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Wednesday, December 4, 2019

Clearing mines

Clearing mines and other ordinance left on the world's fields of battle is dangerous and expensive and is taking far too long for the farmers who want to get back on their land and farm in safety. Doing it by hand as is done at present is so slow that it will never be finished. I don't know if it is true but I have read that some first world war battle fields are still being cleared. All the un-exploded ordinance and especially the mines are exerting a huge toll in life and limb among the innocent citizens of the area who didn't want the war in the first place. Why can't we mechanize mine clearing.

Start with a main battle tank such as the British Centurion, Israeli Merhava or Soviet T series tank. Strip it of the turret and gun and every bit of equipment that was necessary for battle. With the reduced weight we now have lots of spare power available. Weld on a cupola where the turret was located that can withstand the shrapnel from an exploding tank mine and equip it with the standard prism system so that the driver can drive in safety from within the tank.
 Image result for image british centurion tank

Connect a realy grunty hydraulic motor to the main engine. Now we are ready to start.

Build a cylinder with teeth/scoops which is a little longer than the width of the tank and suspend it on arms coming from the sides of the tank. The arms raise and lower the cylinder hydraulically to control the depth of cut. This is a little like the huge equipment that harvests coal but is a cylinder, not a wheel.
 Image result for surface Coal mining equipment image

 The cylinder is situated in front of the tank and rotates with the forward side moving upwards. A hydraulic motor rotates the cylinder at, say, about 60 revolutions per minute. The cylinder is robust enough to take the explosion of a tank mine. Remember, the mine is no longer tamped and its force can blow upwards and outwards. The cylinder scoops up the top, say, 50cm of soil and pushes it backwards over the top of the cylinder, dropping it into a vibrating grid made of really grunty steel bars. The mesh size is such that it catches tank mines. anti-personell mines and cluster munition. The grid has an orbital vibration so that anything caught is bounced off to one side and dropped in a windrow beside the tank. Anything surviving this rough treatment is exploded by a sapper.

Below this grid is a second grid of finer mesh that catches anything down to a M16 bullet. This material is also conveyed to the same side of the tank and sieved out material is dropped in the same windrow. The soil drops between the cylinder and the  front of the tank.

Any valuables including brass go to the owners of the fields. They deserve some recompense for what they have suffered.

The driving compartment is air conditioned. Most of the battle areas of the world are tropical and the driver must be comfortable to be able to operated for many hours a day. Make the driving space like a modern agricultural tractor.  Remember, with all the extraneous weight removed, we have lots of spare power.

While we are at it, lets analyze the soil and if it needs something like lime or some nutrient to make it fertile lets add it to the discharging soil. Attach a couple of hoppers to the back of the tank and a metering system to add whatever is necessary to the soil. Once again, the farmers deserve something extra for their long suffering.

 Image result for image fertilizer spreading equipment

A grader attached to the mine clearing crew finishes off the cleared field.

 Image result for image graders operating

All finished areas are, of course, entered in a GIS map using GPS technology so in years to come, it is clear which areas have been cleared. Start with the most arable land so that the farmers can get on with their lives.

Surely the engineers that came up with battle tanks with all their sophistication could come up with a machine to clear mines rapidly and effectively. How great would it be if one of the engines of destruction, the main battle tank, did some good instead of harm.

Saturday, October 26, 2019

Touch Screens in cars

Touch Screens in cars are a really, really bad idea.  Look at all the kerfuffle world wide about using a cell phone in a car.  At least with a cell phone, you're likely to be holding it up by the steering wheel as you dial or touch the green icon to answer the phone.  Or, shudder, you type in some destination into the navigator.  Some part of your vision still records what is going on on the road.  With a touch screen you have to take your eyes right off the road to operate them and it is not a one touch operation.  You have to do multiple touches to get to the application you want to use.
 Image result for image touch screen in car

Remember those old car radios.  There was a nob on one side to turn it on and off and to increase or decrease the volume.  There was another nob on the other side to tune in the stations.  Then between the two nobs were five or six pull-out, push-in buttons.  You pulled one out, tuned the radio and then pushed it back in again.  From then on if you wanted that station you just pushed that button.  Ditto with the rest of the pull-out buttons.  You had five or six different stations all at your finger tips, all without taking your eyes off the road.
 Image result for image old car radios

Or come forward a little to a more modern radio.  Up at one corner is a toggle switch which you can feel.  Once more no need to take your eyes off the road.  Push it quickly and the radio tunes up or down  depending on which side of the button you pushed.  Hold it down for 2 seconds until you hear a beep and it will run up or down the radio spectrum until it finds the next channel.  On the other side is a second tactile toggle button.  Push one side and the volume goes up, the other side and the volume goes down.  In all of this no need to take your eyes off the road.

