50 Group 6 L-R: Wong Jie Shan, Ir Prof Dominic Foo and Woon Zhe Tao
51 Pinch-based approach for the optimisation of enhanced weathering and biochar application networks Zhe Tao Woon, Jie Shan Wong, Dominic Chwan Yee Foo, Yin Ling Tan Abstract: Carbon management systems that incorporate negative emission technologies (NETs) are essential in achieving international environmental standards, reducing greenhouse gas emissions, and addressing climate change. One such NET is enhanced weathering, which speeds up the naturally occurring process of mineral weathering in order to absorb carbon from the atmosphere. It relies on established technologies and, if commercially implemented through carbon management networks (CMNs), has the potential to sequester significant amounts of carbon. However, planning CMNs for enhanced weathering presents challenges similar to optimising supply chains for current product systems. In this paper, an extended pinchbased approach is presented, with the incorporation of grand composite curve (GCC) to accurately determine the system targets and CMNs for enhanced weathering. To illustrate these approaches, two case studies on enhanced weathering CMNs are presented, in which both case studies have shown positive results. The first case study on the GCC pinch analysis approach generated an entirely new and optimal CMN for the system while the second case study on the inter-region integration approach generated results that led to lower excess materials and unutilised sink capacity in both systems. In order to lessen change of climate in the forthcoming years and mitigate large amount of emissions for greenhouse gas (GHG), negative emissions technologies (NETs) will be required. One of the NETs that are related to the advancement of commonly-existing mechanisms is biochar (BC) application. BC has the benefit of depending on sophisticated part systems, as compared to other NETs. If implemented commercially via carbon management network (CMN), this technology offers the possibility of carbon sequestration from the atmospheric emissions at the range of several gigatons per year (Gt/y CO2). Despite that, formulating prospective CMN would pose equivalent difficulties as optimising supply chains for present output schemes. For the planning of CMN based on BC application, a pinch analysis (PA) approach is developed in this work. To obtain the optimal structure objectives and synthesise the respective CMN, PA is allowed to be applied by framing the planning process as a sink-source issue common in the implementation of process integration (PI). For this planning problem, the basic concepts of PA are proven to be applicable. To demonstrate this technique, a case study on BC application CMN is solved. Keywords: Grand Composite Curve (GCC); Carbon dioxide removal (CDR); Carbon management network (CMN); Carbon sequestration; Pinch Analysis (PA); Optimisation; Process integration (PI)
52 Group 7 L-R: Viggy Tan Wee Gee, Ir Prof Dominic Foo and Sitoh Yiann Yiann
53 Optimal reaction pathways synthesis using P-graph attainable region technique (PART) Yiann Sitoh, Viggy Wee Gee Tan Abstract: At the heart of process synthesis, developing a chemical reaction equation is considered the first and most crucial step. Over the years, many methods have been employed for process synthesis with a few standing out as more efficient methods. One of the methods is the attainable region (AR) theory. AR states that a region of all possible configurations can be defined with all the potential products and reactants. The second method is process network synthesis (PNS). PNS is a technique to optimise a flowsheet based on the feasible materials and energy flow. In PNS, a commonly used tool is the P-graph which could produce a fast and friendly optimal result for PNS problems. P-graph attainable region technique (PART) is introduced as an integration of both AR and P-graph to generate optimal reaction pathways for a given process. Several case studies were used for the study of PART in this paper, namely nitric acid synthesis and carbon dioxide hydrogenation. The reaction equation of a conventional nitric acid synthesis was generated using P-graph. All the solution structure was also digested and translated into process block diagrams and AR plot. The AR plot is a meaningful plot that consists of all optimal solution pathways. In the second and third case studies, the PART has indicated that carbon dioxide can be hydrogenated directly to form dimethyl ether and gasoline, respectively. The second case study has demonstrated the effect of temperature on carbon dioxide (CO2) hydrogenation using AR technique. The process that converts carbon dioxide to dimethyl ether is more thermodynamically favourable at lower temperature. The benefit of integrating the P-graph framework with machine learning model like decision tree classifier was also demonstrated in the third case study as it solves topological optimisation problems without scaling constraints. Optimal synthesis routes derived from P-graph’s mutual exclusion solver in the case studies were compared with reactions reported in literature and showed great correlation. The reactions collectively possess Gibbs free energy of not more than zero, and negative enthalpy of formation. With PART, the case studies have demonstrated that the synthesis of dimethyl ether and gasoline using CO2 hydrogenation via methanol intermediate and carbon monoxide intermediate from Fischer-Tropsch synthesis is feasible with no work and heat requirement. All case studies have demonstrated visual advantage of P-graph and data-driven applications.
