%0 Journal Article 
%A Roncal, Tomás
%A Lorenzo, Leire
%A Prieto-Fernández, Soraya
%A Ochoa-Gómez, José R.
%T Purification and concentration of formic acid from formic acid/gluconic acid mixtures by two successive steps of nanofiltration and reactive liquid-liquid extraction
%D 2022
* Elsevier
%X A downstream process for the purification and concentration of formic acid (FA) from FA/gluconic acid (GA) mixtures, obtainable by a coupled biocatalytic reaction of CO2 reduction and glucose oxidation, has been developed. The process involved two technologies: i) a first nanofiltration (NF) step to separate FA and GA, and ii) a second reactive liquid-liquid extraction (RLLE) step to concentrate FA. The NF process, using a Synder NFX membrane, consisted of three NF steps separated into two divergent lines, named permeate and retentate pathways. The first NF was common for both pathways, resulting in a permeate strongly enriched in FA and depleted in GA, and a retentate with opposite characteristics. In the permeate pathway, this first permeate was subjected to a second NF to obtain a 99.6% pure FA permeate. In the retentate pathway, an additional NF step on the first retentate resulted in a concentrated 99.4% pure GA retentate. The final diluted FA permeate was concentrated by RLLE using tri-N-octylamine as extractant in n-octanol, and a final back-extraction with NaOH. The optimized RLLE process involved a 100-fold volume decrease and resulted in a final FA solution (as sodium formate) of 174.5 g/L, 78 times more concentrated than the feed.
%@ 1383-5866
%K Formic acid
%K Gluconic acid
%K Downstream
%K Nanofiltration
%K Reactive liquid-liquid extraction
doi 10.1016/j.seppur.2022.120492
%U http://hdl.handle.net/11556/1257
%~ GOEDOC, SUB GOETTINGEN