A more luxurious system has all the tactile buttons on the steering wheel.

If we are all up tight about cell phones, how much more dangerous are touch screens.

And don't get me started on autonomous cars.  Besides the fact that I really like driving, they seem to me to be a bad idea.

Have you ever heard of a soft-ware program that couldn't be hacked.  Recently we have had the UK health system computers hacked and bank after bank.  If anyone should have state of the art protection surly it is these institutions.  Just imagine what happens when some warped 14 year old genius in his mom's basement manages to hack into the system and shut down one of the functions.  Whole cities come to a stand still.  And this could happen even if only a small percent of the cars are autonomous.

Worse still, have you being paying attention to the revelations of Snowdon and Manning.  The secret services have little or no inhibitions against causing collateral damage (killing innocent bystanders) and being human they also make mistakes.  Imagine they have decided that a certain car is carrying a terrorist they want to eliminate.  They send the car into a tree or over a cliff at high speed.  Or they targeted your car by mistake or perhaps they send the car into oncoming traffic and you just happen to be on the other side of the road.

In addition, with your car continually connected to the internet of things (G5), they always know where you are and what you are doing.  And don't give me that old saw that if you are not doing anything wrong you have no problems.  That is such a  discredited a argument that it doesn't deserve another paragraph. This really is a Big Brother scenario.

Have you ever heard of a computer program that didn't need patches and upgrades to fix glitches that the programmers didn't anticipate.  In the first death in a self driving car, the computer didn't recognize a truck coming from the side and thought it was a road sign.  We don't need programmers experimenting with our lives as we travel down the road at highway speeds.

What do I want in a car.  I want all the great engineering that is coming out in Electric cars but none of the bells and whistles.  And I want the lower price that comes with this.  I want any controls to be tactile, not touch screen.  And I want the pleasure of driving my own car.  This isn't for everyone but I bet there is a huge market out there for such a car. If I need navigation, I'll velcro my phone on to the dash board.

If you want to wow me, make all surfaces of the car generate electricity when they are in the sun.  No, I don't expect to be able to drive just on the power the skin of my car generates but it will be a nice little bonus and might get me home. when  I have forgotten to charge up when I should have.  Some years ago a home made electric car visited us here in New Zealand.  He pulled a trailer and the top of the trailer was covered with solar panels.  He said he could carry on driving at 20k/hr if it was a sunny day but his batteries were flat.

Wednesday, October 2, 2019

A new Battery technology

What would you say to a battery for static use that could be completely charged and discharged with no degradation of it's capacity over time.  A battery that today will hold ten kWh and in one year it will still have the same capacity. A battery that has no self discharge and so if you charge it up and come back in a year it will still have the same charge. Better still, a battery that uses very common cheap materials in it's chemistry so should be pretty cost-effective when production ramps up. And none of it's materials (like Cobalt) are produced in countries that use child labor.

This is the hype around a new battery chemistry and they are already in production.

Now just a disclaimer here.  I am basing this article on the literature around this battery and have no experience myself in owning such a battery.  In fact, they are in the stage of ramping up production and I haven't been able to find what they cost at present or what they project the price will be in the future.

This is a flow battery meaning that a fluid is pumped through the battery that does 'the  necessary'.  It is a plating battery that plates Zinc onto 'shelves' of plastic (dosed with carbon, I believe, for conductivity) during the charging phase.  The Zinc is stripped from the plates back into solution during discharge.  The other ion is Bromine so this is a Zinc bromide battery.

It has been developed in Australia and production at present is quite small, measured in hundreds per week  but, clearly, if it's promise is fulfilled, production is bound to climb as revenue flows in from initial sales.

The cycle efficiency of this battery is said to be 75-80%.  If you put in a kWh* you will get an effective 0.75kWh back out.

* A kilowatt hour - in other words, a kWh could provide one kW for one hour (or half a kW for two hours etc.)

A disadvantage (minor) is that the plates must be stripped every three days to stop the build up of spicules of Zinc that would damage adjacent plates. In other words it must be totally discharged.  Apparently this is automated so it happens without your intervention.  I'm not sure what happens to the electricity which will be produced during a full discharge cycle but I can imagine it will be fed into the grid with the amount you earn from this being determined by the policy of your power company.

