Electricity, Heat Engine, Superheated Dry Steam, Coal-Fired Power Plant, Geothermal Power Plant and Waste-to-Energy Plant

Posted by PITHOCRATES - November 7th, 2012

Technology 101

(Originally published August 1, 2012)

Geothermal Power Plants and Waste-to-Energy Plants each produce less than Half of 1% of our Electricity

We produce the majority of our electricity with heat engines.  Where we boil water into steam to spin a turbine.  Or use the expanding gases of combustion to spin a turbine.  The primary heat engines we use are coal-fired power plants, natural gas-power plants and nuclear power plants.  The next big source of electricity generation is hydroelectric.  A renewable energy source.  In 2011 it produced less than 8% of our electricity.  These sources combined produce in excess of 95% of all electricity.  While renewable energy sources (other than hydroelectric) make up a very small percentage of the total.  Wind power comes in under 3%.  And solar comes in at less than 0.2% of the total.  So we are a very long way from abandoning coal, natural gas and nuclear power.

Two other renewable energy sources appear to hold promise.  Two heat engines.  One powered by geothermal energy in the earth.  The other by burning our garbage.  In a waste-to-energy plant.  These appear attractive.  Geothermal power appears to be as clean as it gets.  For this heat isn’t man-made.  It’s planet-made.  And it’s just there for the taking.  But the taking of it gets a little complicated.  As is burning our trash.  Not to mention the fact that few people want trash incinerators in their neighborhoods.  For these reasons they each provide a very small percentage of the total electric power we produce.  Both coming in at less than half of 1%.

So why steam?  Why is it that we make so much of our electrical power by boiling water?  Because of the different states of matter.  Matter can be a solid, liquid or a gas.  And generally passes from one state to another in that order.  Although there are exceptions.  Such as dry ice that skips the liquid phase.  It sublimates from a solid directly into a gas.  And goes from a gas to a solid by deposition.  Water, though, follows the general rule.  Ice melts into water at 32 degrees Fahrenheit (or 0 degrees Celsius).  Or water freezes into ice at the same temperature.  Water vaporizes into steam at 212 degrees Fahrenheit (or 100 degrees Celsius).  Or steam condenses into water at the same temperature.  These changes in the state of matter are easy to produce.  At temperatures that we can easily attain.  Water is readily available to vaporize into steam.  It’s safe and easy to handle.  Making it the liquid of choice in a heat engine.

Today’s Coal-Fired Power Plant pulverizes Coal into a Dust and Blows it into the Firebox

A given amount of water will increase about 1600 times in volume when converted to steam.  It’s this expansion that we put to work.  It’s what pushed pistons in steam engines.  It’s what drove steam locomotives.  And it’s what spins the turbines in our power plants.  The plumes of steam you see is not steam, though.  What you see is water droplets in the steam.  Steam itself is an invisible gas.  And the hotter and drier (no water) it is the better.  For water droplets in steam will pit and wear the blades on a steam turbine.  Which is why the firebox of a coal-fired plant reaches temperatures up to 3,000 degrees Fahrenheit (about 1,650 degrees Celsius).  To superheat the steam.  And to use this heat elsewhere in the power plant such as preheating water entering the boiler.  So it takes less energy to vaporize it.

To get a fire that hot isn’t easy.  And you don’t get it by shoveling coal into the fire box.  Today’s coal-fired power plant pulverizes coal into a dust and blows it into the firebox.  Because small particles can burn easier and more completely than large chunks of coal.  As one fan blows in fuel another blows in air.  To help the fire burn hot.  The better and finer the fuel the better it burns.  The better the fuel burns the hotter the fire.  And the drier the steam it makes.  Which can spin a turbine with a minimum of wear.

In a geothermal power plant we pipe steam out of the ground to spin a turbine.  If it’s hot enough.  Unfortunately, there aren’t a lot of geothermal wells that produce superheated dry steam.  Which limits how many of these plants we can build.  And the steam that the planet produces is not as clean as what man produces.  Steam out of the earth can contain a lot of contaminants.  Requiring additional equipment to process these contaminants out.  We can use cooler geothermal wells that produce wet steam but they require additional equipment to remove the water from the steam.  The earth may produce heat reliably but not water.  When we pipe this steam away the wells can run dry.  So these plants require condensers to condense the used steam back into water so we can pump it back to the well.  A typical plant may have several wells piped to a common plant.  Requiring a lot of piping both for steam and condensate.  You put all this together and a geothermal plant is an expensive plant.  And it is a plant that we can build in few places.  Which explains why geothermal power makes less than half of 1% of our electricity.

