Oil Palm Ash Research Articles

The improvement of available phosphorous of reclaimed-mining soils with coal fly ash and empty fruit bunches of oil palm treatments

Abstract Reclaimed-mining soil (RMS) were categorized as having an acidic pH, low organic carbon (C), low available phosphorous (P), and high contents of aluminium (Al) and iron (Fe); therefore, soil ameliorants were essentially added to this soil for improving soil fertility. The purpose of the research was to measure the impact of combining empty fruit bunches of oil palm (EFBOP) and coal fly ash (CFA) on the available P of RMS. Three rates of CFA application: 0, 75, and 150 Mg ha−1 and three rates of EFBOP application: 0, 25, and 50 Mg ha−1 were organized using a completely randomized design. A 1000 g of soil was placed to an experimental pot, and then CFA and EFBOP according to the treatment were added to the pot. The mixture of soils, CFA, and EFBOP were homogenized, and then incubated at 70% water holding capacity for 45 days. Available P, total P, Al-P, Fe-P, soil pH, and exchangeable Al were quantifies following the completion of incubation period. The findings of this research indicated that available P rose from 3 mg kg−1 of control (soil without treatment) to 5-41 mg kg−1 of soils with different amounts of CFA and EFBOP addition. The application of CFA and EFBOP also resulted in increases in soil pH from 4.33 in the control to pH 4.48-6.23. Additionally, the levels of Al-P, Fe-P, and exchangeable aluminum decreased with the application of CFA and EFBOP. The findings of this study highlight the potency utilizing industrial and agricultural wastes as soil ameliorants for improving available P to support plant growth on the reclaimed-mining soils.

Sustainable alternative activators from the textile mercerizing water for the durable and cost-effective flyash-GGBS based geopolymer concrete

By considering the current global challenges such as greenhouse gas emission and waste disposal management, the exploration of geopolymer concrete is highly focused now-a-days. On the other hand, the use of costlier commercial activators acted as the major drawback for the practical existence. Although the recent geopolymer researchers suggested the use of alternative activators from various resources such as palm oil ash, olive ash etc, the application of which are not appreciably promoted due to the complex derivation process. To overcome these effects, in this paper, first time, an attempt is initiated to develop a cost-effective geopolymer concrete by using textile mercerizing water as an alternate activator system. The viability of using mercerizing water instead of commercial sodium hydroxide activator was studied initially. By conducting the pH electrode test and Infrared Analysis, the alkalinity and the presence of sodium metal cations responsible for the reaction kinematics were confirmed. Also, the molar concentration of sodium cations in the mercerizing water was quantified using chemical titration analysis. The feasibility of using mercerizing water in the preparation of geopolymer was assessed using workability, mechanical strength and sustainability. From the results, it was inferred that the developed geopolymer concrete with 100 % textile mercerizing water exhibited the maximum strength of 46.9 MPa, 5.16 MPa and 5.81 MPa respectively under compression, tension and flexure which are almost equivalent and slightly better than the control geopolymer concrete. Also, the developed geopolymer concrete using 100 % textile mercerizing water and the combined flyash-GGBS binder system showcases the highest post-fire residual strength and 48 % reduced water absorption. The cost of construction of geopolymer concrete was significantly reduced by 58.43 % and showed 10.28 % reduced carbon footprint due to the complete replacement of sodium hydroxide solution using textile mercerizing water. The findings of this research work will lead to the development of equivalent molar sustainable activator from the textile mercerizing water and the exploration of eco-friendly and durable geopolymer concrete in an affordable price.

Enhancing the Durability of Green Concrete through the Utilization of Nano-sized Palm Oil Fuel Ash and Nano-sized Eggshell Powder

