Acid Rain

Question 1

What is the source of SOx?

Answer 1

S from coal, 99% is SO2

Question 2

What is the source of NOx?

Answer 2

High T combustion, NO emitted and forms NO2 in air.

Question 3

Consequence of Al mobilised?

Answer 3

Fish loss in Scandinavia

Question 4

Consequence of Mg depletion?

Answer 4

Forest death in Germany

Question 5

What happened in 1952 London?

Answer 5

4000 excess deaths led to tall chimneys and clean air acts.

Question 6

Liming soil and lakes

Answer 6

Low S coal, dash to gas

Question 7

FGD plants

Answer 7

Cost millions (expensive), Radcliffe on Soar and Drax, Turns limestone to gypsum

Question 8

Production methods of coal gasification

Answer 8

Favours gas turbine over steam turbine.

Question 9

Health effects

Answer 9

SOx, aerosols and NO2 causes respiratory distress

Question 10

Major source of SOx and NOx?

Answer 10

SOx - coal, increasing NOx source - vehicles

Question 11

All acid deposition

Answer 11

Snow, mist, dry, direct impact on trees and buildings

Question 12

Rain pH

Answer 12

Dissolved CO2 rain pH 5-6

Question 13

SOx and NOx input

Answer 13

Fossil fuels - acid vinegar

Question 14

SOx and NOx

Answer 14

S oxidation in fuel and N high temperature combustion from N2 and O2 in air, catalytic ally and photochemically oxidised

Question 15

SO4(2-)

Answer 15

Not deposited, less prone to dry composition than SO2 , travels in atmosphere - days, falls by wet deposition, rainout and wash out

Question 16

Impacts

Answer 16

Spring - acid flush, affect spawning, Al mobilised, reduce fish ability to take salt in through gills

Question 17

Forest death

Answer 17

Deciduous trees less affected, foliage low surface area, leaves shed, photochemical oxidants O3

Question 18

Crops

Answer 18

Yield reduction, others stimulated, sulphur deficiency consequence of fGD

Question 19

Human health

Answer 19

Heavy metals in water, fish food + drinking water, high Cu levels

Question 20

Building materials

Answer 20

Metals and stone (marble) corroded

Question 21

1980s early 1990s

Answer 21

Dense acid hazes

Question 22

Short term solutions

Answer 22

Limit lakes and streams, low S fuels, Fluidized bed combustion system, FGD, vehicle, catalysts, lean burn engines

Question 23

FGD Flue Gas Desulphurisation

Answer 23

Wet scrubbing, 90% efficient in removing SOx, expensive, produce sludge - environmental problem, water demand 4000 gallons/ min, 1000 mega watts

Question 24

Fluidized bed combustion FBC

Answer 24

Efficient - upward air flow, boilers direct contact with bed - heat, transferred by conduction, lower temperature 3000 degrees, lees NOx produced, 90% S removed, emissions comparable to natural gas

Question 25

Integrated gasification/ combined cycle (IGCC)

Answer 25

Clean burning fuel, turbines driven by hot gases from coal combustion, waste heat used to produce steam, efficient electrical power, particulates trapped, low emissions, loss water used, emissions comparable to natural gas

Question 26

SOx

Answer 26

1-2% in SO3

Question 27

Anthropogenic SO2

Answer 27

SO2 from coal combustion, no effective way of removing S from coal matrix compared to oil and gas

Question 28

SO2 characteristics

Answer 28

Unstable at high temperature, independent of O2 in contrast to C. Most soluble of gaseous pollutants

Question 29

SO2 Fate

Answer 29

No catalyst - slow process, dry deposition or acid rain