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The cement industry, known for its high energy consumption and significant carbon emissions, is facing the challenge of reducing its emissions. The calcination process and the use of coal as fuel in the kiln are the primary contributors to carbon emissions in cement production. A smart energy system incorporating two decarbonisation strategies can be a solution to this issue. The strategies include the usage of alternative fuel and the incorporation of a carbon capture unit. In this paper, a mathematical model of a smart energy system has been formulated to optimise the energy flow based on the demand in a cement plant. The model aims to minimise the total annualised cost of a smart energy system. A case study is solved to illustrate this model. The case study focuses on optimising a smart energy system to decarbonise the daily operations of a cement production plant. Results from the case study show that the two decarbonisation strategies should be implemented simultaneously in order to thoroughly decarbonise a cement production plant. As a result, a daily cost of USD 221,811 is required to reduce carbon emissions by 1,313 t in the cement production plant.

Perovskite oxides with high oxygen ionic conductivity have played major roles in five important devices of significance for clean energy future and automated manufacturing, i.e., solid oxide fuel cell, solid oxide electrolysis cell, oxygen permeable membranes, gas sensors, and oxygen pumps, all of which exhibit different performance requirements and challenges. Although improving the oxygen ion transport within the perovskite lattice serves as the key to increasing the efficiencies of perovskites’ components in these devices, the different criteria, structures, and/or physicochemical properties often become the complicating factors. It is understood that the oxygen ion transport performance of perovskite is mainly determined by the crystal structure, the A/B-site cations and their content, and the oxygen vacancies. This perspective overviews these factors, which can be manipulated to adapt the needs for different devices. Brief discussions are then made on the concepts, status, and outlook of each device together with the strategies for improving the device performance. The summaries and insights provided in this review are anticipated to promote more strategic research and development directions and activities in these important applications.

In this study, one-part alkali-activated mortars are formulated using circulating fluidised bed combustion (CFBC) fly ash, derived from lignite (brown coal) combustion, as the precursor, and sodium hydroxide (NaOH) and sodium metasilicate (Na2SiO3) as the solid activators. Experimental findings indicate that an increase in solid activator-to-precursor ratio correlates with improved workability and compressive strength of the mortars. The influence of Na2SiO3-to-NaOH ratio on the compressive strength of the mortars is apparent only in mixes with a high solid activator-to-precursor ratio of 0.4 and 0.5, indicating its relatively lesser significance compared to the solid activator-to-precursor ratio. The mechanism through which an increase in the solid activator-to-precursor ratio improves the compressive strength of the mortars is elucidated using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The results indicate that increasing the solid activator-to-precursor ratio enhances the degree of alkali-activation for fly ash, thereby improving the compressive strength with increasing solid activator-to-precursor ratio.

Globally, the rise in the environmental awareness on the reduction of greenhouse gas emissions has spurred the development of carbon capture and utilization (CCU) technologies, including membrane separation. Among the membrane separation technologies, dual-phase carbonate membrane is feasible for post-combustion carbon capture given its high thermal and chemical stabilities at high temperatures. The integration of carbon capture and dry reforming of methane (DRM) in a catalytic dual-phase carbonate membrane reactor to function as a single device for syngas production is an emerging area of research. This paper aims to provide a comprehensive review on the progress of the dual-phase carbonate membranes and membrane reactors in carbon capture and syngas production. The working mechanism and performance of three types of carbonate membranes in CO2 separation from various aspects (i.e., material selection, membrane configuration, modifications on the materials, and operating conditions) are thoroughly examined. Additionally, an overview of the reactions involved (i.e., DRM, steam reforming of methane (SRM), and partial oxidation of methane (POM)) and catalyst design (i.e., nickel-based supported with metal oxides and zeolites) is provided. A detailed comparison of the performance of the catalytic dual-phase ceramic-carbonate membrane reactor using different types of catalysts for syngas production is presented. Finally, the review is concluded with a discussion of the challenges, recommendations, and future insights on the development of dual-phase carbonate membranes and membrane reactors.

This study demonstrates the successful integration of process simulation using CHEMCAD into Sunway University's Chemical Engineering Thermodynamics curriculum, replacing the traditional lab sessions. This approach has two main benefits, i.e., it provides early exposure to process simulation software, bridging theory and practice, and it supports new chemical engineering programs where labs may not be fully operational. Aligned with Sunway University's commitment to innovative educational approaches, the impact of this integration on the students’ learning experiences is evident through feedback collected from a comprehensive survey conducted with a group of seven students enrolled in Chemical Engineering Thermodynamics in April 2023. The survey's three sections gathered the students’ perceptions, enjoyed aspects, challenges faced, and suggestions. Findings highlight the students’ positive views on the integration, enhancing comprehension of thermodynamics concepts and real-world applications. They also recognized the value of hands-on simulation experience for essential process simulation skills. The students appreciated the practical relevance in highlighting thermodynamics’ real-world importance. Challenges related to software access and technical issues were addressed, with planned improvements. The students expressed interest in deeper learning, including complex simulations, graphical representation use, and external resource access. While many found the integration effective, suggestions for more hands-on engagement and research resource access were noted.

