Pretreatment of lignocellulosic biomass is essential to obtain high efficiency of biofuel production owing to the recalcitrance of the biomass. Usually, chemical catalyst, such as dilute acid, sodium hydroxide or ammonia treatment, based pretreatments were employed and now considered in industries. However, such pretreatment processes should be followed additional steps, for example filtration of the solids, washing of the biomass with deionized water, pH neutralization and drying of the solids for downstream enzymatic hydrolysis. During the additional steps, large quantity of wastewater would be generated and it should be treated before leasing into the environment. According to NREL report, the capital costs related to these treatments encompass about 21% of the total biofuel process cost.
This study proposes a convenient butanol production process using planetary milling. The planetary milling was effective to reduce the size and crystallinity of biomass. Without using chemical catalyst, 84.02% of glucose conversion efficiency was obtained while no biomass was lost. The sugar solution produced from Pinus rigida did not cause growth inhibition in Clostridium beijerinckii NCIMB 8052. Fermentations performed using the product of this process showed slightly higher solvent and acid yields when compared to pure glucose based fermentation.
- Lee, S., H. Lee, R.J. Mitchell, “Analysis of Clostridium beijerinckii NCIMB 8052’s transcriptional response to ferulic acid and its application to enhance the strain tolerance“, Biotechnology for biofuels, 2015. Vol 8, 68. (IF=6.04)
- Kwon, J.H., Lee, S., Lee, J., Hong, Y., Chang, J.H., Sung, D., Kim, S.H., Sang, B., R.J. Mitchell, H. Lee, “Improved sugar production by optimizing planetary mill pretreatment and enzyme hydrolysis process” BioMed Research International, 2015. Vol 2015, Article ID 267538 (IF=1.579)
- Kim, H.J., S. Lee, R.J. Mitchell, H. Lee, “Environmentally friendly pretreatment of plant biomass by planetary and attrition milling“, Bioresource Technology, 2013, Vol 144, pp50-56.
- Monnappa, A.K., J.H. Lee, R.J. Mitchell, “Detection of furfural and 5-hydroxymethylfurfural with a yhcN::luxCDABE bioreporter strain“, International Journal of hydrogen energy, 2013, Vol 38, pp15738-15743.
- Kim, H.J., J.H. Chang, B. Jeong, H. Lee, “Comparison of milling modes as a pretreatment method for cellulosic biofuel production” J. Clean Energy Tech, 2013, Vol 1, pp45-48.
Jeong Heo Kwon 1,2, Hyunsoo Kang3, Byoung-In Sang2, Yunje Kim4, Jiho Min5, Robert J. Mitchell3, Jin Hyung Lee1Show Affiliations
- Korea Institute of Ceramic Engineering and Technology (KICET), 101, Soho-ro, Jinju-si, Gyeongsangnam-do 52851, Republic of Korea
- Division of Chemical Engineering & Bio Engineering, Hanyang University, Seoul, Republic of Korea
- School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
- Division of Chemical Engineering, Chonbuk National University, Jeonju, Jeonbuk, Republic of Korea
A facile butanol bioproduction process was developed using planetary milling, and Pinus rigida wood waste as a model substrate for fermentable sugars. The use of planetary milling as the pretreatment eliminates the need for washing and transfer of the biomass prior to enzymatic hydrolysis. Moreover, using this pretreatment process resulted in the production of only 0.072 ± 0.003 g/L soluble phenolic compounds, a concentration that was not inhibitory towards Clostridium beijerinckii NCIMB 8052. As the milling was performed in a compatible buffer (50 mM acetate, pH 4.8), the enzymatic hydrolysis step was initiated by simply adding the cellulase cocktail powder directly to pretreated biomass without washing the biomass or exchanging the buffer, resulting in a glucose yield of 31 g/L (84.02%). Fermentation of the hydrolysate samples by C. beijerinckii NCIMB 8052 gave slightly better butanol yields than cultures grown in a typical lab media (P2), with final concentrations of 6.91and 6.66 g/L, respectively.Go To Bioresource Technology