C.T.S.G. Alembic

Description:

In the past few years many research articles have appeared about biobased solvents. They are often inherently considered green, but this does not necessarily have to be the case. Considering for example that solvents are used over a long period, the impact of their process performance might be much larger than the impact of their production. And during the process performance, depending on the nature of the solvent, more or less solvent losses might be expected.

So, to evaluate solvents properly, not only the actual TIC, TOC, TAC (total investment cost, total operational cost, total annual cost) should be evaluated but also the LCA should be considered to evaluate impacts. For the LCA analysis and process simulation, we need sufficient information, which may need some experimental work in the early phase of this assignment.

As a model case, we will investigate the use of various diluents in the extraction of cobalt. Cobalt extraction in urban mining is a very important example for circular economy development. Cobalt can be extracted using the extractant Cyanex 272 and it is well-known that this can be done using kerosene as diluent. We would like to replace kerosene with another diluent that is potentially more  sustainable, for example tetramethyloxolane (TMO) or guaiacol, two biobased alternatives. To do this properly, we first develop a process design for the Cyanex 272 in kerosene process, in which you extract Co from an acid leach solution (we make a model solution), then back-extract/precipitate a Co-salt that potentially can be used for battery production. Next, we couple the process design (Python) to the LCA evaluation (Brightway, also written in Python) and analyze the impact of the benchmark process. Then, for the alternative solvents, we evaluate the effectiveness of the process using the same key parameters as the kerosene-based process.

Supervisors:

Nick Kumar (tutor) - n.kumar-3@utwente.nl
Prof. dr. ir. Boelo Schuur (supervisor) - b.schuur@utwente.nl
​​​​​​​Prof. dr. ing. Meik Franke (other member) - m.b.franke@utwente.nl

Assignment

In this project, you will

1. Develop a process simulation model for Co extraction and back-extraction/precipitation based on experimentally validated data
2. Couple the process simulation to a LCA
3. Evaluate the individual impacts of the solvent production phase, the use phase, and end-of life
4. Investigate on the production processes for TMO and guaiacol
5. Validate experimentally these solvents for the extraction process (measure distribution, precipitation data)
6. Make process simulation and LCA for the alternative solvents and compare