Production of fatty acid derivatives

Abstract

Methods and compositions for producing fatty acid derivatives, for example, fatty esters, and commercial fuel compositions comprising fatty acid derivatives are described.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 245,943, filed Sep. 25, 2009, the contents of which are hereby incorporated in their entirety herein.BACKGROUND OF THE INVENTION[0002]Petroleum is a limited, natural resource found in the Earth in liquid, gaseous, or solid forms. Petroleum is primarily composed of hydrocarbons, which are comprised mainly of carbon and hydrogen. It also contains significant amounts of other elements, such as, nitrogen, oxygen, or sulfur, in different forms.[0003]Petroleum is a valuable resource, but petroleum products are developed at considerable costs, both financial and environmental. First, sources of petroleum must be discovered. Petroleum exploration is an expensive and risky venture. The cost of exploring deep water wells can exceed $100 million. In addition to the economic cost, petroleum exploration carries a high environmental cost. For example, offshore exploration distur...

AI Technical Summary

Benefits of technology

[0063]In a further aspect, the invention features a method of producing a biologically-derived diesel fuel of commercial quality according to commercial standards (e.g., ASTM or ANP). In some embodiments, the method comprises fermenting carbohydrates using a genetically modified microorganism described herein. The process provides a direct route for producing fatty esters, for example, fatty acid esters such as fatty acid methyl esters or fatty acid ethyl esters, without the need of producing oils, which are later chemically transesterified with the concomitant production of large quantities of glycerol. The fuel composition thus produced can be utilized as a diesel fuel alone, or be blended with petroleum diesel according to customary proportions, resulting in clean emission profiles and low amounts of impurities and / or undesirable contaminants.

Problems solved by technology

Petroleum is a valuable resource, but petroleum products are developed at considerable costs, both financial and environmental.

First, sources of petroleum must be discovered.

Petroleum exploration is an expensive and risky venture.

In addition to the economic cost, petroleum exploration carries a high environmental cost.

For example, offshore exploration disturbs the surrounding marine environments.

After a productive well is discovered, the petroleum must be extracted from the Earth at great expense.

Petroleum extraction also carries an environmental cost.

For example, petroleum extraction can result in large seepages of petroleum rising to the surface.

Offshore drilling involves dredging the seabed which disrupts or destroys the surrounding marine environment.

In addition to the shipping costs, there is also the environmental risk of devastating oil spills.

Obtaining these specialty chemicals from crude petroleum requires a significant financial investment as well as a great deal of energy.

It is also an inefficient process because frequently the long chain hydrocarbons in crude petroleum are cracked to produce smaller monomers.

In addition to the problems with exploring, extracting, transporting, and refining petroleum, petroleum is a limited and dwindling resource.

As the world's demand for fuel increases, the emission of greenhouse gases and other forms of air pollution also increases.

Hence, in addition to damaging the environment locally (e.g., oil spills, dredging of marine environments, etc.), burning petroleum also damages the environment globally.

Industrial-scale biodiesel production is thus geographically and seasonally restricted to areas where vegetable oil feedstocks are produced.

However, glycerin is an undesirable byproduct of the transesterification process.

This increases costs and the amount of energy required for fatty ester production and, ultimately, biodiesel production as well.

Furthermore, vegetable oil feedstocks are inefficient sources of energy because they require extensive acreage for cultivation.