is to conserve the wildlife.
The project is based on a reedbed constructed as a 'natural' tertiary treatment system
after normal treatment of sewage and water run-off for the expansion of the CATS
Natural Gas Treatment facility at Teesside. The design used has drawn upon the
experience of the Centre of Alternative Technology, Wales in the construction and
operation of small scale sewage treatment systems using macrophytes (aquatic plants).
The treated effluent passes through stone filters before entering the reedbed. It is then
channelled around a series of dividing walls before passing into a settling pond from
where it discharges into an outfall pond. The reedbed has been planted as a
monoculture using the Common Reed (Phragmites Australis), using pot-grown reeds in
one half of the bed and locally transplanted reeds in the other half. This has allowed
conservationists to determine the type of reed most suited to this site.
The intermediate pond has been planted with a variety of aquatic plants including Water
mint (Mentha Aquatica), Yellow flag (Iris Pseudacorus) and Marsh Marigold (Caltha
Palustris). Apart from the natural beauty of these plants, they support micro-organisms
to further improve the water quality.
How do the Reedbeds improve the water quality?
Most sewage and surface water degrades eventually in receiving waters. However,
the micro-organisms that break down organic material need oxygen from the water,
reducing its availability to aquatic life. Therefore, in order to reduce the effects of
sewage in the environment it must first be treated.
The CATS Terminal horizontal flow reedbed acts like a gravel pool with effluent
entering at one end. As the pool is topped up, water overflows at the opposite end.
Physical, chemical and biological processes break down and reduce organic and
inorganic matter in the water and cleaner water is discharged into the environment.
Independent studies by environmental consultants in 1996 showed that the terminal
had not only restored the area as close as possible to its original condition but, in
some places, the natural habitat had actually been enhanced.