54 Keywords: Attainable region; Process network synthesis; P-graph; Nitric Acid Synthesis; Carbon dioxide hydrogenation, Dimethyl ether synthesis, Gasoline synthesis
55 Group 11 L-R: Ang Xiao Tong, Prof Lam Hon Loong and Elida Ngu An Rong
56 Synthesis and optimisation of sustainability performance for palm oil biomass waste-to-wealth supply network with P-Graph approach Xiao Tong Ang, Elida An Rong Ngu, Hon Loong Lam Abstract: Palm oil, is one of the most widely used vegetable oils in the world and is a crucial ingredient in the food, cosmetics, and biofuel industries. However, its production generated a significant amount of biomass waste, including oil palm trunks (OPT), oil palm fronds (OPF), empty fruit bunches (EFB), palm kernel shell (PKS), mesocarp fiber (MF) and palm oil mill effluent (POME). This waste is traditionally disposed of through landfilling and open burning cases significant environmental pollution and greenhouse gas emissions. To address this issue, a waste-to- wealth (WtW) approach is proposed to utilise palm oil biomass waste as a resource to produce valuable products such as bioenergy, biorefinery, bioproduct etc through a variety of technologies. In this study, the P-graph approach is utilised to develop sustainable biomass network structures that promote circularity and profitability, while minimising environmental impact. The P-graph is a mathematical modelling technique that utilised a graphical-theoretical approach to optimise complex systems with multiple objectives and constraints. Therefore, it is widely used to optimise the design systematically by synthesising the supply chain network. Two scopes have been proposed in this study: (1) Sustainable circular economy (CE) in the palm oil industry and (2) Optimisation of biomass network in the palm oil industry with the consideration of economic and environmental perspectives. The objective of the CE analysis was to evaluate the circularity and profitability of the biomass WtW. This analysis demonstrated that there is a positive correlation between the circularity and profitability of the network which generated positive net present values for the palm oil industry. While the objective of the second scope was to assess the environmental and economic performances of palm oil biomass WtW network structures in terms of carbon emissions of the industry. As compared with the current practice of biomass waste management, the optimised solution structure has a huge reduction in the carbon emission rate with a positive gross profit which indicates its economic viability and minimises the environmental impacts. The palm oil biomass waste utilised as a resource of CE and carbon emission reduction can contribute to developing a sustainable palm oil industry.
57 The WtW approach provides positive economic benefits while reducing the environmental impact of palm oil production by converting the generated biomass waste to valuable products. In conclusion, the recycling of biomass waste provided a promising strategy for a CE and reduced carbon emissions in the palm oil industry. However, further research into this approach is required to fully exploit its potential in terms of economic and environmental benefits. Keywords: P-graph; Palm oil biomass; Waste-to-wealth; Sustainability.
58 Group 12 L-R: Nur Haziq Nur Misuari, Prof Lam Hon Loong and Lim Tau Hung
59 Integrated synthesis pathway of plastic for hydrogen production for a sustainable energy transition: A P-graph approach Lim Tau Hung, Nur Haziq Nur Misuari, Hon Loong Lam Abstract: Hydrogen production from plastic waste has emerged as a promising solution to address both the growing demand for clean energy and the environmental challenges associated with plastic waste management. However, it is a relatively new and developing method while further evaluation is necessary to improve the process pathway, particularly in terms of accessing its profitability and sustainability. This research introduces a comprehensive and systematic process network synthesis model to optimize the sustainable hydrogen production pathway using P-graph framework, to address the aforementioned issue. The study includes the incorporation of a sustainability index (SI) to the P-graph model to identify an optimal pathway that maximises profitability, alongside environmental and social aspects. In terms of sustainability evaluation, five different scenarios are evaluated to identify the optimal process pathway, including linear base model, self-sustainable circular model, circular model with environmental and social impact, and circular model with SI. The results show that plastic gasification followed by steam methane reforming and water gas shift reforming is the most sustainable pathway with an SI of 0.8407 and a gross profit of 533,431,000 USD/y. Another study incorporated combined heat and power (CHP) on the off-gas stream and a 10% hydrogen blend stream, while also considering carbon emissions was performed. The optimal technology selection was found to be catalytic pyrolysis integrated with steam reforming, which offers high conversion and low proportional capital and operating expenditures, resulting in a gross profit of 29,430,000 USD/y. The implementation of CHP generates steam and power that can be recycled or sold for revenue generation. When considering the carbon emissions in the case of technology selection and implementation of CHP, significant profit was observed with minor changes to the structure in the implementation of CHP. These two studies highlight the potential of using plastic waste for hydrogen production and offer insights into the optimization of sustainable and profitable pathways. By employing P-graph methodology and considering various sustainability aspects, the research provides valuable insights and strategies for tackling the challenges of plastic waste management while advancing the circular economy and meeting energy demands. This research is expected to be beneficial for decision makers, especially in the recycling industry to consider sustainable hydrogen production pathways from plastic waste while making a positive impact on the global environmental crisis. Keywords: Plastic to hydrogen production; P-graph optimization; Sustainability index; Power generation; Process network synthesis
