Energy management for conversion of methanol into gasoline and methanol into olefins

CATEGORY: METHANOL

PATENT

Energy management for conversion of methanol into gasoline and methanol into olefins

United States Patent Application 20120051953

Inventors: O'rear, Dennis J. (Penngrove, CA, US)

Application Number: 12/807065

Publication Date: 03/01/2012

Assignee: Chevron U.S.A. In.

Abstract:

A process is disclosed for the conversion of a hydrocarbonaceous assets into gasoline. The hydrocarbonaceous assets are converted at a first methanol production facility into methanol by processes comprising gasification and methanol synthesis. At least a portion of the methanol is shipped to a second gasoline production facility that is at least 10 miles in distance from the first location. At the second gasoline production facility, at least a portion of the methanol is converted by a MTG process to produce a gasoline and LPG components and steam. At least a portion of the methanol may also be used in a methanol to olefin process to produce olefins and steam. The olefins may be alkylated with olefins to produce alkylates which may mixed with the gasoline. The steam from one or both of the MTG or MTO processes may also be used by processes such as driving pumps to unload the methanol, driving pumps to deliver the gasoline product, driving compressors to liquefy the LPG components, driving generators to produce electricity, heating other substances, to gasifying imported LNG, and combinations thereof.

FIELD

The present disclosure generally to methods for making gasoline by integration of methanol to gasoline (MTG) and methanol to olefins (MTO) processes.

DESCRIPTION OF THE RELATED ART

The developed and developing world markets need supplies of transportation fuels. Gasoline is one of the major fuels in use today and the near future. Petroleum is often found at sites remote from market sites. Petroleum can be readily transported to refineries near the markets where it is refined into gasoline.

In contrast, other hydrocarbonaceous assets are more difficult to transport as they are viscous or dense liquids, gases or solids. Examples of such hydrocarbonaceous assets include natural gas, coal, and plant based feedstocks such as wood, corn, switch grass, etc. These hydrocarbonaceous assets can be converted into methanol by various well know processes, including gasification, to form synthesis gas followed by methanol synthesis. Non-limiting examples well known to those skilled in the art for converting hydrocarbonaneous feedstocks into synthesis gas for conversion to methanol include steam methane reforming, partial oxidation, gasification, combined reforming and autoreforming.

The methanol can then be readily shipped to sites near the market sites where it can be converted into gasoline by a Methanol to Gasoline (MTG) process. Unfortunately, the MTG process produces significant quantities of light paraffins. These light paraffins are rich in non-quaternary isoparaffins, but these isoparaffins have low value because their high volatility makes blending into gasoline difficult or impossible. These isoparaffins then must be used in lower value applications such as fuel, and where possible, liquefied petroleum gas (LPG). Isopentane is particularly difficult to use because it cannot be used in either gasoline or in LPG.

Methanol to Olefins (MTO) is another process that converts methanol to a useful product, light olefins (ethylene, propylene and butenes). Ethylene is the olefin currently in geatest demand, and having the highest value. The propylene and butenes have lower value and improved uses for these olefins are desired.

There is a need for a process wherein otherwise hard to transport carbonaceous assets are converted to methanol. Then, the methanol is received at a gasoline manufacturing facility wherein the methanol can be efficiently converted into gasoline products.

In the current practice, the conversion of hydrocarbonaceous assets into gasoline at remote locations followed by shipping the gasoline to markets does not fully utilize the energy in the hydrocarbonaceous asset. This lost energy is equivalent to poor carbon management throughout the product value chain and increased greenhouse gases.

It is desirable to convert hydrocarbonaceous assets that are in locations remote from market into transportation fuels for use in developed markets. In the 1970's Mobil commercialized a technology in New Zealand which converted natural gas into methanol, and then converted the methanol into gasoline by a Methanol-to-Gasoline process (MTG). However recent concerns over energy management and greenhouse gas emissions have created a need for an improvement in this process.

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