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 a fertilizer plant. the fertilizer plant is a complex and repairable engineering system comprises of various units viz. shell gasification and carbon recovery, desulphurization, co-shift conversion, decarbonation, nitrogen wash and ammonia synthesis etc. one of the most important functionaries of a fertilizer plant is ammonia syn-thesis unit. this unit consists of five subunits arranged in series and parallel configurations. for the evaluation of performance and analysis of availability, a performance evaluating model has been developed with the help of mathematical formulation based on markov birth-death process using probabilistic approach. the findings of this paper are therefore, considered to be useful for the analysis of availability and determination of the best possible maintenance strategies in a fertilizer plant concerned.