The coconut fiber is produced in large quantities in Brazil, even though very small quantities are being used by some industries, mainly cordage mats and handicrafts. An alternative usage would be the use of these fib...The coconut fiber is produced in large quantities in Brazil, even though very small quantities are being used by some industries, mainly cordage mats and handicrafts. An alternative usage would be the use of these fibers in biosorption of heavy metals from aqueous solutions. This present study aimed to evaluate the potentiality of cadmium biosorption by coconut fiber. The coconut fibers were used at kinetic analysis, influence ofpH and adsorption isotherms were also carried out. It can be concluded that there is great potential for the use of coconut fiber, and the optimum pH for adsorption was around 5.0. The adsorption kinetics is fast and equilibrium occurs within 120 min. The Langmuir isotherm was considered the most suitable to describe the experimental data.展开更多
The criticisms regularly formulated towards clay or soil, in general, are its weak mechanical qualities and low water quality. Therefore, it is necessary to find techniques to improve the properties of this material, ...The criticisms regularly formulated towards clay or soil, in general, are its weak mechanical qualities and low water quality. Therefore, it is necessary to find techniques to improve the properties of this material, which is widely used worldwide. Here, we propose stabilizing clay with coconut fiber as a solution to enhance its mechanical properties. To do this, we used an experimental method, first determining the geotechnical properties of the clay and then its mechanical properties. The geotechnical study using the Proctor Test revealed that the dry density of the clay is γb = 1.42 g/cm3, and its water content is W = 22.3%. By applying the rolling method, the Atterberg limits were determined: liquid limit Wl = 63.6, plastic limit Wp = 27.9, plasticity index Ip = 35.7, and consistency index Ic = 1.46. With 25 P = 35.7 1.3, according to the water classification, it falls into class A3ts. The mechanical part focused on compression and flexural strengths obtained using a PROETI hydraulic press. We obtained a flexural strength of 0.63 MPa for simple clay (BA);0.89 MPa for clay + 0.25% fiber (BAF1/4);1.68 MPa for clay + 0.5% fiber (BAF1/2);1.87 MPa for clay + 0.75% fiber (BAF3/4);and 3.91 MPa for clay + 1% fiber (BAF1). As for the compression strength, BA = 5.90 MPa, BAF1/4 = 6.395 MPa, BAF1/2 = 6.292 MPa, BAF3/4 = 6.065 MPa, and BAF1 = 5.423 MPa. The addition of fiber has thus improved the mechanical qualities of the simple clay. These stabilized bricks can be used for sustainable and bioclimatic construction, providing higher durability and good comfort.展开更多
The current energy crisis could be alleviated by enhancing energy generation using the abundant biomass waste resources. Agricultural and forest wastes are the leading organic waste streams that can be transformed int...The current energy crisis could be alleviated by enhancing energy generation using the abundant biomass waste resources. Agricultural and forest wastes are the leading organic waste streams that can be transformed into useful alternative energy resources. Pyrolysis is one of the technologies for converting biomass into more valuable products, such as bio-oil, bio-char, and syngas. This work investigated the production of bio-oil through batch pyrolysis technology. A fixed bed pyrolyzer was designed and fabricated for bio-oil production. The major components of the system include a fixed bed reactor, a condenser, and a bio-oil collector. The reactor was heated using a cylindrical biomass external heater. The pyrolysis process was carried out in a reactor at a pressure of 1atm and a varying operating temperature of 150˚C, 250˚C, 350˚C to 450˚C for 120 minutes. The mass of 1kg of coconut fiber was used with particle sizes between 2.36 mm - 4.75 mm. The results show that the higher the temperature, the more volume of bio-oil produced, with the highest yield being 39.2%, at 450˚C with a heating rate of 10˚C/min. The Fourier transformation Infrared (FTIR) Spectroscopy analysis was used to analyze the bio-oil components. The obtained bio-oil has a pH of 2.4, a density of 1019.385 kg/m<sup>3</sup>, and a calorific value of 17.5 MJ/kg. The analysis also showed the presence of high-oxygenated compounds;carboxylic acids, phenols, alcohols, and branched oxygenated hydrocarbons as the main compounds present in the bio-oil. The results inferred that the liquid product could be bestowed as an alternative resource for polycarbonate material production.展开更多
