Development and evaluation of open-ended learning activities to support chemical engineering students' development

There are myriad challenges in developing a stimulating yet supportive curriculum in many subject areas, and recent shifts in course entry demographics and employer expectations have made this especially challenging in chemical engineering. As a discipline, there has been a gender shift in recent years towards greater women student representation at undergraduate level and an increase in global industry sector demand for chemical engineering graduates. This has raised issues of inclusion, to allow women students to participate equally in learning activities and wider opportunities, as well as those of graduate skills development, tempered by reports from the Confederation of Business Industry, which indicate that employers are dissatisfied with the skill sets offered by graduates.;This work sets out to address these concerns through evaluation of active learning and makes recommendations regarding integrated learning, where group work is used to develop students' professional competencies in tandem with their transferable skills. Engineering education has developed over the years to include many instances of group based working that focusses on problem based learning, however, the full extent of the impact that this may have on students' development is little understood or studied. This thesis explores the role of problem-based learning in facilitating students' engagement with specific components of a chemical engineering degree within UK Higher Education, including surveys of staff and student perceptions of group working and skills development, statistical evaluation of student attainment and appraisal of course (re)design.;Despite significant group work and problem based learning focussed on developing openended working, teaching staff identified issues with students' abilities to deal with such problems in chemical engineering and to accept open-endedness itself. By identifying openendedness as a threshold concept, it has been possible to study the impact that the timeline of teaching has on student development and achievement. This work presents a strategy for vertical alignment of teaching within the chemical engineering degree to support student development and foster student confidence and autonomy.;Within this context, the use of group working is key and the thesis also investigates the role of tutors within this educational framework and how such activities impact on the inclusion of women in engineering subjects. Additional work to redevelop early years teaching to address the identified threshold concept and, specifically, its role in the capstone design project is reported and students' perceptions of skills development has been investigated to understand the impact that working in such an environment has on the transferable skill sets of these cohorts.;The insights gained show that tutor supported problem based learning can be key in nurturing critical evaluation skills in students, often requiring them to explain their reasoning and work with unknown quantities. The role of women students in group working changes with their increased awareness of social expectations to adapt to normalised views of women's roles; this happens early in their University career and sets working parameters for the remainder of their degrees, so addresses the early imbalance in role assignment that may be observed. The successful incorporation of problem based learning activities in early years helps students overcome the liminality that results from open-ended working, with wider impact, beyond the classroom, in providing advanced skill sets and working practices that will enhance employability.;Students demonstrate increased engagement, mitigated stress, bolstered confidence and reduced confusion, while student retention is also improved. By surveying current students and graduates, a link between experiential practice and high skills confidence is observed; hence, it is recommended that students are encouraged to reflect on their learning experiences and that integrated learning be promoted to develop all skills effectively. The work also indicates that using problem based learning in early year classes, to underpin advanced project working in later years, is worthy of consideration for chemical engineering teaching as well as the wider engineering discipline.There are myriad challenges in developing a stimulating yet supportive curriculum in many subject areas, and recent shifts in course entry demographics and employer expectations have made this especially challenging in chemical engineering. As a discipline, there has been a gender shift in recent years towards greater women student representation at undergraduate level and an increase in global industry sector demand for chemical engineering graduates. This has raised issues of inclusion, to allow women students to participate equally in learning activities and wider opportunities, as well as those of graduate skills development, tempered by reports from the Confederation of Business Industry, which indicate that employers are dissatisfied with the skill sets offered by graduates.;This work sets out to address these concerns through evaluation of active learning and makes recommendations regarding integrated learning, where group work is used to develop students' professional competencies in tandem with their transferable skills. Engineering education has developed over the years to include many instances of group based working that focusses on problem based learning, however, the full extent of the impact that this may have on students' development is little understood or studied. This thesis explores the role of problem-based learning in facilitating students' engagement with specific components of a chemical engineering degree within UK Higher Education, including surveys of staff and student perceptions of group working and skills development, statistical evaluation of student attainment and appraisal of course (re)design.;Despite significant group work and problem based learning focussed on developing openended working, teaching staff identified issues with students' abilities to deal with such problems in chemical engineering and to accept open-endedness itself. By identifying openendedness as a threshold concept, it has been possible to study the impact that the timeline of teaching has on student development and achievement. This work presents a strategy for vertical alignment of teaching within the chemical engineering degree to support student development and foster student confidence and autonomy.;Within this context, the use of group working is key and the thesis also investigates the role of tutors within this educational framework and how such activities impact on the inclusion of women in engineering subjects. Additional work to redevelop early years teaching to address the identified threshold concept and, specifically, its role in the capstone design project is reported and students' perceptions of skills development has been investigated to understand the impact that working in such an environment has on the transferable skill sets of these cohorts.;The insights gained show that tutor supported problem based learning can be key in nurturing critical evaluation skills in students, often requiring them to explain their reasoning and work with unknown quantities. The role of women students in group working changes with their increased awareness of social expectations to adapt to normalised views of women's roles; this happens early in their University career and sets working parameters for the remainder of their degrees, so addresses the early imbalance in role assignment that may be observed. The successful incorporation of problem based learning activities in early years helps students overcome the liminality that results from open-ended working, with wider impact, beyond the classroom, in providing advanced skill sets and working practices that will enhance employability.;Students demonstrate increased engagement, mitigated stress, bolstered confidence and reduced confusion, while student retention is also improved. By surveying current students and graduates, a link between experiential practice and high skills confidence is observed; hence, it is recommended that students are encouraged to reflect on their learning experiences and that integrated learning be promoted to develop all skills effectively. The work also indicates that using problem based learning in early year classes, to underpin advanced project working in later years, is worthy of consideration for chemical engineering teaching as well as the wider engineering discipline

