Durability of Lightweight Concrete Using Oil Palm Shell as Aggregates

Oil Palm Shell (OPS) concrete can be used in different fields of construction. To determine more accurately the fields of application, it is important to know and understand the behaviour of OPS concrete over the long term and when it is in aggressive environments. This paper presents the results of studies conducted on the durability of OPS concrete. Water absorption capacity, electrical resistivity and apparent diffusion of chloride ions have been measured on different concrete samples. In addition, the behaviour of OPS concretes to carbonation was studied in an environment rich in carbon dioxide. Results show that OPS concrete has an absorptivity of 0.97 kg/m2·h1/2, an electrical resistivity of 64.37 Ω·m and an apparent diffusion coefficient of chloride ions of 3.84 × 10-12 m2/s after 90 days. All these results of OPS concrete are very close to those of concrete with normal aggregate and other lightweight concrete, which mean OPS concretes have globally good properties with regard to durability.

Short Review on the Use of Oil Palm Shell in Concrete and Activated Carbon

Oil palm is known as Elaeis guineensis, found in Africa, South East Asia and China. Oil palm shell is used to prepare activated carbon because of high carbon content, high surface area, highly developed porosity and low price. During the physical activation, carbonization occurs in order to create porosity in the raw material. Literature review indicated that carbon material was impregnated with chemical agents such as phosphoric acid, potassium hydroxide, sulphuric acid, sodium hydroxide and zinc chloride in chemical activation process. Experimental results showed that the obtained activated carbon was used in hydrogen storage purpose, supercapacitor, gases and liquid phase adsorption process. On the other hand, oil palm shell was used in manufacturing lightweight concrete because of lighter and will not produce toxic substance. The bulk density and compressive strength of oil palm shell-based concrete were 500 - 600 kg/m3 and more than 25 MPa, respectively.

Performance of an activated carbon made from waste palm shell in simultaneous adsorption of SO_x and NO_x of flue gas at low temperature

This study examined the individual and simultaneous adsorption of SOx (SO2) and NOx (NO-NO2) on activated carbon prepared from waste palm shell. The adsorption process was examined in a fixed bed reactor at low temperatures (100―300℃). For individual adsorption without any catalytic activation, SOx showed good adsorption whereas NOx was very much poor. In the simultaneous adsorption of SOx and NOx, SOx showed greater adsorption affinity than NOx. For palm shell activated carbon (PSAC) impregnated with metal catalyst (Ni and Ce) the concentration adsorbed profile showed that the amount of SOx adsorbed decreased regularly, while the amount of the adsorbed NOx increased irregularly. The properties of the pure and impregnated PSAC were analyzed by BET, SEM and EDX. These investiga-tions indicated that PSAC impregnated with metal catalyst is the determining factor in the adsorption of SOx and NOx simultaneously.

Characteristics of reactivity and structures of palm kernel shell (PKS) biochar during CO_2/H_2O mixture gasification

Palm kernel shell(PKS)biochars with different levels of carbon conversion were initially prepared using a tube furnace,after which the reactivity of each sample was assessed with a thermogravimetric analyzer under a CO_2 atmosphere.The pore structure and carbon ordering of each biochar also examined,employing a surface area analyzer and a Raman spectroscopy.Thermogravimetric results showed that the gasification index R_sof the PKS biochar decreased from 0.0305 min^(-1) at carbon conversion(x)=20% to 0.0278 min^(-1)at x=40%.The expansion of micropores was the dominant process during the pore structure evolution,ad mesopores with sizes ranging from 6 to 20,48 to 50 nm were primarily generated during gasification under a CO_2/H_2O mixture.The proportion of amorphous carbon in the PKS biochar decreased significantly as x increased,suggesting that the proportion of ordered carbon was increased during the CO_2/H_2O mixed gasification.A significantly reduced total reaction time was observed when employing a CO_2/intermittent H_2O process along with an 83.46% reduction in the steam feed,compared with the amount required using a CO_2/H_2O atmosphere.

