Fossil Fuel(ed) Pollution

Cutting the topic

Questions

  1. What pollutants cause what risks? (Here: heat & oxides of carbon, sulfur & nitrogen)
  2. Can society judge "danger" level of pollutant and stay below it (locally/globally)?

First question is huge, requiring more research. Any answers are provisional. Scientifically, any risk estimate should be set high; political and economic pressures push toward low estimate.

The 2nd question echoes "tragedy of commons."

Heat

Thermodynamics teaches that any energy produced has accompanying heat, typically twice the energy.

Heat Islands. Cities are heat islands -- typically degrees warmer than rural area. Two reasons:
    (i) large consumption of energy and
   (ii) large surfaces absorb energy that reradiates or
         requires more cooling (energy!).
How bad is this?

Measuring Danger of Pollutants

Definitions: dose = potency × exposure
health risk = dose × exposed populations

Pollutant size matters
The nose can reject large particles and the lung can tolerate, if with irritation, smaller ones.
Dangerous sizes. Particles smaller than 2.5 µm are trapped in lungs. Soluble ones pass into blood. (PM2.5)

Health risk is hard to set. Concentration levels are low and potency is hard to measure. Different countries, states and cities set different levels. 2005 State of the Air, American Lung Assoc.

Many pollutants. In additions to the oxides of C, N & S, chemical processes supply dangerous elements: Pb, Cd, Ni, Be, Hg, As, V & Cr. Don't forget asbestos and polycyclic organic matter.

Where is safe? Rural areas are less polluted; less populated countries are better. But much pollution crosses boundaries.

Cleaning Up Atmospheric Pollutants

Few can doubt pollutants are hazardous to human health and to the whole ecoculture. The Clean Air Acts (1970, 1977, 1990) set standards administered by EPA.

For the "worst" five, sources are diverse:
PollutantPrimary Sources
SO2 fuel combustion
NO2fuel combustion, industrial processes, transportation
mercury (Hg)all combustion (fuel, stationary)
COtransportation
volatile organic compounds (VOC)stationary combustion, transportation

Worst states are OH, TX, PA, IN, KY

Sources are surprisingly broader

Largest sources of NO2 in troposphere (within 5-9 miles of earth) are burning biomass, automobiles and ships at sea!

Long distance travelers.
Saharan sand in Miami.
Ancient Asian dust in Greenland ice.
American pollution reaches Britain; by jet stream?
Asian haze over entire Northern Hemisphere.

Cleaning up our own mess

Are we succeeding? and at what cost?

The Phase I targets of CAAA largely met. NO2 is a disappointment &rarr even smaller decrease in ozone
National Air Quality 1989-1998
Pollutant CO2PbSO2 PM10NO2Ozone
% Reduction39563925144
Costs versus Benefits
199020002010
Est. Compliance Costs$7 B$26 B$27 B
Act. Compliance Costs$2 B$8 B$9 B
Estimated Benefits$110 B
( includes better health, visibility, better crops)

Why was cost less than anticipated?

Most cost uncertainties were associated with reducing SO2. In the 1980s when CAAA was under active discussion there were fears that

Mere $0.8 B/yr produced reduction greater than requested. Most utilities switched to low-sulfur coal, altho many went for expensive scrubbers. Also coal transport cost dropped. But the real surprise was ...

Pollution trading

Novel feature of 1990 CAAA was allowances: the right to emit ton of SO2 good in any year. At any year's end, company must "pay" as many allowances as its total emissions that year. The utilities could freely buy, sell, or bank allowances

Initially allowances granted yearly on historical basis. Renewable sources could earn allowances on basis of electricity generated, pollution avoided or set-asides (fraction of allowances).

Use.The 1992 price of $250/allowance dropped in a decade to $100. S-loaded Ohio sold many out of state.

Coal industry added western coal to its eastern and prospered. But historical lost of jobs in eastern coal mines continued.

First step of CAAA achieved

Goals met at a cost less than expected. Clever engineering gets most of the credit for new, effective technologies: fluidized bed burners, scrubbers in combustion discharge stacks. Emission (allowance) trading also allowed flexibility to keep costs low.

Fuel switching was the unexpected event that kept cost low. Low-sulfur coal from Wyoming and Montana (& its 0.5% sulfur) produced automatic reduction over midwest coal (4-6% sulfur). As we return to midwest coal in the future, either future technological breakthru or added costs (financial or environmental) await.



To cite this page:
Fossil Fuel(ed) Pollution
<http://www.physics.ohio-state.edu/~wilkins.5/energy/Resources/Lectures/fossil-pollut.html>
[Tuesday, 12-Dec-2017 03:15:53 EST]
Edited by: wilkins@mps.ohio-state.edu on Thursday, 11-Oct-2007 09:29:05 EDT