Palm Kernel Expeller Research Articles

Bio-refinery of palm kernel expeller waste into attached microalgal biodiesel, the life cycle analysis of waste biomass-to-energy

The exploitation of solid carbon waste in the form of palm kernel expeller served two purposes: (i) providing nutrients for microalgal growth and (ii) serving as a medium for the adhesion of microalgal cells. This study examined the life cycle assessment of biodiesel production from attached microalgae, a less explored domain as compared with conventional microalgal system focusing on energy and environmental feasibility aspect. The computed environmental impact indicated that harvesting and lipid production had contributed significantly to the overall impact, though the global warming potential remained low (5.2 × 10−4 kg CO2 eq.). The establishment of scenario analysis had revealed that solvent recovery options resulted in about 48–55 % damage recovery, giving significant decline in the environmental impacts. In terms of energy sustainability, the study revealed a net energy ratio of 0.52, suggesting that the energy output is less than the energy invested. While falling short of ideal energy sustainability, the ratio surpassed that of conventional petroleum diesel and many previous microalgal technologies. Despite challenges, the findings accentuated the importance of continuous improvement in microalgal biofuel processes for enhancing energy efficiency and reducing environmental impact.

Influences of superfine-grinding and enzymolysis separately assisted with carboxymethylation and acetylation on the in vitro hypoglycemic and antioxidant activities of oil palm kernel expeller fibre

The synergistic effects of ultrafine grinding and enzymolysis (cellulase and Laccase hydrolysis) alone or combined with carboxymethylation or acetylation on the hypoglycemic and antioxidant activities of oil palm kernel fibre (OPKEF) were studied for the first time. After these synergistic modifications, the microstructure of OPKEF became more porous, and its soluble fibre and total polyphenols contents, and surface area were all improved (P < 0.05). Superfine-grinding and enzymolysis combined with carboxymethylation treated OPKEF exhibited the highest viscosity (13.9 mPa∙s), inhibition ability to glucose diffusion (38.18%), and water-expansion volume (3.58 mL∙g−1). OPKEF treated with superfine-grinding and enzymolysis combined with acetylation showed the highest surface hydrophobicity (50.93) and glucose adsorption capacity (4.53 μmol∙g−1), but a lower α-amylase-inhibition ability. Moreover, OPKEF modified by superfine-grinding and enzymolysis had the highest inhibiting activity against α-amylase (25.78%). Additionally, superfine-grinding and enzymolysis combined with carboxymethylation or acetylation both improved the content and antioxidant activity of OPEKF's bounding polyphenols (P < 0.05).

Flex commodities and intertwining world-ecologies: Indonesian palm waste as an environmental fix in the New Zealand dairy industry

Palm kernel expeller (PKE), a by-product of the palm oil production process in Indonesia, has evolved into a billion-dollar export ‘flex’ commodity to feed cows in intensified dairy production in New Zealand. As the PKE trade grew in New Zealand, the dairy industry became a transnational behemoth and a leading global exporter. Through our examination of PKE, an understudied commodity, we reveal the ways that ecological degradation to local, regional, and world-ecologies are exacerbated and intertwined. This paper argues that neoliberalisation of regulatory and trade policy, both within and between the two countries, laid the groundwork for the growth of the ecologically destructive palm oil operations of Indonesia as well as the intensified dairy operations in New Zealand, both of which rely on dispossession of Indigenous lands. Our theorisation builds on the flex commodity literature by analyzing the ways PKE became an ‘environmental fix’ and part of a transnational waste regime linking two semiperipheral regions. This environmental fix for the dairy industry temporarily limits the negative impacts of climate change induced drought. The world-ecology(ies) of such ‘fixes’ is becoming increasingly urgent and increasingly tenuous in the face of climate change.