If you have more than one of these 10kWh batteries, power resulting from the stripping cycle could be fed into the other half of your batteries.  While operating,,,, one battery (or bunch of batteries) would be in use (discharging) while the other half would be charging.

Incidentally, some recent information on the mega Lithium ion battery provided to Australia by Tesla has shown some interesting results.  This battery holds 100mWh* of power and cost $66m.  It's first anniversary will be in November and based on the present rate of return, it will have returned $20m by that time.  A 30% pa rate of return.  Wow!!!  It is installed in a large wind farm so presumably the earnings are due to not having to waste wind-generated power when the grid is producing all it needs.  The power is then sent to the grid when the demand and hence the price is high.

* megawatt hour - one mW equals 1000kW

They could also be earning by buying power to charge the battery when power from the grid is in excess and hence cheap, and selling it back when there is a demand.

Another interesting wrinkle is that the response time of the battery is so fast when demand increases or decreases, unlike other sources of electricity, that the quality of the power is increased.  In other words the voltage and frequency are stabilized, unlike when other generation sources  with slower response times are cut in and out of the grid.

Presumable this quality improvement would be the same with any battery system including the ZnBr battery.

Of course, Li ion batteries degrade over time and this is partially compensated for by battery management systems that don't ever charge up the battery to it's full capacity or discharge it to zero.  This slows but does not stop the decrease in it's capacity over time.  Of course it means that the effective capacity of a Li battery is less than it's rated capacity.  Note that Tesla, in an emergency, can send a signal to her cars, allowing the owners to use the full capacity of the battery (at the expense of the longevity of the battery).

This points up the great advantage of the ZnBr technology over the Li technology.  The cost over time is bound to be less, and even more so when the price of the Zn battery per kWh becomes less than the cost of the Li battery as it is bound to do because of it's less expensive materials.  Note that this technology is only for static applications.  The Li ion battery is still king for mobile applications.

ps.  There is a Zinc bromide gel battery in the works.  No idea what it's characteristics are.

Thursday, September 26, 2019

Arctic Tsunamis

When a piece of the edge of the continental shelf breaks loose and plunges into the abys, localized but quite severe Tsunamis can result.  They are localized because usually the slump is only a few kilometers wide - basically a point source in world geography terms and, as the wave spreads out over a greater and greater circumference, the energy decreases in proportion to the distance from the source.

By contrast the waves that travel across oceans and cause huge damage at far distant locations are the ones produced by earthquakes in which one side of a long crack (fault) in the sea bottom suddenly rises or falls. A good example of that was the boxing day earthquake off the coast of Summatra on December 26, 2004        .

That is not to say that these point source earth quakes, caused by a slump at the edge of the continental shelf, do not travel far distances.  They do.  But their energy decreases quickly with distance from the source.  So what does this have to do with the Arctic Ocean.  First a little background.

Most continents are surrounded by a continental shelf.  This is a relatively shallow gently sloping area from the shore to the continental drop off where the continental slope starts.    At the drop off, the gradient increases sharply and the Continental Slope leads down to the abyss.  The continents surrounding the Arctic ocean are no exception and the Continental Shelf off Russia is particularly wide.

Permafrost is frozen earth and extends downward to a depth of from a few meters to kilometers, depending on location and past history.  Under thick ice sheets there is no permafrost.  Under the Antarctic, for instance,the bottom of the ice hovers around zero degrees C and there are streams and lakes of liquid water.  Ice is a  good insulator  and geological heat seeping up from the earth has to transverse kilometers of ice before it reaches the air at many tens of degrees below freezing.

It has been found that the land under the Continental shelves of America and Russia in the Arctic ocean have thick layers of permafrost.  Therefore they were not glaciated during the last continental glaciation when sea level was as much as 120m lower at the maximum extent of the ice.  I know this sounds odd.  I find it so as well but if it was covered by an continental ice sheet there would not be permafrost. Perhaps the ice sheet left the continental shelf early in the melt and the permafrost was created before the ocean inundated the shelf.

There is another type of 'permafrost'.  It occurs when methane is in contact with water under pressure.  With enough pressure, methane ice, known as methane clathrate can form at a temperature of as much as 30 degrees C but in the ocean with the deep ocean temperature at a couple of degrees above freezing, you need a pressure equivalent to about 300m of water. (31 atmospheres). Warm this clathrate or reduce the pressure and the clathrate will begin to break down, turning into gaseous methane and liquid water.