In spite of being a raw material of virtually unlimited availability due to the massive consumption of the highly popular coconut water, fiber produced from green coconut is much less used than the dried coconut fiber...In spite of being a raw material of virtually unlimited availability due to the massive consumption of the highly popular coconut water, fiber produced from green coconut is much less used than the dried coconut fiber. The objective of this study was to investigate the performance of green (white) coconut fiber as a cushioning material for use in packaging systems. The mechanical performance of both green coconut fibers in their natural state as well as those molded into the shape of cushioning pads were evaluated by shock absorption tests. The results showed that the fibers without agglutination agents exhibited the best performance when submitted to increasing static loads by presenting the greatest capacity to reduce impact acceleration. In addition, green coconut fiber presented behavior similar to that of cellulosic cushioning materials and in certain situations can be considered effective in protecting products that are considered fragile.展开更多
Microbial, vegetal or animal organic matter, which has potential to be transformed into energy, is considered biomass. Among the various alternative energy sources, biomass is the only one with the possibility of gene...Microbial, vegetal or animal organic matter, which has potential to be transformed into energy, is considered biomass. Among the various alternative energy sources, biomass is the only one with the possibility of generating a class of substances of interest for fine chemistry （ketones, aldehydes, alcohols, phenols, etc.）. From biomass, it is possible to produce bio-oil using pyrolysis, a thermodegradation process. The quality of the bio-oil depends on the process conditions （pyrolysis temperature, heating temperature, etc.） and biomass used. In this paper, the pyrolysis （using a fixed bed reactor） of three biomasses （coconut fiber, coffee grounds and sugar cane straw） is studied. The results indicated that the bio-oil yields for all biomass were similar, approximately 37%. The chemical profile obtained by gas chromatography coupled with mass spectrometry （GC/qMS） showed high amounts of fatty acids in the coffee grounds bio-oil and aliphatic and aromatic hydrocarbons in coconut fiber bio-oil, whereas guaiacols were the predominant components of the sugar cane straw bio-oil.展开更多
Stone Matrix Asphalt(SMA)is a gap graded mix;characterized by higher proportion of coarse aggregate,lower proportion of middle size aggregate and higher proportion of mineral filler.In the present laboratory study,com...Stone Matrix Asphalt(SMA)is a gap graded mix;characterized by higher proportion of coarse aggregate,lower proportion of middle size aggregate and higher proportion of mineral filler.In the present laboratory study,commonly available one conventional VG 30 bitumen and another modified binder,namely CRMB 60 have been used along with a non-conventional natural fiber,namely coconut fiber which is abundantly available in India to provide improved engineering properties and at the same time preventing the usual draining of binder in SMA.The role of a particular binder and fiber with respect to their concentrations in the mix is studied for various engineering properties.Marshall procedure has been followed to determine the optimum binder and optimum fiber contents and also to study the relative advantages of fiber addition in the SMA mixtures.Thereafter,the engineering properties under both static as well as repeated load conditions and moisture susceptibility characteristics have been studied.It is observed that only a marginal 0.3%coconut fiber addition brings significant improvement in the engineering properties of SMA mixes.展开更多
The coconut palm tree leaf sheath fibers were analyzed by FTIR spectral analysis, Chemical, X-ray and thermo gravimetric methods to assess their suitability as reinforcements in the preparation of green composites. Th...The coconut palm tree leaf sheath fibers were analyzed by FTIR spectral analysis, Chemical, X-ray and thermo gravimetric methods to assess their suitability as reinforcements in the preparation of green composites. The morphology of the untreated and alkali treated fibers was studied by scanning electron microscopic method. The FTIR and chemical analyses indicated lowering of hemi-cellulose content by alkali treatment of the fibers. The X-ray diffraction revealed an increase in crystallinity of the fibers on alkali treatment. The thermal stability of the fibers was found to increase slightly by alkali treatment. The tensile properties of these fibers increased on alkali treatment. The mechanical and other physical properties indicated that these fibers were suitable as reinforcements for making the green composites.展开更多
