R. Shanthini 15 Aug 2010 “In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we have been taught.” – Baba Dioum

R. Shanthini 15 Aug 2010 Energy and the Environment Part I CES August 2010 Prof. R. Shanthini Dept of Chemical & Process Engineering Faculty of Engineering University of Peradeniya

R. Shanthini 15 Aug 2010 Describe the major energy technologies Assess the impact of the use of energy from the environmental (ecological) point of view Demonstrate a comprehensive understanding of - energy sufficiency (conservation) - energy efficiency - energy security and - sustainability issues Learning Objectives

R. Shanthini 15 Aug 2010 Global primary energy consumption in 2006 ≈ 15.8 TW = 15.8 x W Global population in 2006 ≈ 6.56 billion Global energy consumption per person in x W 6.56 x 10 9 ≈ 2.4 kW Source: International Energy Annual 2006 (posted Dec 19, 2008) ≈

R. Shanthini 15 Aug 2010 How is electric power produced using oil, coal or natural gas?

R. Shanthini 15 Aug 2010 How is electric power produced using oil, coal or natural gas? Diesel engine Gas Turbine (GT) Steam Turbine (ST) Combined Power Plant (GT & ST)

R. Shanthini 15 Aug 2010 Gas Turbine (GT) Steam Turbine (ST) Combined Power Plant (GT & ST) Steam / Gas entry Steam / Gas outlet

Comp- ressor air Combustion Chamber fuel Gas Turbine gases to the stack Gen compressed air hot gases Gas Turbine Power Plant

R. Shanthini 15 Aug 2010 Gas Turbine to produce Electricity

R. Shanthini 15 Aug 2010 Gas Turbine driving a Jet Engine

gases to the stack Work Gen compressed air hot gases Combustion Chamber Comp- ressor Gas Turbine Gas Turbine Power Plant air fuel out

Heat in Gen compressed air hot gases Combustion Chamber Comp- ressor Gas Turbine Gas Turbine Power Plant gases to the stack air fuel Work out Work in

Heat in Gen compressed air hot gases Combustion Chamber Comp- ressor Gas Turbine Gas Turbine Power Plant gases to the stack E ff = - air fuel Work out Work in Work out Total Work in Heat in Work out

= 22 – 28% Energy Loss - [ - ] = = 72 – 78% of heat released by the fuel for 50 to 100 MW plant Gas Turbine Power Plant E ff = - Work in Work out Total Heat in Work in Heat in Work out Total

Heat in Gen compressed air hot gases Combustion Chamber Comp- ressor Gas Turbine Gas Turbine Power Plant gases to the stack air fuel Work out Total Work in 72-78% Energy Loss? Where are they lost???

Heat engine converts heat into work Heat engine (ex: gas turbine) W out Q in Q out E ff = W out Q in engine (must happen according to the 2 nd Law of Thermodynamics) ≠ 100%

Cold reservoir at T C K (Ex: Atmosphere) E ff Carnot = TCTC 1 - THTH Hot reservoir at T H K (Ex: Combustion chamber) Heat engine converts heat into work Heat engine W out Q in Q out E ff = W out Q in engine E ff engine E ff Carnot < (must happen) The 2 nd Law of Thermodynamics ≠ 100% <1

Steam Turbine Gen Steam Turbine Power Plant

C saturated water hot gases Steam Turbine Gen compressed water superheated steam Condenser Pump cooling water saturated steam Steam Generator (Boiler / Furnace) Steam Turbine Power Plant

R. Shanthini 15 Aug 2010 Steam Turbine to produce Electricity Oil could be used instead of coal. Steam engines are also used to power the train.

C saturated water Gen compressed water superheated steam cooling water Pump Steam Turbine Condenser Steam Generator Steam Turbine Power Plant saturated steam hot gases Heat Work out Total Work in Total

= 30 – 40% Energy Loss = 60 – 70% of heat released by the fuel for 200 to 800 MW plant Steam Turbine Power Plant E ff = - Work in Heat in Work out Total - - ] = Work out Total Work in Heat in Total [

C saturated water Gen compressed water superheated steam cooling water Pump Steam Turbine Condenser Steam Generator Steam Turbine Power Plant saturated steam hot gases Heat Work out Total Work in Total Loss??? Where???

atmospheric air fuel GT gases to the stack C hot gases ST cooling water Combined Power Plant

atmospheric air fuel GT gases to the stack ST Combined Power Plant C hot gases ST cooling water

E ff = Heat released by fuel Net Work out at GT & ST =36 – 50% Energy Loss = 50 – 64% of heat released by the fuel for 300 to 600 MW plant Combined Power Plant

Nuclear Power Plant C Pressurized water ST cooling water CORE Control rods Containment PWR

R. Shanthini 15 Aug 2010 Nuclear Power Plant to produce Electricity

= Heat released by nuclear fuel Net Work out at ST =31 – 34% Energy Loss = 66 – 69% of heat released by the fuel for 500 to 1100 MW plant Nuclear Power Plant E ff

R. Shanthini 15 Aug 2010 According to the 2 nd Law of Thermodynamics when heat is converted into work, part of the heat energy must be wasted Power generation type Unit size (MW) Energy wasted (MW) Diesel engine – 22 Gas Turbine – 78 Steam Turbine – 560 Combined (ST & GT) – 380 Nuclear (BWR & PWR) – 760

R. Shanthini 15 Aug 2010 Source:

R. Shanthini 15 Aug 2010 Where does all the lost heat from power plant go?

R. Shanthini 15 Aug 2010 atmospheric air fuel GT gases to the stack ST Combined Power Plant C hot gases ST cooling water

R. Shanthini 15 Aug 2010 Waste heat from power plant can be used for domestic or industrial heating purposes. It is known as cogeneration, and efficiency can be increased up to 80% in cogeneration applications. Discussion Point 1: What are the possibility for cogeneration applications in Sri Lanka? Take 05 mins.

R. Shanthini 15 Aug % - 70% lost in producing electricity 2% - 20% lost in transmitting electricity Generation, transmission and end-use losses

R. Shanthini 15 Aug 2010 Electric power sector 70% energy losses Transport sector Industrial sector Residential & Commercial sector 80% energy losses 25% energy losses 20% energy losses Typical energy losses in an industrialised country

R. Shanthini 15 Aug 2010 Transport sector E ff Carnot = TCTC 1 - THTH TCTC THTH = Flame temperature = Exhaust Temperature E ff Carnot = 600 K K 70% = mostly uses Internal Combustion Engines

R. Shanthini 15 Aug 2010 A Typical Car: 100 kJ 63 kJ 18 kJ 17 kJ 2 kJ Engine losses in fuel energy conversion, In engine cooling and with exhaust gases Energy for accessories Standby Idle Fuel Energy 6 kJ 12 kJ Driveline losses 2.5 kJ 4 kJ 5.5 kJ Aerodynamic drags Rolling resistance Braking Source:

R. Shanthini 15 Aug 2010 Is there a problem in burning oil and coal to make electricity and to drive automobiles in such an inefficient manner? Discussion Point 2: Take 15 mins.

R. Shanthini 15 Aug 2010 The supreme Greek God Zeus told Prometheus: “You may give men such gifts as are suitable, but you must not give them fire for that belongs to the Immortals.” – Roger Lancelyn Green Tales of the Greek Heroes Puffin Classics End of Part I (short Break)