This perspective article highlights our opinions on the imperative of incorporating Process Intensification (PI) into undergraduate chemical engineering education, recognizing its pivotal role in preparing future engineers for contemporary industrial challenges. The trajectory of PI, from historical milestones to its significance in advancing the United Nations’ Sustainable Development Goals (SDGs), reflects its intrinsic alignment with sustainability, resource efficiency, and environmental stewardship. Despite its critical relevance, the absence of dedicated PI courses in numerous undergraduate chemical engineering programs presents an opportunity for educational enhancement. An exploration of global PI-related courses reveals the potential of educational platforms to fill this void. To address this gap, we advocate for the introduction of a standalone PI course as a minor elective, minimizing disruptions to established curricula while acknowledging the scarcity of PI expertise. The challenges associated with PI integration encompass faculty workload, specialized expertise, curriculum content standardization, and industry alignment. Surmounting these challenges necessitates collaborative efforts among academia, industry stakeholders, and policymakers, emphasizing the manifold benefits of PI, faculty development initiatives, and the establishment of continuous improvement mechanisms. The incorporation of PI into curricula signifies a transformative approach, cultivating a cadre of innovative engineers poised to meet the demands of the evolving industrial landscape.

Malaysia is the second largest producer and exporter of palm oil. Though several works have explored achieving emissions reduction in the palm oil sector, there existing gaps in analysing pathways for achieving net-zero emissions. Moreover, there are limited studies that evaluate the potential of palm oil biomass utilisation pathways based on emissions reduction capabilities, the cost of emissions reduction, and the technology readiness for implementation. Therefore, this study analysed decarbonisation pathways for the upstream and midstream segments of the palm oil sector in Malaysia, encompassing oil palm plantations and palm oil mills. Various sources of greenhouse gas emissions in oil palm plantations and palm oil mills were identified and estimates of emissions were determined as theoretical emissions. The current emissions were established based on the current best practice in the plantation and mill. Several biomass conversion technologies for the recovery of palm-based by-products and conversion into value-added products to decarbonise the palm oil sector and evaluated strategies to attain net-zero status are considered. In this work, the analysis considered both the existing technologies that are adopted by plantations and mills as well as the emerging technologies that have scope for implementation. With the proposed approach, the current emissions level for crude palm oil (CPO) production in Malaysia is estimated as 1121.49 kg CO2-eq/t CPO. In current industry practice, empty fruit bunch (EFB) is underutilised as mills are typically located at rural areas with lack of suitable transportation. Besides, the lack of accessibility to the grid also limits the potential of converting EFB into electricity as supply for national grid. This work examined various pathways for EFB utilisation under different scenarios evaluating their contribution potential towards net-zero target in an energy self-sustained CPO production. As shown in the results, converting EFB to briquettes and pellets are able to achieve the net-zero objective. Furthermore, EFB-biochar and EFB-syngas pathways also exhibit the potential to accomplish the net-zero target. Note that this work also assessed the technologies’ readiness levels, identified challenges in implementation, and proposed several recommendations.

This paper explores the integration of large language models (LLMs), such as ChatGPT, in chemical engineering education, departing from conventional practices that may not be universally accepted. While there is ongoing debate surrounding the acceptance of LLMs, driven by concerns over computational instability and potential inconsistencies, their inevitability in shaping our communication and interaction with technology cannot be ignored. As educators, we are positioned to play a vital role in guiding students toward the responsible, effective, and synergetic use of LLMs. Focusing specifically on distillation column design in undergraduate mass-transfer courses, this study demonstrates how ChatGPT can be utilized as an auxiliary tool to create interactive learning environments and simulate real-world engineering thinking processes. It emphasizes the need for students to develop critical thinking skills and a thorough understanding of LLM principles, taking responsibility for their use and creations. While ChatGPT should not be solely relied upon, its integration with fundamental principles of chemical engineering is crucial. The effectiveness and limitations of ChatGPT are exemplified through two case studies, showcasing the importance of manual calculations and established simulation software as primary tools for guiding and validating engineering results and analyses. This paper also addresses the pedagogical implications of integrating LLMs into mass transfer courses, encompassing curriculum integration, facilitation, guidance, and ethical considerations. Recommendations are provided for incorporating LLMs effectively into the curriculum. Overall, this study contributes to the advancement of chemical engineering education by examining the benefits and limitations of LLMs as educational aids in the design process.

The occurrence of antibiotic pollution has become a concerning issue to public health, where the adsorption of antibiotics on bentonite-based adsorbent represents an attractive solution to reduce the antibiotic residue in wastewater. In this work, the bentonite-chitosan composite was synthesised and the adsorption isotherms of amoxicillin, ampicillin, and doripenem were investigated experimentally at temperatures between 303.15 and 323.15 K. The bentonite-chitosan composite was characterised by scanning electron microscope, electron dispersive X-ray spectrophotometer, surface area and porosity analyser, powder X-ray diffractometer, Fourier transform infrared spectrometer, and thermogravimetric analyser to examine the structure of the synthesised adsorbent. The experimental data were also correlated with models of Langmuir, Freundlich, Toth, and Dubinin-Radushkevich. The experimental results showed an enhanced adsorption of all antibiotics on the bentonite-chitosan composite compared with raw bentonite despite having a much smaller BET surface area and pore volume. On the other hand, the Toth model provided the best estimates on the adsorption isotherms, though Langmuir constants were mostly recovered particularly in the lower temperature range. From the fitting results, the adsorptions of all antibiotics were implied to be endothermic and associated with monolayer formation. Within the tested temperatures, the adsorption capacities of the bentonite-chitosan composite computed by Toth model were found to be 51.9–86.1 mg g−1 for amoxicillin, 66.1–83.3 mg g−1 for ampicillin, and 78.4–96.0 mg g−1 for doripenem.

