Because only industrial ethylene glycol has color and taste, and some parts will change color when heated.

To put it bluntly, industrial grade ethylene glycol is non-standard ethylene glycol, which is lower than the national standard.

Because polyester-grade ethylene glycol and coal-based ethylene glycol are superior products, the first-class products either have no taste or have a little taste.

This kind of ethylene glycol is cheap, but its disadvantages in use are also obvious, among which are odor and color.

At present, the corresponding experiments have been done online, in which the odor problem of petroleum grade non-standard ethylene glycol can be solved by debonding resin, and the effect is satisfactory. But you need to buy a set of pressurizing equipment and corresponding raw materials, which obviously increases the cost and loses the advantage of non-standard ethylene glycol, which is why major manufacturers no longer purify it.

At present, there is no good solution to prepare non-standard ethylene glycol from coal. The problem of heating discoloration can be solved by additives, but the taste problem can't be solved or the cost is too high.

I once saw a vendor put this raw material into a storage tank and then pumped the bottom of the ethylene glycol storage tank dry with an air pump. This part thinks that with air politics and law, the taste will be obviously reduced, but at the same time, some ethylene glycol will be volatilized. This effect is very slow, but it is also the lowest cost at present.

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