mid-IR dataset from low molecular weight permeate of ultra-filtered spent sulfite liquor.

The dataset consists of FTIR spectra of ultra-filtered spent sulphite liquor (UF-SSL) from softwood pulping obtained from one paper mill biorefinery plant with the purpose of real-time quantification of the sugar content of UF-SSL. Data collection was performed using a submerged mid-IR probe placed in a continuously stirred tank reactor and reference sugar measurements were performed using HPLC. Spectra were obtained of raw and spiked UF-SSL. As "low complexity" case 25% UF-SSL from one batch was analysed for its 3 most abundant sugars (mannose, xylose, glucose) and as "high complexity" case 25/50/75% UF-SSL from 2 batches was analysed for its 5 most abundant sugars (the latter + galactose, arabinose). In both cases, independent single sugar spikes and simultaneous multiple sugar spikes were performed. Real time in-line data was generated by stepwise and gradual changes in sugar composition over time with a run time of >200 h.