Process and Reagent for Removal of Oxygen from Hydrocarbon Streams

Abstract

A method of using a sulfided iron reagent to remove oxygen from gaseous and liquid fluid streams such as natural gas, light hydrocarbon streams, crude oil, acid gas mixtures, carbon dioxide gas and liquid streams, anaerobic gas, landfill gas, geothermal gases and liquids, and the like is disclosed. In a preferred embodiment, the reagent is made by mixing, agglomerating and shaping finely powdered ferrous carbonate, preferably siderite which are used to remove oxygen from a hydrocarbon or carbon dioxide stream that also contains sulfur compounds such as hydrogen sulfide.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates to a method for using a reagent composition for removing oxygen from a variety of fluids, and particularly from liquid and gaseous hydrocarbons and carbon dioxide. The method is especially useful for removing oxygen from gaseous hydrocarbon streams, light liquid hydrocarbon streams such as natural gas liquids (“NGL”), crude oil, acid-gas mixtures, carbon dioxide gas and liquid, anaerobic gas, landfill gas, geothermal gas, and the like.[0003]2. Description of Related Art[0004]At times oxygen is present as a contaminant in various gaseous and liquid hydrocarbon and carbon dioxide streams. In some cases, the oxygen is the result of a natural gas field that is contaminated with oxygen. Other times oxygen is often unintentionally introduced through processing of the gaseous hydrocarbon streams. One example of this is when a compressor is used to increase the pressure of low pressure gas, such as coal s...

AI Technical Summary

Benefits of technology

[0011]According to another embodiment of the invention, the amount of oxygen in a liquid, gas, or mixed gas and liquid stream comprising sulfur-containing compounds is reduced by causing the stream to pass through a reagent bed consisting essentially of particulate material comprising from about 70 to about 100 weight percent ferrous carbonate, preferably in the form of aggregated particulate siderite. The absorbent bed most preferably comprises a plurality of pellets comprising from about 70 to about 100 weight percent ferrous carbonate in combination with an amount of a binder such as calcium aluminate cement that is sufficient to hold the reagent in a desired physical configuration for a desired service life. It will be appreciated by those of ordinary skill in the art upon reading this disclosure that the amount of the inventive reagent that is needed in the absorbent bed will depend upon factors such as the reagent particle size, the bed density, the effective surface area of the reagent particles, the amount of reagent that is available to absorb the oxygen, the amount of sulfur-containing compounds in gas or liquid stream being processed, and the temperature, pressure, velocity and residence time of the gas or liquid stream being treated as it passes through the bed.

Problems solved by technology

Other times oxygen is often unintentionally introduced through processing of the gaseous hydrocarbon streams.

The presence of oxygen in gaseous and liquid hydrocarbon streams such as a natural gas stream can cause various problems.

It can also interfere with further treatment of the gas stream.

This makes it difficult to remove hydrogen sulfide from various hydrocarbon streams that also contains oxygen.

In fact, many pipeline companies will discount the value of a natural gas stream that contains high levels of oxygen or may even refuse to accept natural gas streams that contain more than a certain level of oxygen.

The use of oxygen removal systems for gaseous hydrocarbon streams is not widespread and there is a lack of an economical way to remove low levels of oxygen from natural gas streams.

However, the presence of oxygen in the gaseous stream inhibits the removal of the sulfur compounds.