Our process engineering team in Finland comprises of more than 30 experts in the sector. Our expertise and experience cover almost all industrial process areas. We are particularly strong in processes involving renewable energies, the petrochemical and distilling industries, and power plants.

Whether you need help with innovating a completely new plant or in further development of production in an existing facility, our experts can assist you in achieving your goals. We collaborate closely with our designers in other sectors to provide functional turnkey solutions that also take maintenance aspects into account as part of process engineering, for example.

Our core areas of expertise include refinery, distilling and power plant technologies, but our extensive experience is available for all kinds of issues regarding process technologies.

Our PROCESS TECH+ service portfolio covers everything process engineering: dimensioning, balance calculations, piping and instrumentation diagrams with lists, and process descriptions and training. If necessary, we can use the Aspen Plus simulation software for modelling and solving process issues. We also conduct construction supervision and deployment tasks on construction sites.

Vanessa Tuokila-Ruohonen

Vanessa Tuokila-Ruohonen

Vice President

Process & EHS

+358 408 011 560


Preliminary assessments and preliminary engineering



Energy analyses

Sevage solutions

Steam and condensate systems

Explosion and heat radiation calculations


In the preliminary assessment phase, we build the concept and draft preliminary balance and dimensioning calculations to make it possible to proceed with the project. During preliminary planning, ideas are refined into diagrams and lists that make it possible to calculate investment costs in connection with other areas being planned and estimate the facility’s future operational costs. This way, accurate and correct information is available before making the final decision on the investment. We have gained experience in preliminary planning for improving the efficiency of existing processes or modifying them.





Have you encountered issues in a process that used to function as expected? Our process experts can help you find the root cause of the problem and to solve it.






Process engineers can often assist in the selection of optimal equipment and in negotiations with suppliers when procuring process equipment. An experienced engineer can help find the optimal solution in a supplier’s product portfolio; this will also speed up the procurement process as unnecessary tendering rounds can be avoided.


Energy has its cost, regardless of the form it is used in, and energy usually amounts to the highest operational expense over the entire lifecycle of a process. The possibilities to optimise processes can be analysed by looking at the energy consumers and producers. We look for solutions that can be implemented immediately and innovative solutions that make use of new technologies for these items that can be optimised. We calculate the payback periods for different savings and optimisation items and give recommendations on how to proceed with development projects.






Rejlers has gained experience in the sewage sector in a number of projects. Our expertise in planning and project management services covers processes related to potable water, sewage treatment and sludge treatment. Our experts have conducted projects for potable water and sewage processes in industrial production plants and delivered sewage solutions for the municipal sewage sector. We assist our customers in modernisation projects for old sewage plants and offer independent expert support in the selection of the sewage handling equipment supplier. Our special areas of expertise include a wide range of different pre-treatment methods (such as DAF, CPI), biological treatment processes (ASU, MBR, MBBR), secondary settling methods and processes related to sludge treatment.


Steam and condensate systems are often involved in various different processes. When running status and capacities change, the condensate system may restrict the operation of the main process. We set the different running parameters and suggest improvements, if necessary, to optimise the operation of the steam and condensate system and, as a result, the actual process.







When handling or storing flammable or explosive materials, it is important to know the consequences of a container or warehouse exploding in an accident or the heat radiation from a fire. We can model the effect of pressure caused by an explosion and the amount of heat radiation from a fire and plan sufficient protection to minimise additional damage in these events.