Concrete is often regarded as a material representing robustness and long-lasting properties in contemporary society. The manufacture and utilization of cement are responsible for environmental contamination. Green concrete, often known as GC, has been increasingly recognized as a key material in the global concrete industry. Palm Oil Ash (POA) is a significant Lightweight Aggregate (LA) used in GC. Palm Oil (PO) processing generates POA as a by-product, which is thrown out in open areas and landfills without treatment, leading to environmental degradation. The pozzolanic activity is enhanced by grinding POA to nanoparticles, known as NPOA. Egg Shells (ES) are a type of biowaste that originates from eateries. They are deposited in landfills, producing toxic gases and inflicting environmental harm. Nano-sized ES Powder (NESP) contains a significant quantity of calcium oxide, which is crucial for hydration in concrete formation. Also, POA can serve as a fractional replacement for cement in concrete. This paper offers a study that utilized NPOA to improve the subpar performance of LA for GC produced with POA aggregate. The study involved replacing a portion of the cement with NPOA at 5%, 10%, and 15% ratios. Additionally, NESP was used as an admixture at a ratio of 1.5% to produce green concrete in cubes and cylinders. The concrete samples (in the shape of cubes and cylinders) are exposed to a curing process for 7, 14, and 28 days, respectively. Afterward, these samples are examined to evaluate their performance and measure their strength. The Conventional concrete is produced using an M20 grade mix. It is then compared to GC, both with and without NPOA concrete, using cube and cylinder models.

Investigation of Calcination Duration on the Surface Morphology and Specific Surface Area of Zeolite-Chitosan Composite with Oil Palm Ash for Potential Water Contaminant Remediation

This research investigates how varying calcination durations affect the surface characteristics of a Zeolite-Chitosan composite with oil palm ash, aiming to determine its water contaminant removal potential. Three different calcination durations (1, 2, and 3 hours) are studied. The synthesis involves mixing oil palm ash with Zeolite-Chitosan, followed by varying-duration calcination. Scanning electron microscopy (SEM) and surface area analysis (SAA) are used to assess surface characteristics. Initial findings indicate that changing calcination duration significantly impacts the composite’s surface features and specific surface area. Longer calcination leads to increased surface roughness and higher specific surface area. The 3-hour calcination results in the highest surface roughness and specific surface area among the durations tested. These findings suggest that calcination duration is crucial in altering the composite’s structural properties, which could affect its efficacy in adsorbing water contaminants. Ongoing research aims to better understand the relationship between calcination duration and the composite’s adsorption performance, ultimately optimizing the synthesis of the Zeolite-Chitosan composite with oil palm ash for efficient water contaminant remediation.

Properties of Sustainable Concrete Containing Different Percentages and Particles of Oil Palm Ash as Partial Sand Replacement

Oil palm shell (OPS) in concrete is well studied as an alternative material of fine aggregate in concrete, as a way to use agricultural waste, and helps to contribute to environmental sustainability and economical construction cost. However, OPS addition will lead to lower properties of the concrete, and much research focuses on treating the OPS to overcome it. Many previous works focused on replacement without examining the effect of different particle sizes of OPS. Hence, this study focuses on the performance of concrete with different particle sizes of OPS as sand replacers in concrete at 25% and 50%. The physical and permeability properties of concrete prepared with OPS particle sizes in the ranges between 600μm to 4.75mm (L), 300μm to 1.18mm (M), and of less than 600μm (S) and two different percentages of 25% and 50% by weight as sand replacement are examined. More than 200 cubes, cylinders, and prisms were tested to determine their physical, mechanical, and permeability properties. The workability was measured by the slump height, the mechanical properties by the compressive strength test, flexural strength test, splitting tensile test, ultrasonic pulse velocity (UPV) test, and rebound hammer test. While the permeability properties by the water penetration test, sorptivity test, and rapid chloride permeability test. The findings showed that increasing the particle sizes of OPS would reduce concrete’s physical and permeability properties. The optimum OPS particle size for structural concrete grade 30 is less than 600μm. With OPS particles of 600um, green concrete using OPS can be made for medium to low-strength applications in the construction industry.

Properties of Palm Oil Ash Geopolymer Containing Alumina Powder and Field Para Rubber Latex

