We present the design and evaluation of a simulation-based learning approach implemented in a second-year chemical engineering module, integrating Aspen HYSYS with a methanol production case study to embed sustainability and develop student awareness of the United Nations Sustainable Development Goals (SDGs). Through process simulation, we enable students to model complete flowsheets, explore scenario-based analyses, and evaluate sustainability-driven process modifications. Within a structured mini-design project involving reaction and separation systems, we require students to analyse mass and energy balances, optimise process performance, and evaluate trade-offs between efficiency and sustainability. We also ask students to identify and justify relevant SDGs within their designs. Our analysis of student outputs shows improved ability to link engineering decisions with sustainability objectives, enhanced energy-focused reasoning, and stronger systems-level thinking. Overall, the results highlight the effectiveness of simulation-based learning in integrating technical competence with sustainability literacy in undergraduate chemical engineering education.

Global demand for palm oil has risen due to its widespread use in the food industry, low production costs, and socioeconomic benefits, leading to increased production and significant waste generation in the form of empty fruit bunches (EFB). A sustainable solution is the production of acetophenone (AP), a reliable octane booster, through the catalytic hydrogenation of lignin derived from EFB, offering an alternative to the conventional ethylbenzene oxidation process. Yet, no environmental assessment has been performed on the proposed route to identify the impact of the emissions generated during the proposed AP production. In this study, for the first time, a life cycle assessment (LCA) of production of octane booster components derived from EFB is generated. There were four stages in the LCA: (i) goal and scope; (ii) life cycle inventory; (iii) life cycle impact assessment; and (iv) data interpretation. The environmental performance was assessed in several impact categories, with the global warming potential (GWP) value of 3.58 kg CO2-eq/kg AP. The results showed that total electricity consumption is the main GWP drivers. This study also revealed that the result of AP production from lignin does not deliver lower greenhouse gas emissions under the current process configuration when compared with several fossil-based octane boosters. Finally, sensitivity and Monte Carlo analyses were performed to evaluate the key LCA model parameters for potential improvements. These analyses revealed that the GWP score of the lignin-based octane booster ranged from 3.09 to 4.15 kg CO2-eq/kg AP, influenced by total electricity consumption. Hence, reducing energy consumption in AP production could lead to a remarkable decrease in the GWP making this process more sustainable. Process flow diagram of valorisation of palm oil empty fruit bunch into octane booster component.

This paper introduces a novel approach to optimizing reactive distillation (RD) process before heat-integration (HI) to achieve greater energy savings in the subsequent heat-integrated configuration. While conventional approaches prioritize minimizing "overall energy consumption" before implementing HI, this study proposes minimizing the energy consumption of the RD column (RDC) first prior to HI to achieve more significant energy savings. Heat-integrated neat design RD and thermally coupled reactive distillation (TCRD) were investigated in this study. By comparing two scenarios, i.e., First scenario; minimizing overall energy consumption and Second scenario; minimizing the energy consumption of the RDC before HI, our findings demonstrated that the latter approach consistently achieves higher energy savings, ranging from 31.64% to 46.08% relative to the base case, following HI. Additionally, we observed that the hybrid heat-integrated configuration in our study has a higher energy consumption than the double-effect configuration. This was attributed to their shared dependence on RDC after HI. Altogether, our findings challenge conventional practices and offer an alternative pathway to enhance energy efficiency in industrial processes.

The purpose of this paper is to explore the possibility of extending a new perspective previously identified for neat design (DOI: 10.1016/j.seppur.2024.131201) to the excess design of reactive distillation (RD) configurations. In earlier research, we proposed to minimize the energy consumption of the RD column (RDC) prior to heat-integration (HI), instead of the conventional method of minimizing overall energy consumption, to achieve a more significant energy savings. This study extends the investigation to two specific configurations, i.e., excess design (1) RD and (2) thermally coupled reactive distillation (TCRD). The purpose of exploring such extension is because the excess design of RD is different from those of neat design due to the additional degree of freedom (DOF) available, such as the purity of recycled component. Our findings revealed that, minimizing the energy consumption of RDC results in higher energy savings for excess configurations. Post HI, the excess design RD and TCRD achieved energy savings of 27.65% and 27.55%, respectively, compared to the conventional RD base case. Furthermore, our study highlights the importance of considering XLLK-R as a design variable when performing process optimization for excess design.

