Production of renewable diesel by pyrolysis and esterification
The present invention relates to a process and apparatus for the production of diesel fuel from feedstocks containing fatty acids, glycerated fatty acids, and glycerin by catalytic and/or non-catalytic pyrolysis followed by esterification. Specifically, the present invention relates to the production of Renewable Diesel having low glycerin, water, and sulfur content.
1. An industrial process for preparing Renewable Diesel from a feedstock of vegetable and/or animal origin comprising:
subjecting the feedstock to catalyzed pyrolysis to produce a pyrolyzed composition comprising carboxylic acid;
esterifying said carboxylic acid with alcohol in a counter-current reactive distillation column to yield a fuel according to either ASTM D396 or ASTM D975, wherein the fuel comprises less than 5 ppm sulfur, less than 0.20% by weight total free glycerin, less than 0.15% by weight residual methanol, and less than 300 ppm water.
2. The process of claim 1 , wherein said pyrolysis is carried out in a direct fired furnace or a heat exchanger.
3. The process of claim 1 , wherein said pyrolysis and said esterifying are carried out in a direct fired or indirect heated batch distillation column.
4. The process of claim 1 , claim 2 or claim 3 , wherein said pyrolysis is carried out in the presence of steam.
5. The process of claim 1 , wherein said esterification is carried out using a solid catalyst.
6. The process of claim 5 , wherein the solid catalyst is an ion exchange resin catalyst comprising —SO3H or —CO2H functional groups.
7. The process of claim 1 , wherein the alcohol is selected from methanol, t-butanol, isobutanol, or a mixture thereof.