Most geopolymer binder is produced using raw materials comprising powder with high silica and alumina content. Additionally, fine aggregate is prepared with river sand for high bulk density. This research proposes using palm oil ash (POA) for the main binder and palm oil clinker (POC) for the fine aggregate. The chemical composition of POA has high levels of silica but low alumina, so it must undergo partial replacement with alumina powder (AP). POA and POC are waste by-products of electrical power plants. The properties to be investigated include compressive strength, bulk density, water absorption, and microstructure. The effect of mixture composition, i.e., POA and field Para rubber latex (FPRL), on those properties is of particular interest. POA was substituted by AP and FPRL at 2.5%, 5%, 7.5%, and 10%, and at 1%, 3%, 5%, and 10%, respectively. Geopolymer mortars were cured at ambient temperature for 24 hours and kept at ambient temperature until testing. The compressive strengths of the geopolymer mortars were tested at 1, 7, and 28 days. The results showed that the optimal mixture consisted of 5% AP in the case of AP only and 1% FPRL in the case of FPRL only, while the ternary optimal mixture of 1% FPRL and 7.5% AP achieved higher compressive strengths than the control (CT) sample at 28.16, 19.98, and 25.30 MPa, respectively, after 28 days of curing. Bulk density increased with the addition of AP and FPRL. The microstructures of the geopolymer samples investigated using SEM-EDX showed the presence of different elements with different mixtures and displayed a dense, compact geopolymer matrix with high compressive strength. Using large amounts of POA in combination with AP and FPRL improved the environmental aspects of landfill disposal. Doi: 10.28991/CEJ-2023-09-05-017 Full Text: PDF

Effective utilization of agricultural ashes in development of sustainable geopolymer concrete

The use of concrete is widespread in the construction industry due to its successful and desirable properties. As industrial and urban development rapidly increases, the demand for concrete is also reaching new heights compared to other materials. In this regard, there is a pressing need for alternative materials to replace cement and industrial by-products. This paper proposes the effective utilization of agricultural ashes, including rice husk ash (RHA), bagasse ash (BA), and palm oil ash (PA), in geopolymer concrete. The study evaluates fly ash-based geopolymer concrete's compressive strength and microstructural performance by replacing fly ash with varying percentages of agricultural ashes. The results show that including agricultural ashes in the fly ash-based geopolymer blends yields higher strength than the 100% fly ash-based geopolymer concrete. However, using higher dosages of agricultural ashes decreases strength and forms micro-cracks in the geopolymer phases. Therefore, using 20% RHA or 15% BA or 15% PA as a precursor in fly ash-based geopolymer concrete can produce sustainable construction material and contribute to greener construction. Green concrete can help advance the circular economy and promote environmental protection.

Enhanced glycerol dry reforming over Ni/SBA-15 synthesized from palm oil ash: Effect of GHSV

The current research investigated the effect of gas hourly space velocity toward the GDR reaction using Ni/ SBA-15 catalyst derived from palm oil ash (P). The SBA-15(P) was prepared by hydrothermal technique and loaded with 3 % Ni via ultrasonic-assisted impregnation technique. The physio-chemical features of the unloaded and loaded Ni on the SBA-15(P) were characterized via BET, FTIR, XRD, H2 TPR, and TEM. In a vertical reactor made up of stainless steel operating at 800 °C, 1 atm, with various gas hourly space velocities (18000, 24000, 30000, and 36000 mL/g-1 s−1), the catalytic performance of the Ni/SBA-15(P) was investigated. The exceptional inclusion of active Ni particles with the SBA-15(P) support and strong Ni-O-Si interaction were demonstrated by FTIR, H2 TPR, and TEM, respectively. The highest catalytic activity (glycerol conversion = 43.24 %, H2 yield = 30.60 % and CO yield = 59.76 %) of Ni/SBA-15(P) was achieved at 24000 mL/g-1s−1. The higher the GHSV (30000 and 36000 mL/g-1s−1), the lower the syngas yield (H2 and CO) and glycerol conversion due to the less CO2 and glycerol molecules adsorbed on the active centers of the Ni/SBA-15(P) catalyst. Moreover, shorter contact time interaction between reactant molecules and the active site would build up the pressure inside the reactor system and favor carbon plugging during the catalytic process. Meanwhile, Ni loaded on SBA-15(P) at lower GHSV (20000 mL/g-1s−1) was low catalytic activity due to the limitation of existing molecules interacting with catalyst active sites. At lower GHSV (20000 mL/g-1s−1), Ni/SBA-15(P) exhibited poor catalytic performance because of the limited ability of molecules to interact with the catalyst active sites.

Oil palm leaf ash's effect on the growth and yield of Chinese cabbage (<i>Brassica rapa</i> L.)

