Wood designs sustainable methanol plant for leading chemical producer, Perstorp

Wood’s scope included both a greenfield downstream plant design and a challenging redesign of a brownfield facility.

Wood’s scope covered the methanol reactor, relevant storage tanks and shipping facilities at the port, as well as the modification of the existing gasification unit to supply the syngas for methanol production. All utilities also had to be revamped to suit new modifications. and revamped all utilities.

Wood redesigned the wastewater treatment plant to supply the treated water required for the production of green hydrogen for the new dedicated electrolysis facility. Due to the variety of feedstocks required by both the syngas and methanol production units, Wood designed with flexibility in mind to cover many different operating cases.

Delivering project excellence in a challenging brownfield revamping project

Wood approached the challenge of retrofitting existing facilities with a consolidated methodology, end to end engineering expertise, deep knowledge of process and global expertise. Wood’s experts in the UK, Milan and Chennai collaborated on the various designs required for this project.

The first step to a brownfield revamping project is to conduct a field survey to determine the status of the existing installations. Both traditional engineering techniques and a laser scan were combined, building a 3D model to highlight any possible inconsistencies with existing technical installations. This built a holistic knowledge of the facility’s condition and prevented any margin of uncertainty and considerations of subsequent project phases.

The existing gasifier was installed in a steel structure of about twenty meters high and required to be close coupled through a transfer line to a new waste heat boiler to be allocated in the same structure. The structure is delimited on the west side by a decommissioned gasifier and pipe rack, while on the east side an internal access road bounds the area.

On the south side, the boiler water circulation pumps were installed and other production facilities are located farther in the same direction. An interconnecting pipe rack runs to the north of the structure, with space constraining piping expansion loops. With such a limited space availability and the constraints of the existing concrete basements and foundations, Wood implemented a tailor-made strategy based on few key concepts.

Revamping solutions are always carefully reviewed to optimise the new structures both in terms of their locations and heights. A key element is the segregation of process fluids, to avoid any possible incompatibility arising from shell and tube heat exchangers heating oxygen, biogas and liquid hydrocarbon streams.

A newly added structure to the north side of the gasifier was designed to locate the liquid hydrocarbons and biogas pre-heaters on the ground floor, while on the top floor the oxygen pre-heating exchangers and the water coolers are installed. Such structure is limited in height due to the interference of an existing flare piping expansion loop.

The syngas cooling section was placed in a second new structure located to the south of the existing one, satisfying the routing of two-phase flow lines.

Constructability studies were carried out in parallel with the engineering development to optimise the procedures and sequence of the construction activities. The tie-ins into the existing piping were identified, categorised and prioritised for execution during the next factory turnaround.

Supporting a groundbreaking initiative

Wood has provided engineering expertise, global reach and technological capability to complete this complex brownfield modification for Perstorp.

Wood delivered this contract on time, working closely with Perstorp and technology licensors to overcome unexpected constraints and specific design requirements, such as the flexibility of the operation to cope with the high variety of feedstocks for both the syngas and the methanol unit.

Throughout the duration of the project, meetings with client and licensors were held to ensure alignment on the project objectives and control the development of the design, fitting to the schedule and the quality of the deliverables.

Project Air stands as a truly groundbreaking sustainable methanol initiative. We look forward to seeing its start up in 2028.

Project Air is Co-Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Climate, Infrastructure and Environment Executive Agency (CINEA). Neither the European Union nor the granting authority can be held responsible for them.