Enhanced microalgal hydrogen production subsisting on visible light TiO2 nanotubes photocatalyst pre-treated palm kernel expeller

The present study investigated the application of photocatalytic process using TiO2 nanotubes (NTs) photocatalyst as an effective pre-treatment method for palm kernel expeller (PKE) in increasing its biodegradability to enhance the microalgal hydrogen production via dark fermentation. A series of TiO2 NTs photocatalysts were synthesized via employing electrochemical anodization of Ti foil at various voltages each in different types of electrolytes (choline chloride-ethylene glycol (ChCl-EG), choline chloride-urea (ChCl-U), choline chloride-glycerol (ChCl-Gly)). Increasing trend of average NTs diameters at 26.14 ± 1.30, 73.01 ± 1.94 and 122.00 ± 13.32 nm was observed for 25, 30 and 35 V in synthesizing TiO2 NTs using suitable ChCl-EG electrolyte, respectively. The high 35 V had resulted in noticeable pore ruptures within this TiO2 NTs photocatalyst. The PKE pre-treated by TiO2 NTs photocatalyst anodized at optimum 30 V in ChCl-EG electrolyte had demonstrated the highest releases of biochemical oxygen demand (BOD5) and soluble chemical oxygen demand (SCOD) concentrations at 594 and 607 mg/L, respectively. Moreover, the microalgal efficiency of BOD5 conversion and hydrogen yield were also consistently maintained from third cycle of TiO2 NTs photocatalyst's reutilizations, signifying the stability of TiO2 NTs photocatalyst.

Review Of Value Added Tax On Palm Kernel Expeller After The Supreme Court Decision (Putusan Mahkamah Agung) Number 70P/HUM/2013

Palm Kernel Expeller (PKE) is a by-product of the secondary processing of fresh fruit bunches (FFB). The problem related to VAT arises when there are differences in interpretation of the regulations relating to the transaction of PKE, whether transcation of PKE is subject to VAT which is subject to tax invoice code or transcation which receives facilities of the exemption from VAT which are subject to tax invoice code 08. This research uses a normative-empirical approach by using main documents in the form of supreme court decision on judicial review of PKE case. The research results show that the judge concludes that the implementing regulations for the transaction of PKE used for animal feed must be in line with Supreme Court Decisions Number 70P/HUM/2013 and SE-24/PJ/2014. Second, both tax authorities and taxpayers must find out information about PKE’s buyers because PKE has other benefits besides being used for animal feed. If it is used for other things, then the transaction is contrary to the aim and purpose of providing VAT facilities in the form of exemption.

Oil palm kernel globulin antihypertensive peptides: isolation and characterization, ACE inhibition mechanisms, zinc-chelating activity, security and stability.

Introduction: The oil palm kernel (OPK) expeller is the main byproduct of palm oil, but its utilization is limited. Methods: To obtain angiotensin-I-converting enzyme (ACE) inhibition peptides with Zn-chelating capacity, defatted oil palm kernel globulin hydrolysates (DOPKGH) were subjected to Sephadex G-15 gel electrophoresis, reverse-phase high liquid performance chromatography, and UPLC-ESI-MS/MS analysis. Results and discussion: Five representative oligopeptides, including Gln-Arg-Leu-Asp-Arg-Cys-Lys (QRLERCK), Leu-Leu-Leu-Gly-Val-Ala-Asn-Tyr-Arg (LLLGVANYR), Arg-Ala-Asp-Val-Phe-Asn-Pro-Arg (RADVFNPR), Arg-Val-Ile-Lys-Tyr-Asn-Gly-Gly-Gly-Ser-Gly (RVIKYNGGGSG), and Glu-Val-Pro-Gln-Ala-Tyr-Ile-Pro (EVPQAYIP), without potential toxicity and allergenicity, were identified in DOPKGH. Of these, only EVPQAYIP showed both ACE-inhibitory activity (IC50: 102.75μmol/L) and Zn-chelating capacity (11.69mg/g). Molecular docking and inhibition kinetics showed that EVPQAYIP was a competitive inhibitor of ACE because it could bind to Glu384, Lys511, and Gln281 (belonging to the central S1 and S2 pockets, respectively) of ACE. Moreover, EVPQAYIP affects zinc tetrahedral coordination in ACE by binding to Glu411; the amino and carboxyl groups of EVPQAYIP chelate with zinc ions. During gastrointestinal digestion, the ACE inhibitory activity of EVPQAYIP was relatively stable. Additionally, EVPQAYIP enhanced zinc stability in the intestine and exerted antihypertensive effects in spontaneous hypertensive rats. These results suggest the potential application of OPK peptides as ingredients in antihypertensive agents or zinc fortification.