<abstract> <p>The production of Chinese cabbage (<italic>Brassica rapa</italic> L.) has not been able to keep up with consumers' demand. Appropriate application of fertilizers is a key element in boosting plant productivity. One of the problems faced when fertilizing is that plant nutrient uptake has low efficiency. The application of basic nitrogen–phosphorus–potassium (NPK) fertilizers is typically the main emphasis of traditional agriculture, whereas the need for micronutrients, including Si, receives less consideration. Organic and inorganic materials are sources of Si nutrients. Currently, organic materials include straw or rice husks. The use of oil leaf palm waste as a source of nutrients is relatively still rare. The oil palm leaf ash in the production of Chinese cabbage is still not yet been researched. This analysis aims to know the optimal of oil palm leaf ash for the growth and yield of Chinese cabbage. The growth parameters measured 40 days after planting: leaf number, plant height, crown diameter, and fresh weight were impacted by the usage of oil palm leaf ash. A combination of oil palm ash at a concentration of 3.75 kg/m<sup>2</sup> and manure at a concentration of 1500 kg/m<sup>2</sup> produced the greatest results. In general, the usage of oil palm leaf ash affected the growth of Chinese cabbage, but the results could not be statistically separated from the role of manure as a source of NPK for plants. It was also demonstrated that the use of oil palm leaf ash increased the resistance of Chinese cabbage to armyworms. Therefore, Si for agriculture it can be utilized from oil palm leaf ash as a natural source.</p> </abstract>

A Review on The Compressive Strength and Workability of Concrete with Agricultural Waste Ash as Cement Replacement Material

Concrete is commonly used as a construction material because of the important properties is broadly utilized as development materials within the development segment. Unfortunately, the component of cement within the concrete results in many side-effects such as affecting the environment. Therefore, this paper presented the review of essential to seek out an alternative materials which may be utilized as cement replacement materials by reutilizing agricultural waste ash. Selected agricultural waste ash which are Palm Oil Fuel Ash (POFA), Rice Husk Ash (RHA), Groundnut Shell Ash (GSA), Sugarcane Bagasse Ash (SBA) and Oyster Shell Powder (OSP) were review in terms of their compressive strength and slump height of the mixture. The treated palm oil ash which is going to be used as partial cement replacement material for the proper design mix and optimal ash replacement. The replacement percentage of palm ash in the concrete were set at 10%, 20%, and 30% by weight with the optimal replacement ratio of the supplementary cementitious content. Palm Oil Fuel Ash (POFA) is a material that having sufficient requirements to be a good pozzolana and cementitious material according to ASTMC618 in terms of chemical composition. POFA is a material that consists high silica contents. By having more silica contents, it will help to improve the properties, in particular its compressive strength, bond strength, and abrasion resistance. After conducting several research, it was concluded that the optimal replacement for POFA is 20% and it is better to have finer POFA. POFA also proved some of the important properties is the CO2 emissions would be reduce.

Applications of Oil Palm Ash and Various Types of Organic Fertilizer on Acid Soil (Ultisol) for Onion (Allium ascalonicum L)

Onion production in Riau Province is still low, while the demand is quite large. Therefore, it is necessary to increase production. This study aimed to determine the effect of the application of oil palm ash and various types of organic fertilizers on ultisol soils on the growth and production of shallots. The design used was a completely randomized factorial design consisting of 2 factors. The first factor was the provision of oil palm ash which consisted of 4 levels of treatment, namely: 0, 200,400, and 600 g/plot. The second factor is various types of organic fertilizers which consist of 4 levels of treatment, namely: without giving organic fertilizer, chicken manure, tankos compost and corn litter bokashi. The parameters observed were plant height, number of tubers per clump, wet tuber weight per clump, dry tuber weight, percentage of tuber weight loss, relative growth rate and nutrient uptake. plants, number of tubers, wet weight per clump, dry weight per clump and tuber weight loss, the best treatment was giving palm ash 400 g/plot and corn litter bokashi. The main effect of giving palm ash bunches was real on all observation parameters, the best treatment was 400 g/plot. The main effect of organic fertilizer was real on all observed parameters. The best treatment was corn litter bokashi.