Liquid marbles are soft matter objects characterised by a liquid droplet enclosed within a hydrophobic particle coating, preventing wetting. This distinctive structure serves as active sites for solid-liquid-gas reactions. However, the impact the chosen coating material has on liquid marble stability, particularly regarding the number of coating layers and material wetting, remains uncertain. There is a need for a modelling approach to predict the overall lifetime considering these coating characteristics. This study reveals that for PTFE liquid marbles evaporating at ambient temperature, smaller coating particles (250 nm) extend their lifetime by forming a multilayered coating. Conversely, using larger particle sizes (200 μm) results in the formation of monolayer liquid marbles with shorter lifetimes than their equivalent naked droplets. Additionally, a higher number of particle layers and a larger contact angle generally enhance the liquid marble's lifetime. For multilayered liquid marbles comprised of smaller particles (250 nm), the particle contact angle is found to have a more significant impact than the number of layers on lifetime extension, whereas the opposite holds true for larger particle sizes (20 μm). A modelling approach using the reactor engineering method for liquid marble evaporation demonstrates excellent agreement with experimental results, yielding an R2 of 0.996. The implementation of this specific model, capable of assessing lifetime across various physical modifications, will enhance our understanding of liquid marble properties before their application in biomedical, microreactor, and green technologies.

In this study, a comprehensive process for production of an environmentally friendly octane booster (acetophenone) from lignin is presented, along with a detailed techno-economic analysis. Recognizing that much of the prior research on octane boosters has been confined to experimental lab-level investigations, this study develops comprehensive process design to unravel the intricacies of large-scale acetophenone production. The acetophenone production process involves catalytic hydrogenolysis, which also yields phenol as a valuable side product. Based on the process flow diagram, mass and energy balances were developed, revealing significantly improved yields and purity of acetophenone compared to industry standards, reaching 0.74 kg acetophenone per kg of lignin and 99 wt%. In the techno-economic analysis, calculations involving fixed capital investment (FCI), operating costs, and working capital were conducted based on a feed of 100 kg/h of dry lignin. The results indicate FCI at 2.72 million USD, operating costs at 1.09 million USD per year, and working capital at 0.57 million USD. Assuming a 20-year operational lifespan, the payback period is estimated at 6.09 years, as depicted by the cumulative cash flow diagram. Moreover, techno-economic analysis demonstrates a net present value (NPV) of 3.24 million USD at a 10% discount rate, an internal rate of return (IRR) of 22.73%, and a return on investment (ROI) of 34.39%. These positive outcomes underscore the robust profitability of the proposed acetophenone production plant derived from lignin. Additionally, a sensitivity analysis on the IRR indicates that increasing the production capacity could further enhance profitability, reaffirming the feasibility of the plant’s operation. Crucially, this study highlights the potential for sustainable and economically viable production of acetophenone, offering an environmentally friendly alternative to toxic octane boosters and advancing the development of sustainable fuel additives. Graphical Abstract

The spatial reaction engineering approach (S-REA) was used to simulate hot air drying of sawdust. The studies extended the previous work reported in literature where the sawdusts were dried using hot air at 70 degrees C, 80 degrees C, and 90 degrees C. The simulated results were found to agree well with the experimental moisture content (R-2 > 0.98) and temperature (R-2 > 0.82) profiles. In a further analysis using S-REA, the spatial profiles of moisture content and vapor concentration were generated to understand better the physics behind. Simulation also revealed that the external mass transfer resistance was more dominant as compared to the internal diffusion resistance. The vapor concentrations were observed peaked at time range of about 10 800- 18 000 s and dropped thereafter upon further heating. This observation could be supported by the variation in the vapor effective diffusivities where peak diffusivity values typically occur after most of the moisture evaporates towards the end of drying.

