Air Products and Chemicals, Inc.

Arthur Ramsden Smith

Donald W Woodward

Rakesh Agrawal

Michael S Chen

Robert M Thorogood

Declan Patrick O'Connor

James Christian Sorensen

Eric W Scharpf

William Curtis Kottke

Steven L Feldman

John Lloyd Dillon, Iv

Jorge Anibal Mandler

David M Espie

Thomas Joseph Ward

Declan Patrick O'connor

Donald Winston Woodward

David Miller Espie

An integrated gas turbine and air separation process and system having an air separation unit integrated with a gas turbine-driven air compression system which operates using fuel as the primary energy source. Feed air for the air separation unit is provided by two separate compressors driven by the gas turbine expander wherein one compressor provides air to the air separation unit and to the gas turbine combustor, and the other compressor provides feed air to the air separation unit. The ability to control an integrated air separation/gas turbine process during off-design or turndown conditions is improved by the use of two air compressors in the present invention compared with the usual single compressor gas turbine system. In the design of the integrated gas turbine and air separation system, the power requirement for a given air compression duty can be matched more readily to the power output of an available expansion turbine when two air compressors are used rather than a single air compressor.

Air separation process and system with gas turbine drivers

A cryogenic air separation process wherein one or more pressurized product streams enriched in oxygen, nitrogen and argon are produced by cryogenic distillation. One or more of the product streams are pressurized above the operating pressure of the distillation column by introducing a pressurizing fluid into a vessel containing a lower pressure product liquid. In the design of the system the pressurizing fluid can be air or streams enriched in oxygen, nitrogen or argon. Product stream pressurization is accomplished without the use of mechanical pumping devices.

Pressurized liquid cryogen process

An air separation system and a partial oxidation system for the production of synthesis gas are integrated wherein the air separation system provides the oxygen for the partial oxidation process and byproduct nitrogen is utilized to generate refrigeration for pretreatment of the partial oxidation feed gas. The partial oxidation feed gas is predominantly methane, and typically is obtained from natural gas which contains lighter components such as nitrogen.

Feed gas pretreatment in synthesis gas production

Oxygen is produced in an integrated gas turbine-driven air separation process in which heat of compression is recovered from the compressed air feed for the air separation process by heat transfer with the waste nitrogen-rich stream from the air separation process, and the heated waste nitrogen-rich stream is utilized to generate steam. This steam is used to provide a portion of the work to drive the feed air compressor, either by introduction into the gas turbine combustor for expansion with combustion products in the gas turbine expander or by expansion in a separate steam turbine. The process is useful for oxygen production in remote locations where low-cost fuel is readily available and moderate energy efficiency is acceptable, but where capital equipment costs are high and operating complexity is undesirable.

Integrated air separation and combustion turbine process with steam

Pressurized byproduct gas from an air separation system is work expanded and the resulting work is used to compress supplemental feed air which is combined with a main feed air stream to supply a total air feed to the air separation system. Supplemental air can be provided only during off-design operation when the main feed air stream is insufficient to provide the total air feed to the system. Alternatively, supplemental air can be used continuously in combination with a reduced main feed air stream to provide total feed air to the system.

Supplemental air supply for an air separation system

Oxygen is produced by compressing air to provide a first and a second pressurized air stream, separating the first pressurized air stream into an oxygen-rich product stream and a nitrogen-rich byproduct stream, and combining the nitrogen-rich byproduct stream with the second pressurized air stream. The resulting combined stream is heated by indirect heat exchange with a hot process stream and is work expanded in a gas turbine expander. At least a portion of the expander shaft work is utilized for the air compression step. Fuel is combusted with the expander discharge stream to provide the hot process stream for heating the combined stream prior to expansion. The use of this integrated indirectly-fired gas turbine to provide pressurized feed air for the air separation system improves the availability and reliability of the integrated system compared with conventional directly-fired gas turbine systems.

High availability gas turbine drive for an air separation unit

An integrated gasification combined cycle (IGCC) power generation system is operated at off-design conditions by introducing a supplemental fuel into the combustion turbine combustor to compensate for deviations from system design conditions. Such deviations include changes in ambient temperature and changes in the amount of extracted air required for the air separation system. The invention allows operation of the combustion turbine at or close to its maximum design power output and other components in the IGCC system at or close to their respective design points.

Operation method for integrated gasification combined cycle power

An integrated gas turbine/air separation system is operated at or below full system load by feeding the air separation unit with air from a dedicated air feed compressor and optionally with extracted air from the gas turbine air compressor. When the gas turbine air compressor discharge drops below a selected pressure at part load conditions, the flow of extracted air to the air separation unit is discontinued and the air separation unit operates at constant pressure supplied only by the air feed compressor. This mode of operation is particularly useful in an integrated gasification combined cycle (IGCC) power generation system and allows the design of the oxygen and nitrogen product compressors such that the compressors operate at high efficiency during full load IGCC operation.

Operation of integrated gasification combined cycle power generation

An integrated gasification combined cycle (IGCC) power generation system is operated with a cryogenic air separation system which produces oxygen used in a gasification system to produce fuel gas for the IGCC combustion turbine and pressurized nitrogen which is introduced into the combustor for control of nitrogen oxides and increased combustion turbine output. The air separation system produces argon as an additional product, and the air separation system preferably operates in the feed pressure range of about 100 to about 160 psia. The compressed air feed for the air separation system and the compressed combustion air for the IGCC system are provided independently in separate compression steps.