Application of palm oil mill waste to enhance biogas upgrading and hornwort cultivation

The potential of oil palm ash (OPA) to enhance H2S and CO2 removal from biogas by scrubbing with maturation pond effluent (MPE), and further the treatment of biogas scrubber effluent (BSE) by Ceratophyllum demersum L. (hornwort) cultivation were investigated in this study. The results show that OPA + MPE solution with pH 9.3 and alkalinity 7525 mg CaCO3/L was obtained with 0.7 kg/L OPA loading. A pilot scale scrubber was used to study the effects of absorbent flow rates of 60–210 L/h on upgrading to 300 L/h field biogas stream. At 210 L/h, the CO2 removal efficiencies were 33% and 53% for MPE and OPA + MPE, respectively. To approach 100% H2S removal efficiency, the minimum flow rates were 120 L/h for MPE and 90 L/h for OPA + MPE. 50–150 g wet weight of hornwort in 30 L diluted POME were loaded to investigate appropriate initial hornwort loading level for hornwort cultivation. The highest specific growth rate of 0.045 day−1 with biomass production of 3.8 g/day were obtained with a 50 g initial loading. Among the wastewaters (MPE, OPA + MPE, and BSE) treatment using hornwort cultivation, the highest 0.035 day−1 specific growth rate and 2.6 g/day biomass production of hornwort were obtained in diluted BSE cultivation, and in 3 weeks of cultivation. COD, nitrate, phosphate, and alkalinity decreased by 76%, 76%, 55%, and 5%, respectively. The Eco-Efficiency concept for palm oil mill waste utilization proposed in this study has a high potential for enhanced biogas upgrading by using OPA + MPE, and hornwort is a good candidate for BSE post-treatment integrated with biomass production.

Predicting the uniaxial compressive strength of oil palm shell lightweight aggregate concrete using artificial intelligence‐based algorithms

AbstractBecause natural coarse aggregates were depleting rapidly, concrete industry has been trended toward substitute aggregates from industrial by‐products or waste. One of the waste materials is oil palm ash (OPS), which is widely generated in the processing of palm oil in the tropics. Concretes made with OPS to estimate the compressive strength (CS) is cost and time consuming. This study aims to propose novel hybrid models by concepts of extreme gradient boosting (XGB) model optimized with different optimization algorithms such as sine–cosine algorithm, multiverse optimization algorithm (MVO), and particle swarm optimization for predicting the uniaxial CS (UCS) of oil palm shell lightweight aggregate concrete (OPS). Also, the multivariate adaptive regression spline model is also developed to present a meaningful relationship between input and output variables. To this aim, a data set containing data samples for concrete made with OPS was gathered from the published literature. Results show that all models have acceptable performance in predicting the UCS, representing the admissible correlation between observed and predicted values and models' robustness. In the training step, the value of , the root mean square error, and the variance accounted factor for MVO–XGB are 0.9713, 1.5777, and 97.129. These values in testing phase are 0.9019, 2.6786, and 89.158. Therefore, the MVO–XGB model outperforms others, and the results demonstrate the ability of the MVO algorithm to determine the optimal value of XGB parameters.

Effect of calcination temperature on Ce/OPA catalyst in HDPE catalytic pyrolysis to fuel grade liquid product

Catalytic pyrolysis of plastic polymers is becoming an important method for the conversion of plastic materials into valuable chemicals and fuel production. The effect of calcination temperature on cerium loaded on oil palm ash (Ce/OPA) catalyst and products in catalytic pyrolysis of HDPE plastic were studied. The catalysts were synthesized via wet impregnation method and calcined at 500 °C, 750 °C and 1000 °C. The surface morphology and surface structure of the catalysts were also analyzed. The catalytic pyrolysis was done in a batch reactor at 450 °C with 15 mL.min−1 of N2 and 10:1 of plastic-to-catalyst weight ratio for an hour. The liquid products of the pyrolysis were analyzed via mass spectrometry GC-TCD, GC–MS, FTIR, bomb calorimeter and viscometer. It is found the Ce/OPA catalyst that calcined at 500 °C for four hours showed better catalytic pyrolysis activity and has largest specific surface area (10.77 m2.g−1) and and pore volume (0.032 cm3.g−1) than the catalyst that calcined at 750 °C (4.52 m2.g−1 and 0.029 cm3.g−1) and 1000 °C (3.70 m2.g−1 and 0.006 cm3.g−1). The Ce/OPA catalyst that calcined at 500 °C catalytic cracked the HDPE waste with less solid yield (25.2 wt%) and more gas yield (18.40 wt%). Meanwhile, the Ce/OPA that calcined at 750 °C and 1000 °C produced the most gases product (14.4 wt%), but the gas products that was rich in CH4 and H2 achieved when Ce/OPA that calcined at 1000 °C was used. This is because a cation-disordered phase formed in the Ce/OPA catalyst during high-temperature calcination, thereby decreasing the oxygen storage/release capacity and lowering the catalyst’s pore volume and surface area. The liquid products with calorific value ranging from 50.34 MJ.kg−1–50.39 MJ.kg−1 and viscosity value between 1.06cP-1.29cP were also obtained. However, the calcination temperature did not affect the liquid product properties. In conclusion, the calcination temperature significantly affected the catalytic activity of Ce/OPA and improved properties of products.

