An open letter to Z energy

 

We were all so proud when you bought out Shell.  We had our own power company instead of being royally screwed by overseas companies.   Our delight was complete when you told us you were going to be an 'Energy' company.  We pictured you gradually shifting to charging the ever increasing electric cars with the roves of your stations covered with solar panels and a large battery at each station, storing excess and even stabilizing the voltage and frequency of the local grid. 

For heaven sake, you have some 250 stations country wide.  With a one mWh battery at each station, you would have had more capacity than even the upgraded Hornsdale.  You would have had a country-wide distributed energy storage capacity.  And it wouldn't have been a financial sacrifice on your part.  These batteries are ridiculously profitable in their own right. Hornsdale paid off the whole $66m investment in her 100mWh battery in three years. 

We pictured you taking a whole range of waste streams and turning them into petroleum products by pyrolysis or one of the other known processes.  All our plastic waste, used rubber tires, used engine oil, tallow, wood and paper, electronic equipment etc. etc. would have been diverted from land fills which are degrading New Zealand.

Now we are back where we started or worse.  You are selling off Z to an Australian company.  Do you realize that Ausi banks take about one billion Kiwi dollars our of this country every 6 months.  Now we will have our major fuel provider doing the same. 

To top it off, you and the other owners of Marsden point are going to shaft our strategic capacity to refine our own petroleum products and make us dependent on overseas suppliers for them.

 

Just another New Zealand success story.  So sad.

The costs of not Pyrolyzing

 Pyrolysis is a method for turning a whole range of waste streams into petroleum products such as cooking gas, gasoline, diesel fuel, airline fuel and all the way up to tars.  It is done by heating the material in question in an enclosed retort up to, typically, 5000C.  In a petroleum refinery, this would be called cracking.  If you heat heavy crude (long chain molecules) up to a high temperature it cracks the long chains and produced more of the more valuable short chain molecules.

It seems only right and logical that a pyrolysis unit/business should be credited with the costs it avoids.  In other words, we must take externalities into account.  Some of the worst abuses of people and the natural world occur because we don't take the true cost of our actions into account.

There are costs of not treating your waste streams by pyrolysis.  Some of them are general to all waste streams.  Some applying to specific wastes.  First the general ones.

General Costs of Not Pyrolyzing

Sending waste to land fill

First, a waste dump charges money per ton for waste that they store.  For specific wastes they often charge more.  Secondly, a waste dump typically fills up a formerly beautiful valley with garbage, removing it from public use and thirdly if not managed very carefully, water leaches out of the waste dump and pollutes the water down steam from the dump

Sending waste overseas

Hard to believe that this is actually a thing.  We used to send our waste plastic to China before they became a tad sensitive to being the garbage disposal country.  It hurt their pride.  Now, at least here in New Zealand, we send it to another country.  I won't say which one.  I don't want to hurt their feelings.  They don't dispose of this plastic in an acceptable way (pyrolysis for instance) and it blows into their streams, lakes and rivers and is carried to the ocean.  I don't think I have to detail the damage that plastic does in the ocean.  It has been covered again and again in article after article.

Costs for Specific Waste Streams

Used Tires

Leave a tire outside in any orientation you like.  After the first rain look inside.  No matter which way you oriented the tire, there is now a little pool of water inside.  As we all know, the weather is warming and various organisms are moving poleward.  One such class of organism are the mosquitoes.  A particularly noxious group are the Culex mosquitoes and A aegypti   They transmit a particularly noxious range of diseases.  Aegypti can breed in an upturned bottle cap. A massive  pile of tires is a huge mosquito breeding farm.

Of course then there is a fire danger with some really toxic smoke being produced and a leaching danger with some chemicals being leached by rain into the ground. 

Wood 

Starting at lumber mills, they produce great quantities of off cuts with no value and saw dust.  The saw dust has some value to horticulture and the off cuts can be sold as fire wood.  However, if you pyrolyze this waste, you produce completely green petroleum products and charcoal.  The charcoal can be incorporated into agricultural soils where it serves the same function as humus and last for a very long time, sequestering carbon in the process.  This lowers the financial obligation of a country under the Koyota protocol. 

 

If you build quality buildings from engineered wood, you, of course, sequester even more carbon for significant periods.

Treated wood is another problem all together.  Tannelized wood has been pressure treated with a mix of Chrome Copper and Arsenic salts.  There are many off cuts during the building process and over time, buildings will be demolished and this wood burnt.  The ash is toxic and you don't want it incorporated into your soils or sent to a land fill.  If pyrolyzed, the ash can be sent to a refinery and the metals recovered and kept out of the environment.  Otherwise, over time we are polluting our soils.

Electronic Equipment 

Electronic equipment is mostly plastic these days.  In addition it contains a wide variety of valuable metals.  All can be recovered by pyrolyzing the equipment and sending the ash to a refinery

Plastic  

When plastic is burnt in a normal 'bonfire', it releases dioxides.  The formula is C₆H₃O₂.  It is a liquid at room temperature and is used in transformers to suppress sparking.  Heated in a properly designed pyrolysis unit, dioxides are broken down into harmless compounds.  If left in nature, they accumulate in the fat and concentrate as they go up the food chain.  They are carcinogenic.  Eliminating dioxides from the environment reduced health costs. 

