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Optimization of Ammonia Production to Meet Marketing Objectives

IP.com Disclosure Number: IPCOM000218832D
Publication Date: 2012-Jun-07

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The IP.com Prior Art Database

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OPTIMIZATIONOF AMMONIA PRODUCTION TO MEET MARKETING OBJECTIVES

Timothy B. Challand Paul E. Nicks

The M.W. Kellogg Company Three Greenway Plaza Houston, Texas 77046-0395

March 1989

Kellogg's Ammonia Optimizer representsthe application of state-of-the-artcontrol and optimization techniques to the operation of ammonia plants. The packaged hardware/software product is suitable for both new and existing plants. Capabilities include provision for the operator to respondto changingmarket conditions. Maximum production or minimum energy consumption scenarios are automatically allowed for

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Optimizer on overall ammonia plant profitability.

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Optimization of Ammonia Production

I NTRODUCTI0N
The Ammonia Optimizer as developed by The M.W. Kellogg Company comprises a combinationof process control hardwareand computer software The system provides for advanced process control of the major control loops within the ammonia plant, as well as the capability to perform on-line optimization calculations. The latest technology in process stream analysis is also utilized to provide accurate, reliable informationto the control system.

The Optimizer was designed to provide operators of Kellogg ammonia plants with a tool to improveoperating margins. At the time development started on the Optimizer, market conditions for ammonia productionwere very poor. Fuel prices were high and the value of the ammonia producedhad slumped. Although conditions have improved somewhat in the last year, the need for tight control over operating costs remains. This has required that the Optimizer be a low-cost, highly efficient, integrated package that can be "added-on" to a plant's existing control system. Simply scrapping the old controls and installing a modern Distributed Control System (DCS) with a Process Computer was ruled out due to the high initial cost and consequent marginalpayout.

In the case of new ammonia plant designs, the technology contained within the Optimizer would be applied through a modern DCS system. This requires a different packaging of the system with much of the data acquisition and man-machine interfacing being assignedto the DCS. Much of the early interest in the Optimizer has been been focused on the upgrade option. Consequentlythis paper concentrates on this aspect. However it should be borne in mind that new plants would also benefit from the advanced control and optimization systems described here.

PR-
There were four major objectives to the Optimizer development effort. The system was designed to be low cost, to be supervisory in nature, to utilize industrially proven hardware, and to offer benefits in terms of reduced energy consumption or increased ammonia production.

Low cost for revamp projects is obtained by deciding not to scrap the existing controls, but by providing an "add-on" system. Recent developments with microprocessorsnow permit complex computational tasks to be performed by microcomput...