We generate approximately 87% of our Electricity from Coal, Natural Gas and Nuclear Power

So these are some the problems with geothermal.  Burning trash has even more problems.  The biggest problem is that trash is a terrible fuel.  We pulverize coal into a dust and blow into the firebox.  This allows a hot and uniform fire.  Trash on the other hand contains wet mattresses, wet bags of grass, car batteries, newspapers and everything else you’ve ever thrown away.  And if you ever lit a campfire or a BBQ you know some things burn better than other things.  And wet things just don’t burn at all.  So some of this fuel entering the furnace can act like throwing water on a hot fire.  Which makes it difficult to maintain a hot and uniform fire.  They load fuel on a long, sloping grate that enters the furnace.  Mechanical agitators shake the trash down this grate slowly.  As the trash approaches the fire it heats up and dries out as much as possible before entering the fire.  Still the fire burns unevenly.  They try to keep the temperature above 1,000 degrees Fahrenheit (about 538 degrees Celsius) .  But they’re not always successful.

They can improve the quality of the fuel by processing it first.  Tearing open bags with machinery so people can hand pick through the trash.  They will remove things that won’t burn.  Then send what will burn to a shredder.  Chopping it up into smaller pieces.  This can help make for a more uniform burn.  But it adds a lot of cost.  So these plants tend to be expensive.  And nowhere as efficient as a coal-fired power plant (or nuclear power plant) in boiling water into superheated dry steam.  Also, raw trash tends to stink.  And no one really knows what’s in it when it burns.  Making people nervous about what comes out of their smoke stacks.  You add all of these things up and you see why less than half of 1% of our electricity comes from burning our trash.

This is why we generate approximately 87% of our electricity from coal, natural gas and nuclear power.  Coal and nuclear power can make some of the hottest and driest steam.  But making a hot fire or bringing a nuclear reactor on line takes time.  A lot of time.  So we use these as baseload power plants.  They generate the supply that meets the minimum demand.  Power that we use at all times.  Day or night.  Winter or summer.  They run 24/7 all year long.  Natural gas plants add to the baseload.  And handle peak demands over the baseload.  Because they don’t boil water they can come on line very quickly to pickup spikes in electrical demand.  Hydroelectric power shares this attribute, too.  As long as there is enough water in the reservoir to bring another generator on line.  The other 5% (wind, solar, geothermal, trash incinerators, etc.) is more of a novelty than serious power generation.

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Electricity, Heat Engine, Superheated Dry Steam, Coal-Fired Power Plant, Geothermal Power Plant and Waste-to-Energy Plant

Posted by PITHOCRATES - August 1st, 2012

Technology 101

Geothermal Power Plants and Waste-to-Energy Plants each produce less than Half of 1% of our Electricity

We produce the majority of our electricity with heat engines.  Where we boil water into steam to spin a turbine.  Or use the expanding gases of combustion to spin a turbine.  The primary heat engines we use are coal-fired power plants, natural gas-power plants and nuclear power plants.  The next big source of electricity generation is hydroelectric.  A renewable energy source.  In 2011 it produced less than 8% of our electricity.  These sources combined produce in excess of 95% of all electricity.  While renewable energy sources (other than hydroelectric) make up a very small percentage of the total.  Wind power comes in under 3%.  And solar comes in at less than 0.2% of the total.  So we are a very long way from abandoning coal, natural gas and nuclear power.

Two other renewable energy sources appear to hold promise.  Two heat engines.  One powered by geothermal energy in the earth.  The other by burning our garbage.  In a waste-to-energy plant.  These appear attractive.  Geothermal power appears to be as clean as it gets.  For this heat isn’t man-made.  It’s planet-made.  And it’s just there for the taking.  But the taking of it gets a little complicated.  As is burning our trash.  Not to mention the fact that few people want trash incinerators in their neighborhoods.  For these reasons they each provide a very small percentage of the total electric power we produce.  Both coming in at less than half of 1%.

