Master’s thesis for Borealis explores the techno-economics of replacing cracker furnaces with methanol-to-olefins technology

Lotta Pulkkinen is a fresh M.Sc (Chem.) graduate from Aalto University, who recently completed her Master’s thesis based on the R&D work she made at Borealis. The topic of her thesis supports the SPIRIT programme’s theme aiming to CO2 reduction by exploring new methanol concepts and alternative routes to bypass the cracker furnaces.  

Lotta Pulkkinen starts by saying how the topic of her thesis, “Techno-economic assessment of replacing furnaces with methanol-to-olefins technology”, had a perfect match with her own interests and field of study. She was looking for a topic in the field of chemistry with high interest in plant and process design, and as Borealis wanted to explore the possibilities of finding new methanol concepts and routes to bypass the cracker furnaces, she was immediately engaged with the topic.

Lotta says: “Olefins, such as ethylene and propylene, are typically produced from fossil-based feedstock in a steam cracking process, which is an energy-intensive process resulting in a lot of carbon emissions. Methanol-to-olefins (MTO) in turn is a technology, where methanol is converted to olefins in a fluidized-bed reactor in the presence of a SAPO-34 catalyst. As an industrially proven technology, it can thus provide an alternative route to olefin production. To achieve net emission benefit, the methanol used as a feedstock needs to be sustainable bio-methanol or so-called e-methanol from carbon capture.”

The MTO technology was proposed and analysed to replace some of the conventional steam cracking furnaces to mitigate the large carbon emissions and to replace the conventional fossil-based feedstock with sustainable methanol. By integrating the MTO unit integrated into the existing cracker, major synergy benefits in downstream processing can be achieved.

In the case study, a MTO unit of 700 kt/a methanol feed was designed and simulated. A majority of the reactor product is water that is needed to separate from the product with quenching. As the methanol conversion is not complete, leftover methanol and by-product DME is extracted with additional absorption columns.  The produced hydrocarbons, ethylene and propylene, are further purified in the existing cracker separation and conditioning sections. As the catalyst in the MTO reactor is affected by coking it must be regenerated regularly by combustion. The direct greenhouse gas (GHG) emission from the MTO process are seven times lower than what is emitted in traditional naphtha cracking When using methanol feedstock derived from direct air-captured CO2 the net emission falls even negative and the olefins produced can act as a carbon sink.

To summarise the techno-economic impact, Lotta says that the biggest impact on the MTO process cost of production comes from the sustainable methanol feedstock cost. To make MTO process financially attractive, feedstock cost needs to be reduced, or olefin product premiums need to be increased.

Ismo Savallampi and Mikko Rönkä from Borealis were guiding Lotta during her thesis work. Mikko Rönkä says: “Borealis is constantly looking for novel ways to produce polyolefins from sustainable feedstock and with low CO2 footprint. Lotta’s work gives us excellent insight into an attractive methanol- to-olefins production route.“ 

After her graduation, Lotta joined Infinited Fibre Company and is now part of the development and design activities for the company’s flagship plant for circular textile fibre processing. The experiences gathered within Borealis and SPIRIT programme gives a good basis for the exciting new challenges on circular textiles.



We use cookies to distinguish you from the other users on our website. This helps us to provide you with a good browsing experience and allows us to improve our website if needed. By continuing to browse our website, you agree to our use of cookies.