An updated review of adhesively bonded joints in composite materials

Non-wood lignocellulosic biomass is abundantly available, low cost, easy to process and consists of a short growth and harvest period; therefore, it is introduced as a potential feedstock biomass for bioethanol production. Common non-wood lignocellulosic biomasses are categorised into agricultural residues, native and non-wood plant fibres. The potential of non-wood lignocellulosic biomass as a resource for cellulosic ethanol production are determined and, analyzed in the context of their chemical composition, fibre production yield, total cellulose availability as well as the enzymatic saccharification efficiency after pretreatment. Based on the obtained data, agricultural residues show significant advantages in all contexts over other non-wood lignocellulosic biomasses. Moreover, pretreatment plays an important role in enhancing the enzymatic accessibility and hydrolysability of non-wood biomass. This review found that various pretreatments could be applied to enhance the enzymatic hydrolysability of different biomasses; however the major factors that vary the effectiveness of particular pretreatment on improving of different biomass hydrolysability have not been clearly highlighted. In addition, even though enzymatic saccharification of pretreated biomass is mainly highlighted in most of the cellulosic ethanol studies to evaluate the improvement of biomass hydrolysability, this data is unable to show the total glucose that obtained from the untreated biomass directly. In this study, the importance of total glucose yield is emphasized and it is calculated from various research data by multiplying the solid recovery yield by the enzymatic saccharification yield of the pretreated biomass, as it presents the percentage of the total glucose that could be converted directly from the original biomass. This work verifies that besides enzymatic saccharification yield, the solid recovery yield is also one of the major factors to be identified in cellulosic ethanol study.

The world availability of non-wood lignocellulosic biomass for the production of cellulosic ethanol and potential pretreatments for the enhancement of enzymatic saccharification

A review on the environment-friendly emerging techniques for pretreatment of lignocellulosic biomass: Mechanistic insight and advancements

that the frequency of androgenesis is still unacceptably low. Spontaneous diploidisation of calluses from pollen grains often occurs and the high percentage of albinos is still a major problem in some laboratories. Despite the opnrrusm of most of the authors for their techniques. and the final very short survey of the application of tissue culture techniques to rice improvement. the way ahead is not outlined very clearly. There is no discrimination between techniques already yielding results. and those whose potential lies well into the future. For example. there is enthusiasm for hybridisation by protoplast fusion of rice with sorghum. but regeneration cannot be attained from the protoplasts of either species individually. In contrast. IRAT (lnstitllt de Recherches Agronomiques Tropicalesi have produced commercial hybrid rice seed in only three years. but there is no exploration of the application of such results. It must be concluded that there is still a need for more basic research whilst acknowledging that much progress. particularly with anther culture, has already been madc. Jennet Blake

Book Review: Forest Products and Wood Science. An Introduction:

Handbook For Pulp Paper Technologists

Pretreatment is an important step in the conversion of biomass to bioethanol. In this study microwave-assisted oxalic acid (MOA) pretreatment was chosen to pretreat oil palm empty fruit bunch (OPEFB) to enhance enzymatic saccharification of the biomass. The objective of this study was to determine an optimum pretreatment condition for reducing sugar production, which could be further fermented by yeast to produce ethanol. Preliminary study was conducted to determine the range of duration of heating and temperature that will be used in the optimization by using response surface methodology (RSM). Central composite design (CCD) was used with three independent variables (duration of heating, temperature and acid concentration). Reducing sugar yield per initial biomass was used as a response variable. Preliminary study, that was conducted at 160, 170, 180, 190, and 200 °C for 5, 7.5, 10, 12.5, and 15 min, shows that pretreatment at temperature of 170–190 °C for 5–10 min produced higher reducing sugars than other conditions. Optimization using RSM shows that the optimum condition of MOA pretreatment of OPEFB was at 190 °C for 3 min with 1.1% oxalic acid, which resulted in as much as 34.60% reducing sugars after enzymatic saccharification. The pretreated OPEFB was then characterized and compared with untreated OPEFB. MOA pretreatment successfully removed 50.57% of lignin and 76.56% of hemicellulose from the OPEFB that were confirmed by a decrease or disappearance of the absorption bands of functional groups at 1339–1650 cm−1 and 1735 cm−1, respectively.

Optimization of Microwave-Assisted Oxalic Acid Pretreatment of Oil Palm Empty Fruit Bunch for Production of Fermentable Sugars