Insight on the Ultrastructure, Physicochemical, Thermal Characteristics and Applications of Palm Kernel Shells

The ultrastructure and physicochemical and thermal properties of Palm Kernel Shells (PKS) in comparison with Coconut Kernel Shells (CKS) were investigated herein. Powder samples were prepared and characterized using Surface Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Chemical and elemental constituents, as well as thermal performance were assessed by Van Soest Method, TEM/EDXA and SEM/EDS techniques. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) were also performed for thermal characterization. SEM/EDS and TEM/EDXA revealed that most of the PKS and CKS materials are composed of particles with irregular morphology;these are mainly amorphous phases of carbon/oxygen with small amounts of K, Ca and Mg. The DSC data permitted to derive the materials’ thermal transition phases and the relevant characteristic temperatures and physical properties. Thermal Transition phases of PKS observed herein are consistent with the chemical composition obtained and are similar to those of CKS. Nonetheless, TGA/DTG showed that the combustion characteristics of PKS are higher than those of CKS. Taken together, our results reveal that PKS have nanopores and can be efficiently used for 3D printing and membrane filtration applications. Moreover, the chemical constituents found in PKS samples are in agreement with those reported in the literature for material structural applications and thus, present potential use of PKS in these applications.

Analysis of Lateritic Soil Reinforced with Palm Kernel Shells for Use as a Sub-Base Layer for Low-Traffic Roads

In tropical areas,palm oil production generates significant amounts of waste,including palm kernel shells.The use of this waste in the civil engineering sector,presents a very challenging task.In the present study,the production of lateritic soil(A-2 in GTR classification and A-7-6(9)in HRB classification)reinforced with palm kernel shells is considered.In order to improve their performances,these materials are mixed using the Fuller’s parabolic law.Moreover,experimental tests are used to characterize the physical and mechanical geotechnical properties of the lateritic soil.After characterizing the matrix(i.e.,lateritic soil)and the inclusions(i.e.,palm kernel shells)in their natural state,it is found that Avrankou’s lateritic soil has a high level of fine particles(56.6%),high plasticity(PI=21%)and low lift(ICBR=17%);which makes it unusable in the pavement layer.Results also prove that the mixture composed of 39%of lateritic soil volume and 61%of PKS with a CBR index equals to 30 and the mixture composed of 45%of lateritic soil,40%PKS and 15%of lagoon sand with a CBR index equals to 41 can be used as sub-base layer for roads for low and medium traffic,respectively.

Size Variation of Palm Kernel Shells as Replacement of Coarse Aggregate for Lightweight Concrete Production

The utilization of palm kernel shells (PKS) as an alternative to conventional materials for construction is desirable to promote sustainable development. The purpose of this study is to investigate the properties of lightweight concrete produced with different sizes of PKS of 6, 8, 10, 12 mm and mix (consisting of 25% each of the four sizes). RPK sizes were used to replace coarse aggregate in the concrete and cured for 7, 14, 21 and 28 days. The tests performed on the concrete are dry density, compressive strength, flexural strength, EDS and SEM. It was revealed that the densities of the concrete specimens were all less than 2000 kg/m3, which implies that the PKS concrete satisfied the requirement of lightweight concrete for structural application. The compressive strength of the 12 mm PKS concrete specimens at 28-day of curing was 10.2 MPa which was 4% to 15.9% better than the other PKS sizes concrete. The flexural strength of the 12 mm PKS concrete specimens at 28-day of curing was 2.85 MPa which was also 3.2% to 57.07% better than the other PKS sizes concrete. It was also revealed by the SEM analysis that there was a good bond between the palm kernel shells and the mortar. A high calcium-silicate content was found in the concrete which resulted in a Ca/Si ratio of 1.26 and Al/Si ratio of 0.11. The study therefore concludes that size variations of PKS as replacement of coarse aggregate have an influence on the properties of the lightweight concrete and recommends 12 mm PKS for use by construction practitioners for lightweight concrete structural application.

Effects of Palm Kernel Shell on the Microstructure and Mechanical Properties of Recycled Polyethylene/Palm Kernel Shell Particulate Composites

The effect of palm kernel shell on the microstructure and mechanical properties of recycled polyethylene (RLDPE) reinforced with palm kernel shell particulate composite was evaluated to assess the possibility of using it as a new material for engineering applications. The composites were produced by compounding and compressive moulding technique by varying the Palm kernel shell particle from 5-25vol% with particles size of 150, 300 and 400 μm. The microstructure (SEM/EDS) and the mechanical properties of the composites were investigated. The hardness of the composite increases with increase in palm kernel shell content and the tensile strength of the composite increased to optimum of 5vol%. Scanning electron Microscopy (SEM) of the composites surfaces indicates fairly interfacial interaction between the palm kernel shell particles and the RLDPE matrix. The composites produced with 150 μm particle size have the best properties of the entire grade. Hence this grade can be use for interior applications such as car seat, dash board, and car interior for decorative purposes or other interior parts of automobile where high strength is not considered a critical requirement.

