From Sea To Shining Sea

…And all the rivers and lakes in between

Pure water - Drinking water - With air, as Jacques Cousteau has been often quoted, “the two essential fluids, on which all life depends, have become global garbage cans.”
We have seen the “Hubbard Peak” for oil described as the point in time at which the supply of oil begins to decline until, at the end, the supply is gone. (See our blog #3 “The Learning Curve and the Hubbert Peak” Jan 24, 2009)

We cannot imagine that the supply of water would ever be “used up.” After all, water covers 71 percent of the earth. The question is whether the supply of clean, drinkable, water would decrease while a world population continues to increase.

We will talk about the world-wide water situation later. Now we are looking at conditions in the United States and along the border with Canada.

Every day the US consumes, on average, some 345 Billion gallons of fresh water. That amount of water would cover the entire state of Rhode Island to a depth of one foot! And the breakdown of that figure is interesting – and important

136 Billion gallons go to irrigation
136 Billion go to electric power plants
47 Billion go to public and domestic supply
26 Billion for industrial use.

Of the public and domestic category about half goes to the domestic or home use. That works out to be about 75 gallons a day per person at home.

All this is based on a current US population of 303,824,640 in mid 2008. The population figure is expected to increase at the rate of 0.88% per year (accounting for births and deaths).

Using this data, by the year 2020 the US will need an additional 2,535,375,234 gallons of good water per day. And this does not account for any increase in agriculture needed to support the increased number of people.

Clearly the world faces a possible shortage of water due to increased population, uneven supplies of clean water and other factors. In our next report we will discuss some of the solutions as they apply in the US, Canada and around the world.

Here again, there is hope if proper action is taken.

Air & Water - Continued

When we last left our itinerant energists we and they were concerned about ensuring clean air and water for succeeding generations. We had reviewed some scenarios through which we might generate electricity and desalinate water at the same time or clean up some dirty water as another by-product of power generation.

Let’s look a little closer.

Scene 1 was the ideal where you had a usable waterfall near ocean or salt (brackish) water. A mile or so is not far away but there are not very many good sized waterfalls that close.

Scene 2 was where a supply of natural gas was fairly close to the shore. This is more likely than Scene 1 but the message for both of these scenes – is desalinization of the ocean and sea water.
Ocean water contains more than just salt and the chemistry of the category known as “seawater” will be examined later. Our purpose today is to determine the feasibility of providing generation of electricity coincident with the removal of salts and other matter from seawater or polluted land water to provide that most critical and desirable commodity – clean drinking water.

There are three basic methods for desalination; Vaporization (or distilling), Electrolytic Processing and Reverse Osmosis. We will look briefly at these and come to a surprising and pleasing recommendation.

There are several time honored means of distilling water to its purest state; boiling and flashing in order to create water vapor which is then condensed to usable liquid.

In electrodialysis, water is placed in a container with negative and positive electrodes to which the salt and other unwanted ions are attracted and collected for removal. This method was tried on a large scale in Saudi Arabia in 1958 but the extreme electrical demands made it impractical except where abundant energy was available.

The third and most promising system is the Reverse Osmosis Process (ROP). In this procedure water is subjected to great pressure which forces it through a special membrane which passes only pure water leaving behind more concentrated salt water.

The proven economics of ROP are what put the “icing on the cake.” While the flash distillation system costs about $4.00 per 1,000 gallons of product, ROP costs about $2.00 per 1,000. ($0.002).

An ROP motor 10 HP at 30 GPM costs $0.16 per hour to run.

30 GPM = 1800 Gallons per hour Power cost = $0.0000888 / gallon – not bad.

(For Comparison, tap water in NY and CT runs under $0.0007 per gallon – but that’s from reservoirs (rainwater). Super market bottled water runs $1.20 per gallon (90% for bottle, label & cap) = $0.12/gal water).

So, we can see that when taken together with energy from the cheap hydro power – or waste heat from gas fired generator – the generation/desalination process makes a lot of sense- especially in areas where fresh potable water is not available.

The major problem is – how do we get the processes to where they are most desperately needed? Please stay tuned.