Madeleine Royère-Koonings
, François-Xavier Branthôme
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From the conference held by Francesco Rossi (Rossi Ingegneria Alimentare) during the World Tomato Processing Congress (Budapest, 9-12 June 2024, “Technology and innovation in the tomato processing industry” session).
Francesco Rossi has been holding the position of Sales Director at Rossi Ingegneria Alimentare since 2023. Previously he has held the roles of Technical Director and Project Manager. Francesco graduated with honors in Mechanical Engineering from the University of Parma in 2006 and joined Rossi Ingegneria Alimentare in 2010. Starting from 2012, he has led the development of MVR technology evaporators, and since 2021 he has guided the design of the first range of high-efficiency enzymatic deactivators for tomato. In 2023 he oversaw the company rebranding.
From processing and recipe formulation to industrial and retail filling and packaging, Rossi Ingegneria Alimentare is one of the world’s leading food engineering companies, and its research and development has a strong focus on technologically advanced and sustainable solutions for tomato processing.
“When I was a child, I once asked my grandfather: what do you do in your factory?”
He answered: “We build machines to make tomato sauce. – Why…?
When he started the business, after the war, a lot of tomatoes were grown around Parma. But there was no means to preserve that. There was a need. It was as simple as that.
Years later, when I decided to join the company, I asked myself the same question: Why? There are a lot of machines to make tomato sauces, we’d rather find something that the customers really need.
During the Congress, the word of sustainability was brought up many times; it is clear there is a need for that. For us at Rossi, sustainability means to develop efficient technologies, that create greater value for our customers, respect environment, and improve the life of the world consumers.
Today we will see some numbers about the ecological footprint of tomato processing in the plants, which opportunities may arise from the ecological transition, how technologies can help us catch these opportunities, and what about the challenges that we need to face to be successful.
How much energy will be used by raw tomato processing plants during the next season? We estimate it over 16 terawatt/h (16x1012 watt/h); this is the amount of energy that is generated by the biggest power plant in the world in more than two months of production; and the amount of emissions from these plants will be more than 3 million metric tonnes of equivalent CO2, about what is produced by 700,000 cars in one year.
The data on fresh water consumptions are very variable from site to site; however, if we stay on the low side of the range, the total volume will exceed that of 100 Empire State Buildings.
What would you think if I told you that using better technologies, that power plant will run for only two weeks instead of two months? And that those cars would be only 100,000 instead of 700,000? And that the Empire State Buildings could be only 15 instead of 100?
We are in the middle of an ecological transition and there is a big push for that, especially from certain governments. Key enablers of this process are energy efficiency, decarbonization and waste re-use. Moreover, if you follow these principles, some interesting opportunities may arise for you, such as direct cost reduction and, for some countries, tax avoidance and investments incentives.
You want to discover what the biggest opportunities are: we have mapped them out, analyzing the weight of each process step for different types of tomato products. Here I present only a summary of the results.
If we consider a weighted average based on the different products volumes, we come up with the conclusion that approximately 93% of the energy on average comes from two steps: evaporation and enzymatic inactivation. And because these two steps rely heavily on steam, at least for the current technologies, also 94% of the emissions are generated from these same steps. When we look at water usage, most of it is applied for tomato washing, followed by water replenishment in boilers and other utilities.
Now we know where we should focus our attention; but if we want to catch these opportunities, we have to make sure to do that while answering the industry needs; I don’t know each of you personally but we partner several tomato processors and we are pretty confident that you will recognize some of these needs: quality, reliability, efficiency, affordability, flexibility, time to market and of course sustainability itself.
Let’s see how technologies can help answer these needs.
Starting from the low-hanging fruits, mechanical vapor recompression, by now everybody will know about it: it is the evaporation technology that is 13 times more efficient than the tomato industry average.
Two technologies are already well proven on tomato. First, falling film, which is applied on tomato since the early 2000’s; it is a technology that is suitable mainly for refined juice pre-concentration or at relatively low concentration; its main advantage is that it has the lowest energy requirement and its main limitation is that it requires quite frequent cleanings.
Hybrid flow MVR: it was introduced by our company in 2012 and it has seen a considerable success in recent years. Some of you have already installed it so you know what we are talking about. It is applied to a wider range of products, including refined and coarse purées, and to higher concentration up to 16 °Bx. Among the main advantages, it is extremely flexible, and it has very long duty cycles – typically it is able to run for the entire season without stopping. As a main limitation, it still requires a separate finisher if you want to produce paste.
Let’s now move to newer emerging technologies.