This work presents a two-step method to reduce the energy consumption (in terms of the reboiler duty) of a natural gas sweetening process via a physical-chemical solvent mixture (Step 1) followed by a techno-economic analysis of 15 different absorber-stripper configurations (Step 2). Initially, an amine-based sweetening process using a H2S-free sour gas was simulated on Aspen HYSYS and the simulation results were validated against real plant data. In Step 1, different ratios of Sulfinol-M and Sulfinol-D based sweetening process were simulated and the superior physical-chemical solvent mixture that provides the lowest reboiler duty while meeting the sweet gas CO2 product concentration specification (i.e., less than 2 mol.%) is the Sulfinol-M solvent that contains 38 wt.% methyl diethanolamine (MDEA), 40 wt.% Sulfolane, and 22 wt.% water. This Sulfinol-M based model is then optimized via a parametric analysis to further improve its performance in terms of the reboiler duty prior to Step 2. The optimized Sulfinol-M based model achieved 65% saving in the reboiler duty while fulfilling the CO2 concentration specification in product gas relative to the base case. In Step 2, four main absorber-stripper configurations, namely absorber intercooling (AI), lean amine stream split flow (LASSF), rich amine stream split flow (RASSF), and mechanical vapor recompression (MVR) along with their 11 possible combinations were simulated in an attempt to decrease the energy consumption of the process and hence, ranked based on their total cost of production (TCOP). The results revealed that the integration of LASSF + RASSF provides the best option as it achieved the lowest TCOP of $4.60 M while fulfilling the CO2 concentration in product gas and contributed to 6.39% savings in the reboiler duty compared to the optimized conventional Sulfinol-M based model.

Wet torrefaction (WT), also named hydrothermal carbonisation (HTC), has been regarded as one of the highly studied thermochemical process pathways for biomass-to-solid fuel conversion in the last decade (2012–2021). Catalysts have been added in the WT or HTC of lignocellulosic biomass for various applications (i.e. solid fuel synthesis, carbon material synthesis, pre-treatment, sugar production, ash content removal, and the study of reaction kinetics). Regardless, there is no review on the addition of catalysts in WT to produce hydrochar as fuel, specifically on the role of catalysts in the formation of ‘secondary deposits’, which refers to deposits that have been observed on the hydrochar. This review discusses the fundamentals of WT and how the lignocellulosic biomass components in various biomass, operating process parameters, and catalysts affect the fuel properties of the hydrochar product. For catalytic WT and HTC, relevant studies in different yet interrelated applications are overviewed, where insights are given based on the effect of catalyst addition on the properties of hydrochar and the promotion of ‘secondary deposits’. The ‘secondary deposits’ established in carbon material synthesis studies can reveal the relationship between catalyst addition and formation. On top of that, it also serves as a complimentary knowledge to enhance the understanding of how these deposits can be used to increase the higher heating value of the hydrochar, which is lacking in the existing hydrochar synthesis studies. Therefore, the aim of this review is to provide insights into the addition of catalysts for the synthesis of hydrochar for fuel application.

Pyrolysis oil can be used as a precursor to synthesize value-added biochemicals. Co-pyrolysis of two or more feedstocks generally improves the selectivity and yield of the target compounds. In this work, oil palm trunk (OPT) was subjected to single-feed pyrolysis and co-pyrolysis with polypropylene (PP) from 500 to 700 °C. The highest pyrolysis oil yield of 26.33 wt.% was obtained from OPT at 700 °C, which mainly contributed by the lignin decomposition in OPT. Phenolics (51.77–57.78%) and oxygenates (36.31–46.99%) were the major compounds detected in the OPT-derived pyrolysis oil. The addition of PP enhanced the formation of hydrocarbons (5.19–10.22%) and decreased the contents of phenolics (34.01–41.85%) in the co-pyrolysis oil. In the case of co-pyrolysis, the intermolecular reactions between PP and OPT-derived radicals led to the formation of ketones and alcohols, which contributed to the increase of oxygenates content. The highest oil yield of 16.17 wt.% was obtained at 600 °C from co-pyrolysis, the oil of which contained mainly phenolic compounds, oxygenated compounds (i.e., ketones and furans), and hydrocarbons. These findings highlighted the potential of oil derived from the pyrolysis of OPT (single feed) and co-pyrolysis of OPT and PP (binary feed) for the production of value-added chemicals.

The demand for flexibility and rechargeability in tandem with high energy density, reliability, and safety in energy‐storage devices to power wearable electronics has translated to significant advances in flexible solid‐state Zn–air batteries (FSZABs) technology. FSZABs using self‐supported bifunctional air electrodes are currently one of the most attractive alternatives to Li‐ion battery technology for next‐generation wearable electronics. Unlike the conventional powder‐based air electrodes, self‐supported bifunctional air electrodes offer higher electron‐transfer rate, larger specific surface area (and catalyst–reactant–product interfacial contact area), mechanical flexibility, and better operational robustness. To realize their potential nonetheless, self‐supported bifunctional air electrodes should have high and stable bifunctional catalytic activity, low cost, and environmental compatibility. This review first summarizes the three typical configurations and working principles of FSZABs. Then, significant development of self‐supported bifunctional air electrodes for FSZABs and efficient synthesis strategies are emphasized. The review concludes by providing perspectives on how to further improve the electrochemical performance of FSZABs and their suitability for next‐generation wearable electronic devices.

