Every grade of glycerine, from crude to USP -- and where each one goes

Crude (typically 80 % glycerol, with 85 and 88 % also trading), technical grade at 98 to 99 %, and refined pharmacopoeia material at 99.5 % and above. Around them trade the dilute streams -- sweet water, soap lyes -- and refining residues. The grade is really a price band, and the analysis decides the band.

The co-product of transesterification and of fat splitting: typically 80 % glycerol with water, ash, MONG and residual methanol. It prices on five numbers -- glycerol, water, ash, MONG and methanol -- and sells to refiners, oleochemicals, biogas plants and, within the catalogue ceilings, feed.

Purified glycerine at commonly 98 to 99 %, sold into industrial uses where pharmacopoeia compliance is not required: resins, antifreeze, concrete additives, general chemistry. The rung above crude and below pharma, and priced against the alternatives rather than against the pharmacopoeia.

Glycerine meeting the United States Pharmacopeia monograph: an assay of not less than 99.0 % C3H8O3, with the identification, impurity and labeling requirements that go with it. USP and Ph.Eur. material trade globally into pharmaceutical, food and personal care uses.

The European Pharmacopoeia has two monographs: Glycerol, the anhydrous material (monograph 0496, assay typically 99.5 % and above), and Glycerol 85 %, the aqueous solution (monograph 0497). Both are pharmacopoeia grades with the same documentation obligations; the 85 % solution is the common commercial form.

The dilute glycerol-bearing water from fat splitting -- the hydrolysis of fats into fatty acids and glycerol. Concentrated, it becomes crude glycerol; the EU feed material catalogue names exactly this route in its crude glycerine entry 13.8.1.

The glycerol-bearing lye left over when oils and fats are saponified to make soap. Salt-heavy by nature of the process, priced accordingly, and also named in feed catalogue entry 13.8.1 as a source of crude glycerol.

The trade's name for refining and esterification residue streams: heavier, coloured material that specialist processors take and energy outlets burn. Low rung, real market.

Origin and process: vegetable (natural) glycerine comes from fats, oils and their co-product streams; synthetic glycerine comes from petrochemical feedstocks such as propylene. The molecule is the same, and pure glycerol of either origin classifies under CN 2905 45 00 -- but origin matters to buyers with renewable or certification claims.

Yes -- that is glycerolysis. Free fatty acids plus glycerine become glycerides, industrially at roughly 200 °C often over zinc-based catalysts, without the waste water of acid esterification. It suits the 20 to 50 % FFA streams that would otherwise saponify, and published work runs it on crude glycerine itself.

The reaction of glycerol with free fatty acids (or triglycerides) to form mono-, di- and triglycerides. As a pretreatment it converts the FFA in a rough feedstock into neutral glycerides a biodiesel or renewable diesel plant can process. Peer-reviewed work reports FFAs below 2 % after treatment at 200 °C.

Yes: the bio-based route hydrochlorinates glycerine with HCl to dichloropropanols and dehydrochlorinates them to epichlorohydrin. It was commercialised precisely to use biodiesel by-product glycerine, and it is one of the largest single chemical outlets for the molecule.

Epichlorohydrin, propylene glycol and 1,3-propanediol (both by hydrogenolysis), plus esters, polyglycerols and specialty derivatives. The chemistry raises glycerine above its energy value -- which is why purity and consistency command premiums.

Crude glycerine within the written ceilings of feed catalogue entry 13.8.1: methanol up to 0.5 %, salts to 7.5 %, MONG to 4 %, with sodium and potassium declared above 1.5 % and nickel above 20 ppm. The refined entry 13.8.2 starts at 99 % glycerol on dry matter.

The roughest crudes: anaerobic digestion prices glycerine as an energy-dense co-substrate, tolerant of material no refiner wants, with strong demand in Belgium and the Netherlands. The floor of the ladder, and the reason glycerine always has a home.

By distillation or by ion exchange, as the feed material catalogue itself describes for its refined entry -- taking concentrated crude to 99 % on dry matter and beyond. Salt and MONG are what the process fights, which is why refiners price them so hard at the crude end.

Yes -- crude, technical, refined and pharmacopoeia material, plus sweet waters, soap lyes and residue streams. The buyer list narrows as the specification tightens; we say plainly which rung a cargo belongs on and which buyers fit it.