The influence of sulfuric acid concentration in aqueous glycerol during microwave pretreatment on the chemical content and morphological characteristics changes of pretreated EFB were investigated. After pretreatment, the pulp was further subjected to enzymatic hydrolysis. The micro-morphology and crystallinity of original and pretreated EFB were observed by scanning electron microscopy (SEM) and X-ray diffraction. Lignin content of pretreated EFB was determined, while hydrolysate after enzymatic hydrolysis was also analyzed the reducing sugar content. These results indicated that microwave assisted acid pretreatment of EFB caused weight loss. Evaluation on effect of varying acid concentration and residence times results 1 % acid concentration for 12.5 min as the best pretreatment condition. Under the best pretreatment condition, lignin removal was about 59.16 % with the reducing sugar yield per original EFB was 25.09 or 55.85 % per pretreated EFB. The acid–glycerol catalyst successfully improved reducing sugar yield compared to both untreated and biological pretreated samples. SEM images revealed that the pretreated of EFB surface changed noticeably and the increase of crystallinity degree of pretreated EFB indicated a great effect on amorphous region to crystalline region. The addition glycerol in reaction mixture both acid and alkaline has synergistic effect to increase reducing sugar yield. Much volume of glycerol in mixture has great effect to improve enzymatic hydrolysis performance than that of acid ones. The highest reducing sugar yield is produced as much as 98 % when EFB irradiated using glycerol–acid ratio of 1:2 for 12.5 min at 1 % acid concentration. The addition glycerol of 2 fold can increase 3.9 fold reducing sugar yield in the best pretreatment condition. Microwave assisted acid pretreatment in aqueous glycerol was an effective way to increase reducing sugar yield of EFB by lignin removal and fiber disruption.

Microwave Assisted Acid Pretreatment of Oil Palm Empty Fruit Bunches (EFB) to Enhance Its Fermentable Sugar Production

Developing an effective pretreatment for the conversion of lignocellulosic biomass to ethanol is an important effort in reducing the cost of this process. Microwave-assisted pretreatment is considered a green technology that can effectively break down lignocellulosic structures. The objective of this study was to investigate the most effective temperature for microwave-assisted oxalic acid pretreatment regarding the structural characteristic changes of oil palm empty fruit bunches (OPEFB) fibers. The fibers were subjected to microwave-assisted oxalic acid pretreatment at 160–200 °C with 2.5 minutes heating time and a liquid to solid ratio of 10. The effectiveness of the pretreatment was determined based on its delignification selectivity, morphological characteristics, and functional group changes. Microwave irradiation of OPEFB fibers at 180 oC was effective in increasing the cellulose content by 24%. This pretreatment resulted in 1.82 delignification selectivity. More than 50% of the hemicellulose of the OPEFB was removed after this treatment, which was confirmed by a decrease of the absorption bands of functional groups at 1732 cm -1 . The increase of pretreatment temperature disrupted the morphological structure of the OPEFB and removed its hemicellulose but did not change its functional groups and lignin content.

Disruption of Oil Palm Empty Fruit Bunches by Microwave-assisted Oxalic Acid Pretreatment

Fast growing wood species has become more promising as alternative wood sources to solve the gap between wood demand and supply. In this study, we focus on their fiber characteristicsand the wood density to determine their potential utilization. Thirty fast growing species were taken from secondary forest at PT Sari BumiKusuma, Central Kalimantan, Indonesia. Several hardwood and softwood species, which are commonly used in pulp and paper industries, were used as a comparison.The result showed that these species are low to high density (0.18-0.86). It is interesting to note that the fiber lengths of the 5 wood species were greater than commonly hardwoods, and similar with fiberlengths of softwoods. The fibers of the woods have good runkle ratio and the flexibility values. There were 7 potential species to be used as alternative wood material for pulp and paper: Endospermumdiadenum , Dillenia sp., Adinandradumosa , Adinandra sp., Naucleajunghuhnii , Neonaucleagigantea and Ficusfulva .

Exploration of Unutilized Fast Growing Wood Species from Secondary Forest in Central Kalimantan: Study on the Fiber Characteristic and Wood Density☆

In order to know the proper use of lignin derived from pulping process of A. mangium, it is important to study the characteristics of lignin obtained from this species. The objective of this research was to study the characteristics of lignin isolated from kraft pulping black liquor of A. mangium. Lignin was isolated from the black liquor by single step and two step acid precipitation. The lignins were characterized for their moisture, ash, acid soluble lignin (ASL), and acid insoluble lignin (AIL) contents. Elemental composition, FTIR spectra, UV spectra, and microscopic structure using SEM were also analyzed. The yield of lignin obtained through one step precipitation of black liquor (45.76%) was much higher than that through two step precipitation (7.38%), while ash contents of lignin from one step and two step precipitations were almost the same. Ultimate analysis shows that carbon content in lignin from one step precipitation was lower than that from two step precipitation, while hydrogen, oxygen, ni...

Lucky Risanto

Papers

Optimization of Microwave-Assisted Oxalic Acid Pretreatment of Oil Palm Empty Fruit Bunch for Production of Fermentable Sugars

Microwave Assisted Acid Pretreatment of Oil Palm Empty Fruit Bunches (EFB) to Enhance Its Fermentable Sugar Production

Disruption of Oil Palm Empty Fruit Bunches by Microwave-assisted Oxalic Acid Pretreatment

Exploration of Unutilized Fast Growing Wood Species from Secondary Forest in Central Kalimantan: Study on the Fiber Characteristic and Wood Density☆

Chemical characterization of lignin from kraft pulping black liquor of Acacia mangium