An other wrinkle in this story is as follows.  If methane seeps up from disintegrating organic material or from deep deposits of coal, shale or oil and meets the bottom of a layer of permafrost, it can form a clathrate at a much shallower depth than would be necessary in the open ocean.  The permafrost acts like the lid on a pressure cooker and as the methane accumulates at the bottom of the permafrost, the pressure rises until it combines with the moisture there to create a methane clathrate.  It is likely that the blow-out features seen on the Arctic sea bottom are the result of the permafrost weakening enough under increased ocean temperature for this high pressure methane to blow holes both below and above the ocean.  Some such holes have also been found on land.

So what does all this have to do with future Tsunamis in the Arctic Ocean. 

Sea water in the Arctic freezes each winter and during the summer the melting ice keeps the water cold.  This effect is lessening year by year with ever larger areas of the Arctic ocean now clear of ice for ever longer periods in the summer.  Open water, as has often been stated, absorbs solar energy unlike ice and snow which reflect the sunlight back into space.  The surface layer of fresher cold water is about 200m deep and the continental shelf is roughly 100m below the surface. The Continental shelf is bathed in this surface layer of fresher water which is gaining more heat year after year.  Clearly a formula for the melting of both types of permafrost.  But that is not all.

 At present, with the prevailing high pressure area over the Arctic, the air circulation is predominantly clockwise.  This causes a predominantly clockwise circulation in the ocean.  Due to Coriolis, anything moving in the Northern Hemisphere veers to the right.  To-the-right in a clockwise circulating system is toward the center.  Because of this, the Arctic ocean tends to hold on to floating ice and to the floating fresh water from the rivers entering the ocean.

As the ocean warms, we can expect more and stronger storms in the Arctic which, in the Northern Hemisphere are counter clockwise rotating bodies of air.  This will push on the water below inducing a counter clockwise water circulation.  In a counter clockwise rotating body in the Northern Hemisphere, to-the-right is away from the center.  We can expect this floating layer of fresher water to thin as it is sent outward to be expelled through the Fram Straight.

Below this fresher water is the warmer more salty Atlantic water.  If it comes close enough to the surface to bath the Continental Shelves of Russia and America, we can expect the melting of the permafrost and methane clathrate to accelerate.  Besides venting methane into the atmosphere; a powerful greenhouse gas, this will remove the 'glue' that is holding the sediments together.  A recipe for Tsunami-causing land slides.

Another effect adds to the potential for melting the undersea permafrost, resulting in eventual Tsunami-causing-slumps.  As there is more open water, winds can induce larger and longer waves in the Arctic due to the greater fetch* and storms can become stronger due to warmer open water contributing humidity to the overlying air.  The circle of rotation of a particle of water as a wave goes by decreased with depth.  The formula says that for every ninth of a wave length, you go down into the ocean, the circle of rotation halves.  Longer waves project their effect much deeper than short waves of the same height.

*Fetch - the distance of open water over which a wind can blow.

So, for instance, for a eighteen meter long wave, one meter in height, if you go down two meters, the circle of rotation of a particle of water will be half a meter.  For a one meter high wave with twice the length (36m) you would have to go down 4 meters before the circle of rotation would have decreased to half a meter.

If the effect of the surface waves penetrates sufficiently deeply, they induce waves between the surface cold fresher water and the deeper warmer saltier water.  These waves break, just as do surface waves as they reach shallow water.  This will cause mixing of the layers, weakening the density gradient between the layers and facilitating future mixing.  But there is a much more worrying possible result.

Tsunami waves are both very large and very long. After the first Tsunami which is caused by a slump at the top of the continental slope, we can expect to see that there has been major mixing between the two layers in the Arctic ocean.  If it has been sufficient, this should rapidly accelerate the process as warmer saltier Atlantic water bathes the continental shelf, leading to more Tsunamis and greatly accelerated melting of surface ice -- which will further increase the amount of heat absorbed in the surface water from the sun.  The first Tsunami caused by a slump looks to be not only a severe tipping point but a further strong indication that we have indeed had a severe effect on our environment. 

Thursday, September 5, 2019


The world has a mountain of spent tires, plastic, (much of it dirty), wood wastes, tallow from abettors  used engine oil and even old clothes with no recycle value.  All these and probably many other waste streams can be pyrolyzed.  So what is pyrolysis.

Any carbon based material, if heated in a retort without oxygen, breaks down into a range of chemicals, many of them alkanes.  Classically, the gaseous part of the output is cycled back to the retort and burnt to provide the heat to power the process.  That is simply a waste.  The lighter fractions from pyrolysis are LPG and can be compressed into tanks and used for domestic heating and cooking. The lightest fraction, methane, can be turned into methanol as we have done for years In New Zealand.   We used the methane from oil wells but can equally use methane from pyrolysis.