So why steam?  Why is it that we make so much of our electrical power by boiling water?  Because of the different states of matter.  Matter can be a solid, liquid or a gas.  And generally passes from one state to another in that order.  Although there are exceptions.  Such as dry ice that skips the liquid phase.  It sublimates from a solid directly into a gas.  And goes from a gas to a solid by deposition.  Water, though, follows the general rule.  Ice melts into water at 32 degrees Fahrenheit (or 0 degrees Celsius).  Or water freezes into ice at the same temperature.  Water vaporizes into steam at 212 degrees Fahrenheit (or 100 degrees Celsius).  Or steam condenses into water at the same temperature.  These changes in the state of matter are easy to produce.  At temperatures that we can easily attain.  Water is readily available to vaporize into steam.  It’s safe and easy to handle.  Making it the liquid of choice in a heat engine.

Today’s Coal-Fired Power Plant pulverizes Coal into a Dust and Blows it into the Firebox

A given amount of water will increase about 1600 times in volume when converted to steam.  It’s this expansion that we put to work.  It’s what pushed pistons in steam engines.  It’s what drove steam locomotives.  And it’s what spins the turbines in our power plants.  The plumes of steam you see is not steam, though.  What you see is water droplets in the steam.  Steam itself is an invisible gas.  And the hotter and drier (no water) it is the better.  For water droplets in steam will pit and wear the blades on a steam turbine.  Which is why the firebox of a coal-fired plant reaches temperatures up to 3,000 degrees Fahrenheit (about 1,650 degrees Celsius).  To superheat the steam.  And to use this heat elsewhere in the power plant such as preheating water entering the boiler.  So it takes less energy to vaporize it.

To get a fire that hot isn’t easy.  And you don’t get it by shoveling coal into the fire box.  Today’s coal-fired power plant pulverizes coal into a dust and blows it into the firebox.  Because small particles can burn easier and more completely than large chunks of coal.  As one fan blows in fuel another blows in air.  To help the fire burn hot.  The better and finer the fuel the better it burns.  The better the fuel burns the hotter the fire.  And the drier the steam it makes.  Which can spin a turbine with a minimum of wear.

In a geothermal power plant we pipe steam out of the ground to spin a turbine.  If it’s hot enough.  Unfortunately, there aren’t a lot of geothermal wells that produce superheated dry steam.  Which limits how many of these plants we can build.  And the steam that the planet produces is not as clean as what man produces.  Steam out of the earth can contain a lot of contaminants.  Requiring additional equipment to process these contaminants out.  We can use cooler geothermal wells that produce wet steam but they require additional equipment to remove the water from the steam.  The earth may produce heat reliably but not water.  When we pipe this steam away the wells can run dry.  So these plants require condensers to condense the used steam back into water so we can pump it back to the well.  A typical plant may have several wells piped to a common plant.  Requiring a lot of piping both for steam and condensate.  You put all this together and a geothermal plant is an expensive plant.  And it is a plant that we can build in few places.  Which explains why geothermal power makes less than half of 1% of our electricity.

We generate approximately 87% of our Electricity from Coal, Natural Gas and Nuclear Power

So these are some the problems with geothermal.  Burning trash has even more problems.  The biggest problem is that trash is a terrible fuel.  We pulverize coal into a dust and blow into the firebox.  This allows a hot and uniform fire.  Trash on the other hand contains wet mattresses, wet bags of grass, car batteries, newspapers and everything else you’ve ever thrown away.  And if you ever lit a campfire or a BBQ you know some things burn better than other things.  And wet things just don’t burn at all.  So some of this fuel entering the furnace can act like throwing water on a hot fire.  Which makes it difficult to maintain a hot and uniform fire.  They load fuel on a long, sloping grate that enters the furnace.  Mechanical agitators shake the trash down this grate slowly.  As the trash approaches the fire it heats up and dries out as much as possible before entering the fire.  Still the fire burns unevenly.  They try to keep the temperature above 1,000 degrees Fahrenheit (about 538 degrees Celsius) .  But they’re not always successful.

