Carbon monoxide reduction in the flue gas during biochar production from oil palm empty fruit bunch

Biomass carbonization technology is implemented to produce charcoal with high-calorific content. However, this technology releases pollutant gases, which adversely affect ambient environment and human health. This study proposed a catalytic gas treatment method using platinum-supported alumina catalyst (Pt/γ-Al2O3) for carbon monoxide emission reduction in oil palm empty fruit bunch carbonization. Carbonization released a rather high carbon monoxide concentration of 5558 ± 53 mg m−3 in the flue gas, exceeding the permissible limit of 1000 mg m−3. At 2.5 wt% of catalyst dosage, the carbon monoxide emission substantially was reduced to 595 ± 9 mg m−3, achieving 89.3% carbon monoxide removal efficiency. This was due to oxidation by the platinum-supported alumina catalyst (Pt/γ-Al2O3), which was done at low temperature, thus transforming carbon monoxide into carbon dioxide. The catalyst demonstrated reusability, attaining >80% carbon monoxide removal efficiency for 5 consecutive carbonization cycles. The biochar produced contained a high energy content of 24.6 ± 0.7 MJ kg−1, which was suitable to be used as a coal substitute

Waterless purification using oil palm biomass-derived bioadsorbent improved the quality of biodiesel from waste cooking oil

The utilization of adsorbents produced from biomass for tertiary treatment of industrial wastes has gained much interest compared to the conventional methods such as flocculation and coagulation. In the present study, a bioadsorbent produced from pressed-shredded oil palm empty fruit bunch was used to remove impurities from crude biodiesel derived from waste cooking oil. The purification process was performed using 1 to 5 wt% bioadsorbent loadings under continuous stirring at 500 rpm for 1 h. After purification using 5 wt% of bioadsorbent loading, 89.7% of residual methanol, 81.7% of water, 36.7% of free fatty acid and 98.6% of potassium were successfully removed. This met the European Biodiesel Standard (EN14214). In comparison to commercial adsorbents and the water washing method, purification using the oil palm empty fruit bunch derived bioadsorbent resulted in higher removal of free fatty acids, potassium, water impurities and a smaller loss of fatty acid methyl esters. It was found that the use of the bioadsorbent improved the biodiesel quality besides its benefits of ease of operations and avoidance of waste water production

A holistic treatment system for palm oil mill effluent by incorporating the anaerobic-aerobic-wetland sequential system and a convective sludge dryer

An integrated treatment system which incorporated an anaerobic-aerobic-wetland sequential system (AAWSS) and a convective sludge dryer (CSD) was established to treat highly polluting palm oil mill effluent (POME) in a shorter retention period and with a smaller area requirement. Before actual treatment, a start-up operation was performed to achieve optimal degradation performance. The strategy involved a stepwise feeding from 0.2 to 1 m3 d−1 at three day intervals for 15 days. During the operation, the lowest hydraulic retention time of 21 days was achieved and the biogas production was gradually increased from 1442 to 11,028 kg d−1with the increase of organic loads from 0.46 to 2.2 kg m−3 d−1. COD, VSS and VFA were almost completely (99%) removed, whereas the average percentage removals of SS and TN were 96% and 72%, respectively. To demonstrate the plant’s robustness in treating POME, the AAWSS was proceeded with a 360 days operation. A slight deterioration in COD and SS removals were observed from day 225 to day 265 due to an organic shock load. One unanticipated finding was that the AAWSS regained its stability shortly thereafter thus ensuring consistency of the treatment performance for long-term use. Further treatment with CSD was designed to produce a clear effluent that surpassed the industrial effluent discharge limits at low-cost. By referring to mass balance, the production efficiency achieved 95% condensate yield, leaving 7% concentrate and 2% dewatered solids as byproducts

Kinetic and thermodynamic of heterogeneously K₃PO₄/AC-catalysed transesterification via pseudo-first order mechanism and eyring-polanyi equation

The use of carbon-based catalysts has drawn so much interest in biodiesel production due to improved reaction performance. However, there was lack of comprehensive studies in term of its kinetic and thermodynamic perspective. Therefore, a methodical study is essential to uncover the influence of the carbon catalyst with respect to reaction rate and yield. This study represents kinetic and thermodynamic of heterogeneously K₃PO₄/AC-catalysed transesterification. It was done correspondingly via pseudo-first order mechanism and Eyring-Polanyi equation, whereby, under the optimal reaction temperature of 333.15 K, all data have fitted satisfactorily in both models with resulted R² of 0.99, respectively. Activation energy (Ea) and Gibbs free energy (ΔG) were calculated as 34.2 kJ mol⁻¹ and −33.68 kJ mol⁻¹, indicating the reaction was exergonic and spontaneous at high temperature

