Pakarab Fertilizers Limited (PFL) operates a 300 MTPD Urea Plant of Snamprogetti technology with HP, MP, LP, and Vacuum sections. The site has been facing Natural gas crisis since 2012 that led to the long term (as many as 3 years) and short term shutdowns of the Plant. Long term Preservation of Urea Plant became challenging because of budget constraints and the unavailability of utilities sometimes. This was a dilemma but sequential improvement in the preservation procedures was kept on done based on the learnings and experiences at site. The mothballing methods used for CS & SS piping and equipment, cooling water heat exchangers, CO2 compressors, centrifugal and HP pumps, Instrumentation and electric equipment were developed and discussed in this paper. The preservation method adopted for CS piping resulted in 55% reduction in Nitrogen consumption. The plant was successfully demothballed after 3 years of preservation. The problems that were faced and the cracks in weld joints and the scaling that were recorded are also discussed. To this date, the consolidated work on the plant preservation is not available and this is an effort to share the experiences and the procedures that were developed for the plant preservation and reliable and safe operation afterwards.
This paper was presented at the 2020 CRU Nitrogen & Syngas Conference in The Hague.