甲醇 — Frequently Asked Questions

The reaction needs about 11 % methanol on oil mass, and plants charge roughly twice that to drive the equilibrium, then recover the excess by distillation. Net consumption after recovery is therefore close to the stoichiometric amount plus losses, with extra methanol needed where high-FFA feedstocks are esterified.

Water hydrolyses esters back into free fatty acids, which the alkaline catalyst converts into soap. That lowers yield, consumes catalyst and slows glycerine separation. Specify a water maximum, commonly around 0.1 % w/w for reference grades, and keep drums and tanks closed, because methanol absorbs moisture from air.

Yes. Excess methanol is recovered from the ester and glycerine phases by flashing and distillation and recycled. Recovered methanol carries water, especially after esterification, so it must be dried to the reactor specification before reuse. Recovery performance has a direct effect on net consumption.

Yes, where actual values are calculated: the emissions from producing the methanol count as a process input. Renewable or low-carbon methanol can improve the result, but only when supported by documentation recognised by your scheme. Confirm the approach with your certification body.

It is highly flammable, with a flash point around 10–12 °C and a flame that is hard to see in daylight, and it is toxic by ingestion, inhalation and skin contact. Use closed transfers, earthing, ventilation and suitable protective equipment, and follow the safety data sheet.

Your purity and water limits or reference specification, whether conventional or renewable methanol is needed, the volume, drum or ISO tank packaging, delivery point and Incoterm, and the documents you require, such as a certificate of analysis and safety data sheet.