The HDS3 plant for desulfurization and denitrification of vacuum gas oils has been in operation since 1981. In mid-2016, the mechanical life end of one of the two reactors was reached and had to be replaced by a new desulfurization reactor. On 22/04/2016 we announced the mechanical completion of the HDS3 plant that could produce ‘on spec’ shortly after. We remained accident-free and able to fully satisfy the client, TÜV and the labour inspectors." says Pörner Managing Director Peter Schlossnikel.

The project in detail

OMV already commissioned the Pörner Group in June 2013 with the Extended Basic Engineering (FEED) and, in March 2014, with the detail engineering, procurement, construction supervision and commissioning support of the project. Colleagues worked in close cooperation in Leipzig and Vienna to complete the FEED, which served, among other things, as a basis for costing and provided all relevant engineering documents and the implementation strategy. The FEED also saw the order of the new reactor with a diameter of 5 m, a total height of about 25 m and a total weight of 382 tons, designed to withstand 465 °C at 80 bar. After only four months, the detail engineering was handed over to OMV.

The engineers had to integrate the new, larger reactor into the existing plant configuration and into the safety concept, they also had  to develop and implement a new – state of the art - emergency shutdown procedure, in coordination with OMV and the licensor, without changing the shutdown conditions and the remaining plant components. In addition, it was necessary to find a new space, with enough room for the supply conveyor and erection.

After a year of preparation and planning, the construction work could begin, where the engineers had to cope with the familiar limited space and an operating H2S-processing plant.

“The column was engineered and ordered on schedule, the project objectives were reached regarding timeliness, quality and costs thanks to  concise implementation." reflects OMV project manager Manfred Scharner, proudly on the HDS3 project and thanks the entire project team for their professional support.

Transport and assembly XXL

On 20 and 21 June 2015, the reactor was transported out with wide media interest. The new reactor was shipped to the Albaner harbor, from where it was driven by special transport means at night to the nearby refinery site. For this unusual event a variety of logistical challenges had to be overcome, such as a bridge reinforcement, blocking the A4 motorway and the establishment of a makeshift ramp. Just the logistical planning and necessary official permits for this transport took 2 years.

Once it arrived at the refinery, the reactor was again transferred to a special "self-propelled modular transporter” (SPMT). By means of this SPMT, the reactor was carried to the plant. To fit the reactor under a pipe bridge with an available gap of only 8 cm, the reactor had to be transferred to a special hydraulic displacement device, as the height of the SPMT would not have fitted. By means of the hydraulic displacement device, the reactor was lowered as far as possible in height and hydraulically "slid" under the pipe bridge. After crossing the pipe bridge, the reactor was re-loaded on the SPMT and transported to the gantry crane and the erection area.

For the raising of the 25 m high reactor, a specially designed mounting gantry crane was required, whose temporary foundations, construction and dismantling was a project in itself with many requirements. The separate parts of the mounting gantry crane had to be delivered in many individual shipments and assembled in still-operating plants with only a few centimeters clearance.

Even the weather had to play along: stable weather conditions were necessary for the safe erection, with no wind or rain. It was also necessary to consider that the safety-related shutdown of neighboring plants required three days lead.

Then it was time: the reactor was raised by the mounting gantry crane vertically, rotated into position, added to the foundation and bolted in - mission accomplished.

Precise preparation minimizes TAR work

Since downtimes in refineries are getting shorter, accurate preparation of the construction and assembly work is extremely important. The assembly planning already starts during the engineering phase. Due to the carefully prepared pre-TAR-work, stoppage work was reduced to a minimum and the reactor could be integrated quickly in the plant.

The daily coordination, led by OMV, ensured the smooth implementation and Project manager, Tomas Rieder, announced the mechanical completion and operational readiness of the plant on time on 04/22/2016 for OMV.

See here the awarded movie of the transportation and erection of the reactor