Liquid metal catalyst for biodiesel production

Abstract

Molten metal or molten metal alloy catalysts for transesterification reactions are provided. In particular, readily available molten tin is used as a catalyst for biodiesel production. Catalysts comprising tin alloys with low melting point temperatures to allow for low operation temperatures are also provided. The molten catalysts remain in the reaction zone and do not contaminate the product stream, thereby product separation and recovery are manageable. By using molten tin catalysts, it is possible to produce a high quality glycerol as a second valuable product. Furthermore, wide quality ranges of reactants (alcohol and oil) are available for biodiesel production with molten tin catalysts.

Description

FIELD OF THE INVENTION[0001]The invention relates generally to biodiesel production. More particularly, the present invention relates to catalysts for biodiesel production.BACKGROUND[0002]In recent years, biodiesel production has increased nationwide. Biodiesel production generally includes the reaction of alcohol and oil to produce esters (biodiesel) and glycerol. The amount of biodiesel currently produced, however, can only accommodate a small fraction of the total amount of diesel consumed. Methods and processes to more effectively produce biodiesel from a wider range of feedstocks would enable greater amounts of biodiesel production, thereby making biodiesel use more widespread.[0003]The major problem in the biodiesel production market is the cost of feedstock, with other substantial costs due to the polishing of the product and the treatment of waste process streams. In particular, well-established methods of producing biodiesel rely on the use of a homogeneous consumable catal...

AI Technical Summary

Benefits of technology

[0008]In a preferred embodiment, the catalyst includes molten tin. In another preferred embodiment, the catalyst includes molten tin alloyed with at least a second metal, such as lead, indium, bismuth, copper, antimony, silver, or any combination thereof. The alloy preferably has a lower melting point than the melting point of unalloyed tin. In an embodi

Problems solved by technology

The amount of biodiesel currently produced, however, can only accommodate a small fraction of the total amount of diesel consumed.

The major problem in the biodiesel production market is the cost of feedstock, with other substantial costs due to the polishing of the product and the treatment of waste process streams.

These traditional methods, however, are restricted by the use of oils with low free fatty acid concentrations, generally only found in expensive feed stocks, such as palm, canola, or soybean oil.

In addition, traditional biodiesel production methods require expensive and time-consuming process steps to remove excess catalyst from the biodiesel and glycerol products.

Though glycerol can be a valuable secondary product, the glycerol produced using traditional catalysts is often of low quality and has little market value.

Furthermore, the batch-wise operation requires long reaction times in multiple large reactors, which create significant variation in product quality and composition.

The large product quality variations dictate continuous and costly product analysis.

Though these methods reduce some of the difficulties associated with traditional biodiesel production methods that rely on consumable liquid catalysts, they generally require high operational temperatures and pressures.

Extreme reactor conditions create many difficulties for heterogeneous catalytic and non-catalytic reaction systems, including the necessity of large alcohol-to-oil ratios, specialized materials, and unwanted by-products side reactions.

Large alcohol-to-oil ratios and by-products production demand high recovery and removal costs, respectively.

In addition, the elevated temperatures and pressures create large energy demands, which increases the energy costs and decreases the environmental value of biodiesel production over standard diesel production.

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