They can improve the quality of the fuel by processing it first.  Tearing open bags with machinery so people can hand pick through the trash.  They will remove things that won’t burn.  Then send what will burn to a shredder.  Chopping it up into smaller pieces.  This can help make for a more uniform burn.  But it adds a lot of cost.  So these plants tend to be expensive.  And nowhere as efficient as a coal-fired power plant (or nuclear power plant) in boiling water into superheated dry steam.  Also, raw trash tends to stink.  And no one really knows what’s in it when it burns.  Making people nervous about what comes out of their smoke stacks.  You add all of these things up and you see why less than half of 1% of our electricity comes from burning our trash.

This is why we generate approximately 87% of our electricity from coal, natural gas and nuclear power.  Coal and nuclear power can make some of the hottest and driest steam.  But making a hot fire or bringing a nuclear reactor on line takes time.  A lot of time.  So we use these as baseload power plants.  They generate the supply that meets the minimum demand.  Power that we use at all times.  Day or night.  Winter or summer.  They run 24/7 all year long.  Natural gas plants add to the baseload.  And handle peak demands over the baseload.  Because they don’t boil water they can come on line very quickly to pickup spikes in electrical demand.  Hydroelectric power shares this attribute, too.  As long as there is enough water in the reservoir to bring another generator on line.  The other 5% (wind, solar, geothermal, trash incinerators, etc.) is more of a novelty than serious power generation.

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Carbon, Carbon Cycle, Crude Oil, Petroleum, Hydrocarbons, Oil Refinery, Cracking, Sweet Crude, Sour Crude, Gasoline and Diesel Engines

Posted by PITHOCRATES - April 25th, 2012

Technology 101

Crude Oil is made from Long Chains of Carbon Atoms Bonded Together with a lot of Hydrogen Atoms Attached Along the Way

Carbon.  It’s everywhere.  And in everything.  Like all matter it cannot be created.  Or destroyed.  It just changes.  As it creates the circle of life.  The carbon cycle.  Plants and trees absorb carbon out of the atmosphere.  And converts it into biomass.  Into wood.  And into animal food.  Where the digestive system converts it into carbon-based living flesh and blood.  That exhales carbon.  Plants absorb carbon and release oxygen.  Plants can’t grow without carbon.  And we can’t breathe without plants growing.  Carbon is constantly changing.  But never created.  Or destroyed.  From diamonds to pencils.  From sugar to carbonated soda.  From plastics to human beings.  It’s everywhere.  And everything.  Why, it’s life itself.

Carbon is a time traveler.  Carbon that once traveled through the atmosphere disappeared millions of years ago.  Buried underneath the surface of the earth.  Under intense heat and pressure.  Plankton and algae and other biomasses decayed until there was almost nothing left but carbon atoms.  Long chains of carbon atoms.  Forming great, restless pools of black goo beneath the surface.   Waiting for the modern world to arrive.  Waiting for the internal combustion engine.  The jet engine.  And plastics.  When they could be reborn.  And see the light of day again.

Crude oil.  Petroleum.  Black gold.  Texas tea.  Hydrocarbons.  Long chains of carbon atoms bonded together with a lot of hydrogen atoms attached along the way.  In the ground they’re mostly long chains.  When we get them above ground we can break those chains into different lengths.  And create many different things.  C16H34 (hexadecane).  C9H20 (nonane).  C8H18 (octane).  C7H16 (heptane).  C5H12 (pentane).  C4H10 (butane).  C6H6 (benzene).  CH4 (methane).  Some of these you may be familiar with.  Some you may not.  Methane is a flammable gas.  Hydrocarbon chains from pentane to octane make gasoline.  Hydrocarbon chains from nonane to hexadecane make diesel fuel, kerosene and jet fuel.  Chains with more carbon atoms make lubricants.  Chains with even more carbon atoms make asphalt.  While chains with 4 carbon atoms or less make gases.  All these things made from the same black goo.  A true marvel of Mother Nature.  Or God.  Depending on your inclination.