Production of biochar from oil palm frond by steam pyrolysis for removal of residual contaminants in palm oil mill effluent final discharge

Advances in biochar production and modification have extended the applications of biochar to wastewater treatment. However, not all feedstocks produced porous biochar at a moderate temperature suitable for wastewater treatment. In this study, biochar was produced from oil palm frond using steam pyrolysis at 500 °C and pulverized to granular and micro-fine particles. Both biochar particles were characterized and applied as adsorbents for treating final discharge of palm oil mill effluent. The effluent was also filtered and treated to examine the effect of suspended solids on adsorption capacity. The biochar had Brunauer-Emmett-Teller surface area of 406.6 m2 g−1. Pulverization eliminated the residual macropores in granular biochar, created new external surface area, and exposed constricted nanopores, which resulted in increasing the surface area to 457.7 m2 g−1. The adsorption capacity decreased from 24.6 to 6.1 mg g−1 for chemical oxygen demand and 49.0 to 10.9 Pt–Co g−1 for color by increasing the dosage of micro-fine biochar from 5 to 30 g L−1. The total suspended solids affected the adsorption capacity of granular biochar by blocking residual macropores that provide access to adsorption sites in micropores and mesopores. At 30 g L−1, the micro-fine biochar exhibited an effective reduction of chemical oxygen demand from 224 to 41.6 mg g−1 and color from 344 to 15 Pt–Co g−1 making the wastewater suitable for reuse in palm oil mills and safe for discharge into the aquatic environment

Emerging development of nanocellulose as an antimicrobial material: An overview

The prolonged survival of microbes on surfaces in high-traffic/high-contact environments drives the need for a more consistent and passive form of surface sterilization to minimize the risk of infection. Due to increasing tolerance to antibiotics among microorganisms, research focusing on the discovery of naturally-occurring biocides with low-risk cytotoxicity properties has become more pressing. The latest research has centred on nanocellulosic antimicrobial materials due to their low-cost and unique features, which are potentially useful as wound dressings, drug carriers, packaging materials, filtration/adsorbents, textiles, and paint. This review discusses the latest literature on the fabrication of nanocellulose-based antimicrobial materials against viruses, bacteria, fungi, algae, and protozoa by employing variable functional groups, including aldehyde groups, quaternary ammonium, metal, metal oxide nanoparticles as well as chitosan. The problems associated with industrial manufacturing and the prospects for the advancement of nanocellulose-based antimicrobial materials are also addressed

Utilization of biomass-derived activated carbon as catalyst support and bioadsorbent in biodiesel production using waste cooking oil as feedstock

The depletion of non-renewable fossil fuels and the growing environmental awareness, biodiesel is seen as a promising substitute for the conventional diesel. Its eco-friendly properties such as being renewable, biodegradable and less carbon emission have brought new hope for a greener future. Presently, waste cooking oil and oil palm empty fruit bunch were extensively used as the raw materials for a low-cost feedstock and catalyst for biodiesel production. Apart from its economic objective, exploitation of these abundant waste sources for biodiesel production is a step ahead in saving the environment from pollution, as it is typically being disposed indiscriminately. In this study, improved production of biodiesel from waste cooking oil was achieved by using a newly developed potassium phosphate tri-basic supported activated carbon catalyst. In order to produce high surface area activated carbon, press-shredded oil palm empty fruit bunch was subjected to carbonization at 700ᴼC for 2 h followed by activation with potassium hydroxide at 700ᴼC for 2 h. To produce the catalyst, calcination was performed at different potassium phosphate tri-basic impregnation concentrations (1:0.25 to 1:1 activated carbon to potassium phosphate tri-basic weight ratio) and temperatures (400ᴼC to 700ᴼC). Prior to transesterification, waste cooking oil was analysed for its physicochemical properties and pre-treated to remove moisture and residues. Under the optimum condition of 5 wt% catalyst loading, 12:1 methanol to oil molar ratio at 60ᴼC for 4 h, 98% of biodiesel yield was achieved, which surpassed the European Biodiesel Standard (EN 14214). The catalyst was reusable for 5 successive reaction cycles, achieving almost 80% of biodiesel yield.In addition, the activated carbon produced from the press-shredded oil palm empty fruit bunch was also utilized as bioadsorbent to remove impurities from the crude biodiesel. The purification process was performed using different adsorbent loadings (1 to 5 wt%) under continuous stirring condition at 500 rpm for 1 h. Approximately 89.71% of methanol, 81.74% of water, 36.67% of FFA and 98.61% of potassium (K) were successfully removed after purification at 5 wt% of bioadsorbent loading, which met the European Biodiesel Standards (EN 14214). In comparison to other commercial adsorbents and conventional water washing method, purification using the biomassderived bioadsorbent resulted in better removal of methanol, water and triglyceride impurities with only a small loss of biodiesel yield

