Quality evaluation of dissolving pulp fabricated from banana plant stem and its potential for biorefinery

• Dissolving grade pulp was fabricated from banana plant stem.
• The highest α-cellulose was 94.2% with 78.6% brightness.
• The optimal pulping type was kraft pulping following pre-hydrolysis at 150 °C for 90 min.
• It was found to be difficult to bleach banana plant stem kraft pulp by H2O2 keeping the level of viscosity high.

The study was conducted to evaluate the quality of dissolving pulp of Musa sapientum L. (banana) plant stem and its potential for biorefinery. Introduction of pre-hydrolysis prior to any alkaline pulping process helps to reduce the content of hemicellulose and consequently produce acceptably high content of cellulose pulp. Water pre-hydrolysis was done at 150 °C for 90 min. The amount of lignin, xylan and glucan in the extracted pre-hydrolysis liquor (PHL) was 1.6, 4.9 and 1.6%, respectively. Pulping of pre-extracted chips was done following soda-AQ, alkaline sulfite and kraft process. The ratio of chip to liquor was 1:7 for both pre-hydrolysis and pulping. The kraft pulping process with 20% active alkali and 25% sulfidity at 150 °C for 90 min showed the best result. The lowest kappa number was 26.2 with a considerable pulp yield of 32.7%. The pulp was bleached by acidic NaClO2 and the consistency was 10% based on air-dried pulp. The lowest amount of 7% NaClO2 was used for the bleaching sequence of D0ED1ED2. After D0ED1ED2 bleaching, the pulp showed that α-cellulose, brightness and ash were 91.9, 77.9 and 1.6% respectively. The viscosity was 19.9 cP. Hence, there is a possibility to use banana plant stem as a raw material for dissolving grade pulp and other bioproducts.