1. CE 326 Principles of Environmental Engineering
The Greenhouse Effect
CE 326 Principles of Environmental Engineering
Prof. Tim Ellis
January 26, 2009

2. Greenhouse Effect
Greenhouse effect: n_______ effect of the gases in earth’s atmosphere to trap incident solar radiation
earth is an average of ____ ̊C warmer than if no greenhouse effect
average earth temp would be ____ ̊C instead of current ____ ̊C

3. Global Warming
Global warming: t_______ that the accumulation of specific gaseous compounds is causing an uncontrollable increase in the earth’s temperature with potentially devastating g_______ effects

4. What is Known
naturally occurring greenhouse gases include w______ vapor, carbon dioxide, methane, nitrous oxide, and ozone
concentrations of most are increasing due to a______________ sources
water vapor is the most a__________ greenhouse gas, but its concentrations are closely related to global temperatures and are relatively constant
P_________ of high concentrations of CO2 in past history of the Earth have been accompanied by high temperatures at the Earth’s surface, and periods of low carbon dioxide had relatively low surface temperatures.

5. What is known sea level has risen 4-8 inches over the past century
global mean surface temperatures have increased C since the late 19th century
Greenhouse gases have long lifetimes, ranging from ____ years for methane to about _____ for carbon dioxide to ______ years for nitrous oxide.
Anthropogenic increases in these gases could influence the earth’s climate for many centuries.
The climate system has high i_______, primarily due to the long time scales of ocean dynamical processes.

6. What is known
S__________ particles that form from sulfur dioxide emitted primarily by the burning of coal contribute to local cooling although the magnitude is uncertain.
Decreases of ozone in the lower stratosphere have contributed to c_______ effects in that region.

7. What we think will happen
the stratosphere will continue to c_____ as CO2 concentrations r____. Ozone depletion will add to the cooling.
water vapor in the lower troposphere (0-3 km) will increase about ____% for every 1oC of warming. Relative humidities will stay approximately the same.
The warming of the last c_______ is consistent with model projections of global warming due to CO2 modified by the regional cooling effect of sulfate particles.

8. What we think will happen
D_________ of CO2 over pre-industrial levels (likely to occur in the later half of the 21st century unless emissions are significantly reduced) is projected to lead to a global warming of 1.5 to 4.5oC (2 - 8oF).
by 2100 we can expect temperature increase of _____oC to ____ oC.
Sea-level rise is most likely to be ___ (+/-25) cm by year 2100 with continued rise beyond that time highly likely. Continued high (quadrupled) CO2 could lead to ___+/- m rise in sea level.
Global mean precipitation will increase at ____ (+/-0.5)% per 1oC of warming.

9. Is there a scientific debate over man-made global warming?

10. Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect.

15. Melting the ice cap was a “solution”

16. Air Pollution Control Devices
A________ tower
B__________
C____________ Separator
aD___________ Bed
E______________ precipitator
V___________ scrubber

17. Air Pollution Control Devices
Absorption Tower (Packed Bed, Spray Tower, Wet Scrubber)
D________ of the pollutant gas to the surface of the liquid
T_______ across the gas/liquid interface (dissolution)
D_______ of the dissolved gas away from the interface into the liquid
Henry’s law:
P = HCl
where: P = equilibrium partial pressure of gas, kPa, H= Henry's law constant, kPa⋅m3/g
and Cl = concentration of pollutant gas in liquid phase, g/m3
want to maximize gas liquid contact by maximizing surface area
efficiency will be limited by the solubility of the pollutant

18. Baghouse same principle as the h_____ v______ c_______
bags are cleaned periodically as the p______ d___ across the bag becomes excessive (approximately every 2 hours)
cleaned by mechanical r_________ (used for shake-deflate design)
cleaned by h____ p_________ air jets (used for pulse jet design)
must be a d____ gas stream
potential f____ hazard
bag "r______" with time
develops a fine mat which helps to screen out particles
for p________ removal, or used in conjunction with F____ G____ D_____________ (FGD) applications

20. Cyclone Separator used for particulates larger than ___ μm
gas stream is accelerated through a s___ m_____, centrifugal force moves heavier particles out and down
as the d_____ of the cyclone is reduced, the efficiency increases (as does the pressure drop)
use of m________ tubes in parallel (multiclones) improves efficiency

21. Adsorption Bed surface p__________
p______ or c________ bond with the surface
adsorbents: activated c_____, activated a_____, silica gel, and others
1 ounce of activated carbon has a surface area of ______ acres
bed must be r________ prior to breakthrough

22. Electrostatic Precipitator
w____ in t____ or wire and p____ configurations
wet or dry, wet cleaned by w______ s____, dry by rapping, can be cleaned while in service
c_______ wire imparts an electrical charge (neg), particles are attracted to charged (pos) collecting plates
high p__________ removal efficiencies possible

23. Venturi Scrubber
velocity of gas is a_________ by a factor of four in the throat section where nozzles inject water or solution
high velocity causes a__________ of liquid
pressure drop following the t________ section creates a lot of turbulence resulting in good intermixing
requires s_________ (e.g., cyclone) following venturi to collect particles and liquid

24. T___________ Incineration