Enzymatic catalysis from lab scale to industrial demonstration scale
The largest European oleochemical producer, Oleon, is looking into what enzymes can mean for oleochemistry from an industrial point of view and built a pilot reactor for this purpose at its production site in Oelegem.
Figure 1: Enzymatic pilot reactor in Oelegem as seen from the control room
“Optimize processes to increase sustainability”
“Over these last years we systematically increased the share of renewable raw materials used in our products. In the development of new solutions for our customers, our first reflex has become to start from non-petrochemical products. Additionally, regarding our existing product range, our purchase team is constantly on the lookout for greener alternatives for our current raw materials. Further, in our plants we monitor our energy consumption and our waste streams and set ambitious goals each year to continuously improve the environmental footprint of our products. Optimizations in processes can impact the sustainability of a product to a great extent, however in comparison to a raw material change, they imply more innovative and in-depth research, and often involve important investments and a change in the way of working. Therefore, they are less often undertaken.”
Oleon has successfully taken up this challenge to innovate its processes in the past. Some notable examples are the development of a process to make monopropylene glycol ex renewable feed stock and more recently the patented novel way to produce isostearic acid with improved stability properties from rapeseed.
Using enzymes as catalysts
Today Oleon is looking into what enzymes can mean for oleochemistry from an industrial point of view. It is a fact that the synthesis of esters and structured triglycerides using enzymes as catalysts is not new. Literature dating back several decades discusses the type of enzymes that can be employed and process parameters leading to acceptable yields. Nevertheless, apart from some isolated pilot and industrial efforts, enzymatic catalysis has not yet broken through in the oleochemical industry. Main reasons for this are that this way of working requires a different industrial setup, and accompanying investments, and the fact that enzymes are both expensive in purchase and sensitive to deactivation if not treated correctly, which entails a certain risk. These rather ‘practical’ issues are not discussed in scientific literature. In order to better understand these processes and judge the feasibility, Oleon embarked on a journey together with the VITO research institute to bring enzymatic catalysis to industrial scale at Oleon.
LipaMetics: from lab to pilot scale
The LipaMetics project was a CATALISTI/VLAIO funded research project that finished about two years ago with partners Oleon, VITO, GOVA and Nuscience. It aimed to devise an industrial feasible protocol to make isopropyl palmitate on laboratory scale at VITO and afterwards test this on 150 kg pilot scale at Oleon as a proof of concept (see Figure 1). Although some good initial indications existed in literature, a number of questions needed to be answered: which enzyme can be used and also reused for multiple batches in order to render the project economically feasible? Would a batch or continuous approach be the most suited? Which process conditions for the reaction, but also for the washing and storage of enzymes are most suited to protect the enzymes while still assuring a high quality product?
Those and many other questions were studied in the project and, towards the end, samples of isopropyl palmitate in specifications were obtained and validated at both Oleon and GOVA and Nuscience for their acceptability in the market.
Figure 3: Conversion of palmitic acid to isopropyl palmitate in function of time
Following the feasibility study of this technology, Oleon took a closer look at the viability of a follow-up research project.
Economic considerations
From an economic point of view, this project makes sense: a big cost of producing isopropyl esters is the loss of isopropanol in the classical process due to its high volatility at elevated temperature. Furthermore, being a solvent for cosmetic industry color and odor are important aspects to consider and which are often more difficult to manage at chemical esterification temperatures. Therefore, often post-treatments are needed which both incur extra costs and yield loss and which cannot even remove all unwanted side products. As can be seen from Figure 2, a comparison in odor profile and intensity of two samples of isopropyl palmitate starting from the same raw materials but produced in the enzymatic (no post-treatment) and chemical (including post-treatment), shows clearly the advantage of the enzymatic way of producing. More than just a way to reduce post-treatment, it shows that enzymatic process can result in products with superior quality on the market which offer a competitive advantage.
Figure 2: Odor profile and intensity of isopropyl palmitate made via chemical (S1) and enzymatic catalysis (S2)
Sustainability considerations
From a sustainability point of view this project is equally interesting, given the fact that the use of enzymes allows to work at mild conditions, i.e. temperatures around 65 °C and at ambient pressure, and that enzymes themselves are proteins that naturally occur in the environment. This type of breakthrough projects is in line with the growing demand of cosmetic customers for more natural, greener and more sustainable solution and reinforces the innovative image Oleon has with its clients. Moreover, with the legislation surrounding all that is natural, becoming more stringent, thinking about the future with green glasses on is a necessity. These insights shows that this project is in line with the market trends and expectation and provides solutions for the industry.
INCITE: from pilot to industrial demonstration scale
Convinced that there is a future for enzymatically produced oleochemicals, Oleon together with VITO and six other European partners from Italy, Belgium, France and Germany, answered a Horizon 2020 project call from the European Union for efficient integrated downstream processes (Grant Agreement number 870023) that wants to bring projects from pilot scale to industrial demonstration scale. The project with a total cost of € 17.4 million euros was selected and will receive a funding of €13.3 million over its course of four years (September 2019 till August 2023). The project was named INCITE (Innovative Chemoenzymatic InTEgrated processes) and aims to demonstrate novel integrated upstream and downstream processing for a sustainable, safe and energy efficient production of commodity and fine chiral chemicals, where Oleon focuses on the lipase-based solvent-free synthesis of oleochemical esters. The end goal will be to have an industrial demo unit running on enzymatic catalysis at Oleon’s site in Oelegem near Antwerp in the final quarter of 2021 after which the process will be further studied and optimized for the remainder of the project.
Although the main goal of the project is to focus on the industrial demo unit, a lot of work is still done on laboratory and pilot scale. On laboratory scale a range of different esters is synthesized according to the developed technology in order to demonstrate its flexibility towards other products. Important as well on laboratory scale is the in-depth study of the enzymes and how to treat them. Indeed, as mentioned earlier, enzymes are delicate and costly which poses, from an economic point of view, the biggest risk to our process. Consequently, it makes sense to better understand these enzymes in industrial conditions on a smaller scale first. Work on the pilot installation in Oelegem is of crucial importance to pick up where we left at the end of LipaMetics and optimize this process. From Figure 3 you can see that we reduced reaction time to reach acceptable conversion of the raw materials to the final ester drastically. This was not only needed from a economic standpoint but also to generate optimal data for the engineering work. The latter is a big job as we have no existing enzymatic unit to base ourselves on, meaning that we are truly building an innovative industrial unit.
LIPES: enzymatically split triglycerides into glycerol and fatty acid
Finally, it is worth mentioning that Oleon is involved in the LIPES project, that received funding from the Bio Based Industries Joint Undertaking (Grant agreement No 720743), also under the European Union’s Horizon 2020 research and innovation program. In LIPES, where we also work with enzymes, but this time to enzymatically split triglycerides into glycerol and fatty acid, through an efficient and environmentally friendlier alternative to the traditional and current splitting route. Complementarily to INCITE, the LIPES project is expected to deliver on the enzymatic production of commercially important fatty acids and to showcase their use as intermediates in a wider range of application (dimers for polymer end-products and esters for food, cosmetic, industrial applications).