Water pollution remains a critical concern, one necessitated by rapidly increasing industrialization and urbanization. Among the various strategies for water purification, membrane technology stands out, with polyethersulfone (PES) often being the material of choice due to its robust mechanical properties, thermal stability, and chemical resistance. However, PES-based membranes tend to exhibit low hydrophilicity, leading to reduced flux and poor anti-fouling performance. This study addresses these limitations by incorporating titanium dioxide nanotubes (TiO2NTs) into PES nanofiltration membranes to enhance their hydrophilic properties. The TiO2NTs, characterized through FTIR, XRD, BET, and SEM, were embedded in PES at varying concentrations using a non-solvent induced phase inversion (NIPS) method. The fabricated mixed matrix membranes (MMMs) were subjected to testing for water permeability and solute rejection capabilities. Remarkably, membranes with a 1 wt% TiO2NT loading displayed a significant increase in pure water flux, from 36 to 72 L m2 h−1 bar−1, a 300-fold increase in selectivity compared to the pristine sample, and a dye rejection of 99%. Furthermore, long-term stability tests showed only a slight reduction in permeate flux over a time of 36 h, while dye removal efficiency was maintained, thus confirming the membrane’s stability. Anti-fouling tests revealed a 93% flux recovery ratio, indicating excellent resistance to fouling. These results suggest that the inclusion of TiO2 NTs offers a promising avenue for the development of efficient and stable anti-fouling PES-based membranes for water purification.

The rapid development of textile industries in developing countries has resulted in enormous dye waste, which remains problematic in some areas due to the lack of advanced technology. Adsorption appears as an efficient method for treating dye waste, which often relates to the use of conventional activated carbons produced from non-renewable sources such as coal. On the other hand, biomass is greatly available in developing countries and represents as a cheaper carbon source in the production of activated carbon for dye waste treatment. This research addresses the potential of corn cobs as the raw material of activated carbon, where the synthesis of corn cob-derived activated carbon consists of chemical impregnation by phosphoric acid into corn cobs followed by the pyrolysis process at varied impregnation ratios and temperatures. The experiment showed that the development of pores was enhanced by increasing the pyrolysis temperature but heating beyond 550 °C may cause the pores to collapse. Besides, the optimum impregnation ratio was found to be 4.5:1 as the adsorption kinetics ceased to improve at higher ratio. In addition, the adsorption kinetics were well represented by the pseudo-second-order kinetics model, whereas further investigation revealed that intra-particle step existed but did not control the adsorption process. Moreover, multilayer adsorption is implied by the good agreement of the adsorption data with the Freundlich isotherm.

Abstract The support for the membrane is the basis for the preparation and application of the zeolite membrane. Moreover, its cost and properties directly determine the performance of the zeolite membrane and its industrial applications. A novel porous silicon carbide (SiC) support for zeolite membrane bonded with needle-like mullite (3Al2O3·2SiO2) was prepared using SiC powders as the raw material and kaolin, Al(OH)3, and AlF3 as the needle-like mullite precursor additives via an in situ high-temperature reactions in an air atmosphere. Effects of the support material composition and the sintering temperature on the sintering behavior, pore structure, permeability, and microstructure of the resultant supports were extensively investigated. The needle-like mullite formation consumed silicon oxide (SiO2) and generated a rigid skeleton structure with a good pore structure and bonding phase. Hence, the porous SiC support exhibited high porosity, with relatively large pore size and mechanical strength, which helped improve the support performance. Notably, the porous SiC support sintered at 1480 °C with in situ inter-particle needle-like mullite bonding exhibited excellent filtration and permeability performance. The porous support materials and methods used in this work are suitable for designing and preparing a novel porous SiC support for zeolite membranes.

The dataset reported in this article describes the adsorption isotherms of amoxicillin, ampicillin, and doripenem onto bentonite. Batch adsorption experiments were carried out on single antibiotic solutions with various dosage of bentonite across temperatures from 30 to 50 °C. The adsorbent loading dataset was later obtained by measuring the concentration of antibiotic solution at adsorption equilibrium via UV-Vis spectrophotometer. The dataset was also fitted using various isotherm models including Freundlich, Langmuir, Toth, Hill, and Dubinin-Radushkevich models to further analyze the adsorption behavior. On top of that, orthogonal regression was applied to avoid fitting biasness, whereby the fitting results revealed the highest adsorption capacities of 82.259 mg g−1 for amoxicillin, 78.851 mg g−1 for ampicillin, and 93.278 mg g−1 for doripenem using Langmuir model, which gave an accurate representation of the adsorption isotherm dataset that was consistent with the results of Toth and Hill model.

Over the past decade, the production of fluidised bed combustion (FBC) fly ash has overtaken that of pulverised coal combustion (PCC) fly ash, which provides near future opportunity for its use as a binder material for construction industry. FBC fly ash however exhibits different characteristics (i.e. morphology and chemical and phase compositions) to PCC fly ash. This review aims to overview the generic features of PCC and FBC processes that contribute to their unique product characteristics. The review then discusses and summarises the important characteristics of FBC fly ash and the reported variations in the literatures due to the different coal types and origins, which determine their binding application suitability. Comprehensive discussions are then made on the requirements, mechanisms, and product properties of the four most widely studied routes of using FBC fly ash as binder material, i.e. (i) adding Portland cement to form blended Portland cement; (ii) adding bauxite to form calcium sulphoaluminate cement; (iii) adding granulated blast furnace slag to form supersulphated cement; and (iv) adding alkali activator to form alkali-activated binder. Despite the vast potential of FBC fly ash, there are two key challenges, i.e. (i) lack of standard specification that caters specifically to various FBC fly ashes and (ii) high variation in the final cured product properties. This review will pave a pathway towards wider adoption of FBC fly ash for sustainable construction application.

