principles of environmental science

Principles of Environmental

ScienceProf. Ge Ying

Nanjing Agri. Univ.

Chapter 1 Introduction

Chapter 2 Population and environment

Chapter 3 Energy and environment

Chapter 4 Air pollution and its control

Chapter 5 Sustainable development

Chapter 6 Water pollution and its control

Chapter 7 Soil pollution and its control

Chapter 8 Noise and solid waste

Major contents of the course

EnergyEnergy Sources

Energy Crisis

Solutions to

the energy

crisis

Energy (Energy ( 能量能量 ): The capacity to do work.): The capacity to do work.

Work (Work ( 功功 ): The application of force through ): The application of force through

a distance.a distance.

Power (Power ( 功率功率 ): the rate of flow of energy, or ): the rate of flow of energy, or

the rate at which the work is done.the rate at which the work is done.

Important conceptsImportant concepts

We need energy to：

Energy Demand IncreasesAs World Population Grows

Source: U.S. Department of Labor 2001 Occupational Employment Statistics; EIA, International Energy Outlook, 2004

0

2

4

6

8

10

0 200 400 600 800

Energy Consumed, Quadrillion BTU

Po

pu

lati

on

, B

illi

on

Per

son

s

1970 to 2025

1970

2005

2025

1 BTU =1055joules( 焦耳 )

Per capita energy use and GNP

Energy Consumption in China

20.9%

41.1%

24.5%

8.1% 2.6%

煤炭 石油 天然气 核电 水力

67.1%

6.7% 2.8%23.4%

煤炭 石油 天然气 核水电

China in 1999 World average in 1998

-

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

450.0

1995 1996 1997 1998 1999

Other

Transport

Agric.

Comm.

Residential

Industry

Declining Coal Use in China:Coal consumption by sector (in Mton)

Source: International Energy Agency

能源的类型

能源

一次能源

二次能源

常规能源

新能源

可再生能源

不可再生能源

可再生能源

不可再生能源

Types of Energy

• Primary Energy (一次能源 )

自然界中能提供现成形式能量的能源

• Secondary Energy (二次能源 )

需要依靠其他能源来制取的能源

Primary Energy

Conventional EnergyRenewable — Hydropower

Non-Renewable — Coal ( 煤 ), Petroleum (石油 ), Natural gas (天然气 )

New EnergyRenewable — Solar, Biomass, Wind, Geothermal, Ocean

Non-Renewable — Nuclear

Worldwide Commercial Energy Production

oil (石油 ), coal ( 煤 ), gas (天然气 ), solar (太阳能 ), hydro (水能 )

wind (风能 ), wood (木材 ), peat (泥煤 ), charcoal (木炭 ), manure (堆肥 )

Where are the coal reserves?

Where are the oil reserves?

Where are the natural gas reserves?

Principles of Environmental

ScienceProf. Ge Ying

Nanjing Agri. Univ.

Review of Last ClassReview of Last Class

• Type of energy: Type of energy:

primary and primary and secondary energy

conventional and new energyconventional and new energy

renewable and nonrenewable energyrenewable and nonrenewable energy

• Energy consumption growthEnergy consumption growth

Secondary Energy

Non-Renewable — Electricity (电能 ), gasoline

(汽油 ), Coal gas (煤气 ), etc.

Primary to Secondary Energy: conversion

efficiency is very low.

Review of Last ClassReview of Last Class

• Type of energy: Type of energy:

primary and primary and secondary energy

conventional and new energyconventional and new energy

renewable and nonrenewable energyrenewable and nonrenewable energy

• Energy consumption growthEnergy consumption growth

Energy and environment

WHAT

Types of energy; energy crisis

WHY

Current status of energy consumption

(能源消费的现状 )

HOW

Solutions to energy shortage and pollution

(能源短缺和污染问题的对策 )

Fossil fuels (化石燃料 )

• Solid: coal, world deposits 10 times greater than oil and gas resources combined

• 可燃成分 : carbon and hydrogen

Increasing moisture content

Increasing heat and carbon content

Peat 泥炭(not a coal)

Lignite 褐煤(brown coal)

Bituminous Coal 烟煤(soft coal)

Anthracite 无烟煤(hard coal)

Heat

Pressure Pressure Pressure

Heat Heat

Partially decayedplant matter in swampsand bogs; low heatcontent

Low heat content;low sulfur content;limited supplies inmost areas

Extensively usedas a fuel becauseof its high heat contentand large supplies;normally has ahigh sulfur content

Highly desirable fuelbecause of its highheat content andlow sulfur content;supplies are limitedin most areas

Surface Mine: 露天采煤

Underground Mine: 地下采煤

Advantages

Low cost with huge subsidies( 补助 )

High net energyyield

Ample supplies(225–900 years)

Mining andcombustiontechnologywell-developed

Air pollution canbe reduced withimprovedtechnology (butadds to cost)

煤的优缺点

Disadvantages

Releases radioactive particles and mercury into air

High CO2 emissionswhen burned

Severe threat tohuman health

Severe land disturbance, air pollution, andwater pollution

Very high environmentalimpact

High land use

Fossil fuels (化石燃料 )

• Liquid: petroleum, most used fossil fuel in developed countries

Diesel oil

Asphalt

Greaseand wax

Naphtha

Heating oil

Aviation fuel

Gasoline

Gases

Furnace

Heatedcrude oil

石脑油

沥青

油脂、蜡

石油的分馏

天然气

汽油

航空油

燃料油

柴油

light

heavy

Water pollution

Releases CO2 when burned

Air pollutionwhen burned

Artificially low price encourageswaste and discourages search for alternatives

Need to findsubstitute within50 years

Disadvantages

Low land use

Easily transportedwithin and between countries

High netenergy yield

Low cost (withhuge subsidies)

Ample supply for42–93 years

Advantages

Efficient distribu-tion system

石油的优缺点

Fossil fuels (化石燃料 )

• Gas: natural gas, world’s 3rd largest commercial fuel; produce less CO2 compared to coal and oil

• Main component: methane ( 甲烷 )

Advantages

Low land use

Easily transportedby pipeline

Moderate environ-mental impact

Lower CO2 emissions thanother fossil fuels

Less air pollutionthan other fossil fuels

Low cost (withhuge subsidies)

High net energyyield

Ample supplies(125 years)

Disadvantages

Sometimes burned off andwasted at wellsbecause of lowprice

Methane(a greenhouse gas) can leakfrom pipelines

Releases CO2

when burned

Nonrenewableresource

Difficult to transferfrom one countryto another

Needs pipelines

天然气的优缺

点

可燃冰 可燃冰 (flammable ice)(flammable ice)• CHCH44··HH22O(O( 水合天然气水合天然气 ), new energy in 21), new energy in 21stst century century

• Formation: similar to oil and natural gas, but low Formation: similar to oil and natural gas, but low temperature and high pressure are necessary.temperature and high pressure are necessary.

• 1 m1 m33 = 164 m = 164 m33 natural gas natural gas

total energy = 2-3 times of the sum of coal, oil and total energy = 2-3 times of the sum of coal, oil and natural gas.natural gas.

PrecautionsPrecautions• Difficulty with extraction of flammable Difficulty with extraction of flammable

ice.ice.

• May speed up global warming if CHMay speed up global warming if CH44 is is

released into the atmosphere.released into the atmosphere.

Environmental Effects

Mining (开采 )

Processing (加工 )

Using (使用 )Air, water, soil pollution; solid waste; noise, etc.

Air, water, soil pollution; solid waste; noise, etc.

Disturbed land; mining accidents; mine waste; oil spills, etc.