Let's be more ambitious and set up a dedicated wind turbine to provide the energy for powering the pyrolysis process and use the lighter fractions. A bank of Zinc Bromide or liquid metal batteries can smooth out the power supply with any excess sent to the grid. As with any battery, both of these have their weak points but far outweighed by their strong points.  Both can be charged and discharged fully without any degradation of their capacity over time.

And where would we locate the wind turbine???  Anywhere with access to the grid and good wind.  That's why we have national grids; to transfer power from where it is generated to where it is needed.

If your chemistry is a little rusty, what are alkanes

Alkanes are chemicals containing a chain of carbon atoms with hydrogen atoms on all the remaining bonds. Alkanes are saturated hydrocarbons meaning that there are no double bonds between the carbon atoms.  In ascending order of chain length alkanes are methane(CH4), Ethane (C2H6), Propane (C3H8) Butane (C4H10) and so on all the way up to very long chain tars. [or if you prefer, cooking gas(C1-4), gasoline(C7-9), diesel(C10-15), jet fuel(C13-16) and so forth]

Alkenes are also  produced but are a pain in the kister.  With their double bonds between carbon atoms, they can link up with other chemicals and form 'varnishes' and 'sludges' that you  really do not want in your carburetor.  More about them later.
                            Feed Stock
When tires are pyrolyzed, most of the resulting chemicals are the usual range of alkanes plus carbon and steel.  The steel is from the steel reinforcing in the tires.  Carbon is used in the manufacture of  products such as black plastic pipes, black paint, filters and new tires.  The steel can be accumulated in rail cars and shipped to a smelter.  All Steel mills use a proportion of recycled steel along with the Iron ore they refine.

If the pyrolysis unit is located beside an oil refinery the mixture of alkanes can be fed into the fractionation towers to separate out the various components.  Tires contain sulfur which is used for the vulcanization process so tires are rich in sulfur.  Oil refineries are already set up to remove sulfur from 'sour' crude oils.

Sulfur is a valuable by-product and is a much use element in many industrial processes and particularly for the production of Sulfuric acid which is used in many chemical processes.

Oil refineries  use various methods to 'crack' long chain hydrocarbons to obtain a larger yields of the most needed fractions such as gasoline, diesel and aviation jet fuel and this can be similarly done for the output from a pyrolysis retort. Note that in Finland, a plant to convert tires back into petrol has been set up and is reported to be pollution free.

Wood waste
The usual chemicals are produced when wood is pyrolyzed with char (charcoal) as a by product.  Wood char is a great soil additive which fills a similar function to humus in the soil. Charcoal has a very long life in the soil and hence results in a long term sequestering of carbon. At present, it is not economically worthwhile to produce char for farmers but with a pyrolysis unit producing a lot of this material as a by product, the price of charcoal should come down.  The petroleum products produced from wood are green and the charcoal sequesters carbon from the atmosphere.  In this case a net sequestering of carbon results in the production of Petroleum products.

Plastics, long chain carbon compounds, are easily pyrolyzed.  The plastic doesn't have to be clean.  Food wastes, petroleum products and other contaminants are pyrolyzed along with the plastic. This is a solution to our mountains of plastic and especially those which can't be recycled either because they are the wrong type of plastic or because it is not economic to clean them.  Note that it used to be worthwhile financially, to send these plastics to China before they refused to take any more.  Surly, then it is worthwhile to send them to a pyrolysis unit in your own country.

Clearly, any of these waste materials which have a more valuable second life would not be pyrolyzed.

Just recently (Sept 2019) some numpti of an abattoir poured  tons of hot liquid tallow into their drains.  The congealed fat totally disabled their municipal waste treatment (sewage) plant.  How much is that going to cost in clean up costs, fines and the ecological cost of raw sewage going straight into the environment while they are getting the pumps and pipes unclogged. How much better if they had accumulated  their tallow in a rail car and sent it off to the pyrolysis unit when the car was full.  Here we get into externalities (see below).  

So what else could we do in concert with a pyrolysis unit.

Side lines
With some of the electricity from our dedicated wind turbine or solar panels we could electrolyze water into Hydrogen and Oxygen and store it in large, low pressure tanks.  Why would we want to do this.  First the Hydrogen.


