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Considering KRES and Purifier for Energy Cost Savings and Increasing Capacity in the Ammonia Plant

IP.com Disclosure Number: IPCOM000217512D
Publication Date: 2012-May-08
Document File: 18 page(s) / 1M

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The IP.com Prior Art Database

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Page 01 of 18

KBR

A Halliburton Company

Consider KRES and Purifier for energy cost savings and increasing capacity in the ammonia plant

Avinash Malhotra

Jim Gosnell

Kellogg Brown &Root, Inc. Houston, Texas, USA

  Prepared for presentation at the FAI Seminar 2002, New Delhi, India 16-18 December 2002

Copyright KBR

December 2002

Unpublished

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Page 02 of 18

KBR

A WliburtonCompany

Consider KRES and Purifier for energy cost savings and increasing capacity in the ammonia plant

ABSTRACT

In October 1994, the KBR Reforming Exchanger System (KRES), a simple heat exchanger based steam reforming process used for generation of ammonia synthesis gas, was commissioned in Pacific Ammonia Incorporated's ammonia plant at Kitimat, British Columbia, Canada. KBR has further optimized and improved the design of KRES for synthesis gas generation for large capacity ammonia plants. In 2001 KBR was awarded a contract to supply a 1070 metric fondday KRES as part of an ammonia revamp project in China. In this project KRES replaces an existing fired reformer to reduce the natural gas fuel requirement. This unit is scheduled for commissioning in 2003.

The first ammonia plant using KER's PurifierTMProcess was commissioned in 1966 and had an energy consumptionof 8.3GcaYMT. Since then 15 ammonia plants have been started up using proprietary KBR's PurifierTMProcess. Two more alle in design and construction. Several of these Purifier Plants have proved to be the most efficient and reliable ammonia plants in the world. This technology can also be used to reduce energy consumption and increase capacity of non-Purifier plants

The purpose of this paper is to provide an overview of the various flow schemes where incorporating KRES and Purifier technology along with other energy reducing techniques can effectively reduce the energy consumption and increase the capacity of an ammonia plant. The paper also highlights the cost, environmental, reliability and operability benefits these technologies provide to the ammonia producer.

INTRODUCTION

The initial concept of the KBRs PurifierTMProcess was to use a heat exchange reformer instead of a fired primary reformer. Heat balance considerations require that either excess air or oxygen-enriched air be used in the secondary reformer of such a design. The inventor opted for excess air.(') This meant the excess nitrogen had to be removed in a cryogenic unit downstream, so dryers were needed upstream of the cryogenic unit. The amount of excess air required to make the system work is about 150 percent of the stoichiometric nitrogen requirement.

All of these changes to ammonia plant design in the early 1960s were too much of a departure from conventional thinking for the times. So the heat exchange reformer

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Page 03 of 18

KBR

A Halliburton Company

concept was dropped and replaced by a traditional fired primary reformer. The 50 percent excess process air rate was retained because it has twobenefits. It reduces the size of the primary refo...