The reaction proceeds in the presence of a proprietary solid catalyst, achieving complete conversion to the methyl ester product.
The water produced in the esterification reaction is stripped out of the methyl esters by excess methanol. This methanol/water mixture leaves the reactor as overheads and moves to a methanol column for separation, with the resulting dry methanol recycling back to the esterification reaction column.
The crude liquid methyl esters exit from the bottom of the column then proceed to purification.
A two-stage flash system removes any small amounts of methanol from the crude methyl ester product.
Following pre-heating, the product stream enters flash pot#1 which, operating at atmospheric pressure, removes most of the methanol present.
Flash pot#2, operating under vacuum, removes any final methanol, leaving market-quality biodiesel which is sent to storage. The flashed methanol recycles back into the process.
The Davy biodiesel process can convert a wide range of naturally derived oils. The list of viable feedstocks includes:
- Palm sludge oil
- Palm fatty acid distillate
- Used cooking oil
- Rancid fats
- High fatty acid oils
- Virgin vegetable oils
- Non-edible virgin vegetable oils
- Tallow and other animal fats
- Waste fats and oils
- Algae oils
JM Davy can test other potential feedstocks at our Global R&D Centre in the Tees Valley, UK.
Our propylene glycol (PG) process employs glycerol, the Davy biodiesel by-product, as a feedstock.
Consequently these two Davy flowsheets complement each other perfectly. The clean glycerol stream from our biodiesel process can feed an adjoining PG plant, reducing overall project capital and operational costs by sharing ancillary systems and reducing tankage.
Utilising both Davy processes in this way would enable a single producer to ensure the most efficient use of resources and process outputs.