Experimental and Analytical Study of Water Diffusion in Palm Kernel Shell of Cameroon

Moisture diffusion during soaking of palm kernel shell (Elaeis guineensis) aggregate concerning DURA variety of Cameroon was studied. Parameters like percentage of water gain at the saturation point and the effective moisture diffusivity were the main purposes. The knowledge of the behavior of those shells in presence of the liquid during the realization of the composite materials is important. Gravimetric method with discontinuous control of the mass of sample after immersion at the ambient temperature was used. Palm kernel shell aggregate of two origins and two considerable sizes respectively in mm: Sizes ≥ 16 and 12.5 ≤ Sizes < 16 were used. The rate of water absorption was found to be [6.18% and 11.74%] respectively for Tombel PKS and Bafang PKS and moisture diffusivity of [5.19 × 10-8 and 7.90 × 10-9 m2/s] was also determined according to their irregular shapes by fitted soaking data in Becker’s model.

Industrial Elaboration by Extrusion of PVC Tubes Loaded with Micronized Dura Palm Kernel Shell Powder

We present in this work how to use the dura palm kernel shell powders as loads for the elaboration by extrusion of PVC tubes. The transformation of dura palm kernel shells into micronized shell powder as well as its characterization was the subject of recent work. We carried out, the formulations by using the industrial scales of precision, the mixtures of the instrants with an industrial machine of mark HENSHLLE N˚2 MAIN 570762, the routine tests by ATG/DSC then by IRTF, the extrusion of the tubes with an extruder twin-screw with 9 rooms of transformation finally the tests of conformity by the observations and the analyses. We obtained for the formulations the dosage of 0%, 4.01%, 12.54%, 23.03%, 32.01%, 38.01%, 51.02% representing the percentage of hull powder in the mixture, the machine mixing gave perfectly homogeneous powders, the routine tests showed that the hull powder keeps all its properties until the end of the shaping whatever the percentage of hulls contained in the PVC, the extrusion gave tubes for each formulation and the conformity tests gave perfectly round tubes of diameter 90 × 82 mm, a coloration going from white grey at 0% to dark black at 51.02% showing the influence of the carbon black and the color of the shell powder according to its proportion. The infrared of the tubes obtained shows for each formulation a variation of the CH2 and CH bonds and a decrease of the −OH bonds. The thermogravimetric analyses and the differential calorimetric analyses of the tubes of each formulation, show each time that the quantity of shell powders in the mixture influences the PVC tubes obtained. Thus, we obtain a variation of the phase temperatures according to the dosage, giving from 108.72˚C to 76.56˚C for the glass transition temperature and from 494.71˚C to 414.56˚C for the melting temperature, at the DSC and a progressive decrease of the mass following the heat absorption with each time 4 phases instead of 5 for the unloaded PVC tubes at the ATG according to the dosage.

Design of Steam Turbine for Electric Power Production Using Heat Energy from Palm Kernel Shell

The steam turbine is a prime mover that converts kinetic energy in steam into rotational mechanical energy through the impact or reaction of the steam against the blades. The aim of this study is to design a steam turbine for a small scale steam power plant with target of producing electricity. The turbine is driven by the heat energy from palm kernel shells as a renewable energy source obtained at a lower or no cost. The study was concentrated on design of turbine elements and its validation using computer packages. Specifically, the microturbine design was limited to design, modeling, simulation and analysis of the rotor, blades and nozzle under the palm kernel shell as fuel for the micro power plant. In blade design, stress failures, efficiency and blade angle parameters were considered. In casing volume design, the overall heat transfer and mean temperature, and different concepts were applied. The thermal distribution on stator and rotor was considered in order to determine its level of tolerance. The design software packages used for design validation were Solidworks and Comsol Multiphysics for analysis. Simulation results showed that the designed steam turbine can adequately tolerate change in stress/load, torsion/compression, temperature and speeds.

Experimental Investigation of Lime Treated Palm Kernel Shell and Sugarcane Bagasse Ash as Partial Replacement of Coarse Aggregate and Cement Respectively in Concrete

This experimental research is focused on the effect of concrete made by incorporating lime treated Palm Kernel Shell (PKS) & Sugarcane Bagasse Ash (SCBA) as partial replacements of coarse aggregates and Ordinary Portland Cement (OPC) respectively. An experimental analysis for concrete grade 30 with a mix design ratio of 1:1.97:3.71 of cement:fine aggregates:coarse aggregates with a constant water to cement ratio of 0.5, was used. Physical tests such as workability on fresh concrete and water absorption on hardened concrete of each batch were carried out. Mechanical tests like compressive strength and split tensile strength were carried out on hardened concrete cubes (100 mm × 100 mm × 100 mm) and cylinders (100 mm × 200 mm) at 7 and 28 days. The experimental results obtained in this study indicate the possibility of using up 15% of lime treated PKS and 10% of SCBA for production of structural concrete.

