Preparation and Characterization of Activated Carbons from Palm Nut Shells: Effects of Calcination Temperature on Porosity and Chemical Properties

Activated carbons (ACs) calcined at 400˚C, 500˚C, and 600˚C (AC-400, AC-500, and AC-600) were prepared using palm nut shells from Gabon as raw material and zinc chloride (ZnCl2) as a chemical activating agent. Prepared ACs were characterized by physisorption of nitrogen (N2), determination of diode and methylene blue numbers for studies of porosity and by quantification and determination of surface functional groups and pH at point of zero charge (pHpzc) respectively, for studies of chemical properties of prepared ACs. Then, effects of calcination temperature (Tcal) on porosity and chemical properties of prepared ACs were studied. The results obtained showed that when the calcination temperature increases from 500˚C to 600˚C, the porosity and chemical properties of prepared ACs are modified. Indeed, the methylene blue and iodine numbers determined for activated carbons AC-400 (460 and 7.94 mg·g−1, respectively) and AC-500 (680 and 8.90 mg·g−1, respectively) are higher than those obtained for AC-600 (360 and 5.75 mg·g−1, respectively). Compared to the AC-500 adsorbent, specific surface areas (SBET) and microporous volume losses for AC-600 were estimated to 44.7% and 45.8%, respectively. Moreover, in our experimental conditions, the effect of Tcal on the quantities of acidic and basic functional groups on the surface of the ACs appears negligible. In addition, results of the pHpzc of prepared ACs showed that as Tcal increases, the pH of the adsorbents increases and tends towards neutrality. Indeed, a stronger acidity was determined on AC-400 (pHpzc = 5.60) compared to those on AC-500 and AC-600 (pHpzc = 6.85 and 6.70, respectively). Also according to the results of porosity and chemical characterizations, adsorption being a surface phenomenon, 500˚C appears to be the optimal calcination temperature for the preparation of activated carbons from palm nut shells in our experimental conditions.

Coating of Mineral Acids with Niobic Solid Acid for Preparing Furfural from Nut Shell of Camellia oleifera Abel

Nut shell of Camellia oleifera Abel which has large scale of plantation in mountainous region of southern China is abundant renewable resource. The nut shell is suitable for preparation of furfural, as the content of which is as much as 16% (based the dried nut shell). In early time, mineral acids were employed as typically catalyst for preparing of furfural from the nut shells. These mineral acids could pollute water and corrode equipment. In this paper we used various mineral acids coating with niobic acid as catalysts to investigate reactions for preparation of furfural. Among these catalysts, the catalyst of sulfuric acid coating with niobic acid was found to be very effective, which had higher hammett acidity and better effect of hydrolysis of the nut shells;The catalysts of sulfuric acid coating with niobic acid was characterized, and the conditions of preparation of the catalyst were investigated. The optimum conditions were: sulfuric acid as coating acid, the concentration of sulfuric 1.1 mol/L, impregnation time 8 h, calcination time 8 h and calcination temperature 450°C. Then hydrolysis of the nut shells was explored, the optimum conditions were as follows: dose of catalyst 20%, ratio of solid to liquid 1:15, reaction temperature 100°C, reaction time 4 h;Under this condition, the yield of furfural was 8.7%.

Corrosion Inhibition of Amino Pentadecylphenols (APPs) Derived from Cashew Nut Shell Liquid on Mild Steel in Acidic Medium

In this study, corrosion inhibiting properties of amino pentadecylphenols (APPs) derived from Cashew Nut Shell Liquid (CNSL) on mild steel in aerated 0.10 M HCl at 303 K were studied using Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization measurements. Both methods indicated the potential of a mixture of amino pentadecyphenols to serve as a corrosion inhibitor in mild steel in 0.10 M HCl. Corrosion inhibition efficiencies were observed to increase with increase in the inhibitor concentration, with maximum corrosion inhibition of about 98% at inhibitor concentration of 600 ppm. The adsorption of the inhibitor on mild steel surface was found to obey Temkin adsorption isotherm, signifying physical adsorption of the inhibitor molecules on mild steel surface.