Development of a novel dual-stage method for metaldehyde removal from water

A dual-stage method was developed to first efficaciously degrade metaldehyde into acetaldehyde, before subsequent removal of acetaldehyde using an amine functionalized ion-exchange resin. A range of Macronets, with different surface areas, pore volumes, pore size distributions and extents of functionalisation were evaluated for the depolymerisation of metaldehyde. NMR spectroscopy was used to confirm the compete degradation of metaldehyde by the selected Macronets. Kinetic studies showed that the rates of catalytic degradation were primarily determined by the porous structure of the materials rather than the extent of surface functionalization, since high levels of acid surface groups were observed to decrease the porosity significantly. The rate constants obtained show excellent correlation with non-micro pore volumes, which are of import as the only pores that are accessible to hydrogen bonded metaldehyde molecules; Macronet MN502 exhibits the largest non-micro pore volume and, hence, demonstrated the best kinetic performance. The effect of competing ions on catalytic performance was also studied and the results demonstrate that competing ions compromise the performance of the proposed system to some extent, however, it is notable that a good level of performance is maintained even for competing ion concentrations as high as 100 times that of metaldehyde. Isothermal studies of acetaldehyde onto ion-exchange resin A830, including kinetic evaluation, showed that acetaldehyde could be chemically adsorbed by the resin. Consequently, a dual-column system was proposed, which was determined to effectively degrade metaldehyde (MN502) and remove the resulting by-product, acetaldehyde, via a second fixed bed absorber (A830); this method could easily be adapted to existing facilities in water treatment works, making it very cost-effective and of great practical interest

Adsorption selectivity of CO2 over CH4, N2 and H2 in melamine-resorcinol-formaldehyde xerogels

