Enhanced Breaking of Lignin and Mesopore Formation in Zinc Chloride Assisted Hydrothermal Carbonization of Waste Biomasses

Hydrochars from hydrothermal carbonization of different biowaste materials (dried dandelion, sawdust, coconut shell powder) formed in the presence of aqueous salt solutions were compared to those obtained by the common method in pure water. Hydrochars with increased carbon contents, pore volume and surface areas were specifically obtained from coconut shell powder in the presence of zinc chloride. Compositional and structural changes within the hydrochar products caused by the process conditions and/or the additive were characterized by solid state 13C NMR spectroscopy, proving that cellulose and, in particular, lignin units in the biomass are more easily attacked in the presence of the salt. Under saline conditions, a distinct particle break-up led to the creation of mesoporosity, as observable from hysteresis loops in nitrogen adsorption isotherms, which were indicative of the presence of pores with diameters of about 3 to 10 nm. The obtained hydrochars were still rich in functional groups which, together with the mesoporosity, indicates the compounds have a high potential for pollutant removal. This was documented by adsorption capacities for the methylene blue and methyl orange dyes, which exceeded the values obtained for other hydrochar-based adsorbers. A subsequent physical activation of the mesoporous hydrochars in steam at different temperatures and times resulted in a further drastic increase in the surface areas, of up to about 750 m2/g; however, this increase is mainly due to micropore formation coupled with a loss of surface functionality. Consequently, the adsorption capacity for the quite large dyes does not provide any further benefit, but the uptake of smaller gas molecules is favored.

Mechanical Properties of Pack Carburized SCM 420 Steel Processed Using Natural Shell Powders and Extended Carburization Time

The feasibility of using coconut shell powder (CSP) and dog conch shell powder (DCSP) as carburizing media in the pack carburization of SCM 420 steel was investigated. The carbon content and surface hardness of the carburized specimens prepared with different CSP:DCSP ratios and carburizing durations were examined and compared. A CSP:DCSP ratio of 60%:40% and an extended carburizing time of 12 h were found to increase the carbon content of the carburized specimens to 1.14 ± 0.007 wt%. Furthermore, the surface hardness was significantly improved to 961.3 ± 4.918 HV following water quenching. Finally, the thickness of the carburized layer of the quenched specimens increased by around 2.5 times as the carburizing duration was increased from 3 to 12 h.

Static Mechanical, Heat Deflection And Ageing Properties of Cocos Nucifera Filler Reinforced Vinyl Ester Polymer Composites

Recently, natural filler reinforced polymer composites are important materials for various engineering applications. Hence, this present work focuses on utilization of coconut shell powder (CSP) as a filler in vinyl ester (VE) resin to produce particulate composite specimens. The particulate composite plates with various weights or filler contents from 5 to 30 wt% were fabricated, using compression molding technique. The fabricated composites were subjected to tensile, flexural, impact, hardness, heat deflection and swelling behavior tests to obtain their corresponding material properties. Energy dispersive X-ray (EDX) analysis was carried out on the coconut shell powder/vinyl ester (CSP/VE) composite specimens to investigate into the presence of their elements, in addition to the aforementioned tests. From the experimental results obtained, it was observed that the optimum mechanical properties of CSP/VE composites were obtained at 15 wt% of filler content, having tensile, flexural and impact strengths of 38.70, 105.13 MPa and 33.04 kJ/m2, respectively. Also, the heat deflection temperature (HDT) results varied from 158 (0 wt%, neat VE resin) to 171 oC along various percentages of filler contents. Lastly, the morphological study/analysis of the fractured CSP/VE composite specimens was conducted by using a scanning electron microscope (SEM) to confirm the experimental data/results obtained. It was evident that CSP/VE composite structures could be potential substitutes for some synthetic composites. Also, they are suitable for various engineering applications in aerospace, electrical/electronics and automobile industries, based on their properties.

Adsorption of Oil Spill from Sea Water using Coconut Shell Powder

Oil Spill has resulted in severe impact on marine ecosystem as oil spill can have toxicological effects which when consumed, can affect the human respiratory system. Also, the oil and gas industry has had to deal with a massive amount of waste water as a by-product of the exploration of oil and gas. Methods which are used to purify water from petroleum and oil products are: mechanical, physicochemical, chemical and biochemical. Adsorption is a very effective and easily interpreted physicochemical method. In our study, we have highlighted the benefits and procedure of removing oil from seawater using coconut shell powder which is a natural and easily available adsorbent. UV Spectroscopy has been performed to support the feasibility of coconut shell powder as our agent of adsorption. We studied the effect of bed height with respect to removal efficiency analytically. The removal efficiency increases with increase in bed height. Correlation between the Freundlich adsorption isotherm model and adsorption equilibrium data was done and it was found that adsorption equilibrium data was better than the Langmuir model eventually in our experiment.

​Coconut Shell Powder Reinforced Epoxy Composites: A Review

Fibers are of two type’s natural fiber and synthetic fiber. Natural fibers include those made from plant and animal sources. The natural fiber composites can be very cost effective material and have turned out to be an alternative solution to the ever depleting petroleum sources and have reduced the nuisance of pollution. The production of complete natural fiber based materials as a substitute for petroleum-based products would not be an economical solution. A more viable solution would be to combine petroleum and bio-based resources to develop a cost-effective product with diverse applications. The application of natural fiber-reinforced composites has been extended to almost all fields such as building and construction industry, storage devices (post-boxes, grain storage silos, bio-gas containers etc.), furniture and electrical devices. Coconut shell is a lignocellulosic agro waste which is burnt or left to decay in environment. These can be a very interesting material as filler in biodegradable polymer composites, due to its good thermal stability compared to other agricultural waste. In context to this, review was carried out to assess the coconut shell powder reinforced epoxy composites and their mechanical, structural and thermal properties.

Mechanical Characterization of Areca Fiber and Coconut Shell Powder Reinforced Hybrid Composites

The use of natural fibers in polymer matrix composites are increases because of their advantages like good stiffness, strength, environmental friendly, low cost and biodegradable. In the present investigation, hybrid fiber reinforced composites are fabricated using areca fiber and coconut shell powder (CSP) as reinforcement in epoxy resin. Unidirectional areca fiber and CSP reinforced epoxy composites were fabricated by varying the overall fiber loading (10, 20, 30, and 40 wt.%) and different weight ratios of areca fiber and CSP (1:1, 1:3, and 3:1). Effect of fiber loading and weight ratio on mechanical properties like tensile strength, tensile modulus, flexural strength, flexural modulus, interlaminar shear strength (ILSS), impact energy and surface hardness of hybrid composites were evaluate experimentally. All the hybrid composite samples fabrication and mechanical testing was done as per ASTM standards. The experimental investigation reveals that the tensile, flexural and ILSS properties show their maximum values at 30 wt.% of fiber loading with areca fiber and CSP weight ratio as 1:1. From the impact and hardness results it has been found that composites with areca fiber and CSP weight ratio as 3:1 and 1:1 respectively shows their maximum values at 40 wt.% of fiber loading. Interfacial analysis of the hybrid composites were also observed by using scanning electron microscope (SEM).