Kinetic model derived from machine learning for accurate prediction of microalgal hydrogen production via conversion from low thermally pre-treated palm kernel expeller waste

The depletion of fossil fuel sources and increase in energy demands have increased the need for a sustainable alternative energy source. The ability to produce hydrogen from microalgae is generating a lot of attention in both academia and industry. Due to complex production procedures, the commercial production of microalgal biohydrogen is not yet practical. Developing the most optimum microalgal hydrogen production process is also very laborious and expensive as proven from the experimental measurement. Therefore, this research project intended to analyse the random time series dataset collected during microalgal hydrogen productions while using various low thermally pre-treated palm kernel expeller (PKE) waste via machine learning (ML) approach. The analysis of collected dataset allowed the derivation of an enhanced kinetic model based on the Gompertz model amidst the dark fermentative hydrogen production that integrated thermal pre-treatment duration as a function within the model. The optimum microalgal hydrogen production attained with the enhanced kinetic model was 387.1 mL/g microalgae after 6 days with 1 h thermally pre-treated PKE waste at 90 °C. The enhanced model also had better accuracy (R2 = 0.9556) and net energy ratio (NER) value (0.71) than previous studies. Finally, the NER could be further improved to 0.91 when the microalgal culture was reused, heralding the potential application of ML in optimizing the microalgal hydrogen production process.

Fundamental alteration of cellular biochemicals from attached microalgae onto palm kernel expeller waste upon optimizing the growth environment in forming adhesion complex

Changing the growth environment for microalgae can overall lead to the fundamental alteration in cellular biochemicals whilst attaching onto palm kernel expeller (PKE) waste to form adhesion complex in easing harvesting at stationary growth phase. This study had initially optimized the PKE dosage, light intensity and photoperiod in maximizing the attached microalgal productivity being attained at 0.72 g/g day. Lipid content increased progressively from pH 3 to pH 11, with the highest value observed at pH 11. Meanwhile, in terms of protein and carbohydrate contents, the highest values were obtained by cultivation medium of pH 5 with 9.92 g and 17.72 g, respectively followed by pH 7 with 9.16 g and 16.36 g, respectively. Moreover, the findings also suggested that the low pH mediums utilized polar interactions in the formation of complexes between PKE and microalgae, whereas at higher pH levels, the non-polar interactions became more significant. The work of attachment was thermodynamically favourable towards the attachment formation with values greater than zero which was also aligned with the microscopic surface topography, i.e., revealing a clustering pattern of microalgae colonizing the PKE surface. These findings contribute to comprehensive understanding of optimizing growth condition and harvesting strategy of attached microalgae in attaining the cellular biochemical components, facilitating the development of efficient and sustainable bioresource utilization.

Age-stage, two-sex life table analysis of black soldier fly, Hermetia illucens (Diptera: Stratiomyidae), reared on different organic wastes

Hermetia illucens or black soldier fly (BSF) is an economically important species. BSF larvae are efficient decomposers of various organic wastes and can be integrated into animal feed formulations. An age‐stage, two‐sex life table was applied in this study to evaluate the influence of four different organic wastes, namely, food waste, coconut endosperm, palm kernel expeller (PKE), and chicken manure. The development period, survival, fecundity of BSF adult longevity, adult pre‐oviposition period (APOP), and total pre‐oviposition period (TPOP) were observed to estimate the performance of BSF on different organic wastes. This study was conducted under laboratory conditions at 28 ± 2 °C and 70 ± 10 % relative humidity with a 15-hour light:9-hour dark photoperiod. Raw BSF data were analyzed using the TWOSEX MS‐Chart computer program. Life table parameters showed that food waste and PKE treatments were superior diet choices for BSF larvae compared to chicken manure and coconut waste treatments, with PKE treatment showing the ideal result out of all treatments. The highest net reproductive rate (R0 = 78.5567 ± 14.33) and highest fecundity (467.57 ± 27.28) of BSF occurred in the PKE treatment. Treatment significantly affected the fecundity, intrinsic rate of increase (r), and finite rate of increase (λ).

