Performance evaluation and availability analysis of ammonia synthesis unit in a fertilizer plant

This paper discusses the performance evaluation and availability analysis of ammonia synthesis unit of afertilizer plant. the fertilizer plant is a complex and repairable engineering system comprises of various unitsviz. shell gasification and carbon recovery, desulphurization, co-shift conversion, decarbonation, nitrogenwash and ammonia synthesis etc. one of the most important functionaries of a fertilizer plant is ammonia synthesisunit. this unit consists of five subunits arranged in series and parallel configurations. for the evaluationof performance and analysis of availability, a performance evaluating model has been developed with the helpof mathematical formulation based on markov birth-death process using probabilistic approach. the findingsof this paper are therefore, considered to be useful for the analysis of availability and determination of the bestpossible maintenance strategies in a fertilizer plant concerned.