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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.