In light of environmental issues, lignocellulosic empty fruit bunch (EFB) biomass is promoted as a carbon–neutral, environmentally friendly, and renewable alternative feedstock. A comprehensive environmental assessment of EFB biorefineries is critical for determining their sustainability in parallel with the bioeconomy policy. Nonetheless, no life cycle assessment (LCA) has been performed on co-producing food and biochemicals (furfural and glucose) derived from EFB biomass. This research is the first to evaluate the environmental performance of the furfural and glucose co-production processes from EFB biomass. Environmental analysis is conducted using a prospective gate-to-gate LCA for four impact categories, including global warming potential (GWP), acidification (ADP), eutrophication (EP), and human toxicity (HT). Aspen Plus is used to simulate the co-production process of furfural and glucose as well as generate mass and energy balances for LCA inventory data usage. The findings suggest that the environmental footprint in respect of GWP, ADP, EP, and HT is 4846.85 kg CO2 equivalent per ton EFB, 7.24 kg SO2 equivalent per ton EFB, 1.52 kg PO4 equivalent per ton EFB, and 2.62E-05 kg 1,4-DB equivalent per ton EFB, respectively. The normalized overall impact scores for GWP, ADP, EP, and HT are 1.16E-10, 2.28E-11, 6.12E-10, and 2.18E-17 years/ton of EFB, respectively. In summary, the proposed integrated plant is not only economically profitable but also environmentally sustainable. In the attempt to enhance the Malaysian economic sector based on the EFB, this study has the potential to serve as an indicator of the environmental sustainability of the palm oil industry.

This study aims to propose a new process design, simulation, and techno-economic analysis of an integrated process plant that produces glucose and furfural from palm oil empty fruit bunches (EFB). In this work, an Aspen Plus-based simulation has been established to develop a process flow diagram of co-production of glucose and furfural along with the mass and energy balances. The plant’s economics are analyzed by calculating the fixed capital income (FCI), operating costs, and working capital. In contrast, profitability is determined using cumulative cash flow (CCF), net present value (NPV), and internal rate of return (IRR). The findings show that the production capacity of 10 kilotons per year (ktpy) of glucose and 4.96 ktpy of furfural with a purity of 98.21 and 99.54%—weight, respectively, was achieved in this study. The FCI is calculated as United States Dollar (USD) 20.80 million, while the working and operating expenses are calculated as USD 3.74 million and USD 16.93 million, respectively. This project achieves USD 7.65 million NPV with a positive IRR of 14.25% and a return on investment (ROI) of 22.06%. The present work successfully develops a profitable integrated process plant that is established with future upscaling parameters and key cost drivers. The findings provided in this work offer a platform and motivation for future research on integrated plants in the food, environment, and energy nexus with the co-location principle. Graphical Abstract

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.

Drying process has been employed since ancient times to preserve agricultural products by reducing the moisture content. Solar dryer is one of the most commonly used dryers due to its availability, reliability, and environmentally friendly nature. It is practical in rural areas since solar dryer can be fabricated with a simple design. Despite its potential, designing a long-term, feasible solar dryer is challenging without a good understanding of its performance parameters, such as energy, exergy, economic, environmental (4E) aspect, and its impact on product quality. Therefore, many attempts have been dedicated to conducting these analyses. Nonetheless, the information obtained is only one-dimensional, and they do not reflect the actual behaviour of a solar dryer. This paper aims to provide a comprehensive and critical review of the additional 3E parameters, namely energoeconomic, exergoeconomic, and enviroeconomic. Moreover, the effect of solar drying on product quality parameters (Q) will be discussed. Furthermore, a new idea to perform energy, exergy, environmental, economic, energoeconomic, exergoeconomic, and enviroeconomic (7E) and quality analysis (7E + Q) is proposed and outlined to improve the operability of the solar dryer. It is envisaged that 7E + Q analysis will pave the way for more effective and efficient solar dryers.