Making pyrolysis economic

Pyrolysis, the anaerobic heating of hydrocarbons such as wood, old tires, used engine oil, plastics, tallow and so forth, needs to be economic for it to be undertaken. Below are some suggested ways to increase the financial feasibility of pyrolysis.

 

 Energy conservation

Pyrolysis needs heat energy to cause the various long chain materials to break ('crack', in petrol-chemistry terms)  and the applied heat must be at a temperature of about 500⁰C. But, of course you don't want to be heating the great outdoors.  That is a waste of energy/money.  Super insulation is needed so that you only use  the amount of energy needed to break the bonds. An insulation material that comes to mind is the Aerogel that was used to protect the shuttles during re-entry but cost and availability might be a barrier.

Source of energy

Clearly the energy to heat the retort must be renewable.  Energy must come from hydro, wind, geothermal or solar sources.  Renewable energy continues to go down in price as the hardware to produce it becomes less expensive. There are a couple of possibilities.  With the spot-price-silliness that we have in New Zealand, electric energy is very cheap when it is in excess.  Either the pyrolysis unit can operate, only when energy is cheap or cheap energy can be bought and stored in a mega battery to ensure the continual operation of the pyrolysis unit.  

 

It may be worthwhile for the pyrolysis unit to own it's own renewable energy kit and thus be always paying the wholesale price.  This 'kit' continues to decrease in price.  With a battery as well, excess energy can be sent to the grid when spot prices are high. 

Energy is likely to be one of the largest running costs in a pyrolysis factory.  

 

Externalities

Many  waste streams  can be pyrolyzed to produce either liquid fuels or easily compressed and liquefied fuels.  Many waste streams are problematic if not disposed of somehow.   

There is now a cost to send waste to land fill and a land fill trashes beautiful pristine wild areas which are then no longer an asset to the community.  

Some wastes are direct health hazards such as the leaching of material from them into the ground water or as breeding grounds for mosquitoes (tires).  As the world warms, tropical mosquitoes that carry a range of very nasty diseases will be moving poleward.   

Many pyrolyzable wastes are a fire hazard and the by product of  burning some of them creates the toxic, carcinogenic, dioxane, and fine particulate material.  If they are sent overseas, the receiving country may simply dump them into the ocean.  There is no need to describe why ocean dumping is problematic.

    

The point is that the pyrolysis unit has to be credited for the financial cost it mitigates when a solution is not found for that particular waste and/or for the present cost of taking care of the waste.   Government action may well be necessary to ensure this.

By products

Depending on the feed stock, there are various valuable by products of pyrolysis.

Wood

The by product of wood-pyrolysis is charcoal.  Charcoal can be bagged and sold for barbecues or can be incorporated into agricultural soils, earning carbon credits.  See Terra Preta

 

Plastic (clean or contaminated)

No by products result from the pyrolysis of plastic.  It all converts back into alkenes and alkanes.  The alkenes can be converted into the more useful alkanes by saturating the double bonds with green hydrogen.  Petro-chemical engineers have methods of either bonding low molecular weight fractions into larger molecules or, on the contrary, cracking long molecules into smaller ones to get more of the desired fraction.

Electronic equipment

The pyrolysis of electronic equipment results in a metal rich ash.  As battery recycling ramps up, this ash could likely be sent to a battery recycling facility for the separation and recovery of these metals.  This sort of ash is a far richer source of metals than any natural ore although it is a rather challenging mix.  At present, waste circuit boards are sent overseas for the recovery of their metals.  Most of the weight of a circuit board is plastic.  With pyrolysis, you don't send the plastic  saving on weight and hence expense.

Used tires

By products of the pyrolysis of tires are iron, sulfur and carbon black.  Sulfur can be converted into sulfuric acid, using the oxygen which is a by product of the Hydrogen which has been produced for saturating alkenes.  Sulfuric acid is a very valuable product used in a plethora of chemical processes.  Carbon black is used in air and liquid filters, black paint and in the production of new tires and black plastic.  The iron is sent to an iron refinery where it is combined with iron ore in the smelting process.

Used engine oil

Used engine oils are very variable.  For instance some of them have additives of materials such as molybdenum sulfide.  Presumably this, and any other similar materials would remain after the pyrolysis of used engine oil.  In addition, there may be a small concentration of metal from the engines.  But I suspect that well north of  99% of engine oil should convert into the usual pyrolysis products.  The ash could probably be combined with the ash from electronic equipment and sent to a battery recycling facility.

Tallow

Tallow should not have any by products and rendering is not necessary.  It can be directly pyrolyzed.  However, if tallow is converted into biodiesel  instead of using pyrolysis, glycerine is a by product.  One has to work out if it is worth while to build a separate facility for the chemical conversion of tallow to diesel or to simply pyrolyze this waste stream.

Side economic benefit

If this whole process is kept in the eye of the public as it proceeds, it would seem likely that the petrol company responsible would gain a greater share of an ever diminishing market for petroleum products.  Parts of the output of pyrolysis can be mixed into conventional petrol and diesel, making them 'greener' and done through already existing distribution channels.