TY - JOUR AU - Kekana, Paul AU - Sithole, Bruce AU - Ramjugernath, Deresh PY - 2016/11/24 Y2 - 2024/03/28 TI - Stirred cell ultrafiltration of lignin from black liquor generated from South African kraft mills JF - South African Journal of Science JA - S. Afr. J. Sci. VL - 112 IS - 11/12 SE - Research Article DO - 10.17159/sajs.2016/20150280 UR - https://sajs.co.za/article/view/3682 SP - 7 AB - <div class="field field-name-body field-type-text-with-summary field-label-above"><div class="field-items"><div class="field-item even"><p>Ultrafiltration of lignin from black liquor was carried out in a stirred batch cell using polyethersulfone membranes. Parameters such as operating pressure, feed concentration, stirring rate and membrane cut-off size were varied and their effects on lignin retention and permeate flux were investigated. The operating pressure, feed concentration and stirring rate were varied in the ranges 150–350 kPa, 3–9% and 200–400 rpm, respectively. The membranes used had cut-off sizes of 5 kDa, 10 kDa and 20 kDa. A one-factor-at-a-time experimental design approach was applied in this study. Retention of lignin increased with increases in operating pressure, feed concentration and stirring rate, but decreased with an increase in molecular cut-off size of the membrane. Permeate flux on the other hand increased with increases in pressure, stirring rate and molecular cut-off size of the membrane but decreased with an increase in feed concentration. The extraction of lignin from black liquor was successfully carried out and extraction efficiencies as high as 86% could be achieved depending on the experimental conditions. The study was concluded with the recommendation of conducting additional experiments using a pilot plant in a continuous mode.</p></div></div></div><div class="field field-name-field-significance field-type-text-with-summary field-label-above"><div class="field-label"><strong>Significance:&nbsp;</strong></div><div class="field-items"><div class="field-item even"><ul><li>The extraction of lignin from black liquor was successfully carried out and extraction efficiencies as high as 86% were obtained. The results can be used to extend the ultrafiltration of black liquor to an industrial scale.</li></ul></div></div></div> ER -