In parallel with the departure from fossil fuel to more renewable resources, a more environmental-friendly and sustainable alternative, lignocellulosic biomass (LCB) has gained much research attention recently since it can be converted to numerous by-products, such as biofuels, biomaterials, and biochemicals. LCB, however, has recalcitrant nature, which often hinders its effective fractionation and subsequent conversion. Low transition temperature mixture (LTTM) is a relatively new class of green solvent that exhibits biodegradability, biocompatibility, and low toxicity, which can be prepared from abundantly available hydrogen bond acceptor and donor in nature. Given its high lignin solubility, LTTM has been applied to the LCB pretreatment to delignify the biomass and extract the lignin. This review seeks to overview the progress made over the last decade in LCB pretreatment using LTTM. Discussions are also presented on the mechanisms of the lignin extraction and the effect of the operating conditions with a summary of the performances from various LTTMs to provide a concise guide as to which LTTM at what operating condition can perform well for specific LCB. Despite its potential, the relatively young status of this technology warrants future works to enhance its commercialisation through (i) lowering the viscosity of LTTM by the addition of cheap solvent; (ii) enhancing the recyclability of LTTM; (iii) developing indicator to assess LTTM applicability for a specific LCB; and (iv) techno-economic and life cycle analyses.

Micro-organic contaminants in water have the characteristics of relatively low concentration and degradation, given their stable structures. Ecological balance and human metabolism can be severely affected by their accumulation in the food chain. Besides, extensive human activities and industrialization have accelerated their transmission and accumulation in the environment. So there is an urgent need to treat micro-organic contaminants in water. This review focused on the methods and mechanisms of removing micro-organic contaminants, including biodegradation, advanced oxidation, adsorption, and membrane separation. Notably, the application of membrane separation and its integrated technology in removing micro-organic contaminants, which is less covered in the previous studies. This review also introduced the previous study of developing modified ultrafiltration membranes for simultaneously removing both large- and small-molecule contaminants. These modified ultrafiltration membranes can be applied to remove micro-organic contaminants and are expected to broaden the application of ultrafiltration.

This study reexamined the possibility of improving the separation of binary azeotropic mixture containing tetrahydrofuran (THF) and ethanol from previous work (J Chem Technol Biotechnol 2015; 90: 1463–1472) that rely on the extractive distillation (ED) using ethylene glycol (EG) as solvent. Here, dimethyl sulfoxide (DMSO) is proposed as an alternative solvent for the ED, and its feasibility is preliminary screened and compared against the usage of EG. The conceptual ED using DMSO is designed by manipulating all the design variables until the minimum product specifications (i.e. purity) are achieved. Then, the conceptual design is further optimised using particle swarm algorithm to obtain the ideal column configuration and the performance is compared against the ED using ethylene glycol (EG) and pressure swing distillation (PSD) (i.e. best process) from previous work based on economic and CO2 emission. Overall, the optimised ED using DMSO provides 36% and 37% lower economic and CO2 emission with respect to the ED using EG. In comparison to PSD (i.e. best process) from previous work, it provides 24% and 25% reduction in TAC and CO2 emission. Lastly, a control structure is developed for the proposed ED using DMSO that can effectively handle ± 10% throughput and ± 5% feed composition disturbances without the need of a composition controller as in the case of previous work.

Partial oxidation of methane (POM) is a prominent pathway for syngas production, wherein the hydrogen in syngas product can be recovered directly from the reaction system using a hydrogen (H2)-permeable membrane. Enhancing the efficiency of this H2 separation process is a current major challenge. In this study, Ce0.8Y0.2O2-δ-BaCe0.8Y0.2O3-δ (YDC-BCY) hollow fiber (HF) membranes were developed and characterized for their H2 permeation fluxes. Firstly, YDC and BCY ceramic powders were synthesized using the sol-gel method, followed by the fabrication of YDC-BCY dual-phase ceramic HF membranes using a combined phase inversion–sintering process. Characterization using SEM, powder XRD, EDS, and electrical conductivity tests confirmed the phases of the prepared powders and HF membranes. Well-structured YDC and BCY powders with uniform particle sizes were obtained after calcination at 900 °C. With the addition of 1 wt.% Co2O3 as a sintering aid, the YDC-BCY dual-phase HF membrane achieved densification after sintering at 1500 °C. Subsequently, the influences of sweep gas composition and temperature on the hydrogen permeation of the YDC-BCY HF membranes with YDC/BCY molar ratios of 2:1, 3:1, and 4:1 were investigated. At 1000 °C and a sweep-gas flow rate of 120 mL·min−1, the YDC-BCY HF membrane with a YDC/BCY molar ratio of 4:1 exhibited a peak hydrogen flux of 0.30 mL·min−1 cm−2. There is significant potential for improving the hydrogen permeation of dual-phase ceramic membranes, with future efforts aimed at reducing dense layer thickness and enhancing the membrane material’s electronic and proton conductivities.

The challenges to commercialize biomass industry includes biomass supply shortage which is dependent on geographical location and seasonality. Most of the present biomass supply chain studies had not considered incorporation of supply chain uncertainties that may lead to overestimation of financial performance. Therefore, a hybrid framework was proposed via integration of stochastic Monte Carlo Simulation model with element targeting approach (Biomass Element Life Cycle Analysis, BELCA-P-graph model) to perform scheduling and economic analysis for the biomass supply chain. The BELCA-P-graph model aimed to generate a baseline for the feedstock ratio of each input biomass. This was then input into the stochastic model, capable of estimating the financial probability of the supply chain while incorporating supply chain uncertainties (i.e., biomass element characteristics, transportation-related parameters, raw material pricing, biomass availability, market demand, and selling price of final product). Results showed that biomass shortage had decreased the mean Net Present Value (NPV) of the base case scenario (without consideration biomass supply shortage) by 1.39%–12.21%. Storage capacity consideration had decreased the mean NPV by 11.59%–12.21%. The sensitivity analysis found that syngas demand and syngas selling price uncertainty offered significant impact on the mean NPV outcome.