Older Coastal Refineries make more Expensive Gasoline than the Newer Refineries due to the Availability of Sweet versus Sour Crude

Another great carbon-based product it bourbon.  Made from a corn sour mash.  We heat this and the alcohol in it boils off.  That is, we distill it.  We run this gas through a coiling coil and it condenses back into a liquid.  And after a few more steps we get delicious bourbon whiskey.  Distilleries give tours.  If you get a chance you should take one.  You won’t get to sample any of the distilled spirits (insurance reasons).  But you will get a feel for what an oil refinery is.

An oil refinery works on the same principles.  Boil and condense.  And cracking.  Cracking those long hydrocarbon chains apart into all those different chains.  Long and small.  Into liquids and gases.  Even solid lubricants and asphalt.  All made possible because of their different boiling points.  The gases having lower boiling points.  The solids having higher boiling points.  And the liquids having boiling points somewhere in between.

Refineries are complex processing plants.  Not only because of all those different hydrocarbon chains.  But because of the crude oil introduced to these plants.  For there is light sweet crude.  And heavier sour crude.  The difference being the additional stuff that we need to remove.  Such as sulfur.  An environmental problem.  So we have to remove as much of it as possible during the refining process to meet EPA standards.  The sweet crudes are lower in sulfur.  Making them the crude of choice.  But this has also been the most popular crude through the years.  So its resources are dwindling.  Making it more expensive.  As are all the products refined from it.  Especially gasoline.  The more sour crudes have higher sulfur content.  And require more refining steps to remove that sulfur.  Which means additional refinery equipment.  So the older refineries that were refining the light sweet crude can’t refine the heavier sour crudes.  Which is why the refineries along the coasts make more expensive gasoline than the newer ones in the interior refining the heavier sour crudes.  Due to the availability of sweet crude versus sour crude.

The Modern World is brought to us by a Complex Economy which is brought to us by Petroleum

One of the main uses of refined crude oil is fuel for internal combustion engines.  In particular, gasoline engines and diesel engines.  Which are very similar.  The difference being the mode of ignition.  And, of course, the fuel.  Gasoline engines compress an air-fuel mixture in the cylinder.  At the top of the compression stroke a spark plug ignites this highly compressed and heated mixture.  Sending the piston down.  If the combustion occurs too early it could place undo stresses on the piston connecting rods and the crank shaft.  By trying to send the piston down when it was coming up.  Causing a knocking sound.  Which is a bad sound to hear.  And if you hear it you should probably make sure you’re using the right gasoline.  If you are you need to have you car serviced.  Because continued knocking may break something.  And if it does your engine will work no more.  So this is where octane comes in the blending of gasoline.  It’s expensive.  But the more of it in gasoline the higher the compression you can have.  And the less knocking.  Which is its only purpose.  It doesn’t give you any more power.  The higher compression does.  Which the higher octane allows.  Using the higher octane gas in a standard compression engine won’t do anything but waste your hard earned money.

And speaking of higher compression engines, that brings us to diesel engines.  Which are similar to gasoline engines only they operate under a higher compression.  And don’t use spark plugs.  These engines compress air only.  Which allows the higher compression without pre-ignition.  At the top of their compression stroke a fuel injector squirts diesel fuel into the hot compressed air where it combusts on contact.  Diesel fuel has a higher energy content than gasoline.  Meaning for the same volume of fuel diesel can take you further than gasoline.  Which is why trucks, locomotives and ships use diesel.  But diesel tends to pollute more.  The smell and the soot kept diesel out of our cars for a long time.  As well as the difficulty of starting in cold climates.  Advanced computer controlled systems have helped, though, and we’re seeing more diesel used in cars now.

The modern world is brought to us by a complex economy.  Where goods and raw materials traverse the globe.  To feed our industries.  And to ship our finished goods.  Which we put on trucks, trains, ships and airplanes.  None of which would be possible without a portable, stable, energy-dense fuel.  That only refined petroleum can give us.  It’s better than animal power.  Water power.  Wind power.  Or steam power.  For there is nothing that we can use in our trucks, trains, ships and airplanes other than refined petroleum products today that wouldn’t be a step backwards in our modern world.  Nothing.  Making petroleum truly a marvel of Mother Nature.  Or God.  Depending on your inclination.

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