Influence of Palm Oil Fuel Ash on Strength Properties of Concrete

Cement which is highly responsible for hydration enthalpy and also the cost of cement which makes it uneconomical. The only way to deal with this kind of challenge is by introducing different products to replace certain amount of cement. An environmental friendly waste product produced from agricultural industries known as POFA (Palm-oil-fuel-ash) can be replaced with certain percentage of cement replacement in concrete and still attain similar strength such as conventional concrete. This paper intention is to focus changes on mechanical, strength properties of M30 grade concrete by using (POFA) palm-oil-fuel-ash. It is very much efficient in reducing cement expenses and also enhances the strength when engineered in technical aspects. When this agro waste palm oil ash is added, very less quantity of co2 emission takes place with reduction in liberation of heat from concrete. With the incorporation of palm oil fuel ash in various incremental order of (0, 10, 20, 30, 40) % replacement by cement in concrete, certain amount of change in behavior in concrete strength parameters namely compression strength, split tensile strength, and flexure strength is noted. M30 grade of concrete is considered while performing tests and analyzing, it shows that 10% replacement of cement by palm oil ash (POFA) gave high strength compared to conventional concrete. All the results generated are compared against control mix which gave an impression of improvement in (mechanical, strength) parameters of concrete in a positive way which helps balance the environment and also achieve sustainability of the concrete.

The Effect of Palm Oil Ash Ash on Micro Nutrient Uptake by Soybean Roots in Peatlands

Research on the potential of oil palm cassava ash as an ameliorant in increasing micronutrient uptake by soybean roots on peat soil was carried out from August 2020 to February 2021, at the wire house of the Faculty of Agriculture, Indragiri Tembilahan Islamic University, Riau Province. The purpose of this study was to observe the interaction between the dose of Palm Oil Ash (AJKS) and nutrient uptake by the roots of several soybean varieties and to obtain the optimum dose of AJKS in increasing the uptake of micro nutrients Cu, Zn, Fe and Mn by soybean roots. the Tanggamus, Slamet and Anjasmoro varieties. This study used a separate plot design with 3 treatments as main plots were 3 soybean varieties: V1 = Tanggamus variety (tolerant), V2 = variety, Slamet (moderate), V3 = Anjasmoro variety (sensitive). The sub-plots were 4 doses of AJKS administration consisting of: A0 = Without AJKS treatment, A1 = 300 kg/ha AJKS, A2 = 600 kg/ha AJKS and A3 = 900 kg/ha AJKS with 3 replications. The results of the study concluded that the application of oil palm cassava ash (AJKS) in general increased the uptake of micronutrients by soybean plant roots on peatlands. There was an interaction between the dose of AJKS and soybean varieties on the absorption of Cu, Zn and Fe in the roots of Tanggamus, Slamet and Anjasmoro soybeans. Administration of 900 kg/ha AJKS gave the highest micronutrient uptake of Cu, Zn, Fe and Mn both in Tanggamus, Slamet and Anjasmoro varieties, but optimal results were generally achieved at a dose of 600 kg/ha AJKS.