Net energy and techno-economic assessment of biodiesel production from waste cooking oil using a semi-industrial plant: a Malaysia perspective

To promote the growth of the biodiesel industry, many countries have started allocating initial inducements to start-up companies to set up the infrastructure for its production facilities. Thus, comprehensive economic assessments are vital to keeping businesses on the right track in the long run. In this present study, net energy ratio (NER) and macroeconomic assessment are investigated using actual data obtained from biodiesel production from waste cooking oil (WCO) by using a semi-industrial plant. The fuel quality produced has complied with the European Biodiesel Standard (EN 14214) and the net energy ratio (NER) calculated was positive, which, in other words, epitomized a competent-designed production practice. Concerning mass balance, 74.3% of biodiesel, 24.0% of by-product glycerol and 8.9% soap were measured. By applying these as baseline values for scale-up production of 3.68 kt per annum, projected values of total production costs, selling price of B10 fuel, net present value (NPV) and internal rate of return (IRR) were USD 1.78 million, USD 0.47/kg, USD 1.43 million and 60%, respectively. In summary, these projected values are suggestively lucrative, offering strong business growth for 10 years and capable of withstanding the variations of plant capacity and raw material price

Convective sludge drying by rotary drum dryer using waste steam for palm oil mill effluent treatment

Achieving a more sustainable wastewater treatment plant has never been so important. Issues around energy consumption and pollutants removal efficiency are of growing importance in the context of production costs and pollution control. In the palm oil industry, more than 85% mills are managing their palm oil mill effluent (POME) via lagoons, yet the system considered less effective as the quality of the effluent hardly achieved the permissible limits. It is therefore in the best interest of the industry to employ a better practice. Convective sludge drying (CSD) has been shown to have exceptional efficiency in high-strength wastewater treatment. In this study, CSD epitomized the zero-emission of POME treatment due to the fact that; 1) It operates on low-grade steam discharged by the mill instead of electricity, leading to a huge cut on energy consumption, 2) Production of secondary micronutrients-enriched solids by-product (i.e., calcium and magnesium) that can be repurposed as fertilizer, and 3) The decoction produced can potentially be reused to irrigate the existing oil palm plantation for nutrient cycling. The treatment resulted in substantial removal of the chemical oxygen demand (COD), biological oxygen demand (BOD), suspended solids (SS), ammoniacal nitrogen (AN), and oil and grease (OG) down to 2 mg/L, 67.7 mg/L, 40.0 mg/L, 99% of BOD, COD, SS, OG, and AN removal efficiency. The operating cost was valued at USD 1.91 per m3 POME. The pilot-scale operation proved CSD is a viable alternative to the lagoons

High-energy ball milling for high productivity of nanobiochar from oil palm biomass

The current production method of nanobiochar (NBC), an emerging, environmentally friendly nanocarbon material, is tedious and lengthy. Therefore, in this study we aimed to improve the productivity of NBC via high-energy ball milling by manipulating the grinding media and processing time. The particle size distribution of the resulting NBC measured using dynamic light scattering showed that grinding media with steel balls of different sizes were more effective at producing NBC than small uniform steel balls, which failed to produce NBC even after 90 min of milling. Average NBC particles of around 95 nm were achieved after only 30 min of ball milling, and the size was further reduced to about 30 nm when the milling was prolonged to 150 min. Further prolonging the milling duration led to agglomeration, which increased the size of the biochar nanoparticles. The thermogravimetric analysis (TGA) data showed that the duration of milling and particle size did not cause noticeable differences in the thermal stability of the NBC. Based on the FTIR analysis, the chemical structure of the NBC was not affected by the ball milling. The results showed that 60 min of high-energy ball milling is sufficient to produce NBC particles of 75 nm, with a large surface area and high thermal stability. This could prove beneficial in a myriad of applications, ranging from agriculture to composite fabrication