Tallows are generally regarded as one of the “cheaper” fats.

Over the last decade, “renewable energies” or “greener energies” have become popular and especially in Europe there has been a thrust to convert tallow (and vegetable oils) to methyl esters which are sold as biodiesel. Methyl esters from tallow are often called Tallow Methyl Esters (TME).

Although biodiesel cannot entirely replace petroleum-based diesel fuel, there are distinct advantages that justify biodiesel’s remarkable development. 

• Provides a market for excess production of vegetable oil and animal fat.

• Can reduce a producing country’s dependence on imported petroleum fuel.

• Biodiesel being renewable does not contribute to global warming due to its closed carbon cycle. Life cycle analysis of biodiesel shows that overall CO2 emissions are reduced by 78% compared with petroleum-based diesel fuel.

• Biodiesel, compared to petroleum diesel, is non-toxic and biodegradable, and can break down by 98% during the first 21 days of a spill. Petroleum diesel will biodegrade by only 50 % during the same period.

• Biodiesel, being an oxygenated fuel, is a better diesel fuel than petroleum diesel because it has a higher cetane number, is cleaner burning, producing lower exhaust emissions of carbon monoxide, unburned hydrocarbons and particulates than does petroleum diesel.

• Biodiesel blended with petroleum diesel in an amount of only 1–2% can improve the lubricating properties of the fuel. Thus a modern ultra-low-sulfur diesel fuel will have much improved lubricity if it includes biodiesel.

Based on the laboratory–scale results, Flo-Dry designed and built a demonstration plant with a capacity of 1000 l/h proving that:

• Reactive Distillation is an effective process for trans-esterifying tallow (and other fats and oils) to biodiesel.

• Good tallow quality is important in terms of achieving both high reaction rates and yields.

• The continuous and compact features of Reactive Distillation have the advantage of reducing the capital costs and operating costs of a biodiesel plant and also of producing consistently high quality biodiesel.