The cost of not Pyrolyzing

 Pyrolysis - heating various hydrocarbons to break them down into shorter molecules.  

Feed stock - wood, plastic, tires, used engine oil, electronic equipment etc.

Output - cooking gas, gasoline,diesel, jet fuel, road tar etc.

Let's say, for the sake of the argument, that you use renewable electricity to heat the feed stock and the energy content of the resulting products is only equal to the electrical energy that you used. ( like the processing of tar sands).  Would this be a worthwhile enterprise.  Let's look at the side benefits.

 

1/ You produce gaseous and liquid fuels which are very energy dense.  For quite a long time, we will need such fuels to power long range aircraft, heavy machinery, large trucks and so forth.

2/ You avoid the fee for sending the feed stocks to a land fill.  The pyrolysis company accepts them for free

3/  You avoid the cost of sending them overseas (plastic for instance)

4/ You avoid the cost of storing them somewhere

5/ You avoid the health costs of storing them (Piles of rubber tires breed disease carrying mosquitoes and leach poison into the environment.

6/ You avoid the cost of destroying our ocean fauna. (plastics in the ocean kill ocean animals in a range of ways).

7/ You avoid the health costs of microplastic in our environment.  The effects of microplastics are just now becoming apparent.

8/ You produce a range of valuable side products (steel and sulfur from tires, charcoal from wood)

9/ You reduce the amount of oil that must be pumped from the earth.  Pyrolyzing plastic, basically uses oil that has already been pumped (plastic is made from oil). 

10/ Pyrolyzing waste wood from the production of engineered wood, produces green fuel and sequesters carbon in buildings and in the charcoal which is incorporated into soils.  Using engineered wood, displaces concrete, a huge source of carbon dioxide.

11/ Pyrolyzing treated (tanelized) wood keeps this poisonous product from the environment and recovers the arsenic, copper and chromium.

12/ You recycle vital minerals, reducing the amount that must be mined. (electronic equipment is mostly plastic, with a range of valuable metals which can be refined ((separated)).

13/ You extend the life of waste dumps.

14/ You can pyrolyze, and thus dispose of the contents of old dumps that are problematic.

15/  We add to the amazing story of New Zealand.  We are known for such things as our amazing natural wonders, our stance on nuclear power, our grass fed meat (read The Omnivores Dilemma for the alternative - ug), how we look after visitors if they are injured while visiting, our lack of tipping and our almost unique response to Covid.    Solving our waste problems would add to this.  It all translates into cold hard cash as people want to visit and to buy our products in their own countries.

 

I'll add more as I think of them.  In actual fact, the energy content of the liquid and gaseous fuel produced is greater than the input energy by a considerable factor.  The devil is in the design of the pyrolysis units.  Have units that are designed to pyrolyze  each of the various feed stocks and it will be worthwhile having a fractionation tower to  separate the output of the units into their components.

Note that the energy content of alkanes is greater, the smaller the molecule so methane has the highest energy content than all the other alkanes.  In other words, you are adding energy to a substance as you break it down by pyrolysis.