Repository logo
 

Faculty of Engineering and Built Environment

Permanent URI for this communityhttp://ir-dev.dut.ac.za/handle/10321/9

Browse

Author: search.filters.author.Chetty, ManimagalayHas files: Yes

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Minimisation of waste via the valorisation of spent coffee grounds into high-value products
    (Italian Association of Chemical Engineering - AIDIC, 2023-11-30) Singh, Nikita; Chetty, Manimagalay; Deenadayalu, Nirmala
    Spent coffee grounds (SCG) valorisation can produce high-value products to supply cosmetics, petroleum and pharmaceutical industries among others. An overview of the various products achievable from spent coffee grounds valorisation are established, while the effect of temperature, reaction time and solid-to-liquid loading ratio on the yield of caffeine extracted from SCG was investigated. The best extraction solvent between (i) dichloromethane, (ii) 1-ethyl-3-methylimidazolium chloride (IL) and (iii) water was established. Characterisation of SCG using Technical Association of the Pulp and Paper (TAPPI) methods was carried out. Variations of parameters were established using the Box-Behnken design of experiment (DOE) which varied the investigated parameters; (i) temperature (88 – 120 ºC), (ii) reaction time (15 - 35 min) and (iii) solid-to-liquid loading ratio (5 g SCG per 10 -25 mL). The conventional extraction method used dichloromethane as the extraction solvent, whereas the green method used the ionic liquid and water in a Parr pressure reactor. High performance liquid chromatography (HPLC) quantified the yield of extracted caffeine. Recrystallised caffeine is analysed using scanning electron microscopy (SEM), transition electron microscopy (TEM) and energy dispersive spectroscopy (EDS) for its structural properties, crystalline structure and physical analysis, while differential scanning calorimetry (DSC) established the purity of extracted caffeine achieved from each extraction solvent. The expected yield of caffeine is between 4.67 and 8.0 mg/g SCG. According to this experimental methodology, at 120 ºC, 25 min reaction time and 25 mL solvent volume the extraction yield ranged from 2.83 to 3.67 mg/g SCG
  • Thumbnail Image
    Item
    39th Johannesburg International Conference on “Chemical, Biological and Environmental Engineering” (JCBEE-23) Nov. 16-17, 2023 Johannesburg (South Africa)
    (International Institute of Chemical, Biological & Environmental Engineering (IICBEE), 2023-11-16) Chetty, Manimagalay; Rathilal, Sudesh; Tetteh, Emmanuel; Singh, Nikita
    Abstract—Recent energy demand and environmental concerns associated with fossil fuels makes algae biomass a desirable energy source. Algal biomass has a high organic content and a variety of metabolic properties that make it a promising resource for managing wastewater and sequestering CO₂, in addition to producing profitable biobased products. However, the operation and valorization of algae biomass on a large scale are accompanied by significant costs and setbacks. Therefore, the transition towards a biobased economy requires this study to examine emerging technologies that could utilize algae biomass as an industrialized feedstock from the wastewater settings. A comprehensive analysis of various green technologies of producing high-value products (lipids and hydrocarbons) from algae biomass was reviewed. The fundamental principles that limit the cultivation , extraction, and conversion of different types of algae biomasses for commercialization are discussed. Furthermore, the challenges, future research directions and potential opportunities of valorizing algae biomass was highlighted. It was noted that, exploring algae biomass towards sustainable waste management with resources recovery is viable for industrialization.
  • Thumbnail Image
    Item
    Degree accreditation report auto-generation by logic encoding and processing
    (2021-11-10) Chetty, Manimagalay; Rawatlal, Randhir
    Maintaining the accreditation profile of an academic programme is a key activity in so-called professional degrees such engineering, commerce and law. The complexity of the accrediting criteria tends to rise over time as accrediting bodies require quantitative evidence of competence of increasingly specific graduate attributes. Evaluation of graduate attributes may therefore require complex logic processing which challenges the human capacity. This has the negative side effect of discouraging curriculum revision not for pedagogic reasons but simply due to the complexity of evaluating complex logic patterns against a data set whose structure is shifting. These challenges can be overcome through the application of logic encoding and processing. A computing system is better suited to such processing tasks since logic processing is fundamental and well-established to such systems. On the other hand, the efficient representation of a complex accreditation logic rule base then becomes the challenge. This paper describes the representation of the accreditation logic of eight engineering academic programmes at the Durban University of Technology through the AutoScholar Advisor System in preparation for evaluation by the Engineering Council of South Africa. It is shown that the system generates accurate reports even with deeply nested logic structures and with changes in curriculum over time.