Low thermal pre-treatment of palm kernel expeller to enhance microalgal hydrogen production

The production of hydrogen from microalgae has inevitably intrigued considerable interests off late. However, the commercial production of microalgal hydrogen is not yet feasible due to the intricate production processes and expensive procedures. Therefore, this research work intended to streamline the microalgal hydrogen generation by utilizing the organic solid waste, palm kernel expeller (PKE), for converting into microalgal hydrogen. Accordingly, the impacts of low thermal pre-treatment method using hydrolysis process was studied at 50 °C, 70 °C, and 90 °C to overcome the recalcitrance of lignocellulosic PKE in associating with the rate of microalgal hydrogen production. The results evidenced that the maximum hydrogen yield was attained at 638 mL H2/g microalgae under the dark anaerobic environment whilst using PKE that was pre-treated at 90 °C for 4 h. In comparison with untreated PKE, this microalgal hydrogen yield had increased by two folds. The release of inhibitory compounds had increased significantly at 50 °C. Thereafter, the zeroth order model was employed to quantify the kinetics of microalgal hydrogen production. The highest rate was successfully achieved at 128 mL H2/g microalgae-d while subsisting on 90 °C pre-treated PKE for 4 h.

OPTIMAL DESIGN OF ORGANIC RANKINE CYCLE POWER PLANTS FOR EFFICIENT UTILIZATION of BIOMASS ENERGY IN NIGERIA

This study investigated the optimal design choice among four organic Rankine cycle (ORC) configurations for efficient utilization of solid biomass energy in Nigeria. Although vast opportunities exist for large-scale biomass power plants in the country, there has been little or no practical implementation yet, due to the limitation of technical know-how regarding thermodynamic conversion technologies. To bridge this gap, a thermodynamic optimization technique was applied in this study to the ORC. Specifically, the subcritical ORC (SUBORC), the regenerative subcritical ORC (SUBORC-REGEN), the supercritical ORC (SUPERORC), and the regenerative supercritical ORC (SUPERORC-REGEN) configurations were compared using established zero-dimensional optimization models implemented in MATLAB. Results showed that the SUPERORC-REGEN would be the most preferred choice amongst the options compared. Specifically, a palm kernel expeller (PKE) biomass fuel considered could yield about 1.98 MW of power at a thermal efficiency of about 28%. Additionally, it was obtained that the supercritical ORC would always outperform the subcritical types technically, with or without a regenerator. For the regenerative configurations, results showed that the supercritical ORC would generate 113 kW and 429 kW more net power than the subcritical ORC, respectively for n-pentane and n-butane working fluids. Similarly, the study reiterated that adopting a regenerative configuration would improve ORC performance. For instance, the SUPERORC-REGEN yielded 63% and 73% more power than the SUPERORC, respectively for n-pentane and n-butane working fluids. The practical economic implications of the different ORC configurations should be examined in future studies, alongside the investigation of exergy-based optimization potentials on component basis.

Mechanistic behaviour of Chlorella vulgaris biofilm formation onto waste organic solid support used to treat palm kernel expeller in the recent Anthropocene

The capacity to maximize the proliferation of microalgal cells by means of topologically textured organic solid surfaces under various pH gave rise to the fundamental biophysical analysis of cell-surface attachment in this study. The substrate used in analysis was palm kernel expeller (PKE) in which the microalgal cells had adhered onto its surface. The findings elucidated the relevance of surface properties in terms of surface wettability and surface energy in relation to the attached microalgal growth with pH as the limiting factor. The increase in hydrophobicity of PKE-microalgae attachment was able to facilitate the formation of biofilm better. The pH 5 and pH 11 were found to be the conditions with highest and lowest microalgal growths, respectively, which were in tandem with the highest contact angle value at pH 5 and conversely for pH 11. The work of attachment (Wcs) had supported the derived model with positive values being attained for all the pH conditions, corroborating the thermodynamic feasibility. Finally, this study had unveiled the mechanism of microalgal attachment onto the surface of PKE using the aid of extracellular polymeric surfaces (EPS) from microalgae. Also, the hydrophobic nature of PKE enabled excellent attachment alongside with nutrients for microalgae to grow and from layer-by-layer (LbL) assembly. This assembly was then isolated using organosolv method by means of biphasic solvents, namely, methanol and chloroform, to induce detachment.