Fiber-reinforced polymer (FRP) composites have gradually gained wide acceptance as engineering material applications due to their unique advantages including their high strength-to-weight ratio and excellent corrosion...Fiber-reinforced polymer (FRP) composites have gradually gained wide acceptance as engineering material applications due to their unique advantages including their high strength-to-weight ratio and excellent corrosion resistance. This study was carried out with composites prepared by hot press molding method using coconut spathe fiber as reinforcing material and HDPE (from HDPE can as obsolete polymer) as polymer matrix. Composites were made at 150°C under 60 kN load by taking diverse weight percentage (wt.%) of fiber from 0 to 20 of its total weight. In this research investigation, different properties of the composites such as bulk density, water absorption, tensile and flexural properties, impact strength and hardness test properties were carried out. The fiber content enhancement increases the bulk density in all composites. The rate of water absorption improves with the improvement of fiber addition with respect to HDPE in all composites. But the water absorption was not increased uniformly with the increase of fiber addition in composites. In all cases, composites absorbed water very rapidly up to 80 hrs and then water absorption is in saturated condition. The mechanical properties like tensile strength (TS), flexural strength (FS), impact strength (IS) and hardness were observed to be comparatively more enhanced for 5% composite, while further increasing of fiber addition, all mechanical properties changes irregularly. The irregular nature of change might be caused due to the over loading of fiber in polymer matrix.展开更多
Chitosan/coconut (CTS/coconut) composite membranes were successfully prepared by the cross-linking reaction with glutaraldehyde and they were applied in eliminating heavy metals from aqueous solutions. The cross-linke...Chitosan/coconut (CTS/coconut) composite membranes were successfully prepared by the cross-linking reaction with glutaraldehyde and they were applied in eliminating heavy metals from aqueous solutions. The cross-linked membranes were obtained at the ratios of 1/1, 1/1.5 and 1/2 and the coconut fiber was chemically treated by NaOCl/NaOH. The best ratio of CTS/coconut fiber is found to be 1/1.5 which has a relatively high stability with the degree of swelling (DS) and solvent content (SC) of membrane to be 13.33% and 69.88%, respectively. The results also indicate that the CTS membranes showed preferential separation of heavy metals for blend CTS/coconut membranes.展开更多
The coconut structure exhibits inherent impact resistance,with the macroscopically ordered distribution of variable crosssection fibers in its husk playing a crucial role in stress wave propagation and scaling.Inspire...The coconut structure exhibits inherent impact resistance,with the macroscopically ordered distribution of variable crosssection fibers in its husk playing a crucial role in stress wave propagation and scaling.Inspired by the natural structure and fibers,this study proposes a stress wave propagation model for a variable cross-section bar considering viscous effects.A theoretical model for stress wave propagation in a fusiform-shaped bar with variable cross-section is established,elucidating the stress wave scaling effect observed in coconut fibers.Additionally,a quasi-one-dimensional method for analyzing and measuring stress wave propagation is introduced,and an experimental setup is assembled.Experimental validation of the stress wave scaling effect confirms the theory’s accuracy for stress wave scaling in variable cross-section bars.This research provides theoretical guidance and measurement methods for the design of space landers,automobile anti-collision beams,stress wave collectors,and scalers,as well as for impact testing of macro and micro materials and the design of sustainable plant-based materials for impact protection.展开更多
文摘The coconut fiber is produced in large quantities in Brazil, even though very small quantities are being used by some industries, mainly cordage mats and handicrafts. An alternative usage would be the use of these fibers in biosorption of heavy metals from aqueous solutions. This present study aimed to evaluate the potentiality of cadmium biosorption by coconut fiber. The coconut fibers were used at kinetic analysis, influence ofpH and adsorption isotherms were also carried out. It can be concluded that there is great potential for the use of coconut fiber, and the optimum pH for adsorption was around 5.0. The adsorption kinetics is fast and equilibrium occurs within 120 min. The Langmuir isotherm was considered the most suitable to describe the experimental data.
