Process for the treatment of substrate-variable methane emissions

Abstract

The invention relates generally to a system and method the treatment of substrate-variable gaseous emissions comprising dynamic concentrations of organic materials comprising methane and one or more non-methane organic compounds that can be metabolized by methane-oxidizing microorganisms, and in one specific embodiment, to a system and method for the treatment of substrate-variable methane emissions through the use of methanotrophic microorganisms in a species-universal polymer production process. Certain embodiments of the invention are particularly advantageous because they reduce environmentally-destructive methane emissions and produce harvestable end-products.

Description

RELATED APPLICATIONS [0001] This application is the U.S. National Phase application under 35 U.S.C. §371 of International Application PCT / US2005 / 047415 filed Dec. 29, 2005, (published as WO 2007 / 024255), which claims the benefit of Provisional Application No. 60 / 721,938, filed Sep. 29, 2005, and is a continuation-in-part of co-pending patent application Ser. No. 11 / 208,808, filed Aug. 22, 2005, which claims the benefit of Provisional Application No. 60 / 603,857, filed Aug. 24, 2004; wherein patent application Ser. No. 11 / 208,808 is a continuation-in-part of co-pending patent application Ser. No. 10 / 687,272, filed Oct. 15, 2003, now issued as U.S. Pat. No. 6,982,161; and wherein the disclosures of all of these applications are incorporated by reference herein.BACKGROUND OF THE INVENTION [0002] 1. Field of Invention [0003] This invention relates generally to a system and method for the treatment of methane emissions, and in one specific embodiment, to a system and method for the treatm...

AI Technical Summary

Benefits of technology

[0017] In one preferred embodiment, the gaseous emissions (which comprise some amount of methane) from landfills, coal mines, agricultural sites, or petroleum sites are captured and conveyed to a bioreactor containing methanotrophic microorganisms. The gaseous emissions do not need to undergo substantial purification. The microorganisms use the methane as a source of carbon or energy, and, in some embodiments produce useful end-products such as polymers. The polymers can then be used to synthesize various types of biodegradable materials. For example, the polymers can be used to produce plastics because, in some cases, the physical properties of the polymers produced by the methanotrophic microorganisms are very similar to those of polypropylene. However, the polymers produced by the methanotrophic microorganisms are biodegradable, and therefore environmentally friendly. Thus, some preferred embodiments of the invention offer a tremendous benefit to the environment in at least two ways: first, methane emissions are substantially reduced on the front end, and second, a biodegradable polymer is produced in useful quantities as the end-product.

[0021] In one embodiment of the invention, the system comprises means to enable the practical application of methanotrophic microorganisms to methane emissions treatment, particularly in a manner that does not rely on a reduction in the operating costs of treatment. In other words, in one embodiment, methanotrophic microorganisms can be used to reduce methane pollutants in the environment without relying on altering the methanotrophic microorganisms (e.g., by genetic engineering, etc.). In one embodiment, naturally occurring methanotrophic microorganisms are used to reduce the methane concentration of gaseous emissions.

[0025] The viability and utility of methanotrophic emissions treatment may be augmented by increasing the growth or emissions oxidation rate of methanotrophic microorganisms in order to reduce the capital and operating costs of treatment. While this optimization method renders methanotrophic treatment more efficient, it does not overcome the challenge associated with the continuous generation of non-recoverable costs, and no methods are known in the prior art to optimize the methanotrophic bioremediation process in such a way as to enable practical sustainability. Prior to the applicants' invention, the only methods available for treating methane emissions involved environmental degradation and wasted energy associated with the venting, compression, conversion, and / or combustion of methane emissions.

[0028] In accordance with one embodiment of the invention, a novel method for enabling the viable treatment of air containing methane emissions is provided. In one embodiment, methanotrophic microorganisms and air containing methane emissions are mutually-exposed to cause or enable harvestable product formation. The harvestable product may be used or sold. In another embodiment of the invention, air containing methane emissions may be used to create single cell protein, enzymes, polymers, or other bio-based products in a manner that enables product harvest.

[0033] In one embodiment, the invention comprises substantially reducing or eliminating the concentration of nitrogen available to the methanotrophic microorganisms.

[0041] In one embodiment of the present invention, a system to reduce methane emissions or gaseous emissions comprising methane is provided. In one embodiment, the emissions are produced by land fills, waste processing sites, coal mines, and other similar systems created by humans. In another embodiment, the emissions are produced by ruminant animals.

Problems solved by technology

Although the prior art recognized that methanotrophic organisms could use methane to produce polymers, the prior art did not teach or suggest an effective method by which destructive gaseous emissions that comprise methane could be used to produce polymers.

Thus, prior to applicants' invention, the production of useful quantities of polymers by methanotrophic organisms was not feasible, because the process, which (among other drawbacks) required a pure and / or concentrated source of methane, could only be done on a small scale.

Moreover, because a pure and / or concentrated source of methane was required, the costs of operating the system was extremely high.

Images