Elemental Composition of Palm Kernel Expeller Used as Supplementary Stock Fodder

Palm kernel expeller (PKE) is a biowaste by-product of palm oil processing in Southeast Asia that is exported as stock fodder. Global production of PKE totals 11M t yr−1, of which New Zealand imports 1.9M t yr−1, worth &gt;USD 325M, most of which supports NZ’s dairy herd of 5.5M cows. We aimed to determine the concentrations of the chemical elements in PKE imported into New Zealand and compare this to pasture, as well as to assess chemical concentrations against maximum tolerable levels (MTLs) in stockfeed for animal health and ruminant requirements. Palm kernel expeller was analysed for a suite of essential and trace elements using a HNO3 digestion and analysis by inductively coupled plasma-mass spectrometry. Palm kernel expeller contained statistically significantly higher concentrations of B, Mg, P, Cr, Mn, Fe, Ni, Cu and Zn than pasture. Magnesium, P and Fe exceeded MTLs in PKE, whereas Al, S, K and Cu were within 90% of their MTL. The N, P and K contained in PKE represent the equivalent of 14%, 20% and 28%, respectively, of dairy fertiliser use in New Zealand. As PKE contained 3.3 mg Cd kg P −1, there may be potential for PKE to offset fertiliser use in dairy systems, with a low Cd source of P. There were statistically significant differences in elemental concentrations between different batches of PKE indicating that this product is not uniform. Further research of the effects of PKE on animal health is recommended. The excess elements contained in PKE may present risks or benefits to dairy farming systems and determining these would be beneficial in protecting both animal health and environmental sustainability.

Changes in thermomechanical properties of feed in relation to composition and their effect on pellet manufacturing

Due to the growing demand for food, the availability of starch-rich ingredients (e.g. feed grade cereals), whose areal can be used for producing food, is expect to decline. In turn, the use of co-products, from food- and biofuel industry, is expected to increase in livestock feed. However, these co-products are fibre-rich and can negatively affect pellet manufacturing, by reducing pellet quality and increasing energy costs. The thermomechanical properties of feed mashes are considered to be important for agglomeration processes, but its relation to feed composition and its role in pellet manufacturing is poorly understood. The aim of this study was to investigate the effect of fibrous co-product inclusion in feed mashes on their thermomechanical properties and subsequent effects on pellet manufacturing. Treatment mashes were formulated to contain 700 g/kg basic mash, consisting of soybean meal, maize, and soy oil, to which 0–300 g/kg palm kernel expeller, sugar beet pulp, wheat straw and isolated native maize starch were added, according to a four-component mixture design. Treatments were prepared in duplicate, conditioned using a single-shaft conditioner and compacted using a ring-die pelletizer (die hole diameter 6 mm, L/D ratio 12). Pellet quality, production capacity and gross specific mechanical energy consumption per megagram (Mg) were documented. Mash deformability was evaluated by increasing the moisture content of a mash sample to 150 g/kg, followed by compression at 10 MPa and increasing temperature by 4 °C/minute using the Phase Transition Analyzer (PTA; Wenger Manufacturing, Sabetha, KS, US). Inclusion of wheat straw significantly increased mash deformability. Inclusion of isolated native maize starch and fibrous co-products was observed to increase pellet quality in comparison to the basic mash. Mash deformability at compactor temperature was correlated with bulk density (r = −0,83; P < 0.001). Pellet compressive strength was associated with mash deformability (r = 0.78; P < 0.001), but this association was observed to be influenced by wheat straw. Material deformability was correlated with production capacity (r = −0.85; P < 0.001) and energy consumption (r = 0.80; P < 0.001). In conclusion, inclusion of fibrous co-products affects pellet quality in a non-linear relation and increases pellet quality similar to inclusion of isolated native maize starch. Mash deformability could provide an indicator for pellet quality, but the underlying mechanism requires further study. Pelleting of feed mashes with a higher deformability increases energy costs of pellet manufacturing, due to the behaviour during compaction. The thermomechanical properties of feed mashes play a significant role in the pellet manufacturing process.

The Ingestion of Dietary Prebiotic Alternatives during Lactation Promotes Intestinal Health by Modulation of Gut Microbiota.

Palm kernel expeller (PKE), a by-product of palm oil extraction, contains higher amounts of fiber than corn and soybean meal, but offers low energy density, protein value, and amino acid (AA) composition, limiting its use for swine. Recently however, it was reported that dietary fiber has a positive effect on the gut microbiota of the host, and therefore it is necessary to study the effect of PKE feeding on the intestinal microbiota of swine. In this study, we investigated the effects of supplementation with PKE in lactation diets on the gut microbiota composition of lactating sows and their litters. A total of 12 sows were randomly assigned to two dietary treatment groups in a completely randomized design. The treatments were a diet based on corn-soybean meal (CON) and CON supplemented with 20% of PKE. Sow and piglet fecal samples were collected before farrowing, on days 7 and 28 (weaning) after farrowing, and on days 7 and 28 (weaning) after farrowing, respectively, to verify gut microbiota composition by pyrosequencing analysis. The beta-diversity result showed a significant difference only in weaning-stage piglets, but dietary PKE altered the gut microbiota in sows by increasing the abundance of Lactobacillus compared with CON. In piglets, dietary PKE decreased the abundance of opportunistic pathogen Proteus and increased the abundance of potentially beneficial bacteria, such as Prevotellaceae and Prevotella. Our results can be helpful in developing feeding strategies and support the beneficial effects of dietary PKE to improve the gut health of animals.

