Ethanol Production from Oil Palm Trunk: A Combined Strategy Using an Effective Pretreatment and Simultaneous Saccharification and Cofermentation

Background. Oil palm trunk (OPT) with highly cellulose content is a valuable bioresource for bioethanol production. To produce ethanol from biomass, pretreatment is an essential step in the conversion of lignocellulosic biomass to fermentable sugars such as glucose and xylose. Several pretreatment methods have been developed to overcome biomass recalcitrance. In this study, the effects of different pretreatment methods such as alkali pretreatment, microwave-alkali, and alkaline peroxide combined with autoclave on the lignocellulosic biomass structure were investigated. Moreover, ethanol production from the treated biomass was performed by simultaneous saccharification and cofermentation (SSCF) under different temperatures, fermentation times, and cell ratios of Saccharomyces cerevisiae NCYC 479 and pentose-utilizing yeast, Pichia stipitis NCYC 1541. Results. Pretreatment resulted in a significant lignin removal up to 83.26% and cellulose released up to 80.74% in treated OPT by alkaline peroxide combined with autoclave method. Enzymatic hydrolysis of treated OPT resulted in an increase in fermentable sugar up to 93.22%. Optimization of SSCF by response surface method showed that the coculture could work together to produce maximum ethanol (1.89%) and fermentation efficiency (66.14%) under the optimized condition. Conclusion. Pretreatment by alkaline peroxide combined with autoclave method and SSCF process could be expected as a promising system for ethanol production from oil palm trunk and various lignocellulosic biomass.

Characterization of Birch Wood Residue after 2-Furaldehyde Obtaining, for Further Integration in Biorefinery Processing

Latvia is a large manufacturer of plywood in Eastern Europe, with an annual production of 250,000 m3. In Latvia’s climatic conditions, birch (Betula pendula) is the main tree species that is mainly used for plywood production. A significant part of the processed wood makes up residues like veneer shorts, cores, and cut-offs (up to 30%), which have a high potential for value-added products. The aim of this research was to comprehensively characterize lignocellulosic (LC) biomass that was obtained after 2-furaldehyde production in terms of further valorization of this resource. The polymeric cellulose-enriched material can be used in the new biorefinery concept for the production of 2-furaldehyde, acetic acid, cellulose pulp, thermomechanical (TMP) and an alkaline peroxide mechanical (APMP) pulping process. In addition, we experimentally developed the best 2-furaldehyde production conditions to optimize the purity and usability of cellulose in the leftovers of the LC material. The best experimental results in terms of both 2-furaldehyde yield and the purity of residual lignocellulose were obtained if the catalyst concentration was 70%, the catalyst amount was 4 wt.%, the reaction temperature was 175 °C, and the treatment time was 60 min. After process optimization with DesignExpert11, we concluded that the best conditions for maximal glucose content (as cellulose fibers) was a catalyst concentration of 85%, a catalyst amount of 5 wt.%, a temperature of 164 °C, and a treatment time of 52 min.

Valorization of Hemp Hurds as Bio-Sourced Additives in PLA-Based Biocomposites

Sourced from agricultural waste, hemp hurds are a low-cost renewable material with high stiffness; however, despite their potential to be used as low-cost filler in natural fiber reinforced polymer biocomposites, they are often discarded. In this study, the potential to add value to hemp hurds by incorporating them into poly(lactic acid) (PLA) biopolymer to form bio-based materials for packaging applications is investigated. However, as with many plant fibers, the inherent hydrophilicity of hemp hurds leads to inferior filler-matrix interfacial interactions, compromising the mechanical properties of the resulting biocomposites. In this study, two chemical treatments, alkaline (NaOH) and alkaline/peroxide (NaOH/H2O2) were employed to treat hemp hurds to improve their miscibility with poly(lactic acid) (PLA) for the formation of biocomposites. The effects of reinforcement content (5, 10, and 15 wt. %), chemical treatments (purely alkaline vs. alkaline/peroxide) and treatment cycles (1 and 3 cycles) on the mechanical and thermal properties of the biocomposites were investigated. The biocomposites of treated hemp hurd powder exhibited enhanced thermal stability in the temperature range commonly used to process PLA (130–180 °C). The biocomposites containing 15 wt. % hemp hurd powder prepared using a single-cycle alkaline/peroxide treatment (PLA/15APHH1) exhibited a Young’s modulus of 2674 MPa, which is 70% higher than that of neat PLA and 9.3% higher than that of biocomposites comprised of PLA containing the same wt. % of untreated hemp hurd powder (PLA/15UHH). Furthermore, the tensile strength of the PLA/15APHH1 biocomposite was found to be 62.6 MPa, which was 6.5% lower than that of neat PLA and 23% higher than that of the PLA/15UHH sample. The results suggest that the fabricated PLA/hemp hurd powder biocomposites have great potential to be utilized in green and sustainable packaging applications.

