Processing Plant & Technology – Introduction
The 30,000 ton per annum processing plant will be located in Marshmeadows, New, Ross, Co.Wexford and will have the use of the quayside import, export facilities of New Ross Port Company from whom the site is leased. It is planned to have production starting in quarter 1 12008.
The process technology for the project will be supplied by Biodiesel International of Austria who are considered to be the world leader in the field of bio-diesel production from a multi feedstock source. BDI has established a total of 16 plants worldwide, 8 of which are multi feed stock plants capable of processing virgin oils, recycles oils and animal fats. A further 12 plants are in construction due for completion in 2007 / 2008.Argent Energy’s 50,000 ton per annum facility in Motherwell, Scotland is their most recent installation. This plant was commissioned in early in 2005 and is now producing 50,000 tons per year of EN 14214 biodiesel from tallow and recycled vegetable oils.
In simple terms biodiesel is the product you get when a vegetable oil or animal fat is chemically reacted with an alcohol (methanol) and a catalyst (KOH) to produce a new compound that is known as a fatty acid methyl ester (Biodiesel or FAME). This process is called transesterification.
All vegetable oils and animal fats consist primarily of triglyceride molecules as shown schematically below. R1, R2, and R3 represent the hydrocarbon chain of the fatty acid elements of the triglyceride. Note that there is a three-carbon chain called the glycerol backbone that runs along the left side of the molecule. Extending away from this backbone are the three long fatty acid chains. In their free form, free fatty acids ( FFA), have the configuration shown below.
Where R is a hydrocarbon chain of greater than 10 carbon atoms.
The properties of the triglyceride and the biodiesel fuel will be determined by the amounts of each fatty acid that are present in the molecules.
The process that will be used in the proposed plant is called transesterification and involves the splitting of the fatty acids away from the glycerol backbone to give glycerol and biodiesel, a fertiliser. The chemical reaction with methanol and a catalyst is shown schematically below.
The biodiesel then undergoes a series of washing steps before finally being distilled to produce biodiesel which meets the European standard and a distillate by product which can be used to fuel the steam boiler in the process.. The glycerol phase also goes through a refining process where it is separated from the catalyst (KOH) to give crude glycerol (80%) and a potassium based fertiliser.