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A Closer Look At Bicarb

November 13, 2016

Sodium Bicarbonate

Or

Bicarbonate of Soda?

I’m not entirely sure (or sure it matters) but one thing I am sure of is that the moment you step foot in a natural cleaning or natural cosmetic making workshop you’ll be told all about how wonderful this is!

Bicarb is indeed a wonderful thing as I mentioned on my blog back in 2011 but this time I want to look at it from a different angle, a chemical angle.  I want to delve into how it comes into being. How do we ‘make’ bicarb and do we even make it at all?

So Bicarb.

NaHCO3

It occurs naturally and can be made synthetically.

One way of making it is this:

  1. Heat Salt (Sodium Chloride) with Sulfuric Acid to make Sodium Sulfate and Hydrochloric Acid.
  2. Take the Sodium Sulfate and heat it with limestone to form soda ash (Sodium Carbonate).
  3. Take the Soda ash and dilute it into water to make a soda ash solution. Then add Carbon Dioxide to the soda ash solution and increase the pressure until the Bicarb crystals form.
  4. Centrifugal force is used to help separate the bicarb crystals from the liquid/ gas.

 

Another way of making it is the Solvay Process (the most common industrial process used)

  1. Pass CO2 (carbon Dioxide) and NH2 (Ammonia) through a concentrated solution of NAOH (sodium chloride or salt).  This produces Crude sodium bicarbonate as a precipitate.
  2. Heat the crude Sodium Bicarbonate to form soda ash then proceed to step 3 as above.

NB: Ammonia is found in nature but in small amounts, in most cases it is manufactured using the Haber-Bosch process, a process that converts the nitrogen in the air to ammonia (NH3) by hydrogenating it under high temperatures and pressure using a nickle catalyst.  The hydrogen usually comes from methane which is sourced from natural gas.

A third way of making it is to mine for it.

In nature we find the most cost-effective sources of bicarb in the mineral deposits of Nahcolite or Trona. By far the largest natural reserves of Nahcolite/ Trona mineral are in the USA with others found in the lava tunnels of Mt Vesuvius, Italy;  Around Naples, Italy; Across East Africa (ICI have a plant there), Anchara, Turkey and Mexico City plus a number of others around the world.

I’ve found out through writing this that the USA has enough natural mineral to be able to produce its bicarb naturally rather than using the Solvay process whereas Chinese Bicarb is almost entirely made using the Solvay process.

Nahcolite Mineral:NaHCO3

nahcolite-wikipedia

Trona Mineral:Na3(CO3)(HCO3)·2(H2O)

 

trona-mineral

What about mineral waters?

Bicarbonate salts are also found occurring naturally in mineral waters. In Australia the Sydney-Gunnedah basin water is enriched with sodium bicarbonate with a high concentration between Gunnedah and Narrabri. The same is true for parts of the Murray – saline water.  Studies have been conducted into the viability of extracting the bicarb from this water source and found it, to date to be commercially unviable due to it being in an unconcentrated form.  It may well be ethically unwelcome too given the environmental impact this might involve.

So having discovered we can mine for it the next question for me is just how clean and green is Nahcolite / Trona mining (the two minerals can exist together or Nahcolite alone). 

There is a patent for the Nahcolite mining process here.

Basically it looks like you just pump hot water into the hole, increase the pressure and wait for the water to become saturated with the bicarb before removing it and washing and drying it.  In terms of mineral processing that’s about as clean as you can get I guess so the next question is where exactly is this happening and is it sustainable?

Piceance Creek Basin in Northwestern Colorado is where  some of the action is at.   Here are some images from Google:

white-river-colorado

white-river-area

I haven’t been to America let alone set foot in Colorado but from looking up the area online I can see that this really is oil shale country with Colorado producing around 5% of the USA’s natural gas production. On top of that the economy is also enriched by Uranium interests, farming and renewable energy production including a robust and rather large wind farm – Cedar Creek!

But that’s not all. There’s more action in Wyoming where Trona is the main Bicarb-rich mineral. The Wyoming Mining Company manage that has mined over 17 million tonnes and at current rates has reserves that will last another 2350 years!

trona-mine

A patented process of producing Bicarb from Trona can be found here. 

Obviously any mine site disturbs the natural environment but as far as mining goes I’d tentatively suggest this is a pretty clean process and one that is preferable to the synthetic, Solvay process which is definitely quite environmentally impacting.

So when we buy Sodium Bicarbonate how do we know whether it is naturally mined or Synthetically produced being as though that does appear to matter environmentally speaking?

Well I can’t speak for all bicarb manufacturers but this is what I do know from looking at the packets I’ve got in my kitchen and from what I’ve found on the internet.

  • Glitz Green brand of Cleaning Bi-Carb from Pascoe’s has got ‘made in china’ on the packet. Now whether the bicarb is Chinese or not can’t automatically be deduced but as this product is clearly pitching to the green market (easy green cleaning solutions) I’d want to be sure. The website does say ‘natural’ ingredients but as there is no legal definition of the word natural I’m not sure about that either.
  • McKenzies Bicarb  – 100% Australian Family Owned, Made in Australia, Aluminium Free.  Also says ‘made in Australia from imported and Australian Ingredients’.   This leads me to wonder ‘what is the imported ingredient?’ and ‘how many ingredients are in a box of bicarb?’.   On their website they do talk about mining and bicarb being natural but I’m not 100% confident in deducing that this bicarb is of mineral origin. The wording isn’t quite strong enough for me to draw that conclusion so I will ask them.
  • Arm and Hammer – naturally mined bicarb from the USA. 
  • Bob’s Red Mill Bicarbonate of Soda.  Mined mineral.  and aluminium free apparently….

Hang on.  Aluminium free?  When does Aluminium become an issue?

OK so this is a bit of a non issue for Sodium Bicarbonate because it should NEVER contain Aluminium. However baking powder is another issue and contains aluminium in the form of Sodium Aluminium Sulfate as part of the leavening agent.  Whether this is a problem or not (for those who are of the opinion that aluminium is always bad and adds to the risk of developing Auzheimer’s) is for another day but not for the day that we are looking at Bicarb processing.

So that my friends is that.

Mining from Trona or Nahcolite is natural and relatively low impact environmentally.

Manufacturing using the Solvay process is environmentally impactful and utilises petroleum derivatives as well as producing toxic by-products.

 

 

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