Study of Mechanical Properties of Raffia Palm Fibre/Groundnut Shell Reinforced Epoxy Hybrid Composites

The mechanical properties of raffia palm fibre and groundnut shell particulate/epoxy (RPF/GSP/E) hybrid composites have been studied. Raffia palm fibres were treated with 10% NaOH solution at room temperature, and groundnut shell particulate of different sizes;75 μ, 150 μ and 300 μ were also chemically treated with 10% NaOH solution at room temperature. The hybrid composite was produced by hand lay-up technique with (10%, 20%, 30%, 40%, and 50%) reinforcements of raffia palm fibre and ground nut shell particulate in the ratio of 1:1. The treated fibres were taken with required weight fractions laid into the mould of size 200 × 150 × 5 mm3. Groundnut shell particulates were also taken with the required weight fraction, mixed with epoxy resin and the mixture was stirred thoroughly before pouring into the mould. Care was taken to avoid formation of air bubbles during pouring and the produced composite was cured under a load of 25 kg for 24 hours before it was removed from the mould. Effects of loading on the tensile, flexural and impact properties of the composite were evaluated. The significant findings of the results were that: tensile strength varied from 1.88 MPa to 9.56 MPa;Modulus of rupture (MOR) varied from 1.92 MPa to 41.6 MPa. While the modulus of elasticity, (MOE) values were in the range of 131.1 MPa to 4720 MPa and impact strength varied from 0.3 kJ/m2 to 1.6 kJ/m2. From the results obtained, the optimum mechanical properties were obtained at 40% loading of RPF/300 μ GSP/E composite. Considering these results, the composite material can be considered as an alternative material for use in automotive interior panels such as boot liner, side and door panels, rear storage shelf and roof cover.

油棕种壳厚度控制基因SHELL的SNP分子标记开发

油棕属棕榈科多年生木本油料作物,果实含油量高达50%,且单位面积产油量高,享有"世界油王"美誉。油棕果实由外果皮、中果皮、内果皮(种壳)、种子四个部分组成,产油部分主要是中果皮和种子,其中种壳厚度是影响果实含油量的重要因素。SHELL基因控制种壳厚度,是一类MADS-box同源基因,SHELL基因在厚壳种和无壳种中的变异主要是第一个外显子上的两个SNP位点。该研究根据两个SNP位点进行特异标记开发,根据已知的油棕SHELL基因的序列,设计了4对SNP引物。4对SNP引物以2个SNP位点设计,每个SNP位点设计2对SNP标记,并均在引物3'端第二位引入强错配碱基。以2份薄壳种油棕材料和2份厚壳种油棕材料DNA为模板,扩增筛选油棕SHELL基因SNP引物。通过PCR扩增发现,设计的SHELL基因特异SNP标记EgSh(N)-f/EgSh(SNP)-2r能够鉴别油棕厚壳种和薄壳种。再用24株油棕树进行特异性验证,发现该标记能较准确地判断油棕的厚薄壳。该研究结果表明SNP标记EgSh(N)-f/EgSh(SNP)-2r可用来进行油棕种质资源早期分子鉴定,为高产油棕品种选育提供了技术支撑。

Physicochemical and Thermal Characterization of Dura Palm Kernel Powder as a Load for Polymers: Case of Polyvinyl Chloride

This work presents the physical and thermal characterization of the dura palm kernel powder of Cameroon for their use as fillers for polymers composites. The powders of palm kernel were obtained using a percussion grinder mill with an industrial microniser which allowed obtaining a powder less than 50 μm with an apparent density between 0,505 ≤ ρ ≤ 0,680 g/cm3 at 1.56 of relative humidity. The infrared of the powder of palm kernel shows the presence of phenols groups with a large band around 3341 cm-1, -C-H at 2917.02 cm-1 and -C-O at 1040 cm-1 as the main peaks. The polyvinyl chloride of infrared obtained shows the presence of -C-Cl, -CH2 and CH as the mains peaks. The infrared of 12.5% of palm kernel powder with polyvinyl chloride shows an increase of the CH2 and CH bonds and a decrease of the -OH bonds. Thermogravimetric analysis and differential scanning calorimetric analysis of powders, polyvinyl chloride and mixture showed that the mixing powders are intermediate between the polyvinyl chloride and palm kernel powder. The powder decreased the phase temperatures of the mixture from 98.58℃ to 95℃ for the glass transition temperature and from 515℃ to 459℃ for the crystallization temperature. The thermogravimetric curves of palm kernel powder and polyvinyl chloride have showed that these materials lose their different masses in three different phases, and the one of composite (mixture of polyvinyl chloride with 12.5% of palm kernel powder) in two different phases.