Synthesis of Poly(APP-co-EGDMA) Particles Using Monomers Derived from Cashew Nut Shell Liquid for the Removal of Cr(III) from Aqueous Solutions

This work was aimed at synthesizing Cashew Nut Shell Liquid (CNSL) based polymer particles for adsorption of Cr(III) ions from aqueous solutions. Natural CNSL was used as a starting material in synthesizing amino pentadecylphenols (APP). This was achieved through isolating anacardic acid from the CNSL via calcium anacardate procedure, followed by hydrogenation of the alkenyl side chains, and subsequently decarboxylating the product to form 3-pentadecylphenol, which was then nitrated and reduced to a mixture of APP. APP were co-polymerized with ethylene glycol dimethacrylate (EGDMA) to form poly(APP-co-EGDMA) particles. The chemical structures of the synthesized compounds were confirmed by Fourier Transform IR and 1H-NMR. The co-polymer particles were characterized by Scanning Electron Microscopy (SEM) to establish their morphological properties. The prepared co-polymer particles were found to have-NH loading of 46 mmol/g and a maximum adsorption capacity for Cr(III) ions of 16 mg per g of dry polymer particles. The spent polymer particles were recoverable and reusable.

Hard carbons derived from pine nut shells as anode materials for Na-ion batteries

Hard carbons as promising anode materials for Na-ion batteries(NIBs) have captured extensive attention because of their low operation voltage, easy synthesis process, and competitive specific capacity. However, there are still several disadvantages, such as high cost and low initial coulombic efficiency, which limit their large-scale commercial applications.Herein, pine nut shells(PNSs), a low-cost biomass waste, are used as precursors to prepare hard carbon materials. Via a series of washing and heat treatment procedures, a pine nut shell hard carbon(PNSHC)-1400 sample has been obtained and delivers a reversible capacity of around 300 mAh/g, a high initial coulombic efficiency of 84%, and good cycling performance. These excellent Na storage properties indicate that PNSHC is one of the most promising candidates of hard carbon anodes for NIBs.

Gasification of Cashew Nut Shell Using Gasifier Stovein Mozambique

Mozambique relies on wood biomass for meeting its household energy demand. This has been for long referred to as one of the main causes of the ongoing deforestation, mainly around the large cities and village. On the other hand, the country produces large quantities of agricultural crops residue which are still not being appropriately and integrally used as additional source of energy, especially for communities in the countryside where these residues are generated. Cashew nut shells (CNS) are among those residues. This kind of feedstock is said to be of high energy content. However, its utilization as energy source within the country is still poor.In Mozambique, 90% of the households depend on biomass for cooking. Biomass has already emerged in the renewable energy area as one of the promising candidates for the future energy source. Historically, biomass has been a major source of fuel from the existence of making rapid urbanization, but widespread use of fossil fuels in the industrialization has relegated it to a minor source of energy. The CNS Gasifier Stove developed has a thermal efficiency of 35.5% and an energy output of 2.19 kW. The corresponding values for LPG stove and Kerosene stove are 53.53% (0.69 kW) and 39.3% (0.6 kW), respectively. Though the use of CNS gasifier as a fuel is less efficient than the aforementioned one, with the rising oil prices and the search for alternatives to contemporary cooking fuels, it is still a viable alternative in this comparison.

Present Situation and Prospective of Camellia Nut Shells Utilization

With the rapid development of Camellia oleifera industry, more and more Camellia nut shells have been produced, leading to serious environmental pollution problem. This paper reviews the works on the characterization of the physical and chemical properties of Camellia nut shells, active ingredient extraction, its application in chemical production, growing media and animal feed and its properties as a biomass. Based on the review, we proposed a novel all-component high value application strategy to covert camellia nut shells into high value biomasses, which could realize waste recycling and environmental protection.