When longer hydrocarbon molecules are cracked to make more of the short chain molecules,,,, everywhere a chain breaks, there is a free carbon bond that needs filling with a hydrogen atom.  If it is not filled, alkenes will result and as mentioned, these are not desirable in an engine.  If Hydrogen is introduced into the retort at the correct temperature and with the correct catalyst, the hydrogen saturates these bonds converting the alkenes to alkanes.  So how about the Oxygen.

If tires are a feed stock, this will result in considerable amounts of sulfur being produced.  If it is burnt in air it produced Sulfur dioxide.  If mixed with water it produces sulphurous acid. - not very useful.  However if burnt at high temperature in an oxygen rich environment, Sulfur trioxide is produced.  Add this to water and you produce Sulfuric acid which is a much used chemical in industry, not to mention in lead acid batteries.

When sulfur is oxidized (burnt) heat is produced.  It might be possible to capture this heat for use in the processes.

So already were are producing better fuel by saturating broken bonds with hydrogen and  we have a sulfuric acid producing plant on site. We have steel, carbon and charcoal as added by-products for sale.

When calculating the economic feasibility of pyrolysis, externalities must be included.  Externalities are:
 " a consequence of an industrial or commercial activity which affects other parties without this being reflected in market prices" (wikipedia dictionary)

For instance:
*the cost, economic and ecological, of having a mountain of tires leaching poison into the environment, creating a fire danger and providing water pools for mosquito breeding;
*the cost of a mountain of plastic sent to land fill or entering the environment and eventually  the sea;
*the price to store mountains of materials that could be used;
*the price to our environment of having to mine more hydrocarbons instead of using the ones we already have above ground and
*the hydrocarbons we can produce from renewable sources such as wood waste, thus further reducing the amount of crude that must be extracted.

All these sorts of costs should be credited to the plant that is operating the Pyrolysis plant. Our tendency to ignore externalities causes some of the worst abuses in our society today.

                          The Future

Let's look to the future; of what else we could pyrolyze.  

Electronic Equipment
Old computers, radios, communication equipment and so forth are largely plastic these days.  But they also contain many metals.  If they are pyrolyzed, the plastic is converted to the usual gaseous and liquid hydrocarbons but the ash left over contains copper, gold, lead, tin and other metals.  This residue can be sent to a smelter to be separated (refined).  It might be worthwhile to first chop up the material and apply a magnetic and then an eddy current separation.  This will separate out  the  ferrous and not ferrous metals.

Treated timber 
At present there is no place to get rid of treated timber.  Tantalized timber contains copper, arsenic and chromium.  If it is burnt and the ash applied to the soil in the mis-belief that you are adding valuable wood ash to your soil, you will have caused serious contamination.  None of these metals are one's you want in your vegi garden.  All the scrap treated wood from construction could be pyrolyzed as well but one would have to make sure that these chemicals, especially arsenic, were recovered from the output of the process. At the end of a batch-pyrolysis, oxygen should probably be introduced to get rid of any remaining carbon, turning the residue into ash which is now further concentrated and can be sent to a refinery.   

A mountain of nappies, both for infants and now,  more and more from the aged, are created every year.  They can also be pyrolyzed.  Since they will have a high water content, it would probably be necessary to bring the pyrolysis retort up to, say 1100C and hold it there until water vapor ceased to be expelled from the retort.  Some other feed materials might benefit from a similar treatment. A benefit of an initial phase of heating a moist material to just above 100degrees C is that you expel all the air from the retort before starting the pyrolysis cycle.  Remember, all this is done using renewable energy from our dedicated wind turbine or solar panels.

Old waste dumps
Recently a waste dump close to a river was breached by a storm, and the garbage flowed into the sea.  Old dumps which must be removed for whatever reason could also be pyrolized.  In the anaerobic environment in a dump, much of this material is unchanged.  We could clean up the sins of our grandfathers.

Almost none of the materials which can be pyrolized are effected by being stored in a rail car until it is full.  The rail car can then be sent to the pyrolysis unit, which, hopefully, is located within the grounds of a standard petro-chemical refinery.  These cars can be tacked on to existing trains when they are heading in the right direction.  Thus the cost of shipping should be 'reasonable'.  But we must never ignore the cost of externalities as we so often do.  Pyrolysis should be credited with the cost to us, both long and short term, of doing nothing.

A way to take care of externalities might be to guarantee that the plant that is doing the pyrolysis  will be supplied with it's feed stock fob the plant for free.  Just a thought.