Combustion turbine and elevated pressure air separation system with

A high pressure combustion turbine is integrated with a double column cryogenic air separation system by cooling and purifying a portion of the compressed air from the combustion turbine compressor, work expanding a first portion of the resulting cooled air, and introducing the expanded air into the low pressure column. A second portion of the resulting cooled air is further cooled, throttled, and introduced into the high pressure column. A nitrogen product stream is returned to the turbine combustor, and a portion of the nitrogen product stream optionally is cooled, throttled, and recycled into the high pressure column. Preferably the higher pressure column operates at an absolute pressure which is about 20% to about 85% of the absolute pressure of the compressed air from the combustion turbine air compressor. Optionally an oxygen-rich liquid or a nitrogen-rich liquid is withdrawn from the higher pressure column during a period of low nitrogen product demand, stored, and withdrawn from storage to supplement feed to the lower pressure column during periods of high nitrogen product demand. Alternatively, high purity liquid oxygen is withdrawn from the lower pressure column during a period of low oxygen product, stored, and withdrawn from storage during periods of high oxygen product demand to supplement oxygen product withdrawn from the higher pressure column.

High pressure combustion turbine and air separation system integration

A direct ironmaking process in which coal and oxygen are used directly for reducing ore and smelting the resulting sponge iron wherein a high-temperature ion transport membrane process recovers oxygen for use in the ironmaking process. Heat for oxygen recovery is provided by combustion of medium-BTU fuel gas generated by the ironmaking process and/or by heat exchange with hot gas provided by the ironmaking process. The ironmaking and oxygen recovery processes can be integrated with a combined cycle power generation system to provide an efficient method for the production of iron, oxygen, and electric power.

High temperature oxygen production for ironmaking processes

The present invention is an improvement to a process for the conversion of natural gas to produce higher molecular weight hydrocarbon products, wherein the natural gas is partially oxidized to produce a synthesis gas comprising carbon monoxide and hydrogen, wherein the synthesis gas is catalytically reacted to produce the higher molecular weight hydrocarbon products, wherein the conversion process generates excess steam and wherein oxygen used to partially oxidize the natural gas is produced by an air separation process. The improvement is characterized by operating such air separation process at an elevated pressure so that the feed air to the air separation process is compressed to between 8 and 20 Bar(a); expanding at least a portion of the excess steam generated by the conversion process to generate work and using at least a portion of the generated work to drive the compression requirements of the air separation process.

Elevated pressure air separation unit for remote gas process

The present invention is related to an improvement for a process for the generation of electrical power, wherein, in a cryogenic air separation unit, compressed air is distilled into an oxygen product and a waste nitrogen product, wherein at least a portion of the oxygen product is compressed and reacted with a carbonaceous fuel, in a gasifier or partial oxidation unit, to produce a synthesis (fuel) gas comprising carbon monoxide and hydrogen, wherein feed air is compressed in a gas turbine feed air compressor and subsequently saturated; wherein the synthesis gas is combusted with the saturated, compressed, gas turbine feed air in a combustor to produce a combustion gas, which passes through a transition piece and is then expanded in a gas turbine to generate work, wherein at least a portion of the generated work is used to drive the gas turbine feed air compressor and wherein at least another portion of the generated work is used to generate electricity. The improvement is characterized by: (a) supplying at least a portion of the compressed air to the cryogenic air separation unit by withdrawing a portion of the compressed, gas turbine feed air from the gas turbine feed air compressor; and (b) utilizing at least a portion of the heat of compression of the oxygen product to heat water to saturate the compressed, gas turbine feed air. The improvement can be further characterized by feeding at least a portion of the waste nitrogen product to an intermediate stage of the gas turbine feed air compressor, or by injecting at least a portion of the waste nitrogen product as a controllable inert gas coolant, diluent or mass flow enhancing component into at least one piece of equipment selected from the group consisting of the combustor, the transition piece and the gas turbine, or by utilizing at least a portion of heat inherent to the withdrawn portion of the compressed, gas turbine feed air from the gas turbine feed air compressor being fed to the cryogenic air separation unit to warm the portion of the oxygen product fed to the gasifier or partial oxidation unit.

Integrated air separation - gas turbine electrical generation process

A process and system for controlling a cryogenic air separation unit during rapid changes in production. During operation of an air separation unit, demands for oxygen will vary and the pressure of the feed air will fluctuate. The changes in oxygen demand and feed air pressure translate into a ramping, either up or down, of the distillation system pressure in the air separation unit. Because the product streams have tight purity requirements, the ramping system pressure (which could adversely affect product purity) is compensated for. This compensation is by way of a net transfer of refrigeration, in the form of liquid nitrogen, into and out of the distillation system. This transfer of refrigeration is implemented using a storage vessel of liquid nitrogen connected to the reflux path of the distillation system. Liquid nitrogen via the reflux path is removed and stored or added to the distillation system to decrease or increase the refrigeration, respectively.

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Telford, PA, United States of America

Arthur Ramsden Smith