Braskem petrochemical refinery
The Braskem petrochemical refinery near the town of Duque de Caxias is nestled amidst humid green hills less than an hour’s drive from Rio de Janeiro, Brazil. The sprawling site hosts several chemical plants involved in the production of raw materials and further processed chemical products including polypropylene and polyethylene. Stainless Steel World visited the site to speak with Mr. Roberto Funger, Senior Inspection Engineer in the Maintenance Department during a recent visit.
The Braskem petrochemical site includes three different plants. The large UNIB 4 plant receives Ethane and propane from a neighbouring Petrobras site. This is processed through furnaces which refine the gas to produce the raw material for polyethylene and polypropylene. Polyethylene is produced in unit PE9 and polypropylene is produced in PP5. Small quantities of by-products such as gasoline are also produced on site.
The large UNIB 4 plant receives the Ethane and propane gas from a neighbouring Petrobras site. This is processed through a furnace which refines the gas to produce the raw material for polyethylene and polypropylene.
A varied role
“An important aspect of my role in maintaining the integrity of the plant is managing inspection schedules and maintenance planning,” explains Roberto. “It’s essential to ensure inspections are carried out at the correct times, as specified in our plan. Our next major site shutdown is scheduled in 2017. Another on-site two inspectors and I are together responsible for overseeing the inspection planning for the shutdown.
We will study the inspections required, make recommendations and review all the data relating to the shutdown schedule.” On a day-to-day basis Roberto has other priorities to as well. “My job includes some specific tasks relating to the procedures within the inspection department which I regularly review and discuss with our team, to identify any areas in which we can improve our daily work flow.”
Maintaining an aging plant
At just over twenty years old, Polyproylene plant PP5 is considered to be an ‘aging’ plant. “Other units on site such as PE9 and UNIB 4 are only 10 years old so present fewer problems in this respect,” explains Roberto. While most of the plant is relatively easy to shut down and inspect, those equipment which are connected to the flare is a definite challenge, explains Roberts. “Six days are required to clean the flare pipe and the system connected to it. The flare is constantly burning, even when the plant is shut down, with the exception of the six days required to inspect and clean it. The cold section of the flare is constructed of special carbon steel for low temperatures to prevent it becoming brittle and cracking.
Volatile polypropylene market
“PP5 is shut down as required, for example if we have no raw material,” continues Roberto. “The current market situation also affects production; when the price is low it’s not cost effective to produce. As our product is a commodity the market is quite volatile and fluctuates a lot. Currently the market is very good for polypropylene so we are running 24 hours per day.” “There is a very high demand for polypropylene at the moment in the United States; our production level is at the highest it’s been since I’ve worked here. As this affords us very few opportunities for inspection we need to plan very carefully because if we miss a window we don’t have another one.
Material failure
Asked to provide an example of a particular material issue that he has overcome at the Braskem plant, Roberto immediately recalls an interesting issue. “The tubing arrangement for a catalyst is manufactured with a screw-thread connection. The production operators occasionally need to open this connection to clean the pipes and then close it again before running the catalyst system. We noticed that stress corrosion was occurring in the connections, resulting in rupture of the tubing. A laboratory analysis identified the root cause as small quantities of the catalyst being left in the thread containing chlorine which, when mixed with water, was resulting in stress corrosion.
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