PH spurring microalgal cells to subsist onto palm kernel expeller for growing into biodiesel feedstock

The potentiality of microalgae as a feedstock for biodiesel production is actively being explored to resolve the inadequacy of biomass and lipid indexes conundrum, and economic infeasibility associated to the conventional cultivation system. Current study is an extension of a pre-optimized cultivation condition which has further elaborated the impact of pH on attached microalgal cultivation onto nutritional lignocellulosic waste; palm kernel expeller (PKE) by employing a novel periphytic growth and harvesting technique. The highest microalgal density was achieved at 10.9 ± 0.8 g/g-PKE in pH 5 cultivation medium with highest carbon-PKE assimilation. In fact, the microalgal growths under mixotrophic condition demonstrated a positive correlation between pH of cultivation medium and carbon-PKE assimilation by microalgae. The maximum lipid productivity was obtained at 33.1 ± 3.3 mg/L day from the attached microalgae of pH 11 medium. However, the lowest microalgal density was likewise attained at similar pH due to the trigger by which the carbon metabolic activity shifted towards lipid production instead of growth. Owing to the highest microalgal density attained at pH 5 medium, the gap of lipid productivities with pH 11 was narrowed down to merely 7.0 mg/L day. The attached microalgal feedstock harvested from this study was eventually found satiating most of the essential biodiesel properties in compliance with the international standards decreed by ASTM D6751-03 and EN 14214.

Supplementation of a β-Mannanase Enzyme Improves Feed Efficiency in Palm Kernel Expeller Rich Swine Diets

β-Mannans are strongly anti-nutritive polysaccharide fibres found in most vegetable feed ingredients. Estimated content of soluble β-mannans in common grow-finishing diets is only 0.15-0.35%, and in vitro studies have demonstrated that as little as 0.05% soluble β-mannan in feed can elicit a strong innate immune response. This innate response is referred to as a Feed Induced Immune Response (FIIR). Hemicell™ HT (Elanco) is a β-mannanase enzyme for animal feeds breaking down β-mannans, thereby preventing economic losses from this wasteful immune response to β-mannans. The objective was to investigate whether β-mannanase improves feed efficiency in grower/finisher pigs fed diets containing high amounts (5-15%) of Palm Kernel Expeller (PKE). A 3*2 factorial design was applied consisting of 3 treatments (control, PKE, PKE+β- mannanase (PKE+)) and 2 sexes (barrows, gilts) and 2 subsequent batches. Groups were divided over 80 pens resulting in 13-14 repeats per group. Pigs were fed pelletized starter (0-28 d), grower (28-63 d), and finisher diets (63- 99 d). Body Weight (BW) was recorded on days 0, 28, 63, and 99. Feed was offered ad libitum and recorded by pen. For each phase, Average Daily Gain (ADG), Average Daily Feed Intake (ADFI), and Feed Conversion Ratio (FCR) were calculated. Data analysis was performed in R. FCR improved significantly (P=0.004) the first four weeks PKE+ (2.07) compared with Control (2.13). During grower/finisher phases, ADG and ADFI were significantly (P&lt;0.05) higher on PKE and PKE+ compared with Control. Overall, both PKE and PKE+ performed significantly better than Control, which PKE and PKE+ performed similarly. Feeding 10-15% PKE increased ADG and ADFI (potentially due to overestimated energy content of the PKE) both with and without β-mannanase, and resulted in similar FCR. Thus, β-mannanase may improve FCR on high PKE diets from 21 to 39 kg BW.