A Stability Indicating Novel UPLC-PDA Method for the Estimation in Bulk and Capsule Dosage form of Isavuconazole Effective for Mucormycosis Caused by COVID-19 Pandemic

The present research provides a new proven ultra-high-performance liquid chromatographic technique for isavuconazole in both bulk and capsule dosage forms. DIKMA Waters BEH C18(50 x 2.6mm, 1.7m) column was used for chromatographic separation. With the isocratic elution mode, a mixture phosphate buffer: methanol 40:60 v/v, was used as the mobile phase, and the eluent was measured at 253 nm using a UV detector. The strategy has been maintained and validated in accordance with the International Conference on Harmonization Guidelines. Stressed deterioration has also been investigated in acidic, alkaline, peroxide, thermal, and photolytic conditions. Isavuconazole was eluted with the retention time 0.861 minute in this procedure. The calibration curve plots for isavuconazole were found to be linear within the concentration ranges of 1-25µg/mL. With a percentage recovery of 100.18 percent, the limit of detection was 0.025g/ml and the value for limit of quantification was 0.50µg/mL. In a force degradation analysis, the current approach was also determined to be stable. Based on the experiential evidence, the present method was found appropriate of isavuconazole estimation in the form of bulk and capsule.

Glucose and Xylose Productions From Oil Palm Empty Fruit Bunch by Hydrolysis With Enzyme and Acid Using Response Surface Methodology.

Oil palm empty fruit bunch (EFB) is a major cellulosic waste from a palm oil mill. The use of EFB for bioconversion to fuel and valuable products is possible because this biomass is a cheap, renewable and abundantly available. This study was aimed to produce sugars from the alkaline peroxide pretreated EFB (APEFB) by hydrolysis with a commercial enzyme (iKnowzyme acid 2XL cellulase) in comparison with hydrochloric acid. Response surface methodology (RSM) was applied to improve the hydrolysis process. For an enzymatic hydrolysis, the optimum enzyme dose of 40 U/g APEFB and the liquid to solid ratio of 10 ml/g APEFB were investigated at 150 rpm and 50°C for 120 h. After saccharification, glucose and xylose obtained were 65.71 g/l (0.66 g/g APEFB) and 2.14 g/l (0.02 g/g APEFB), respectively. Many acids (acetic, formic, hydrochloric (HCl), nitric, orthophosphoric and sulfuric acids) were used to hydrolyze APEFB. The result showed that HCl was the best acid to produce glucose and xylose from APEFB with low furfural and hydroxymethylfurfural productions. The optimum HCl concentration and temperature for APEFB saccharification were 5.85% (w/v) acid at 114°C for 90 min. The glucose, xylose, furfural, and hydroxymethylfurfural obtained under these conditions were 10.70 g/l (0.11 g/g APEFB), 15.30 g/l (0.15 g/g APEFB), 2.34 g/l (0.02 g/g APEFB) and 0.67 g/l (0.007 g/g APEFB), respectively.

Effect of Ultrasound-Assisted on Sequential Peracetic Acid and Alkaline Peroxide Pretreatment to The Enzymatic Hydrolysis of Oil Palm Empty Fruit Bunch

Enzymatic hydrolysis of oil palm empty fruit bunch (OPEFB) that has been pretreated by modified pretreatment has been investigated in this study. The OPEFB used was pretreated by using sequential peracetic acid – alkaline peroxide solution. As the modification method, the assistance of pretreatment by ultrasound was conducted, in order to increase the enzyme accessibility. Therefore, it enhances the production of reducing sugar on the hydrolysis process. Prior to hydrolysis process, OPEFB was initially treated by using peracetic acid solution, comprise of CH3COOH (> 99%) and H2O2 (30% w/w), assisted by ultrasound for 3 hours at 35oC. Afterwards, OPEFB was treated by using alkaline peroxide solution, comprise of NaOH (40% w/w) and H2O2 (35% w/w), assisted by ultrasound for 10 hours at 35oC. OPEFB that has been pretreated was then subjected to enzymatic hydrolysis process using cellulase enzyme, in order to convert cellulose content into reducing sugar. Enzymatic hydrolysis was carried out at 50oC in a shaker incubator with 150 rpm for 48 hours. In this study, the effect of different enzyme concentration and hydrolysis time towards the sugar concentration in modified-pretreated OPEFB was observed and analyzed. Three different concentrations of enzyme were used, including 1.25, 2.5, and 5 g/L, and reducing sugar concentrations were analyzed at 30 and 45 minutes, and 1, 2, 4, 6, 24, 30, and 48 hours. Based on results, enzyme concentration has a significant effect to the production of reducing sugar. The reducing sugar concentrations obtained at the end of the hydrolysis process were 8.48, 11.06, 19.16 g/L, at the enzyme concentrations of 1.25, 2.5, and 5 g/L, respectively. At any hydrolysis time, the highest sugar concentration has been achieved on the highest enzyme concentration of 5 g/L. Moreover, the effective hydrolysis time were achieved at 6 hours, at all concentration of enzyme, since the production of reducing sugar were insignificant after 6 hours. This study showed an increase in reducing sugar production by 8.25% in the hydrolysis process using OPEFB pretreated by modified pretreatment compared to the non-modified pretreatment.