PATh's projects

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Research Interests and Activities ...

Biorefinery

The biorefinery aims at producing fuels, chemicals and materials from renewable sources such as biomass.
Our major interest is the application of ionic liquids to the development of the biorefinery.

Fuels
Path has been addressing the purification of bioalcohols through liquid-liquid extraction, but also striving to develop methods to design new ionic liquid that can be used as entrainers in azeotropic distillation of alcohols.
The purification of syngas and biogas has also been approached. At Path we study the solubility of gases in ionic liquids aiming at developing separation processes based on these solvents.

Chemicals
Both platform chemicals that are obtained by the biomass conversion, such as organic acids or HMF, and value added compounds present in the biomass such as phenolic antioxidants and phytosterols can be produced from biomass using ionic liquids as catalysts, as in HMF production, or as solvents for extraction and purification. Path is currently active in both these fields but is particularly interested on the extraction of value added compounds from biomass using ionic liquids.

Materials
Electrospinning of cellulose or other biopolymers in ionic liquids aiming at creating nanofibers, and the surface modification of cellulose using ionic liquids as solvents are being studied at Path.

Biodiesel
Path has been active into the development of models to describe the phase equilibria and thermophysical properties of ionic liquids. Our goal is to have reliable thermodynamic models that may produce an improved description of the phase equilibria present in the separation and purification steps of biodiesel productions and also new models that would allow to predict the biodiesel properties. With the extension of CPA to systems of relevance to the biodiesel production the first task was accomplished. The predictive UNIQUAC model was also extended to the description of wax formation in biodiesel with success [Coutinho et al.] and an application is available for download. Models for density and viscosity of biodiesel are currently being developed.

Petroleum Technology

WAXtracker
Problems related to crystallization and deposition of paraffin waxes during production and transport of crude oils have been extensively reported and cost billions of dollars per year to petroleum companies. Oilfield operation and pipeline design require the capacity to anticipate the wax deposition potential of an oil, often from very limited information.
WAXtracker is an user-friendly software that employs a thermodynamic approach to predict wax formation in live and dead oils and refined products such as diesels.
Given the interest that the WAXtracker model arouse and the repeated requests a fully working partial version of WAXtracker is now freely available for download.
The zip file contains an executable version of the code for modelling of low pressure wax formation in fluids, examples of input and output files and a datafile with properties for a broad range of paraffins and solvents.
Information about the thermodynamic model behind WAXtracker is given on the ModellingPhase Equilibria.pdf file. More information about the model and its application to crudes, diesels and synthetic mixtures can be found in several articles available in the publications page.

Recently WAXtracker has been extended to model wax formation in biodiesel[Coutinho et al.]. A modified version of the program is available to download here.

Ionic Liquids

Ionic liquids are amazing compounds, not only due to their unique properties but because they challenge your conventional notions and bring you out of your comfort zone, whatever is your scientific background.
Path is approaching ionic liquids in multiple ways:

Biotechnology

Biosurfactants
Yansan, produced by a wild strain of Yarrowia lipolytica and named after a Brazilian deity, was the first biosurfactant identified at Path labs [Amaral et al.]. It was shwon to have some remarkable emulsifier characteristics. Currently we are studying biosurfactant production from wild strains of other microorganisms isolated from soil contaminated with hydrocarbons for MEOR and bioremediation. Path is working on this subject in collaboration with Prof. Álvaro S. Lima from UNIT, Brazil, and Prof. José Teixeira at University of Minho, Portugal.

Lipase
Lipase is one of the most important enzymes from an industrial point of view. The study of oxygen vectors to enhance lipase production has been an active field at Path, We are currently addressing the use of non fluorinated oxygen vectors and the use of alternative reactor designs to promote lipase production.

Biodiesel synthesis
The effect of pressure on the enzymatic synthesis of biodiesel has been object of study in the last few years

Impact of ionic liquids on enzyme activity and stability
Besides the studies of toxicity to microorganisms, Path has been actively involved in the study of the impact of ionic liquids on the enzymes activity and stability. Being non aqueous solvents with a strong potential impact on biotechnology, to understand how they can affect the enzymes and the mechanism of enzyme deactivation is highly relevant.

Purification of Biomolecules
This is probably the most active area of study in the biotechnology domain at Path. Using ionic liquid, a whole range of Aqueous Two Phase Systems (ATPS) have been developed with characteristics much different from the conventional ATPS based on polymers. Extraction of alkaloids such as nicotine and caffeine, phenolic compounds like vanillin and gallic acid among many others have been object of investigation.

ThermophIL^©2008

An online application for ionic liquids property estimation Open ThermophIL

TPDTL^{© 2017} - Two Phase Diagram and Tie-lines Determination

Program for ternary Liquid-liquid equililbria description, based on Merchuk-type equations, and Tie-line determination.Windows 64-bit Linux

CPA-EoS for the description of VLE and LLE of systems with fatty acid esters.

Predictive UNIQUAC for the prediction of the low temperature behavior of biodiesel.

Models for the biodiesel thermophysical properties.^{comming soon}

Thermodynamic approach to predict wax formation in live and dead oils and refined products such as diesels.

TPDTL Program for Liquid-liquid equililbria description and Tie-line determination. [Windows 64-bit] [Linux]