Adsorption Isotherm and Kinetic Study of Methane on Palm Kernel Shell-Derived Activated Carbon

Activated carbon(AC)was synthesized from palm kernel shell(PKS)using different activating agents,i.e.,steam,carbon dioxide(CO 2),and CO 2-steam,in order to analyze the impact of acti-vating agents on the pore opening of AC.In this study,AC produced from PKS was found to have great potential as an adsorbent for methane storage.The different molecular diffusivity and reac-tivity of the combination of CO 2 and steam succeeded in producing AC with the highest burn-offof 78.57%,a surface area of 869.82 m 2/g,a total pore volume of 0.47 cm 3/g,and leading to maximum methane gas adsorption capacity of 4.500 mol/kg.All types of ACs exhibited the best fit with the Freundlich isotherm model,with the correlation coefficient(R 2)ranging from 0.997 to 0.999,indicating the formation of multilayer adsorption.In addition,the adsorption kinetic data for all ACs followed the pseudo-first-order model showing that the rate of adsorption was dependent on both the adsorbent and the adsorbate and was governed primarily by physical ad-sorption between the pore surface and methane gas.The results of intraparticle diffusion model indicated that the adsorption of methane was affected by both pore diffusion and exterior layer diffusion due to the different adsorption rates.

纤维素酶水解棕榈壳制取乙醇研究

先将棕榈壳置于多功能水解反应器中于200℃,4.0 MPa,液固比15∶1,搅拌转速500 r/min条件下纯水预处理5 min,半纤维素和纤维素含量分别从21.74%,45.42%变为2.35%,47.63%,再以一定比例混合预处理液与棕榈壳残渣,研究液固比,温度,加酶量和时间对棕榈壳糖化工艺的影响,结果表明液固比为16∶1最合适,低温37℃比高温50℃更有利于棕榈壳的糖化,从长时间看,加酶量并不完全与原料转化率成正相关,以小于10 FPU/g为宜。糖化效果取决于β-葡萄糖苷酶对葡萄糖的耐受性以及预处理效果。采用酿酒酵母对糖化液发酵,乙醇得率为77%。通过电镜扫描发现,预处理与酶解后的残渣的结构比原料明显疏松,长条状晶束结构有着不同的程度的破坏,但木质素结构破坏较小。

热解过程中棕榈壳焦的物化结构演变特性

该文主要对生物质热解过程中焦炭物化结构的演变特性与转化机理进行分析研究。在固定床反应器上，以棕榈壳为样品，热解终温从300—1000℃下制得焦炭，采用比表面积和孔径分析仪与傅里叶红外光谱仪等用对不同温度下所得焦炭的物化结构进行深入分析。研究发现煤焦的表面孔隙结构的形成和丰富主要集中在400-600℃，随着碳化温度的升高，孔面积先增大后减小，在约600℃有较高的比表面积；棕榈壳焦内的有机官能团（C=O，C—C，C—H，C-O和OH等）的断裂和缩合也主要发生在中低温度段，同时固体焦内，碳的含量逐渐增加，而氢元素的含量逐渐减少。

棕榈壳热解失重特性及动力学研究

采用热重-红外联用（TG-FTIR）、裂解-气相色谱/质谱联用（Py-GC/MS）技术和小型固定床装置,考察了棕榈壳的热解失重过程和产物特性,并进一步评价了热解半焦的气化反应性。结果表明：棕榈壳热解失重过程大致分为干燥（25-236℃,3.42%）、主失重（236-400℃,52.31%）和炭化（400-850℃,14.90%）3个阶段,1.5级或2级反应可以较好描述棕榈壳热解反应的主失重过程;升温速率10-30 K/min下,反应表观活化能为67.63-76.47 k J/mol;热解过程主要气体产物的释放量顺序分别为CO2、H2O、CH4和CO;600-850℃下,棕榈壳主要热解产物为液相产物,其质量产率36.8%-50.9%,能量产率41.3%-58.9%,主要组分包括苯酚、乙酸、十八烷酸、十六烷酸、4-烯丙基-2,6-二甲氧基苯酚等物质,其中苯酚GC含量较高（12.56%-15.49%）,这可能主要与原料木质素的含量较高有关;固相产物的质量和能量产率分别为20.6%-26.7%和27.4%-35.0%,其CO2气化反应性相对低于稻秆、木粉等常见生物质。