60 Group 27 L-R: Cheah Yi Thung, Ir Dr Wan Yoke Kin and Ho Lih Yiing
61 A two stages fuzzy-game theory optimisation framework and a mathematical synthesis model for wastewater treatment plant (WWTP) in eco-industrial park (EIP) for palm oil industry Cheah Yi Thung, Ho Lih Yiing, Yoke Kin Wan Abstract: Sustainable development of rural areas and agriculture sector has become increasingly important due to the fast population and industrial growth. One of the significant challenges to sustainable development in rural areas is the problem of handling and allocation of wastewater generated in rural area. To treat the wastewater generated in rural area, a sustainable wastewater treatment plant (WWTP) is vital in order to comply with stringent discharge restrictions and protect the environment. In fact, wastewater is rich with nutrients. It is possible to recover the nutrient from the wastewater and reuse it in agriculture sector. Designing a well-established and sustainable WWTP associated with nutrient recovery technology is not an easy engineering task. Elements such as the operating cost and carbon emission of each technology selected have to be addressed when synthesising WWTP. Meanwhile, to ensure sufficient supply of nutrient resources for agriculture sector in rural areas is another challenge for sustainable growth. Resources exchange becomes important in rural areas. Hence, the concept of EcoIndustrial Park (EIP) could be applied for sustainable development of rural area. Different parties or companies could be cooperated to gain maximum profit by exchanging resources and utilities with their partners in EIP while supplying sufficient utilities and resources to the rural area to promote sustainable development, especially the economic and environmental sustainability. However, optimum resources allocation needed to be predetermined to ensure there is a positive profit for EIP while minimising negative impacts to the environment, for example, the carbon dioxide emission. In that context, by mathematical modelling using superstructure based, this paper aims (i) to deliver a decision-making tool to choose the suitable technologies for WWTP synthesis along with nutrient recovery technologies taking into consideration of economic and environmental factors while comply with discharge limit and (ii) develop a two-stage systematic framework with adaptation of game theory and Fuzzy Multi Objectives Optimisation (FMOO) to allow parties in EIP determine the beneficial cooperating parties based on their objectives.
62 As this study considers multi factors, Fuzzy Multi Objectives Optimisation (FMOO) is employed in the work, and it is adapted to figure out the most optimum resources allocation and exchange in EIP and technologies for WWTP synthesis based on the objectives. A palm-based industrial case study is implemented in the study. The case study has been solved using a commercialised optimisation software, Lingo V20.0. Keywords: Eco-Industrial Park (EIP); Fuzzy Optimisation; Game Theory; Mathematical Model; Palm Oil Mill Effluent (POME); Resources Recovery and Allocation; Wastewater Treatment Plant (WWTP)
63 Group 26 L-R: Ashley Tan, Chio Foo Yoong and Cheng Yin Shuen
64 Characterisation of co-precipitated nickel manganese oxide catalysts: Effects of preparation and ultrasonic conditions with nickel recovery optimization through acid leaching Cheng Yin Shuen, Chio Foo Yoong, Tan Ashley Abstract: Nickel manganese oxide (Ni-MnOx) catalysts were synthesized by the coprecipitation procedure for selective catalytic reduction (SCR) of nitrogen oxides (NOx) at low temperature and for methane dry reforming (DRM). The impact of various preparation conditions including precipitation pH, precipitation solution [Ni]/[Mn] ratio and calcination temperature as well as different ultrasonic parameters namely ultrasonic amplitude, irradiation period and pulsing pattern on the characteristics of the catalysts were investigated. To reduce precious metal waste, this research aims to investigate the effects of stirring speed, temperature, solid to liquid ratio, acid concentration (vol%) and digestion time on rate and efficiency of acid leaching for Ni metal recovery. Characterisation of the catalysts were conducted using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halendar (BJH) as well as scanning electron microscopy and energy dispersive X-ray (SEMEDX) to analyze their structural and morphological characteristics. The optimal preparation conditions were found to be 0.5/1 solution [Ni]/[Mn] ratio precipitated at pH 9.0, proceeded by calcination at 500°C for 8 h. Amorphous Ni-MnOx catalysts consisting of the mixed oxide phase, NiMnO3 and exhibiting high specific surface area were formed using these preparation conditions which are essential factors for excellent catalytic activity. It has been proven that the characteristics of the catalysts were significantly influenced by their preparation conditions. Moreover, incorporation of ultrasonication during catalyst preparation enhanced the catalysts’ characteristics. XRD results showed that ultrasonication promoted the formation of NiMnO3 with decreased crystallinity. SEM results showed that ultrasonication smoothens the catalyst surface and suppresses particle agglomeration, forming a more uniform and dispersed catalyst phase. EDX results suggested that ultrasonication resulted in higher active metal and lower oxide content in catalysts. BET results showed a significant increase in BET specific surface area, pore volume and pore size distribution of catalysts with ultrasonication.