Morphological, Structural, Thermal and Tensile Properties of High Density Polyethylene Composites Reinforced with Treated Argan Nut Shell Particles

High Density Polyethylene （HDPE） composites reinforced with treated bio-filler from Argan-Nut Shell （ANS） at various filler contents are prepared by extrusion and injection molding processes. The microstructures of the composites are charac- terized by Fourier Transform Infrared Spectroscopy （FTIS） and Scanning Electron Microscopy （SEM）; the thermal stability is analyzed by Thermogravimetric Analysis （TGA）, and their mechanical properties are investigated by dynamical mechanical analysis and rheological testing. The morphological and structural results indicate an improvement in adhesion between the ANS fillers and HDPE matrix upon alkali treatment. The mechanical properties of the composites show a significant increase in young＇s modulus with the addition of filler, a gain of 58% is marked compared to neat polymer, Thermal analysis reveals that the incorporation of bio-filler in polymer results in a decrease in decomposition temperatures. This research offers an ecological alternative to upgrade the valorization of abundant and unexploited Moroccan resources. In addition, the possibility of finding uses for ANS in composite manufacturing will help open new markets for what is normally considered waste or for use in low value products.

Prediction of performance, combustion and emission characteristics of diesel-thermal cracked cashew nut shell liquid blends using artificial neural network

This paper explores the use of artificial neural networks （ANN） to predict performance, combustion and emissions of a single cylinder, four stroke stationary, diesel engine operated by thermal cracked cashew nut shell liquid （TC-CNSL） as the biodiesel blended with diesel. The tests were performed at three different injection timings （21°, 23°, 25℃A bTDC） by changing the thickness of the advance shim. The ANN was used to predict eight different engine-output responses, namely brake thermal efficiency （BTE）, brake specific fuel consumption （BSFC）, exhaust gas temperature （EGT）, carbon monoxide （CO）, oxide of nitrogen （NOx）, hydrocarbon （HC）, maximum pressure （Pm~,,） and heat release rate （HRR）. Four pertinent engine operating parameters, i.e., injection timing （IT）, injection pressure （IP）, blend percentage and pecentage load were used as the input parameters for this modeling work. The ANN results show that there is a good correlation between the ANN predicted values and the experimental values for various engine performances, combustion parameters and exhaust emission characteristics. The mean square error value （MSE） is 0.005621 and the regression value ofR2 is 0.99316 for training, 0.98812 for validation, 0.9841 for testing while the overall value is 0.99173. Thus the developed ANN model is fairly powerful for predicting the performance, combustion and exhaust emissions of internal combustion engines.

Adsorption of Tartrazine onto Activated Carbon Based Cola Nuts Shells: Equilibrium, Kinetics, and Thermodynamics Studies

The uptake of tartrazine from its aqueous solution by powdered activated carbon prepared from cola nut shells chemically activated with potassium hydroxide (ACK) and phosphoric acid (ACP) has been investigated using kinetics models. Batch isotherm data were analysed with the pseudo-first order, pseudo-second order model as well as the intraparticle diffusion model. For structural elucidation, the materials were characterized using FTIR, XRD and SEM. These analyses revealed that the activated carbons (ACK and ACP) were predominantly mesoporous with several oxygen-containing functional groups dispersed on their surface. The reaction was systematically investigated under various experimental conditions such as contact time, adsorbent dose and pH. For the two adsorbents, the quantity adsorbed of 19.256 mg/g and 18.196 mg/g respectively for ACP and ACK at respective contact times of 5 and 10 min were obtained. The adsorption data were tested with the Langmuir, Freundlich models. Langmuir model was found to best describe the adsorption of tartrate ions with maximum monolayer adsorption capacities of 24.57 and 21.59 mg/g for ACP and ACK, respectively. Results analysis indicated clearly that the pseudo-second order kinetic rate model best fitted the experimental data and therefore was the adsorption controlling mechanism for both adsorbents. Thermodynamic studies revealed that the adsorption process was spontaneous and exothermic for ACP with increased randomness at the solid solution interface, then exothermic but non-spontaneous for ACK. The results show that these activated carbons could be an alternative for more costly adsorbents for the purpose of tartrate ions elimination.