Utilization of microalgae as feedstock has been increasingly gaining attention in recent years due to its capability to be cultured on site at the processing plant that reduces cost of transportation of feedstocks. Certain microalgae species also contain high lipid contents that make them a favourable feedstock for Fatty Acid Methyl Ester biodiesel production process. However, microalgae-based conversion process is still in its infancy. Extensive research on the feasibility study of the microalgae-based industry is critical prior to industrial-scale commercialization to prevent unexpected losses incurred. Therefore, this study aims to perform a preliminary Stochastic Techno-economic Evaluation on Microalgae-based Supply Chain with the incorporation of uncertainties. This is achieved by incorporating four uncertainties (i.e., product selling price, microalgae productivity, cost of microalgae, and conversion process efficiency) into a Monte Carlo Simulation model. Two types of microalgae species will be evaluated and compared in this study, i.e., Chlorella vulgaris and Nannochloropsis sp.. The outcome of this study found that Nannochloropsis sp. is more favorable with a higher mean NPV of USD 970.48 x 106 (higher than Chlorella vulgaris by 0.89 %) and lower standard deviation of USD 695.90 x 106 (lower than Chlorella vulgaris by 12.8 %). A probability-based financial result can allow users to better perform decision-making and analyzing the risk involves in the investment.

The deficiency of natural resources and serious climate change issues have driven the global community’s efforts to optimize energy planning using various process integration approaches. One of the keys to optimize energy planning is through horizontal cooperation among the entities that allows internal trading of resources. The inter-entities collaboration presents a great potential to further enhance the energy planning by attaining bill savings. The attainable bill savings are due to the reduction of conventional fuels, which increases the share of renewables that allows the internal sharing among the entities – P2P (Peer-to-peer) energy sharing concept. In this paper, a linear model of P2P energy sharing is presented and used to study the possible bill savings that different entities may achieve for different collaboration scenarios. The presented P2P energy sharing optimization model allows the synergies among different potential players and identify the most favourable collaboration opportunities. The proposed approach is presented using an illustrative case study in which three players with different energy profiles are considered in both non-cooperative and P2P energy trading cooperative scenarios. The results indicated that the most advantageous coalition enables all the players to mitigate their total electricity bills by MYR 1823.43/month (0.69 % reduction as compared to the non-cooperative scheme), without having one of the players compromising and has a total 40 % of carbon emission reduction goal.

The global effort to hasten the energy transition toward renewable energy challenged the major oil and gas (O&G) industry toward greener revolutionary changes. However, the complexity of the situation made the decision-makers contemplates to achieve a balance between economic and environmental sustainability. Circular economy (CE) is viewed as a potential alternative to pave a greener path for the O&G industry. In this work, retrofitting the O&G industry with biomass conversion technology is proposed to strategize toward a circular industry with the deployment of data-driven optimization approach. Multiple systematic analytical tools (e.g., multi-objective decision analysis (MODM), information entropy) are utilized to synthesize an optimal integration strategy. The developed model determines the optimal biomass retrofitting pathway by evaluating the performances (i.e., revenue, energy consumption, operating expenditure (OPEX), capital expenditure (CAPEX), carbon emissions) of various biomass conversion technologies. Based on the accumulated biomass technology data, the model assigns higher priority to CAPEX, (wj = 0.2764), which has higher sensitivity to change compared to the other criteria (wj = 0.2134 for carbon emissions, wj = 0.2073 for energy consumption, wj = 0.1824 for OPEX, wj = 0.1206 for revenue). The developed model recommends pyrolysis as the optimal pathway given its greatest overall performance score of 91.44 % from TOPSIS. This paper demonstrates the use of data-driven optimization adapting Shannon entropy and TOPSIS to determine the optimal biomass retrofitting pathway for O&G industry towards circularity.

The reactive-extractive distillation (RED) has the advantages of combining the beneficial features of both reaction and separation processes. Relative to the conventional reactive or extractive distillation-based processes, the RED is also less energy intensive as it relies on the reaction heat produced for the subsequent separation process. Therefore, the application of RED for ternary azeotropic separation has become the subject of popular interest, as evident by the increasing number of publications since 2020. This review paper is the first that puts together, in a chronological manner, all the existing studies on the RED to date, starting from the initial three column reactive-extractive distillation (TCRED) to the most recent dividing wall reactive-extractive distillation (DW-RED), for ternary azeotropic separation, so that the rapid progress in this area is summarised and any existing gaps in these studies become easier to identify for future work. The last part of this review provides three potential areas for future work, i.e. analysis of the sustainability of RED, combination of different process intensification strategies to improve the energy efficiency and separation performance, and further exploration on the control studies for the RED.

