Principles of Environmental Science Prof. 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

Energy  Energy Sources  Energy Crisis  Solutions to the energy crisis

Energy ( 能量 ): The capacity to do work. Work ( 功 ): The application of force through a distance. Power ( 功率 ): the rate of flow of energy, or the rate at which the work is done. Important concepts

We need energy to ：

Our country need energy for ： Development of economy –Manufacturing ( 制造 ) –Transportation ( 交通 ) Improvement of people’s lives –Electricity ( 电力 ) –Gasoline ( 汽油 )

Energy Demand Increases As World Population Grows Source: U.S. Department of Labor 2001 Occupational Employment Statistics; EIA, International Energy Outlook, BTU =1055joules( 焦耳 )

History Projections Energy Consumption How much energy do we use every year?

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 1999World average in 1998

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 Energy Renewable — Hydropower Non-Renewable — Coal ( 煤 ), Petroleum ( 石油 ), Natural gas ( 天然气 ) New Energy Renewable — 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 Science Prof. Ge Ying Nanjing Agri. Univ.

Review of Last Class Type of energy:Type of energy: primary and secondary energy primary and secondary energysecondary energysecondary energy conventional and new energy conventional and new energy renewable and nonrenewable energy renewable 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 Class Type of energy:Type of energy: primary and secondary energy primary and secondary energysecondary energysecondary energy conventional and new energy conventional and new energy renewable and nonrenewable energy renewable 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 Heat Partially decayed plant matter in swamps and bogs; low heat content Low heat content; low sulfur content; limited supplies in most areas Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas

Surface Mine: 露天采煤

Underground Mine: 地下采煤

Advantages Low cost with huge subsidies ( 补助 ) High net energy yield Ample supplies (225–900 years) Mining and combustion technology well-developed Air pollution can be reduced with improved technology (but adds to cost) Disadvantages Releases radioactive particles and mercury into air High CO 2 emissions when burned Severe threat to human health Severe land disturbance, air pollution, and water pollution Very high environmental impact High land use

Percolation to groundwater Leaching of toxic metals and other compounds from mine spoil Acid drainage from reaction of mineral or ore with water Runoff of sediment Surface Mine Subsurface Mine Opening Leaching may carry acids into soil and groundwater supplies percolation: 下渗 leaching: 沥滤 runoff: 径流 sediment: 沉积物 drainage: 排水 ore: 矿石 spoil: 矸石

Fossil fuels ( 化石燃料 ) Liquid: petroleum, most used fossil fuel in developed countries

Diesel oil Asphalt Grease and wax Naphtha Heating oil Aviation fuel Gasoline Gases Furnace Heated crude 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 CO 2 when burned Air pollution when burned Artificially low price encourages waste and discourages search for alternatives Need to find substitute within 50 years Disadvantages Low land use Easily transported within and between countries High net energy yield Low cost (with huge subsidies) Ample supply for 42–93 years Advantages Efficient distribu- tion system

Fossil fuels ( 化石燃料 ) Gas: natural gas, world’s 3rd largest commercial fuel; produce less CO 2 compared to coal and oil Main component: methane ( 甲烷 )

Advantages Low land use Easily transported by pipeline Moderate environ- mental impact Lower CO 2 emissions than other fossil fuels Less air pollution than other fossil fuels Low cost (with huge subsidies) High net energy yield Ample supplies (125 years) Disadvantages Sometimes burned off and wasted at wells because of low price Methane (a greenhouse gas) can leak from pipelines Releases CO 2 when burned Nonrenewable resource Difficult to transfer from one country to another Needs pipelines

可燃冰 (flammable ice) CH 4 ·H 2 O( 水合天然气 ), new energy in 21 st centuryCH 4 ·H 2 O( 水合天然气 ), new energy in 21 st century Formation: similar to oil and natural gas, but low temperature and high pressure are necessary.Formation: similar to oil and natural gas, but low temperature and high pressure are necessary. 1 m 3 = 164 m 3 natural gas1 m 3 = 164 m 3 natural gas total energy = 2-3 times of the sum of coal, oil and natural gas. total energy = 2-3 times of the sum of coal, oil and natural gas.

Precautions Difficulty with extraction of flammable ice.Difficulty with extraction of flammable ice. May speed up global warming if CH 4 is released into the atmosphere.May speed up global warming if CH 4 is released into the atmosphere.

Environmental Effects Mining ( 开采 ) Processing ( 加工 ) Using ( 使用 ) Air, water, soil pollution; solid waste; noise, etc. Disturbed land; mining accidents; mine waste; oil spills, etc.