Despite being extremely efficient, MVR evaporators still produce waste streams that carry a considerable amount of thermal energy in terms of process condensate and excess vapor. Usually, these two streams are disposed of in a cooling tower: that is to say we spend energy to cool these streams down and then we throw the water away.
Three years ago we came up with a new idea: if we utilize these streams into the enzymatic inactivation process, first we can greatly reduce the steam consumption; and second, we can get for free clean cold water that can be reused for different process steps, like tomato receiving, or other uses. That is what we call the “virtuous circle of recovery”.
Of course, conventional hot breaks cannot do this; so we come up with a different design that is able to.
With our Metis highly efficient enzymatic deactivator we have developed an exclusive technology capable of reusing condensates and process vapours, reducing boiler steam consumption while generating cold water for use in other processes.
Our engineers have been debating for quite a long time on how we could bring the efficiency to the next level, including for the higher concentrations. Finally we came up with Elettra.
Let’s discover together this new concept of evaporation: first of all, it is able to combine multiple types of product circulation: falling film, hybrid flow, and forced flow; it is also able to utilize a variable type of compression: single fan for low Brix, and double fan for higher Brix. It is suitable for every tomato product, from passata to paste. It grants also some important competitive advantages because it is fully electric - or I’d rather say fully mechanic; it is highly efficient, modular and configurable and most important you can make your finished product in just one machine.
These reflects in significant financial implications: higher saving on energy, and in some cases on emission costs, and an attractive payback on investment.
How much can we save if we apply a Metis inactivator together with this new concept of evaporation in a line? Exactly the numbers I told you in the beginning: we could save on average 75% up to 80% on the total energy consumption; on average 85% up to 90% on the emissions and, if you are curious to know what is the reduction in steam consumption, that is exactly the same numbers as the emissions, 85% up to 90%; depending on the plant’s setup, the water saving could be very variable, from 30% up to almost 100%.
So, if you want these new technologies to be successful, and truly enable the ecological transition in the tomato processing world, you need to make sure that they answer the industry needs; the ability to do this starts from the early design phases of a new project. That is what we have done with Elettra evaporators.
First we identified the main design variables. We have started with how they interact with each other and how they reflect into characteristics that are meaningful to the market. The key message here is: “it’s not enough to build a machine that works with no steam, because there are many ways to do that”. In our vision, the ideal solution should be so flexible that its design can be adapted easily, depending on the product, or the requirements of the plant, while, of course, delivering the highest possible efficiency and the best return on investment.
With regards to the issue of achieving evaporation efficiency at higher concentration, that is what we found out. Initially we identified the sources of energy consumption. These are mainly the power required to circulate the product within the machine, and the power required to fuel the evaporation process.
We mapped out how they depend on the heat exchange surface of the machine; as you can see, there are two opposite trends. So, we were able to identify the curve of the total energy consumption and its minimum point where we have the maximum efficiency. This study also highlighted the fact that the point of maximum efficiency cannot be reached with a single fan; but it falls nicely within the capability of two fans in series. Finally, we plotted the investment return curve: at the maximum of the curve, we have the best design; of course, the curve will change according to the country and to the cost of the energy; but the shape of the curve and the point of – let’s say - optimized design is basically the same.
Needless to say, by the same approach you can also optimize the design of evaporation modules that are suited for low or intermediate concentration; by this example, we have seen how we can design standard evaporation modules that are optimized based on the task they need to accomplish; so that we can achieve the best compromise between efficiency, sustainability, affordability, while preserving the product quality.
The logical next step is to combine different evaporation modules according to the need and according to the product we need to produce; for example, if we need to produce tomato paste, we can combine one falling film module to perform half of the work and an additional hybrid flow module to perform one third of the work and finally a forced flow module to perform the last part of the evaporation.
How good is the combination compared to traditional technology?
You can see on this graph that the improvement is really amazing; so, if the modules can be freely combined with each other, according to the need, then we can achieve the highest design flexibility while, at the same time, we guarantee high reliability, reduced engineering cost and reduced delivery time.
In conclusion, today we have seen what are the tomato industry needs, what are the opportunities that arise from the ecological transition, and where we can find them within the process and how technology innovation can help us catch these opportunities and answer the needs.
“I wish I could talk to my grandfather again and tell him with pride what we are doing today in our factory: we are working to answer the needs of the future. But no worries, it’s still for tomato sauce.”
Some complementary data
On Youtube, THOR Hybrid Flow MVR
Sources: Rossi Ingegneria Alimentare, World Processing Tomato Congress (2024, Budapest)