This study evaluates the effect of wet torrefaction of OPT under autogenous pressures at 3 different relatively low temperatures (i.e. 180, 200, and 220 oC) and extended residence times (i.e. 3, 6, 9, 12, 18, 24, 48, and 72 h) on the hydrochar's physical, chemical, and structural properties. Logarithmic-like increase of HHV profile was observed at the highest temperature of 220 oC, in which a plateau was reached at 24 h. Between temperature and residence time, temperature gave a more significant influence on the characteristics of the produced biochar. The HHV of the biomass sample increases from 16.4 MJ kg−1 in raw OPT to the highest HHV of 26.9 MJ kg−1 when torrefied at 220 oC for 72 h. Van Krevelen analysis shows dehydration was the primary reaction pathway that occurred during wet torrefaction of OPT at 180 oC for 24 h, 200 oC for 24 h, 220 oC for 6 h, and 220 oC for 12 h. Decarboxylation dominates the reaction when temperature and residence time was increased to 220 oC for 24 h, respectively. Further increasing the residence time to 48 and 72 h at 220 oC promotes demethylation as the dominant reaction. FTIR analysis reveals that most hemicellulose and parts of cellulose decomposed when OPT was subjected to lower temperature and/or residence time (i.e. 180 oC for 24 h, 200 oC for 24 h, 220 oC for 6 h, and 220 oC for 12 h). However, increasing temperature to 220 oC and beyond 24 h resulted in carbon-rich and lignin-dense hydrochar, which was observed in powder XRD results where graphite nitrate peak at 2θ of 7.4o appears. Morphology analysis reveals that most of the hemicellulose and cellulose-rich parenchyma was removed when subjected to wet torrefaction at 220 oC for 24 h. The formation of microspheres from the repolymerisation of 5-HMF was observed in large quantities in OPT hydrochar treated at 220 oC for 72 h. Inorganic elemental analysis shows that wet torrefaction of OPT effectively removes K and Cl from the biomass. The removal of K increased with increased temperature, which may partially resolve the corrosion problems in combustion reactions related to silicate deposition. OPT hydrochar from WT under autogenous condition and relatively low temperature exhibits much more improved fuel properties compared to raw OPT.

Oil palm biomass (OPB) represents major portion of the lignocellulosic waste in Malaysia that can be converted into bio-oil. This review aims to provide important insights in OPB-derived bio-oil production by first discussing the chemical compositions of different OPB and their effects to the bio-oil yield and quality obtained from pyrolysis process, followed by discussing the addition of plastics and catalysts into the pyrolysis for bio-oil upgrading, and lastly summarizing the existing technoeconomic and environmental studies and the potential use of process integration and intensification in this topic. Polypropene (PP), low density polyethylene (LDPE), and high density polyethylene (HDPE) have been commonly used in co-pyrolysis of OPB, which can effectively increase the heating value of bio-oil up to 80 % that of diesel. Likewise, acidic, basic, and neutral catalysts have been applied to increase the amount of hydrocarbon and phenol in the bio-oil, further improving the heating value to be comparable to diesel. The bio-oil production from OPB is currently still limited to demonstration scale despite the favorable environmental compatibility and technoeconomic feasibility shown by studies focused on empty fruit bunch (EFB). Several promising advanced pyrolysis processes that integrate other processes such as anaerobic digestion, hydrogen production process, and heat and power generation units as well as the advanced reactor designs are also overviewed here as future innovation of the bio-oil production from OPB, which may play more significant role as the technology matures.

In this work, the effect of wet torrefaction using conventional acid digestion vessel at three different temperatures (i.e., 180, 210, and 240 °C for 3.0 hours) and three different residence times (i.e., 2.0, 2.5, and 3.0 hours at 240 °C) onto the physicochemical, phase, and fuel properties as well as minerals content of EFB and OPT are evaluated. In both EFB and OPT cases, increasing temperature from 180 to 240 °C at 3 hours residence time and increasing residence time from 2 to 3 hours at 240 °C led to the reduction in the mass yield and an increase in the energy density. Generally, OPT hydrochar has lower mass yield relative to that of EFB. Van Krevelen diagram analysis reveals that EFB and OPT experienced dehydration and decarboxylation reactions. Such reactions reflect the occurrence of hemicellulose and partial cellulose decomposition during wet torrefaction as indicated by the changes in the intensities of several FTIR bands as a function of temperature and residence time and also by the changes in the intensities of the three XRD peaks at 2θ of 15.5, 22.7, and 34.6o representing crystalline cellulose phase when subjected to wet torrefaction at 240 °C for 3 hours. XRD peak analysis also indicates the presence of Si, Mg, and CaCO3 in the original and wet torrefied EFB and OPT. XRF results show that wet torrefaction at up to 240 °C for 3 hours can effectively remove K, Ca, and Cl from EFB and OPT and maintain S content at below 3 wt.%, which may partially resolve the slagging and agglomeration problems related to the EFB and OPT use in boiler as well as their SOx emission issue upon combustion.

Although room temperature ionic liquids (ILs) have emerged as potential next-generation electrolytes for their wide electrochemical stability window (ESW), the trade-off between this window and viscosity has hindered their widespread use in energy storage devices. Here, we present for the first time that such a trade-off can be balanced by mixing two ILs with the common anion ([NTf2]−) but different cations ([EMIM]+ and [N1114]+) together. The [EMIM] cation-based IL possesses low viscosity while the [N1114] cation-based IL exhibits wide ESW. Since the concentrations of each IL in the mixtures can result in different electrolyte properties, we demonstrate a systematic approach by exploring the properties of various concentration combinations. In addition, the corresponding cell voltage of their resulting graphene supercapacitors (SCs) accompanied based on the interaction between the binary ionic liquid and the electrodes, and the associated electrochemical performance were studied to determine the optimum electrolyte system for the highest SC energy density. The well-balanced viscosity/ESW trade-off is achieved in binary IL consisting 50 vol% [EMIM][NTf2] and 50 vol% [N1114][NTf2] as evident from the extraordinary electrode specific capacitance of 293.1 F g−1 and the ultrahigh SC energy density of 177 Wh kg−1, which approaches that of a lithium-ion battery.