Reducing cost and ensuring environmental sustainability: Palm kernel expeller as an alternative sculpture material for casting in Ghana

The materials for sculpture in Ghana have always been clay, wood, cement, resin, and silicon. These materials have their limitations. Also, some students do not have the financial strength to purchase them because they are expensive. This situation slows down the pace in the teaching and learning of practical activities in the Sculpture discipline in most Ghanaian educational institutions. Owing to this, the researchers explored the possibility of experimenting with local materials in the home regions of students which could have otherwise been a nuisance in the environment as alternative sculptural materials. The researchers adopted the Double Helix of Praxis Exegesis Model, which is an arts-based method undergird in the eco-innovation theory to investigate the possibility of using palm kernel which is abundant in the Anloga Sobolo community, Kumasi, Ghana as an alternative material for modeling, casting, and carving. The palm kernel expellers were prepared by collecting the kernel, cracking, firing, milling, and cooking to extract the oil, and then the expeller. The palm kernel expellers were mixed with selected binders to produce aesthetically pleasing modeled, cast, and carved works. Findings revealed that palm kernel expeller is non-toxic, environmentally friendly, and cost-effective alternative material for sculpture. The study contends that teachers and students in the sculpture discipline in the various Senior High and tertiary educational institutions in Ghana should constantly explore waste local materials as alternative materials for practical activities in sculpture to reduce cost and to serve as a tool for ensuring environmental sustainability.

Residual palm kernel expeller as the support material and alimentation provider in enhancing attached microalgal growth for quality biodiesel production

Albeit the biodiesel production from suspended microalgal system has gained immense interests in recent years, the domineering limitation of being economically infeasible has hindered this technology from partaking into a large-scale operation. To curtail this issue, attached growth system had been introduced by various studies; however, those were still unable to alleviate the socio-economic challenges faced in commercializing the microalgal biomass production. Thus, this study had developed a novel approach in cultivating-cum-harvesting attached Chlorella vulgaris sp. microalgae, whilst using solid organic waste of palm kernel expeller (PKE) as the supporting and alimentation material for microalgal biofilm formation. The effects of three variables, namely, PKE dosage, light intensity, and photoperiod, were initially modelled and later optimized using Response Surface Methodology tool. The derived statistical models could predict the growth performances of attached microalgal biomass and lipid productivity. The optimum growing condition was attained at PKE dosage of 5.67 g/L, light intensity of 197 μmol/m2 s and photoperiod of 8 light and 16 dark hours/cycle, achieving the microalgal density and lipid content of 9.87 ± 0.05 g/g and 3.39 ± 0.28 g/g, respectively, with lipid productivity of 29.6 mg/L day. This optimum condition had led to the intensification of biodiesel quality with a high percentage of monounsaturated fatty acid, i.e., oleic acid (C18:1), encompassing 81.86% of total fatty acid methyl ester components. Given that the positive acquisition of PKE as an excellent supporting material in enhancing the microalgal density and lipid productivity that had resulted in the commercially viable biodiesel quality, this study served as a novel revolution in augmenting the microalgae and solid waste utilities for sustainable energy generation.

An Assessment of Trace Element Accumulation in Palm Oil Production

African oil palm (Elaeis guineensis) is grown on 17,000,000 hectares in Southeast Asia, producing oil and the by-product, palm kernel expeller (PKE), for export. Elaeis guineensis is typically produced on weathered acidic soils, with fertilisers and fungicides used to increase production. These amendments can contain elevated concentrations of trace elements (TEs), either as the active ingredient (e.g., Cu-based fungicides) or as contaminants, including F, Zn, As, Cd, Pb and U. TEs may accumulate in soil over time, and be taken up by plants, posing a food-chain transfer risk if allowed to exceed soil guideline values. We reviewed available literature on trace elements in soil, plant material, oil and PKE to evaluate the risk of TE accumulation due to phosphate fertiliser and Cu-fungicide use. TE concentrations of Cu, Zn, and Cd were reported to be up to 69, 107 and 5.2 mg kg−1, respectively, in E. guineensis plantation soils, while Cu and As were reported to be up to 28.9 and 3.05 mg kg−1, respectively, in PKE (&gt;50% their permissible limits). Iron, a TE, has also been reported in PKE up to 6130 mg kg−1 (&gt;10-fold the permissible limit). TE accumulation is an emerging issue for the palm oil industry, which, if unaddressed, will negatively affect the industry’s economic and environmental sustainability. There are critical knowledge gaps concerning TEs in palm oil systems, including a general lack of research from Southeast Asian environments and information concerning key contaminants (Fe, Cu, As and Cd) in soils, plants and PKE.