Optimisation of biopulping process by bacteria from rhynchophorus ferrugineus on empty fruit bunch for pulp industry

• Main Author: Mohd Aripin, Ashuvila
• Format: Thesis
• Language: English; English; English
• Published: 2022
• Subjects: TP Chemical technology
• Online Access: http://eprints.uthm.edu.my/8402/1/24p%20ASHUVILA%20MOHD%20ARIPIN.pdf; http://eprints.uthm.edu.my/8402/2/ASHUVILA%20MOHD%20ARIPIN%20COPYRIGHT%20DECLARATION.pdf; http://eprints.uthm.edu.my/8402/3/ASHUVILA%20MOHD%20ARIPIN%20WATERMARK.pdf; http://eprints.uthm.edu.my/8402/
• Institution: Universiti Tun Hussein Onn Malaysia

Lignin removal is an essential phase in pulping process. The conventional pulping process has many challenges such as high chemical and energy consumptions, as well as long period and sensitivity of fungal during fermentation process. A cleaner, cheaper, and more effective lignin removal method attracts the interest of industrialists. This research focuses on optimising lignin removal via biopulping process using several combinations of R. ferrugineus’s gut microbiome such as Klebsiella pneumoniae (K), Serratia marcescens (S), Pseudomonas citronellolis (P) and Enterobacter oryzae (E). The optimum conditions of biopulping process were determined through the design of experiment (DOE). DOE involves two phases: screening the significant parameter using Plackett-Burman design (PBD) and optimising conditions for biopulping process using Box-Behnken design (BBD). The chemical properties of EFB biopulp were characterised according to the Technical Association Pulp and Paper Industry (TAPPI), Chlorite and Kursher-Hoffner methods. On the application side, the handsheets produced were assessed on its physical and mechanical properties according to TAPPI methods. The results revealed that the quadruple culture (KSPE) combination having the highest capacity to degrade lignin by 61.86% (using alkali lignin) with the production of lignin degradation enzymes at 2230.10 U/mL (LiP), 314.84 U/mL (MnP) and 973.80 U/mL (Lac). The biopulping of EFB using KSPE combination identified the optimised conditions as follows; incubation time = 48 h, temperature = 35 °C and glucose load = 5 mL per 100 mL medium with 52.70% of lignin removal. Significantly, the cellulose, hemicellulose, lignin, and extractive contents of the biopulp were recovered at 47.37%, 31.36%, 12.70% and 1.77% respectively. The impact of percentage lignin being removed was reflected on the quality of pulp produced. In this case, the brightness (32.50%), tensile index (9.65 Nm/g), burst index (0.98 kPa.m2/g) and tear index (2.71 mN.m2/g) of handsheet produced were acceptable for the production of printing and writing paper grades. This study had successfully demonstrated the optimised biopulping process of KSPE microbes on EFB. The alternative approach of delignification could promote an effective and greener technology for the future of pulp and paper industries.