Development of Renewable Woodceramics Synthesized from Cashew Nuts Shell Oil

The international issue to be addressed towards realizing a low-carbon society is to reduce the amount of carbon-based underground reserves such as coal, petroleum, and coke, and strongly encouraged to use carbon neutral biomass-derived resources. Woodceramics is a hybrid porous carbon material composed of wood-based biomass and phenolic resin, characterized by high far-infrared emissivity and large specific surface area. Woodceramics has been studied as heating elements and humidity and gas sensors, etc. If this is applied to the inner walls of aging and grain drying furnaces for vegetables and fruits, both ripening and drying are greatly promoted and fossil fuels used in boilers can be significantly reduced. In fact, it can produce black garlic with far infrared rays using a woodceramics brick efficiently. Furthermore, as a substitute for phenolic resin, if plant-based liquefied materials from cashew nut shell oil can be prepared and can be used for manufacturing woodceramics, then all carbon neutral circulating woodceramics made from wood-based biomass is possible to manufacture. On the other hand, woodplastics is a composite material that can be made of wooden materials and plastics, and able to expect the effective use of wood-based biomass and waste plastics.

Elimination, Kinetics and Thermodynamics of Fe(II) Ions by Adsorption in Static and Dynamic Conditions on Activated Carbons in Aqueous Media

This work investigated the removal, kinetics and thermodynamics of iron(II) ions (Fe(II)) by adsorption in static and dynamic conditions in aqueous media on activated carbons (AC-i30min, AC-i1h, and AC-i24h), prepared from palm nut shells collected in the city of Franceville to Gabon, using potassium hydroxide (KOH) as the activating agent. Results on the elimination of Fe(II) in static and dynamic adsorption on prepared activated carbons (ACs) showed that the AC-i24h adsorbent has the best Fe(II) adsorption capacities at saturation (Qsat). The Qsat obtained on AC-i24h in static and dynamic conditions (17.87 and 10.38 mg/g, respectively) were higher than those of AC-i30min (13.89 and 5.54 mg/g respectively) and AC-i1h (14.92 and 8.64 mg/g respectively). Moreover, the static adsorption was more effective in the removal of Fe(II) ions in aqueous media in our experimental conditions. The percentage removal (%E) of Fe(II) obtained on prepared activated carbons in static conditions was better than those obtained in dynamic conditions, especially on AC-i24h, where the %E was 89.27% in static and 61.56% in dynamic. In kinetics, results showed that the pseudo-second-order kinetic model best described the adsorption mechanisms of Fe(II) on prepared activated carbons in static adsorption, with mainly of chemisorption on the solid surfaces. However, in dynamic conditions, the pseudo-first-order kinetic model was more suitable. In addition to the weak interactions between Fe(II) and the activated carbon surfaces, strong interactions (chemisorption) were also observed. Also, thermodynamic data obtained on AC-i24h in static adsorption indicated that the adsorption of Fe(II) was spontaneous and increased with temperature (ΔG˚ H˚ = 503.54 KJ/mol).

Chemical Analysis of Activated Carbon from Bull and Cow Horns Pyrolysis to Be Used as Antidotes

The purpose of this study is to compare the results of chemical analysis of two types of activated from the pyrolysis of bull horn and that of cow. Six samples were used to measure pH, carbon, calcium and to determine adsorbent power. The pH was measured at a temperature of 20˚C using an “ANION 7010 ionomer” pH meter, the carbon (C) content was analyzed using a “EURO EA 3000” analyzer. and the electronic balance: “Sartorius CP-2P”, calcium (Ca) was analyzed using a DFS-8 spectrograph. For the adsorbency test, the 0.15% methylene blue R solution was used. At the end of this study, we found that the activated carbon from the bull horn demonstrated a carbon content that is higher than that of the cow horn (20.79% against 15.63%), activated carbon of cow horn is richer in calcium than that of bull horn (16.27% against 3.69%) and then the pH. The cow horn is higher than that of the bull horn (7.43 versus 6.5). For the adsorbent power, the sample (75% bull horn and 25% cow horn) was recorded with the greatest adsorbent power. Thus, from this study, it can be recommended as an activated carbon antidote to be used for poisonings treatment.