Black silicon (b-Si)-assisted photovoltaic cells have textured b-Si surfaces, which have excellent light-trapping properties. There has been a limited amount of work performed on the theoretical modelling of b-Si photovoltaic cells, and hence, in this work, a coupled optical-electrical-thermal model has been proposed for the simulation of b-Si photovoltaic cells. In particular, the thermal aspects in b-Si photovoltaic cells have not been discussed in the literature. In the proposed model, the finite-difference time-domain (FDTD) method was used to study the optical response of the b-Si photovoltaic cell. Semiconductor equations were used for the electrical modelling of the cell. For the thermal model, the Energy Balance Transport Model was used. The developed model was used to simulate b-Si photovoltaic cells under thermophotovoltaic sources. The impacts of heat generation on the electrical performance of thermophotovoltaic cells are discussed. Simulation results from this study showed that black silicon layer improved efficiency and power output in thermophotovoltaic cells compared to thermophotovoltaic cells with no surface texture. In addition, heat generation due to Joule heating and electron thermalization in b-Si-assisted thermophotovoltaic cells reduced the open-circuit voltage and electrical performance.

In this work, the previously developed techno-economic framework in Kong et al. (2018) is extended to evaluate three different configurations of DRIZO process for natural gas dehydration: Case (i) – recycling of the regenerator overhead, Case (ii) – recycling of the flash vapour, and Case (iii) – recycling of both the flash vapour and the regenerator overhead into the dehydration system. The best configuration of DRIZO process is Case (iii), which is used as a representative case for subsequent comparison against other dehydration processes evaluated in our previous work. Our techno-economic analysis reveals that Case (iii) can regenerate tri-ethylene glycol (TEG) with the highest purity and the lowest TEG loss rate and volatile organic compound (VOC) emission. This translates to the lower water content in the dry product gas and also the higher HHV relative to Case (i) and Case (ii). A higher HHV generally signifies a higher gross profit margin. Nevertheless, DRIZO process is not economically feasible in comparison to the other dehydration processes from our previous work, mainly because of the high capital expenditure and the associated operating cost. Relative to the other dehydration processes, although the gross profit margin for DRIZO process is about $100,000 higher, it is not sufficient to compensate the high capital and operating expenses due to the high TCOP of about $500,000 to $600,000. Therefore, our analysis recommends the use of stripping gas dehydration process that consumes a portion of dry product gas to achieve the desired water dew point specification for its highest gross profit margin. Keywords: Dehydration, Glycol regeneration, Natural gas, Tri-ethylene glycol, Aspen HYSYS, Techno-economic analysis

The shortage of non-renewable power supplies and critical environmental issues such as climate change, urban sprawl, ozone layer depletion and excessive carbon emission are the main driving forces that urged many countries and non-profit organisations fully committed to seeking more sustainable energy sources and energy planning. Various Process Integration techniques have been developed, extended and utilized in the energy planning sector. Based on the literature review, the use of time-sliced based models in energy integration is still limited. This paper aims to develop time-sliced models that can be applied into an energy integration model that promises higher energy efficiency in power generation energy planning. To accomplish this, a two-stage framework involving (i) targeting and (ii) scheduling is proposed. The targeting step is to determine the minimum amount of renewable energy sources needed to meet the carbon emission limit whereas the scheduling step is to discover the optimal scheduling of introduced renewable energy sources to mitigate the total electricity bill. It is proposed that with the aid of adequate planning, the economic benefit of utilising renewable energy can be realized. A case study in Malaysia that incorporates an actual billing system is used to demonstrate the effectiveness of the model in reducing both carbon emission and energy cost simultaneously. With the use of the proposed framework and developed model, 46.9 % of electricity bill can be reduced while emission is reduced by 40 % compared to the initial emission.

Throughout the years, researchers and key stakeholders of the industries have been pursuing sustainable development in industries. It can be in the form of green processing whereby it aims to minimize the environmental emissions, energy consumption and replace the usage of chemicals as raw materials. Many industry players substitute the usage of chemicals for greener raw material in support of the shift towards green processing. One of the processes that has adapted to this shift is the palm biomass-derived ethanol production. However, limited works had incorporated supply chain uncertainties into the techno-economic studies of bioethanol production. Therefore, this paper aims to evaluate the impact of biomass supply chain uncertainties on the techno-economic feasibility of palm-biomass derived bio-ethanol production. To achieve this, a stochastic mathematical model, known as Monte Carlo simulation is developed. This model can generate a financial probability curve that reflects on the various supply chain uncertainties. This probability curve can provide users and investors a bird’s eye view of the potential losses induced by the uncertainties. A Sarawak case study is used to illustrate the effectiveness of the developed model that encompasses five supply chain uncertainties, such as bioethanol demand, bioethanol price, EFB price, EFB availability and transportation fuel price.

Catalytic dehydrogenation coupling of methane (DCM) represents an effective way to convert natural gas to more useful C2 products (C2H6, C2H4). In this work, BaCe0.85Tb0.05Co0.1O3-δ (BCTCo) perovskite hollow fiber membranes were fabricated by the combined phase inversion and sintering method. SrCe0.95Yb0.05O3-δ (SCYb) perovskite oxide was loaded as a catalyst onto the inner hollow fiber membrane surface, which promoted the CH4 conversion and the C2 hydrocarbon selectivity during the DCM reaction. The introduction of steam into the methane feed gas mixture elevated the C2 selectivity and yield due to the alleviation of coke deposition. Switching N2 to air as the sweep gas further increased the C2 selectivity and yield. However, the conversion of methane was limited by both the low permeability of the membrane and the insufficient catalytic activity of the catalyst, leading to low C2 yield.