Vale Fertilizantes (Vale), one of the leading fertilizer manufacturers in Brazil, has four facilities with distinct areas of focus, including phosphate and nitrogen fertilizers. In 2013, the company identified a need in the maintenance and operation of its acid nitric plant to reduce production losses and improve annual production. Vale noticed there was a gap in nitric acid production from 2011 to 2012 and discovered that three pieces of equipment were responsible for the main losses, including two weak acid condensers and a compressor discharge air cooler. The condenser’s losses were due to thickness loss, lack of availability of the spare condenser, and shell cracking.
With a production loss above 14,000 tons in 15 months, Vale aimed to reduce annual loss by 10,000 tons by August 2015. Since the losses were due to corrective stops and efficiency loss, the team also defined two key performance indicators (KPIs):
- Reducing weak acid condensers breakdown by 90%
- Keeping weak acid flow above 13 cubic meters per hour
In an effort to improve its maintenance strategies and improve reliability, Vale implemented Predix Asset Performance Management (Predix APM) (formerly Meridium Enterprise APM), specificaly including the APM Reliability and APM Integrity solutions. These solutions included production analysis, thickness monitoring, and root cause analyses (RCA) capabilities.
Vale partnered with the Predix APM team to perform an RCA audit to analyze the condenser system and document failures, as well as develop strategies to prevent reoccurrence. Before the analysis of the condenser system was performed, its function was unknown and the weak acid flow was under the defined limit. The problem signified a larger challenge that the company needed more than a maintenance fix, and required a cultural change to fully embrace and practice ongoing reliability efforts.
Vale replaced condenser B in May 2012, but a few months later, the weak acid flow was again under the set limit. The RCA helped the team discover that the condenser should have been replaced one year prior. Vale implemented 15 recommendations over a period of two years by utilizing Predix APM. In December 2013, Vale’s maintenance team also conducted thickness monitoring for the first time in periodic maintenance.
By implementing Predix APM, Vale was able to:
- Improve its maintenance strategies and asset reliability
- Avoid 25 days of lost production in one year, which resulted in a savings of $1.4 million
- Corrective maintenance was reduced to zero between 2014 and 2015
- Weak acid flow was now above 13 cubic meters per hour
Before Predix APM was implemented, Vale’s production was around 200,000 tons; after implementation, it was more than 212,000. In addition, the company’s revenue increased by $1.275 million, the maintenance expenses were reduced by $150,000, and the condenser lifespan was extended from two to four years.