                  Other Benefits of Pyrolysis  
Balance of Payments
Whatever materials we product by pyrolysis reduces the amount of Crude we have to import from overseas, improving our balance of payments. The demand for oil is already decreasing as electric cars gain a greater share of the market.  As the years go by, oil from pyrolysis would become a greater and greater proportion of the oil we use as this process continues.

Waste Dumps
Pyrolizing as much of the feed to waste dumps as is possible will lengthen their life and ultimately, as we make use of other materials going to waste dumps, we could eliminate them. Eventually old waste dumps could be mined and eliminated.

Our Green Image
New Zealand depends, to an extent, on her green reputation, for the marketing of her products and especially her agriculture products.  Reducing our use of 'mined' petroleum fits within our story.  

Thursday, August 22, 2019

Arctic Storms

The Arctic, occasionally has really big storms.  They are called polar lows.  They can be as strong as hurricanes.

How do we measure the strength of a storm.
In the open Atlantic ocean, where they are called Hurricanes, one measurement is the pressure in the eye of the storm.  The lower the pressure, the greater the strength of the storm.   Wind speed is also a measure of the storm but let's leave that aside for now.

Storm categories

Storm rating      Mbar in eye     mmHg in eye     Wind Speed Kts
     1                    980                  28.94                  64 - 82
     2                    979 - 965         28.5 - 28.91        83 - 95
     3                    964 - 945         27.91 - 28.47      96 -113
     4                    944 - 920         27.17 - 27.88      114 - 135
     5                 <919 -="" 136="" 157="" 919="" br="" nbsp="">

What powers Hurricanes.
It is mainly the effect of Latent Heat of Vaporization.  If you evaporate water which is already at 100 degrees C, it takes 540calories per gram of water to change the water to water vapor.  To put that into context, it is enough heat to raise that gram of water from zero degrees to 100 degrees five times  and then from zero to 40 degrees as well.  That is a lot of heat.

More important for our discussion, the same amount of heat is released when the water vapor condenses back into liquid water.

How warm must the surface water be to power a hurricane
The critical surface temperature of the water to power a hurricane is about 25 degrees C.  At that temperature, enough water vapor is transferred to the air that if some little disturbance causes the air to rise and cool and begin the condensation process, the heat released keeps the air warmer than the surrounding air.  The rising air sucks  more moist air across the warm sea, to be pulled upward where it cools and condenses out the water and you are well on the way to a thunder storm or a hurricane.

Despite the fact that the H2O is now heavy water rather than light vapor, the heat released into the air is enough to keep the air surging upwards like a hot air balloon.

One more factor is needed.  Coriolis. Air at the equator is traveling  at about 1000mph.  At the pole it is not moving at all, merely turning on the spot once per day.  Think of a body of air moving northward from the equator.  If it travels a mile northward, the rotational speed of the land under it hardly changes.  It would move to the right but very slightly.  Think now of a body of air a mile south of the North Pole traveling toward the pole.  It has a velocity but the pole has none.  It will veer sharply to the right.  But there is another effect at play here.

Just like a skater that pulls in her arms while she is spinning, a body of air gets an added spin by moving it's mass closer to the center of rotation.

Coriolis is hardly felt near the equator but is more and more effective, the closer you get to the poles.  Near the poles, you are moving almost a km nearer to the center of rotation for every km you travel over land.  At the equator, a km over land hardly moves you toward (or away) from the center of rotation at all.

Incidentally, do the exercise in your head of a body moving southward.  You will find that in the Northern Hemisphere, something moving southward is also veered to the right.

In the open Atlantic ocean, all the power for the hurricane is from the suck in the Middle caused, as mentioned, by the release of heat from condensing water vapor.

So how do we have such strong storms over the Arctic Ocean???
Some of the Arctic storms are as strong as  Hurricanes.  For instance, in Aug 2012 there was a Polar Low over the Arctic  Ocean that, if it had occurred in the Hurricane zone further south would have qualified as a high 2 or a low category 3 Hurricane.  (due to the low pressure in the eye which was 966 millibars).

According to the scientists this is because of the high pressure over the ice remaining over parts of the Arctic Ocean.  The ocean water on the surface is no where near the 25 or so degrees that is necessary to power a hurricane so something else must be at play.  it is apparently the 'push' from the high pressure area over the ice.  The pressure gradient caused by the suck in the middle is augmented by the push from the air over the ice.

Apparently polar lows tend to follow the line between open water and the edge of the ice.

