The presence of water in fuels such as diesel can cause operational losses, equipment corrosion, and decreased performance. With this in mind, Patrícia Lucente Fregolente, during her postdoctoral research at the Faculty of Chemical Engineering ( FEQ ) at Unicamp, investigated a method for removing water – in its different forms, soluble or emulsified – present in liquid fuels. The research was supervised by Professor Maria Regina Wolf Maciel, also from FEQ.
The developed technology has led to a water removal process that uses superabsorbent materials, such as polyacrylamide. These materials act as "molecular sponges," absorbing water directly from the fuel without the need for heating or the use of salts. The materials can be regenerated and reused, potentially reducing operating costs and environmental impact.
“One of the problems faced by refineries is diesel turbidity, caused by the presence of water in the fuel. From the beginning, the idea was not only to study the behavior of water in diesel, but to seek an alternative and efficient way to remove it. This proposal arose from my academic experience at FEQ, where I worked on the development of highly hydrophilic polymeric materials. From this convergence of ideas, we structured the postgraduate research project, with support from FAPESP,” explained the researcher.
The result stood out for its ability to act on the two main types of water found in fuels: soluble and emulsified. Soluble water is that which dissolves completely in the fuel, integrating itself into the fluid uniformly – similar to what happens when salt dissolves in water. Emulsified water, on the other hand, does not dissolve but remains dispersed within the fuel in the form of microscopic droplets, like a mixture of oil and agitated water. In both cases, the presence of water brings undesirable effects, such as corrosion of containers.
Subsequently, the research group grew with the arrival of Professor Leonardo Fregolente, who began his career at FEQ in 2017 after working for over a decade at Petrobras. With renewed efforts, the group obtained an addition certificate – an industrial property title that acts as an addition to a main patent, protecting improvements or developments of the original invention. The document then covered an improvement to the initial technology, delivering an absorbent material based on polyacrylic hydrogels with an optimized composition. Compared to the first version, this structure increases the efficiency of water removal from fuel, with the added benefit of mechanical resistance.
“When the research began in 2010, there was an expectation of an increase in the biodiesel content in diesel consumed in Brazil. This change brings important environmental benefits, since biodiesel is a renewable biofuel and contributes to the reduction of emissions. On the other hand, the incorporation makes the diesel more hydrophilic, that is, with a greater affinity for water. Given this scenario, our group realized the need to develop practical and easy-to-apply solutions to remove water from the fuel. At that time, we conducted studies, including thermodynamic ones, to understand how different concentrations of biodiesel influence the incorporation of water into diesel, which helped to underpin the development of the technology,” he explained.
The final technology was developed over a decade of research and relied on an infrastructure that combines biofabrication laboratories with 3D printing and additive manufacturing capabilities. Initially, the studies were conducted on a bench scale, with experimental tests carried out discontinuously, allowing for an understanding of the materials' behavior and the validation of concepts.
Over time, this experimental base evolved into continuous processes, supported by modernized laboratories, such as the Petroleum Valuation Laboratory (VALPET) at Unicamp, and by a pilot-scale plant capable of operating more closely to real-world application conditions. This structural advancement enabled the design and detailed analysis of materials, such as more hydrophilic hydrogels, as well as the precise manufacturing of components through 3D printing, enhancing a robust platform for technology development.
Application of technology by industry
“This proximity between industry and the University is very relevant. Matryx is located in Paulínia, near Unicamp, which facilitates interaction. Furthermore, this relationship contributes to mitigating risks. The process of bringing a technology to market through licensing is complex and involves overcoming several barriers, and proximity to the university helps reduce these uncertainties,” comments Rodrigo Massena, managing partner of the venture.
The company has been in the market for over two decades and saw in Unicamp's technology an opportunity to expand its operations without leaving the field of liquid treatment. The arrival of the method at the factory was made possible by the Inova Unicamp Innovation Agency, which played a central role in complementary areas. Firstly, it developed a strategy for protecting intellectual property and disseminating the technological asset in Unicamp's Technology Portfolio, through content in news reports and on social media.
Secondly, she worked on technology transfer, facilitating the procedures so that the knowledge produced within the University could be licensed and thus reach the industrial environment. It was this set of actions that made the partnership with Matryx possible and allowed the advancement to the current phase of product development. “The expectation is that we will be able to use this technology in some market niches to build devices that will remove this emulsified water, which is extremely stable,” explains Rafaela Carvalhal, Research and Development (R&D) coordinator at Matryx.
In Brazil, commercially available diesel can contain a high proportion of biodiesel compared to other countries. The presence of this type of water can compromise the product's performance, and when levels exceed the limits established by the National Agency of Petroleum, Natural Gas and Biofuels ( ANP ), there is a greater risk of corrosion in diesel engines, associated, among other factors, with the proliferation of microorganisms that develop at the interface between water and fuel.
“With this technology, we intend to reduce emulsified water to acceptable levels and thus keep the diesel preserved for longer. Our expectation is that, within this specific niche, we will be able to develop a device that will be a solution that does not exist today. From what we have seen in the market, current solutions can remove free water; large diesel tanks are tilted and remove some of this water, but not this extremely emulsified water, which does not come out by decantation or phase separation,” comments Carvalhal.
In practice, the solution has potential applications in sectors such as mining and diesel distribution. Currently, the technology is in the technical validation phase and is undergoing testing and adjustments to meet market demands. The next step involves developing a pilot-scale system to evaluate the solution's performance under near-industrial conditions.
Article originally published on the Inova Unicamp website.
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