Sorptive selectivity of melamine-resorcinol-formaldehyde xerogels, towards CO2, CH4, N2 and H2, is reported, where all systems demonstrate potential for selective adsorption of CO2 from corresponding binary gas mixtures. Selected gas mixtures represent important gas separation applications found in industry, i.e. CO2 removal from power plant flue gases (CO2-N2), sour gas sweetening (CO2-CH4), and separation of species in the water-gas shift reaction (CO2-H2). All materials tested exhibit microporous character, enhancing adsorption of small molecules, however, it is the inclusion of a nitrogen-rich material into the gel matrix that results in enhanced selectivities for these systems. Despite the porous character of the gels, under the test conditions used to simulate industrial parameters, all three balance gases, i.e. H2, N2 and CH4, showed low affinities for the xerogels, while CO2 adsorption was notably higher and increased with the inclusion and increased concentration of melamine. Ideal Adsorbed Solution Theory was used to demonstrate significant differences in adsorption uptake, especially for CO2-CH4, and high selectivities for CO2 over N2. In all cases, selected xerogels exhibited industrially relevant adsorption timescales for CO2 over competitor gases, demonstrating the potential of these materials for the selective adsorption of CO2 from process streams

Effect of aromatic amines on the properties of formaldehyde-based xerogels

This study investigates the synthesis of formaldehyde-based xerogels using alternative aromatic precursors, with comparison to traditional resorcinol-formaldehyde analogues, in order to alter the chemical composition of the resulting gels. By replacing resorcinol with aromatic amine molecules, i.e., ammeline, melamine and melem, each expected to undergo similar reactions with formaldehyde as the substituted species, we found that for all substituted gels, at low additive contents, the gel structure was compromised and non-porous materials were formed, as opposed to the most abundant monomers, and therefore, these additives seem to act as impurities at low levels. Working towards higher additive contents, melem monomers exhibited low solubility (~5%), even at elevated temperatures, thereby limiting the range to which melem could act as a substitute, while melamine could be incorporated up to ~40% under acidic conditions, with enhanced microporosity over this range. Pure gels were successfully synthesised from ammeline, but their performance was inferior to resorcinol-formaldehyde gels, while melamine-formaldehyde analogues required acidic reaction conditions but shrank considerably on sub-critical drying, adversely affecting the gel properties and demonstrating their lack of potential as sorbents. This demonstrates the potential for the inclusion of aminated aromatics within resorcinol-based gel systems, however, only as partial substitutes and not complete replacements

Modelling organic gel growth in three-dimensions : textural and fractal properties of resorcinol-formaldehyde gels

Tailoring the properties of porous organic materials, such as resorcinol–formaldehyde gels, for use in various applications has been a central focus for many studies in recent years. In order to achieve effective optimisation for each application, this work aims to assess the impact of the various synthesis parameters on the final textural properties of the gel. Here, the formation of porous organic gels is modelled using a three-dimensional lattice-based Monte Carlo simulation. We model growth from monomer species into the interconnected primary clusters of a gel, and account for varying catalyst concentration and solids content, two parameters proven to control gel properties in experimental work. In addition to analysing the textural properties of the simulated materials, we also explore their fractal properties through correlation dimension and Hurst exponent calculations. The correlation dimension shows that while fractal properties are not typically observed in scattering experiments, they are possible to achieve with sufficiently low solids content and catalyst concentration. Furthermore, fractal properties are also apparent from the analysis of the diffusion path of guest species through the gel’s porous network. This model, therefore, provides insight into how porous organic gels can be manufactured with their textural and fractal properties computationally tailored according to the intended application

A novel activated carbon material from peanut shells for the removal of methyl orange and methylene blue dyes from wastewater : kinetics, isotherms, and mechanism

This study investigated the removal of methyl orange and methylene blue dyes from an aqueous phase using a novel activated carbon material derived from peanut shells. The effects of pH, contact-time, and initial dye concentration on the adsorption performance were evaluated. The adsorption kinetics were fitted with pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, while the adsorption isotherms were modelled using Langmuir, Freundlich, and Sips equations. The results showed that the adsorption of both dyes followed the pseudo-second-order kinetic model, and the Freundlich and Sips isotherm models. The maximum adsorption capacities of the carbon material for MO and MB, according to the Sips model, were 4584 mg/g and 1769 mg/g, respectively. The pH range of 3–11 had negligible influence on the adsorption capacities of both dyes. The adsorption mechanism was mainly attributed to π–π interactions, n–π electron donor-acceptor (EDA) interactions, and pore filling. The activated carbon material exhibited good reusability and stability, achieving over 90% dye removal, after five cycles of adsorption-desorption using hot (90 ± 2 °C) deionized water as the eluent, indicating that the carbon material synthesized from peanut shells is a promising adsorbent for the removal of ionic dyes from wastewater