文摘The criticisms regularly formulated towards clay or soil, in general, are its weak mechanical qualities and low water quality. Therefore, it is necessary to find techniques to improve the properties of this material, which is widely used worldwide. Here, we propose stabilizing clay with coconut fiber as a solution to enhance its mechanical properties. To do this, we used an experimental method, first determining the geotechnical properties of the clay and then its mechanical properties. The geotechnical study using the Proctor Test revealed that the dry density of the clay is γb = 1.42 g/cm3, and its water content is W = 22.3%. By applying the rolling method, the Atterberg limits were determined: liquid limit Wl = 63.6, plastic limit Wp = 27.9, plasticity index Ip = 35.7, and consistency index Ic = 1.46. With 25 P = 35.7 1.3, according to the water classification, it falls into class A3ts. The mechanical part focused on compression and flexural strengths obtained using a PROETI hydraulic press. We obtained a flexural strength of 0.63 MPa for simple clay (BA);0.89 MPa for clay + 0.25% fiber (BAF1/4);1.68 MPa for clay + 0.5% fiber (BAF1/2);1.87 MPa for clay + 0.75% fiber (BAF3/4);and 3.91 MPa for clay + 1% fiber (BAF1). As for the compression strength, BA = 5.90 MPa, BAF1/4 = 6.395 MPa, BAF1/2 = 6.292 MPa, BAF3/4 = 6.065 MPa, and BAF1 = 5.423 MPa. The addition of fiber has thus improved the mechanical qualities of the simple clay. These stabilized bricks can be used for sustainable and bioclimatic construction, providing higher durability and good comfort.
文摘The current energy crisis could be alleviated by enhancing energy generation using the abundant biomass waste resources. Agricultural and forest wastes are the leading organic waste streams that can be transformed into useful alternative energy resources. Pyrolysis is one of the technologies for converting biomass into more valuable products, such as bio-oil, bio-char, and syngas. This work investigated the production of bio-oil through batch pyrolysis technology. A fixed bed pyrolyzer was designed and fabricated for bio-oil production. The major components of the system include a fixed bed reactor, a condenser, and a bio-oil collector. The reactor was heated using a cylindrical biomass external heater. The pyrolysis process was carried out in a reactor at a pressure of 1atm and a varying operating temperature of 150˚C, 250˚C, 350˚C to 450˚C for 120 minutes. The mass of 1kg of coconut fiber was used with particle sizes between 2.36 mm - 4.75 mm. The results show that the higher the temperature, the more volume of bio-oil produced, with the highest yield being 39.2%, at 450˚C with a heating rate of 10˚C/min. The Fourier transformation Infrared (FTIR) Spectroscopy analysis was used to analyze the bio-oil components. The obtained bio-oil has a pH of 2.4, a density of 1019.385 kg/m<sup>3</sup>, and a calorific value of 17.5 MJ/kg. The analysis also showed the presence of high-oxygenated compounds;carboxylic acids, phenols, alcohols, and branched oxygenated hydrocarbons as the main compounds present in the bio-oil. The results inferred that the liquid product could be bestowed as an alternative resource for polycarbonate material production.
文摘In spite of being a raw material of virtually unlimited availability due to the massive consumption of the highly popular coconut water, fiber produced from green coconut is much less used than the dried coconut fiber. The objective of this study was to investigate the performance of green (white) coconut fiber as a cushioning material for use in packaging systems. The mechanical performance of both green coconut fibers in their natural state as well as those molded into the shape of cushioning pads were evaluated by shock absorption tests. The results showed that the fibers without agglutination agents exhibited the best performance when submitted to increasing static loads by presenting the greatest capacity to reduce impact acceleration. In addition, green coconut fiber presented behavior similar to that of cellulosic cushioning materials and in certain situations can be considered effective in protecting products that are considered fragile.
文摘Microbial, vegetal or animal organic matter, which has potential to be transformed into energy, is considered biomass. Among the various alternative energy sources, biomass is the only one with the possibility of generating a class of substances of interest for fine chemistry （ketones, aldehydes, alcohols, phenols, etc.）. From biomass, it is possible to produce bio-oil using pyrolysis, a thermodegradation process. The quality of the bio-oil depends on the process conditions （pyrolysis temperature, heating temperature, etc.） and biomass used. In this paper, the pyrolysis （using a fixed bed reactor） of three biomasses （coconut fiber, coffee grounds and sugar cane straw） is studied. The results indicated that the bio-oil yields for all biomass were similar, approximately 37%. The chemical profile obtained by gas chromatography coupled with mass spectrometry （GC/qMS） showed high amounts of fatty acids in the coffee grounds bio-oil and aliphatic and aromatic hydrocarbons in coconut fiber bio-oil, whereas guaiacols were the predominant components of the sugar cane straw bio-oil.