This study evaluated the energy saving potential of process intensified double column reactive extractive distillation (DC -RED) through three case studies. The results showed that process intensified technologies, thermally coupled reactive extractive distillation (TC-RED) and dividing wall reactive extractive distillation (DW-RED), did not yield any energy savings compared to conventional DC -RED. Contrary to the expectation, the elimination of the remixing effect in the process intensified DC -RED did not lead to any energy savings. Further analysis revealed that the remixing effect was not significant enough to achieve energy savings through process intensification, and the strong reaction exotherm in DC -RED reduced the potential for energy saving. Additionally, the higher interconnection flowrate in TC-RED and DW-RED resulted in higher energy consumption due to the increased boil -up ratio. Moreover, the lower feed temperature to the solvent recovery column (SRC) led to less energy efficiency and larger reboiler duty. An alternative energy saving scheme was proposed by adding a heat exchanger (HEX). The addition of HEX led to energy savings of 37.23 % in Acetonitrile (ACN)/Isopropanol (IPA)/Water separation, 45.62 % in Ethyl Acetate (EA)/Ethanol (EtOH)/Water separation, and 39.21 % in IPA/ EA/Water separation.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Ching Lik Hii, Choon Lai Chiang, Aditya Putranto; Modelling heat and mass transfer processes during drying: Empirical, theoretical and reaction engineering approach. AIP Conference Proceedings 24 January 2023; 2586 (1): 060011. https://doi.org/10.1063/5.0105710 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

Background Here we analysed the possibility of improving the sustainability performance for the recovery of dichloromethane and methanol from a binary azeotropic mixture using different energy-intensified extractive distillation-based processes: side-stream extractive distillation (SSED), thermally coupled extractive distillation (TCED), and extractive dividing wall column (EDWC). The sustainability performance of the different processes was analysed based on three main factors: total annual cost (TAC), CO2 emissions, and condition number. Results The EDWC was found to give the best improvement in terms of TAC and CO2 emissions by about 18% and 21%, relative to conventional extractive distillation (CED). These however were traded-off by the increase in conditional number (CN) by 186 times, signifying a complex dynamic characteristic for the EDWC. Thus, the SSED was suggested as an alternative sustainable option as it also provides significant improvement in TAC and CO2 emissions by about 11%, and 18% with respect to the CED, whilst providing the least reduction in operational controllability, as evidenced by the marginal increase in the CN of about 1.5 times. We also investigated the dynamic performance of the SSED and found that the SSED provides identical dynamic performance in handling both +/- 10% throughput and +/- 5% feed composition disturbances as those of the CED. Conclusion Among the different processes, SSED is the best sustainable alternative that provides compromised steady-state (i.e. TAC and CO2 emissions) and dynamic (i.e. control) performance for the recovery of dichloromethane and methanol. (c) 2022 Society of Chemical Industry (SCI).

For better understanding of transport phenomena, local evaporation rate and water vapor concentration should be taken into consideration when predicting drying behavior. However, to the best of our knowledge, there is no model which explicitly represents this. Predictive modeling of combined infrared-heating and hot air drying (IR-HAD) is useful to assist in designing new dryer units and manufacturing the products with desirable quality. As the quality changes are basically local phenomena, the model should be able to capture the local evaporation rate. In this study, for the first, time, spatial reaction engineering approach (S-REA) was developed and used to describe infrared-heating drying of the food materials by using the reaction engineering approach (REA) to represent local evaporation rate. Benchmarks against the single-phase approach and the results showed that the S-REA gave high accuracy toward the experimental data (R-2= 0.978-0.999). The S-REA successfully provided reasonable predictions of two-dimensional (2 D) profiles of moisture content, concentration of water vapor and temperature. This highlights the accuracy of the REA framework to describe the local evaporation rate during the infrared-heating. The REA-based predicted variables can then be applied to project the local quality parameters for quality assurance in food processing. The model is also ready to be used to audit energy demands in drying systems.

