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.

Air and Water – The Essential Survival Solutions

Some things bear repeating – more than once – and one of those is the statement of the honored Jacques Yves-Cousteau who warned, “Water and air, the two essential fluids on which all life depends, have become global garbage cans.”

There are many, in all locations, in all walks of life and with the best of intentions who are attempting to “clean up the mess.” A major problem is the lack of coordination of these efforts with the result that cross-purposes often wind up making matters worse instead of better.

So we have to “unpollute” both the air and our water supply while still providing those services to humanity that requires the consumption of energy. Not so easy – but not impossible.

Here are some scenarios that promise clean energy and air at greatly reduced cost:

Where falling water exists near salt water (oceans/seas) hydropower can be generated and used for desalination processes as well a normal export of electricity

Where a supply of natural gas is within reasonable distance of the salt water electricity can be generated with the gas and the waste heat recovered to run a desalination process.

Where falling water exists inland, away from salt water, hydropower can be used to provide cleaning services for contaminated “fresh” water that is not usable for drinking, washing or normal human functions.

Where geothermal energy is available and falling water is not, “geo” can be used for generation, desalination and decontamination: - wherever a heat source is needed.

And where are all these Hydro- and Geo- sources and are they available to be used?

Well, for starts there are 159 hydroelectric power plants in 34 states. 78% are using man-made dams to develop falling water, and not nature’s waterfalls.

In 16 continental states there are 85 waterfalls from 3 to 10 times higher than Niagara. (Hawaii has 41 more – big ones). Of course the volume of water passed for power generation is directly related to the width of the waterfall. We are studying this.

In Canada the roles are reversed. In 7 provinces there are 42 major waterfalls many times larger than Niagara. And while there are 55 hydroelectric power plants only 34% of them use man-made dams for falling water.

Message: there is potential on both sides of the border.

As to geothermal potentials, the search for geothermal fields is on – and proceeding with great success. California’s success is famous; it currently has over 2,500 Megawatts of installed capacity.

Idaho has installed its first plant, as has New Mexico. Nevada has 17 power plants with a total output of 318 MW. And in late 2008 Associated Press reported the discovery of a “massive geothermal field” in Utah which is being developed as we speak.

You must have noted by now that all of the geothermal activity is in the West. In areas that mostly don’t have falling water.

Soon we will go into much greater detail regarding the life-saving processes enabled by nature’s replaceable water and earth’s rather large supply of heat.

After all, America is a work in progress