Fossil Fuel Resources

Read Chp 7 in H&K

Read Chp 10 in Bodansky

See www.me.washington.edu/~malte/engr341

Notes with Links, Ch 10 and 11/1/00

Fossil fuels (oil, nat gas, and coal) account for 85% of energy consumption in USA and about 75% in world.

Cheap oil, the fuel most widely used (35-40% of total consumption), in the fuel in shortest supply. Could become scarce in your lifetime.

Average annual growth rates in USA for the 1991-99 period:

For plots, see http://courses.washington.edu/envir203

Lecture for F-3/30

See McKelvey diagram, Fig 7.1, in H&K text.

This is a schematic of the decreasing cost of energy versus the increasing uncertainty of finding the energy resource.

Reserves: "Those resources that are well known through geologic exploration and are recoverable at current prices with current technology."

Reserves are estimated by the energy industry. May be under-estimated to avoid taxes.

See Table 7.1 for proved reserves of oil, nat gas, coal, tar sands, and shale oil in the USA and world. Note on an energy basis oil reserves and nat gas reserves are similar.

Total resource: Estimate the amount of resource (such as oil) per unit volume in each type of geological formation. Then from knowledge of the geological formations existing, estimate the total resource. Bodansky calls the total oil resource the "oil-in-place". The part of this oil-in-place that is thought to be economically recoverable is called the "recoverable resource", or the "economic resource", or the "ultimate resource", or simply the "resource". Note, this definition includes resource not yet discovered. That is, we are pretty sure it is there, but we are not sure where. This definition includes the resource already used and that remaining (the futures).

Behavioristic approach to estimating the resource. See Figs 1.12 (for USA oil) and 7.3 (for world oil). These curves are duel to M King Hubbert. Bodansky in Section 10.2.3 calls these "logistic" curves.

Idea:

Rate of use (or production) of a resource is proportional to Demand times Supply.

Demand is proportional to Dependency on the resource. Dependency is great for a resource widely used.

Let Q = cumulative amount of the resource used (eg, oil).

Let Q¥ = resource (including the part already used).

Then:

dQ/dt = kQ(Q¥ - Q)

Integration of the differential equation gives:

Q/ (Q¥ - Q) = exp[kQ¥ (t – t0)]

where k = rate constant and t0 = time when the peak rate of use occurs.

When t = t0,

dQ/dt)peak = ¼ k Q¥ 2

The parameters k and t0 are estimated by fitting the logistic curve to the actual consumption data.