So let's speculate a bit.
What will happen over the years as the Arctic Ocean is more and more open earlier and earlier and collects more and more heat.  Let's say we have reached the situation in which the Arctic ocean is ice free and remains that way for the final month of the summer.  The sun becomes weaker and weaker and the land cools off rapidly.  Only the top couple of feet of the land warms and cools so it warms and cools  rapidly.  In the fall, the sea has absorbed huge amounts of heat to depth.  Say, now, we have a wee storm that coats the land with white.

Now we have the same situation that created the Aug 2012 storm but much larger.  There is more heat in the water and the land all around the Arctic Ocean is a high pressure area  supplying the push to augment the suck over the ocean.

This looks to me to be the formula for some really large storms.

                Effects of large Arctic storms

There are a number of effects of strong Arctic storms, especially when the ice extent is at low levels and the ice is thin.

When the Arctic is covered with thick ice, the wind can not act on the ocean.  Ice flows can be pushed around a little but with complete ice cover, there is almost no place for them to go.  They can be pushed up into ridges and the leads left behind, freeze over.  This creates thick multi-year ice which is hard to melt.

However, when much of the ocean is ice free and what ice there is, is thin first-year-ice, the storms can not only move the ice around but  waves building up from the wind flowing over open water can smash and fracture this thin ice.

The distance a wind acts on water to create waves is called 'fetch' and the longer the fetch with a given wind speed, the larger and longer the waves

Note that the circle of rotation of a particle of water as a wave goes by, decreases by half for every 9th of a wave length depth.  In other words, the length of a wave greatly increases the depth to which it is felt.

Larger waves crash into land that was once protected by ice and erode it.  This is happening around large parts of the shore line of the Arctic.  Permafrost is exposed which is then  easier to melt.

In addition, surface waves can induce internal waves between the deep salty Atlantic water and the surface, fresher Arctic water.  These waves break when the reach shallow water, mixing the layers.

A really interesting effect is connected to our old friend Coriolis.  The 'normal' weather system over the Arctic ocean is a high pressure area.  This is because the energy of the sun is reflected back into space by the ice and its snow cover so the atmosphere is not heated  from below as is the case in much of the world, the air radiates heat into space resulting in dense falling air.  This high pressure area rotates clockwise as the falling air spreads out heading southward.  And it pushes on the ice and water causing a clockwise rotating gyre, especially just North of Canada, known as the Beaufort gyre.

Remember that everything moving in the Northern Hemisphere veers to the right and in a clockwise rotating gyre, to-the-right is toward the middle.  This is why the Beaufort Gyre collects and holds the fresh water from the surrounding rivers and the ice that floats on the ocean.

The deeper water is warmer but stays down below because of it's saltiness.  It is basically deep Atlantic water.  The layer of lighter, colder surface water is typically about 200m deep.  So what happens when this gyre is reversed by  persistent, stronger storms.  In a counter clockwise gyre in the Northern Hemisphere, to-the-right is away from the center.  We can expect the surface water and ice to be pushed outwards, to be caught by the trans polar current and expelled through the Fram Straights.  This will bring the Atlantic water closer to the surface.

This may be another tipping point.  As the salty Atlantic water comes closer to the surface, it is more easily mixed with the surface water, especially during hurricane strength polar lows.

Also, the mixing of the layers caused by internal waves will reduce the density gradient between the surface and deeper waters.  Once the Atlantic water reaches the surface, the ice will really take a major 'hit'.  We may once again have trees growing right up to the shores of the Arctic Ocean.

Final note
The process doesn't stop with the beginning of freeze up in the middle of September.  You have all heard of the ice-cube-in-the-drink effect.  The drink stays a or very near to zero degrees until all the ice has melted.  the heat seeping into the glass from it's surroundings is used up in melting the ice cube.  Latent heat from solid to liquid is not as much as from liquid to gas but is still substantial.  For water the liquid-gas latent heat is 540 calories per gram while from solid to liquid it is 80 calories per gram.  The same effect works in reverse

As the water in the Arctic freezes over, it releases 80 calories for every gram of water that freezes.  This, of course, doesn't heat up the overlying air.  It simply "tries" to keep the temperature at zero until there is enough ice covering the ocean to provide insulation from the underlying water.  Even then, as more ice freezes on to the bottom of existing ice, the heat produced has to conduct through the ice into the overlying air.  So why is this important.

Remember that the surrounding land is rapidly cooling down as it radiates heat into space and the sun is not replacing this heat in the daytime. The sun no longer shines in the Arctic in the winter.  So all around the Arctic ocean we have cold land and descending  air.  ie, a high pressure area.  This should also be able to create powerful storms at the beginning of the winter freeze-up period.