Turbo Blower RCM Analysis
Updated: Jan 7, 2022
REPLAN Petrobras Refinery, Brazil
Petrobras Paulinea Refinery, also known as REPLAN, started operating in 1972 and is the biggest refinery in Brazil. It is 118km from São Paulo. The refinery has a production capacity of 66.000 cubic meters per day, equivalent to 415,000bpd. It initially had a capacity of 126,000bpd. The refinery produces diesel fuel, gasoline, LPG, naphtha, kerosene, coke, asphalt, solvents and propene. In 2009 the refinery started producing metropolitan and interior diesel fuels with low sulfur content. The refinery also started production of S50 diesel with 50ppm.
REPLAN's production accounts for 20% of Brazil's oil refining capacity. The refinery processes about 80% of domestic oil, the majority of which comes from the Campos Basin offshore Rio de Janeiro. Construction of the refinery helped Brazil save about $200m in foreign exchange annually.
REPLAN's Plant includes the following technical features:
- 2 Distillation units
- 2 Catalytic Cracking units
- 2 Delayed Coking units
- 2 Diesel Hydro treatment units
- 2 Cracked Naphtha Hydrodesulphurization units
- 1 Hydrogen Recovery unit
- 1 Propene Separation unit
The Turbo Blower RCM Analysis:
In 1999, a RCM Analysis was performed to review the SP-2251 Air Turbo Blower, a critical and complex physical asset subsystem, part of the Catalytic Cracking Unit #2 process.
Cracking Catalytic Unit:
Processed load: 8,500m3/day (percentages in mass: 42.2% naphtha, 16.5% light oil, 15.7% decanted oil, 13.1% LPG, 6.0% coke, 5.8% combustible gas, 0.7% acid gas)
Air Turbo Blower System
Primary function: to provide combustion air to the regenerator
Technical data summary :
Axial Blower: Flow rate: 240,000 Nm3/hr
Discharge pressure: 3.0kgf/cm2 (42.67psi)
Manufacturer: DEMAG, Germany
Power: 14,460kw (19,633hp)
Extraction/condensation steam turbine
Cracking Catalytic Unit downtime cost:
Minimum downtime per Air Turbo Blower System failure:
1 day, at a cost of US$350,000 in loss of production (note: year 2000 data)
However, total cost of failure is = x-day downtime plus cost of repair plus any other accountable consequence
The total cost varies depending on the failure mode/cause, sometimes would be very expensive (e.g. lubricating system failure damages may cost US$1million or more plus several days downtime for the Cracking Catalytic Unit).
System average failure rate before the RCM analysis and recommendations implementation:
7 failures/year, at a total cost of US$ 2,45 million in production losses plus cost of repairs
RCM Analysis was performed in a total of 120 hours, distributed in a series of two 4-hr weekly meetings, over 5 months.
Note: The RCM review planning varies accordingly with the circumstances.
RCM Analysis team (SMEs: engineers and technicians):
Operators: 2; Instrumentation: 2; Mechanical maintenance: 3; Electrical maintenance: 1, Facilitator: 1.
Note: All members attended a 21-hr RCM Intro Training to understand the fundamentals of an RCM Review
RCM Analysis scope: discharge pressure control system, anti-surge control system, speed/extraction pressure control system, lubrication and command, electrical power system.
RCM Analysis recommendations (frequency changes, task additions, task removals, redesigns) for implementation:
- predictive/preventive maintenance schedule, including cleaning, gauging, testing, vibration analysis, lubrication/command oil checks, humidity in air instruments checks, filter changes, etc.
- spare parts optimization
- operations routines revision of the existing procedures and development of some new required procedures (regarding process variables readings/comparisons, field variables monitoring, stand-by spare pump operation, etc.)
- Scope review for the turning arounds (TAR) campaigns, including trip tests, instruments actuation tests, failure finding tasks, etc.
- Replacement of the electro-hydraulic I/H converters to CPC (current to pressure converter)
- Installation of an autonomous oil command system
- PLC replacement
- Change the pressure controller indicator to the DCS
- Install a redundancy for a specific pressure transmitter (PT)
- Improvements on the electrical power feeding to the local panel
RCM Analysis total cost (consulting services plus Petrobras team time): US$ 50,000
Cost to implement critical redesigns: US$ 650,000
Total investment: US$ 700,000
RCM Analysis ROI: US$ 700,000 / US$ 2.45million per year = 0.29 years = 3.5 months
System failure rate after the critical redesign recommendations implemented:
no failures for the coming 13 years!
Usually ROI for RCM Analysis is measured in weeks or months. Sometimes you can prevent a catastrophic consequence not accounted, meaning that the ROI is immediate.
Special thanks to both, Mr. Sebastião Pedroso Ramos Junior, BScME, REPLAN's Rotating Equipment Specialist in charge of the project, and to Mr. Nei Pizzatti Sales, BScME, SPES Engenharia's Senior Consultant and RCM Practitioner acting as Facilitator.