Hi, ....I'm Rick, an R&D Chemical Consultant specialising in combustion chemistry - mostly related to bio-fuels and associated, I worked mostly in The USA....and am now semi-retired in Portugal.
I am the person that oversees and guides the development of the recently launched 'Zip Military Fuel Block' so am probably best placed to answer some of the questions without giving away confidentialities or commercial secrets, so read on............ The info below is in the public domain and freely available to researchers.
At the risk of coming over all professorial............
As Tony quite correctly surmised, the material used is a short chain narrow cut methyl ester and not the usual biodiesel type. The chain length chosen - for odour as well as flash point reasons, [capric or C8 has a strong soapy/chemical smell] - is at 10 carbons [methyl decanoate - and has very little odour], and just to be clear, is not the broader cut primarily 16/18 carbons as in biodiesel. This results in a more readily ignitable product, due to the lower flash point and boiling range.
The material is principally derived by esterification of C10 fatty acid found primarily coconut oil or sometimes, palm oil which are relatively rich in this component and is separated by vacuum distillation. There are other oil sources but this is the predominant source at this time. The UK Headquartered company I Consult for, is currently specialising in eco-chemistry driven new product development routes -- and this product is one of the first 'ecosafe' worldwide interest products aimed at Military and outdoor leisure folks, to replace the toxic material 'hexamine' as used as a cooking fuel up to this time.
The liquid material is essentially 'solidified' by use of polymer chemistry techniques, where the Me-Ester is trapped as micro-globules in a closed cell structure and answering a question posed in this string - I am afraid this would not be able to be made at home.
I hope this helps the understanding of the product...........Rick