Recent trend in consumer preferences toward healthy and on-demand-to-make items has mandated food manufacturers to seek more efficient production processes in order to make their businesses sustainable. For powder producers in particular, the business models are drifting from 'ready-made' toward on-the-go items, thus requiring an urgent attention. Here, we present a long short-term memory (LSTM) model for forecasting drying kinetics histories of lactose, low-fat and high fat milk droplet solutions; covering a wide gas-and-material spectrum, utilizing only their initial conditions. Within the examined range, results show that the forecast lactose temperature and mass drying curves have accuracies within 0.9987 and 0.9841 respectively; that improve in the order of training-material-blend/training-data-rows as thus: lactose/3612, lactose-fat/4515, lactose-protein/5317 and lactose-fat-protein/6220. This indicates the impact of data size on the model accuracy and generalization of the trained LSTM network. For low/high fat milk (20–30% total solid), accuracy margins are within 0.0179 and 0.0655 in the range of 1–8 combined test samples. Beyond 8 samples up to 20 combined scenarios, accuracies are capped at 0.9749 for temperature and 0.9000 for mass profiles. Since only the initial conditions are required by the developed model to provide forecasting, this removes cost and time barriers inherent in traditional approaches during new product launch. Future application of deep learning models would integrate the presented LSTM network to consider actual characteristics of material mixing such as colour, texture and taste.

Recycling of waste plastics has become vital due to the threat to the environment the huge piles of those wastes represent, with research revealing High-Density Polyethylene (HDPEs) as the most dominant waste plastics. Because of their dominance and significant environmental impact, this paper reports the economic potential of recycling HDPE waste plastic into liquid fuels via pyrolysis. A risk and benefit assessment are presented to highlight whether the process has reasonable potential prior to the analysis of its corresponding finances. Aspen HYSYS simulation models were used as the basis for the analysis. From this, preliminary cost estimations for the net present value (NPV) of the process, its economic viability, were determined. It is shown that 100 kg/h of waste is not financially sustainable. Retailing the fuel product at a competitive price of £60/barrel would ultimately bankrupt the business. This is a consequence of the extremely high production cost of £198.40/barrel inducing the complete absence of profitability. Furthermore, the operating expenditure is found to be the root cause of the consequential financial decline, totalling £1.46 million per annum. The two most detrimental expenditures for the production cost of the pyrolysis oils were the wages of the skilled operating labour and higher utility fees incurred by the extreme temperature conditions. In addition, an unrealistically optimistic sale price of £300/barrel was also applied to ascertain a positive economic incentive. Even with the increased retail price, the process’ profits are negligible and further highlight the detrimental effect of the undesirably high operational expenditures, once more signifying that the process should not commence in its current state. However, executing such a project in developing countries such as Sierra Leone, Senegal, or Kenya where utilities and manpower, among other operational components, are cheaper, is believed to complement the immense opportunity underlying pyrolysis oil production regarding production quantity and quality.

Shrinkage parameters of highly shrinkable materials such as length, diameter and surface area during drying are difficult to quantify in situ . However, these are significant components of an accurate model. In this study, an attempt to isolate the surface area effect is reported in order to fetch the REA model (reaction engineering approach) parameters without knowing it a priori . Carrot cube and cabbage leaf were selected as experimental material and dried with hot air under a range of conditions. Shrinkages was calculated using an optical method which is used to qualitatively compare with that “calculated” using the current approach. By matching the experimental temperature and moisture content profiles against time after obtaining REA parameters for both samples without knowing the surface area, the surface areas can be “calculated” numerically. Surface area was found to be affected by sample temperature as well as the moisture content. Drying simulations can be well carried out when correlating the surface area against sample moisture content X and temperature T , and it provides the best accuracy in predicting data on T and X vs. time. In addition, carrot cube can shrink ideally while cabbage leaf cannot. The overall relative errors of predicted moisture content and temperature were less than 1%.

REA drying kinetics model has been widely examined for different materials and different operating conditions. Vacuum drying, due to its uniqueness, it presents a challenge for setting up the REA parameters, in particular the specification of the equilibrium activation energy value corresponding to each set of environmental condition. Here, the basic kinetic parameters derived from a convective drying run, is used while the effect of vacuum is captured by the equilibrium activation energy. Upon validation against the experimental data, REA is shown to be applicable. A comparison between the vacuum drying and the convective drying of the same material is also made. The vacuum drying at higher vacuum levels has been predicted, showing the expected behavior. It has been shown that REA is flexible and can be used in vacuum drying related design and optimization studies.