文摘Stone Matrix Asphalt(SMA)is a gap graded mix;characterized by higher proportion of coarse aggregate,lower proportion of middle size aggregate and higher proportion of mineral filler.In the present laboratory study,commonly available one conventional VG 30 bitumen and another modified binder,namely CRMB 60 have been used along with a non-conventional natural fiber,namely coconut fiber which is abundantly available in India to provide improved engineering properties and at the same time preventing the usual draining of binder in SMA.The role of a particular binder and fiber with respect to their concentrations in the mix is studied for various engineering properties.Marshall procedure has been followed to determine the optimum binder and optimum fiber contents and also to study the relative advantages of fiber addition in the SMA mixtures.Thereafter,the engineering properties under both static as well as repeated load conditions and moisture susceptibility characteristics have been studied.It is observed that only a marginal 0.3%coconut fiber addition brings significant improvement in the engineering properties of SMA mixes.
基金supported by University Grants Com-mission,India,Major Research Project(No:33-397/2007(SRF))
文摘The coconut palm tree leaf sheath fibers were analyzed by FTIR spectral analysis, Chemical, X-ray and thermo gravimetric methods to assess their suitability as reinforcements in the preparation of green composites. The morphology of the untreated and alkali treated fibers was studied by scanning electron microscopic method. The FTIR and chemical analyses indicated lowering of hemi-cellulose content by alkali treatment of the fibers. The X-ray diffraction revealed an increase in crystallinity of the fibers on alkali treatment. The thermal stability of the fibers was found to increase slightly by alkali treatment. The tensile properties of these fibers increased on alkali treatment. The mechanical and other physical properties indicated that these fibers were suitable as reinforcements for making the green composites.
文摘Fiber-reinforced polymer (FRP) composites have gradually gained wide acceptance as engineering material applications due to their unique advantages including their high strength-to-weight ratio and excellent corrosion resistance. This study was carried out with composites prepared by hot press molding method using coconut spathe fiber as reinforcing material and HDPE (from HDPE can as obsolete polymer) as polymer matrix. Composites were made at 150°C under 60 kN load by taking diverse weight percentage (wt.%) of fiber from 0 to 20 of its total weight. In this research investigation, different properties of the composites such as bulk density, water absorption, tensile and flexural properties, impact strength and hardness test properties were carried out. The fiber content enhancement increases the bulk density in all composites. The rate of water absorption improves with the improvement of fiber addition with respect to HDPE in all composites. But the water absorption was not increased uniformly with the increase of fiber addition in composites. In all cases, composites absorbed water very rapidly up to 80 hrs and then water absorption is in saturated condition. The mechanical properties like tensile strength (TS), flexural strength (FS), impact strength (IS) and hardness were observed to be comparatively more enhanced for 5% composite, while further increasing of fiber addition, all mechanical properties changes irregularly. The irregular nature of change might be caused due to the over loading of fiber in polymer matrix.
文摘Chitosan/coconut (CTS/coconut) composite membranes were successfully prepared by the cross-linking reaction with glutaraldehyde and they were applied in eliminating heavy metals from aqueous solutions. The cross-linked membranes were obtained at the ratios of 1/1, 1/1.5 and 1/2 and the coconut fiber was chemically treated by NaOCl/NaOH. The best ratio of CTS/coconut fiber is found to be 1/1.5 which has a relatively high stability with the degree of swelling (DS) and solvent content (SC) of membrane to be 13.33% and 69.88%, respectively. The results also indicate that the CTS membranes showed preferential separation of heavy metals for blend CTS/coconut membranes.
基金supported by the National Natural Science Foundation of China(Grant Nos.11922206 and 11832011)theMajor Project of Science and Technology Innovation 2030(Grant No.2021ZD0113100)the 111 Project(Grant No.B16015).
文摘The coconut structure exhibits inherent impact resistance,with the macroscopically ordered distribution of variable crosssection fibers in its husk playing a crucial role in stress wave propagation and scaling.Inspired by the natural structure and fibers,this study proposes a stress wave propagation model for a variable cross-section bar considering viscous effects.A theoretical model for stress wave propagation in a fusiform-shaped bar with variable cross-section is established,elucidating the stress wave scaling effect observed in coconut fibers.Additionally,a quasi-one-dimensional method for analyzing and measuring stress wave propagation is introduced,and an experimental setup is assembled.Experimental validation of the stress wave scaling effect confirms the theory’s accuracy for stress wave scaling in variable cross-section bars.This research provides theoretical guidance and measurement methods for the design of space landers,automobile anti-collision beams,stress wave collectors,and scalers,as well as for impact testing of macro and micro materials and the design of sustainable plant-based materials for impact protection.