某分离螺母壳体裂纹产生原因分析及结构改进

针对某分离螺母发火后壳体上端面产生裂纹的问题,对分离螺母的作用过程进行了仿真,分析了裂纹产生原因,提出了改进措施,并对其有效性进行了验证。结果表明:由于解锁过程中,分瓣螺母轴线与产品轴线的相对位置发生偏移,并且内筒活塞也发生偏转,造成结构间冲击载荷传递不均匀,从而导致壳体上端面锥台根部局部位置受冲击过大而出现裂纹。通过增大内筒活塞对分瓣螺母的接触长度和径向约束,能够改善壳体上端面锥台根部受力不均的问题,从而减少裂纹产生。

澳洲坚果壳活性炭载锌复合抗菌材料的制备及性能研究

以澳洲坚果壳为原料,采用氯化锌活化法制备粉末活性炭作为抗菌材料载体,通过浸渍法将Zn^(2+)负载于活性炭的表面和微孔中,得到活性炭载锌复合抗菌材料。利用碘吸附值、氮气吸脱附、扫描电子显微镜、电感耦合等离子体-发射光谱及抗菌实验对材料进行表征。结果表明:活性炭材料具有多孔结构,比表面积达644.118 m^(2)/g,平均孔径为2.289 nm,碘吸附值为1018 mg/g。以硫酸锌为锌源,炭锌接触时间7 h、炭锌浸渍比1∶25、锌溶液浓度1.0 mol/L时,制备的活性炭载锌复合抗菌材料具有较好的杀菌性能,对大肠杆菌和金黄色葡萄球菌都能达到99.9%的抗菌率。活性炭载锌复合抗菌材料与织物浸渍得到的抗菌织物也具有较好的抗菌效果,展现了良好的应用前景。本研究可为拓宽废弃生物质资源的应用范围提供参考。

澳洲坚果果壳多糖的提取工艺研究

多糖是澳洲坚果果壳中的主要活性物质之一,具有抗肿瘤、调节人体免疫、降血脂等功效。本文采用水提法回流提取的方式,提取澳洲坚果果壳中的多糖,用苯酚-硫酸法,通过UV-1800紫外分光光度计测定了坚果果壳中多糖的吸光度,得出了线性回归方程,计算了多糖提取率。结果表明,澳洲坚果多糖的最优提取工艺条件为:提取时间4h,提取温度90℃,料液比1∶40(g∶mL),此条件下澳洲坚果果壳多糖的得率为5.35%。

我国坚果脱壳机械现状与发展趋势

我国坚果品种丰富,营养价值高,深受人们喜爱,是重要的林果资源之一。坚果加工产业的健康发展,不仅有利于增加林农收入、可持续利用土地资源、改善国家生态环境,还可以促进林业发展和价值转化。为提升坚果业机械化水平,采用实地调研和查阅文献的方法,对国内坚果业机械化发展现状、坚果脱壳机械发展趋势进行分析,提出国内坚果机械化高质量发展的建议,以求促进坚果业机械化发展。

一种文冠果破壳机设计

文冠果是新疆特色林果发展中的重要组成部分,可以很大限度地弥补我国食用植物油的缺口。由于文冠果的硬果皮难以剥离,人工剖果效率低且成本高,国内缺少满足文冠果壳破壳技术要求的机械。该文以文冠果物理和力学特性为基础,设计了一种同时完成分选、分离为一体的文冠果破壳机。采用三叶打板和挤压滚筒配合进行二次破壳,能够有效分离果壳与果仁,通过SolidWorks-Simulation静应力新算例程序,对三叶打板进行静力学仿真特性分析,其中三叶打板的最大应变力为60 MPa,在材料屈服强度内,最大位移量和应变量分别为0.30 mm、0.34 MPa,满足材料强度要求。通过对破壳机的结构参数进行设计优化,极大方便了人们对文冠果的食用,降低了劳动强度和加工成本。

耕地严控背景下皖北地区薄壳山核桃栽培推广与提质增效路径探索

薄壳山核桃作为木本油料树种在皖北地区表现出较强的生态适应性,综合效益显著,详细介绍了薄壳山核桃在该地区的引种栽培状况、当前收益,分析了当前栽培推广中存在的主要问题,并对下一步薄壳山核桃产业化发展路径,提出了参考意见和建议。