Threshold concepts in chemical engineering design

This chapter explores the role of problem-based learning (PBL) in facilitating students’ engagement with design components of a chemical engineering degree at the University of Strathclyde (UoS), where students are required to plan and evaluate a manufacturing process. Teaching staff previously identified issues with students’ abilities to deal with open-ended problems in chemical engineering and to accept open-endedness itself, identifying open-endedness as a threshold concept in design. Work was subsequently undertaken to develop appropriate PBL content to address this threshold concept and associated drop-out rates. A longitudinal programme was engineered to support student learning via a dedicated PBL module, enhancing the students; experience. The benefits of such a programme go beyond the students’ academic career and provide significant impact in achieving success in the real world. The chapter presents findings from this work and builds on the use of threshold concepts in PBL, as introduced in the works of Land and Savin-Baden, relating them to the engineering discipline and reporting on the successful incorporation of PBL activities in early years to help students overcome the liminality that results from open-ended working

Using the perceptions of chemical engineering students and graduates to develop employability skills

Recent years have seen increased global industry sector demand for chemical engineers, subsequent growth of Chemical Engineering (CE) degrees, producing additional qualified graduates. The Confederation of Business Industry have regularly indicated that employers are dissatisfied with skills sets offered by graduates; a 2004 World Chemical Engineering Council (WCEC) survey of experienced and newly employed chemical engineers’ perceptions of their own work skills indicated highest importance for general transferrable skills, with technical knowledge ranked considerably lower. A decade later, we investigate whether chemical engineers, both employed and in education, have similar skills perceptions, by surveying CE undergraduates in penultimate and final years of study, and CE alumni employed in CE roles; all from the University of Strathclyde. Again, transferrable skills were perceived as most important to respondents; as undergraduates gained industrial experience, a shift in perceived relative importance of technical knowledge occurred, again similar to the WCEC survey, otherwise, alumni and students had similar opinions regarding perceived degree of learning of various skills. Alumni were more critical of the quality of education with regards to management and transferrable skills, while female participants perceived business skills as undertaught, feeling considerably overexposed to the potential of research compared to male colleagues. Focus groups showed that male undergraduates valued ‘technical knowledge’ and ‘communicating professionally’; by contrast, female graduates highlighted ‘initiative’ and ‘business skills’. Consequently, training sessions were developed, focussing on transferable skills identified as important by all groups, to be delivered during academic year inductions, aligning skills to year curricula

Effective carbon/TiO2 gel for enhanced adsorption and demonstrable visible light driven photocatalytic performance

A new strategy to synthesise carbon/TiO2 gel by a sol–gel method is proposed. Textural, morphological, and chemical properties were characterised in detail and the synthesised material was proven to be an active adsorbent, as well as a visible light photocatalyst. Homogenously distributed TiO2 is mesoporous with high surface area and, hence, exhibited a high adsorption capacity. The adsorption equilibrium experimental data were well explained by the Sips isotherm model. Kinetic experiments demonstrated that experimental data fitted a pseudo second order model. The modification in electronic structure of TiO2 resulted in a reduced bandgap compared to commercial P25. The absorption edge studied through UV-Vis shifted to the visible region, hence, daylight photocatalytic activity was efficient against degradation of MB dye, as an example pollutant molecule. The material was easily removed post treatment, demonstrating potential for employment in industrial water treatment processes

Influence of operating parameters on biochars produced from Native Scottish wood

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