A cracking revamp

Situated on the shores of the Black Sea, the Lukoil Neftochim refinery at Bourgas is the largest petrochemical complex in the Balkans, with a capacity to process more than 7million tonnes of crude oil a year, or 22 000tonnes a day.

Its sale in 1999 to Lukoil was one of the biggest privatisations to date, with Lukoil acquiring a 58 per cent controlling stake for $101million. Following the acquisition, plans were unveiled for investments in the complex totalling more than $260million over six years.

Now over half way through that investment period, the refinery is well on the way to meeting its expansion targets. The latest unit to be upgraded is the FCCU or fluid catalytic cracking unit, which breaks heavier oil fractions into lighter hydrocarbon components such as olefins and gasoline for further downstream processing in the refinery and petrochemicals complex. The main objectives for revamping the FCCU were to increase its capacity from 1.7million to 2.0million tonnes per year, and generally to modernise the unit with improved control.

After several attempts to make a breakthrough into the on-going expansion work at the refinery - including going through various basic engineering designs for other projects such as the crude and vacuum unit - Foster Wheeler Iberia was awarded the contract to carry out the detailed design for the FCCU revamp in July 2002.

The engineering design was to be based on the basic design originally developed by UOP, of which FW Iberia had previous experience through another revamp project for RPC in Concón, Chile.

New contract awards soon followed, such as the supply of all the main equipment involved in the revamp. Because of transportation difficulties and the size of the equipment involved, some of the plant items had to be finalised on site working with local contractors. Refractory lining supply and installation, along with construction supervision, also came under FW Iberia’s responsibility.

The main modifications proposed for the FCCU involved raising the reactor height by 3m, fitting it out with a new 7m diameter head, new cyclones, all new internals such as riser, riser termination device, chamber and chamber outlet, as well as replacing the refractory lining throughout the entire reactor. A new 9m diameter regenerator head was also to be supplied, along with new cyclones. And, because of the planned increase in capacity, most of the unit’s piping also had to be upgraded.

All the revamp design work was carried out in FW’s offices in Madrid, with UOP involved in several meetings to ensure smooth communications over authorisations and clarifications. For the mechanical equipment supply, FW Iberia selected the leading fabricator Felguera Caldereria Pesada, based in the north of Spain.Felguera assembled the reactor head in two pieces - one being the actual head 7m in diameter, including refractory lining and plenum chamber installation, and the other piece the cylindrical part of the reactor that was to be added to increase its height by 3m.

The construction execution plan was to pre-assemble the reactor and regenerator heads at ground level in the refinery prior to its scheduled shutdown at the end of October last year. Construction started in July and also included the installation of the refractory lining and cyclones, arranged in a ‘jellyfish’ configuration where all the cyclones hang from the reactor/regenerator head. All this equipment was to be lifted and installed in one piece, once the old parts were removed during the planned shutdown.

The scale of the operation can be gauged from the lifting data for the main components - the 145 tonne reactor head has to be lifted to a height of 80m, and the 180tonne regenerator head to 45m. At its peak, the 100,000 manhour revamp project has involved a 180-strong workforce, all of them local contractors except for ten Spanish workers involved in the specialised refractory lining installation.

Modernising the operation of the FCCU has involved the installation of a Honeywell TDC3000 distributed control system, with HPM controllers and digital intelligent transmitters using HART-based communications.

With the refinery due back on stream by the end of 2003, FW Iberia’s operations director José Carlos García Casas commented in early December: ‘During the past year a number of Foster Wheeler Iberia personnel have been working hard, together with an integrated team from Lukoil Neftochim and contractors’ personnel, in the preparation of the revamp. A very aggressive and challenging schedule has been put in place, with many activities being performed in parallel, and a carefully studied sequence of activities. The entire team is now looking forward to the successful completion of the shutdown phase, expecting this to occur just before Christmas.’