65 Optimal sonication intensity and irradiation period is crucial to prevent catalyst damage. For Ni metal recovery, the optimal conditions were stirring speed of 700rpm, leaching temperature of 80oC, solid to liquid ratio of 1:10, acid concentration of 30vol% and a digestion time of 6 hours. By using these optimal leaching parameters, AAS was used to detect the nickel concentration in the leached sample where a nickel percentage recovery of 90.53% was obtained, the economic analysis was conducted, showing a net profit in terms of recycling the spent catalyst. The results can contribute to the development of obtaining a more efficient leaching process towards the recovery of heavy metals from spent catalysts. Keywords: Catalyst preparation condition; Ultrasonic irradiation; Co-precipitation; Nickel manganese oxide catalyst; Characterisation; Nickel recovery; Optimization of acid leaching
66 Group 24 L-R: Ramanath Tamelarasan, Dr Suchithra and Ooi Poh Lae
67 Hydrothermal operations for biofuel and gas sensor applications Ooi Poh Lae, Ramanath Tamelarasan, Suchithra Thangalazhy Gopakumar Abstract: Though hydrothermal processes are widely accepted for many applications, there is still continuous research on alternative processes to reduce the risk of hydrothermal processes. In this project, modifications/replacement of hydrothermal operations were investigated for two applications. The use of biomass as a solid fuel poses several issues that need to be tackled. Wet torrefaction, which involves the treatment in hydrothermal conditions enhances the fuel properties of the biomass. One of the objectives of this research was to study the effect of hydrogen peroxide (H2O2) as an oxidant for the wet torrefaction of palm kernel shell (PKS). The presence of an oxidant can achieve effective biomass pretreatment at lower temperatures than normal wet torrefaction. The effect of H2O2 dosages from 0.0 M to 1.0 M at 200 °C was investigated. The average HHV was 21.62 MJ/kg for different H2O2 dosages which was almost similar to normal wet torrefaction. The XRD analysis indicated the absence of crystalline structure in the torrefied PKS. Therefore, it was concluded that H2O2 did not make a substantial contribution to further enhancing the solid fuel properties during the wet torrefaction processes; instead improved dissolution. The second objective was to develop a semiconductor metal oxide (SMO) electrode to detect acetone gas which is present at high levels in the exhaled breath of diabetic patients. The current research aimed to synthesise H-doped WO3 at ambient conditions via an ultrasonication-assisted hydrogenation route. A preliminary optimisation study was performed to determine the most desirable sonication conditions (50 minutes at 100% power) for the lowest polydispersity index and particle size in WO3 dispersion. Besides, the independent effect of other factors on hydrogenation was studied. These include synthesis temperature (room temperature to 80°C), zinc precursor loading (0.8 to 2.0), and alternative precursor (copper). The H-doped WO3 sample was subsequently subjected to diluted acetone sensing performance. The sample showed a significant reduction in resistance towards diluted acetone of 1000 ppm compared to undoped WO3. Thus, findings from this work offer a potential room temperature-based synthesis method for acetone detection at lower concentrations. Keywords: Wet torrefaction; palm kernel shell; hydrogen peroxide; ultrasonication; tungsten trioxide; acetone sensing
68 Thank You and Best of Luck Students!