Microporous Erionite-activated Carbon Composite From Oil Palm Ash for Doxycycline Antibiotic Removal

Microporous Erionite-activated Carbon Composite From Oil Palm Ash for Doxycycline Antibiotic Removal

Understanding the heterogeneous catalytic mechanisms of glycerol carbonate synthesis on oil palm ash surface: A density functional theory approach

The use of glycerol as an added-value by-product from the transesterification of triglycerides to produce biodiesel has been the subject of intense research due to its versatility in a wide range of applications. In this work, a theoretical study at the density functional theory (DFT) level to categorize the most probable routes to achieve glycerol conversion was performed. Gibbs free energies were computed to assess the feasibility of the steps involved in experimental glycerol carbonate synthesis from glycerol and dimethyl carbonate. The cyclization from methyl glycerol carbonate anion to glycerol carbonate is reasonable due to the computation of the Gibbs free energy amounting to -310.0 kcal/mol, which indicates an exothermic reaction with the spontaneous rising of glycerol carbonate. The assessment of the molecular dimensions at the optimized geometry of glycerol carbonate showed a critical diameter and length of 5.25 Å and 5.90 Å, respectively; with a volume of 127.7 Å3. Charge population analysis provided insights into the electronic transfer during the reaction and the bonding mechanism resulting in the products. Additionally, the heterogeneous catalysis reaction involved in the glycerol carbonate evolution reaction and its subproducts was studied on a periodic surface model of the oil palm fuel ash catalyst in order to evaluate activation energies and the feasibility of the proposed mechanism. That is, the computations revealed an activation energy barrier of 13.4 kcal/mol (0.58 eV), which also certifies the cyclization feasibility in the formation of glycerol carbonate. The results may contribute in the insilico design of the experimental setup to improve efficiency in the process of transesterification reaction of glycerol and dimethyl carbonate to valuable glycerol carbonate.

The Evaluation of The use of Palm Shell Ash Waste to Polymer Modified Asphalt Mixture

The palm oil industry’s development has a strategic role in Indonesia’s economy because Indonesia is the largest country and the largest exporter of palm oil globally. On the other hand, a new problem arises from increasing palm oil ash waste. This has encouraged the use of palm oil ash as filler mix asphalt. In this study, an evaluation of the asphalt mixture’s performance on the surface layer (AC-WC) will be carried out by utilizing palm ash waste as a filler using Starbit E-55 polymer asphalt. Testing the asphalt mixture’s performance using the Marshall method with asphalt content of 6% ± 0.5 and variations in the percentage of palm ash filler used, namely 3, 4, 5, and 6%. Samples are prepared and tested to obtain the stability and volumetric values of the mixture. Based on the results, it was found that the addition of palm ash waste as a filler could increase the stability performance at 3% filler content but there was a decrease in the filler content of 4, 5, and 6% in the test object without the addition of palm ash filler, the highest stability was obtained, namely 2358, 4 kg while the test object with the addition of 3% palm ash filler has a stability of 2503.03 kg at each asphalt content of 6.5%. The flow parameter in the test object continues to decrease along with the increase in the addition of oil palm ash filler, this is in line with the increase in the Marshall Quotient parameter which causes the mixture to become stiffness, this indicates that the mixture can withstand deformation due to traffic loads and shows that this oil palm ash potentially suitable for use as a filler in asphalt mixtures.

Enhancement of Thermophilic Biogas Production from Palm Oil Mill Effluent by pH Adjustment and Effluent Recycling

A sudden pH drops always inhibits the anaerobic digestion (AD) reactor for biogas production from palm oil mill effluent (POME). The pH adjustment of POME by oil palm ash addition and the biogas effluent recycling effect on the preventing of pH drop and change of the archaea community was investigated. The pH adjustment of POME to 7.5 increased the methane yield two times more than raw POME (pH 4.3). The optimal dose for pH adjustment by oil palm ash addition was 5% w/v with a methane yield of 440 mL-CH4/gVS. The optimal dose for pH adjustment by biogas effluent recycling was 20% v/v with a methane yield of 351 mL-CH4/gVS. Methane production from POME in a continuous reactor with pH adjustment by 5% w/v oil palm ash and 20% v/v biogas effluent recycling was 19.1 ± 0.25 and 13.8 ± 0.3 m3 CH4/m3-POME, respectively. The pH adjustment by oil palm ash enhanced methane production for the long-term operation with the stability of pH, alkalinity, and archaea community. Oil palm ash increased the number of Methanosarcina mazei and Methanothermobacter defluvii. Oil palm ash is a cost-effective alkali material as a source of buffer and trace metals for preventing the pH drop and the increased methanogen population in the AD process.