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A narrative review of plastic waste pyrolysis : Challenges and opportunities

A review of waste tyre pyrolysis : a discussion and analysis

  • Authors: Nkosi, N. , Muzenda, E. , Belaid, M.
  • Date: 2019
  • Subjects: Reactor Selection , Types of Pyrolysis Products , Tyre derived Products,
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/403903 , uj:33864 , Citation: Nkosi, N., Muzenda, E. & Belaid, M. 2019. A review of waste tyre pyrolysis : a discussion and analysis.
  • Description: Abstract: Over the years, the prospective of end-of-life tyres as a source of fuel, a chemical feedstock and carbonaceous material through pyrolysis has been explored immensely. Through literature review evaluation and analysis, this paper aims to present and discuss the development of waste tyre pyrolysis process as well as the derived products with their possible application pathways. The various reactors that can be employed during the pyrolysis process are discussed. Furthermore, the different types of pyrolysis processes as well as their influence on product yield are highlighted. The paper drew the conclusion that the pyrolysis literature which has been continuously developed over the years emphasize the need to fully understand how operating conditions such as temperature, pressure, heating rate, retention time, feed size; material feed rate ; reactor selection and the type of pyrolysis influence the selection and optimization of product stream/s.
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A simple static headspace method for phase equilibrium measurement

A study of the variables in the optimisation of a platinum precipitation process

An investigation into the effect of temperature on the leaching of copper-matte

Challenges and opportunities of rural electrification with mini-grids : a mini review

  • Authors: Bambokela, Jonathan Empompo , Belaid, M. , Muzenda E.
  • Date: 2019
  • Subjects: Energy , Framework , Mini-grid
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/403998 , uj:33872 , Citation: Bambokela, J.E., Belaid, M. & Muzenda E. 2019. Challenges and opportunities of rural electrification with mini-grids : a mini review.
  • Description: Abstract: There are presently 600 million of people in Africa without access to electricity. To resolve this issue, 100 million of new connexions are needed. These new connexions require more investments in propice environments. However, most investors have reduced their risk appetite for Africa due to the absence of adequate regulatory and policy framework in the energy sector. Many utilities are no longer bankable and trustworthy like before. Stakeholders do not have sufficient financial resources to build or rehabilitate energy infrastructures. Statistics reveal that public institutions will need the support of the private sector in order to emerge. As such, Public and Private Partnerships (PPPs) leading to strategic investments seem essential for the deployment of the African energy sphere. Mini-grid systems are recommended as potential tools for local electrification that will lead to the economic boom of Sub-Saharan African (SSA) developing countries. The challenge is that a suitable business model for mini-grid is not yet identified and continue to be developed. For this reason, this paper aims at encouraging the development of a regulatory framework and replicable business model that will be used by other mini-grid developers to attract strategic investments to implement projects starting at the village level.
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Fostering biomass-solar PV hybrid mini-grids in offgrid agricultural communities of sub-Saharan Africa : case of the Democratic Republic of Congo, a mini review

  • Authors: Bambokela, J.E. , Belaid, M. , Muzenda, E.
  • Date: 2020
  • Subjects: Biomass , Hybrid , Mini-grid
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/475284 , uj:42869 , Citation: Bambokela, J.E., Belaid, M. & Muzenda, E. 2020. Fostering biomass-solar PV hybrid mini-grids in offgrid agricultural communities of sub-Saharan Africa : case of the Democratic Republic of Congo, a mini review.
  • Description: Abstract: In Africa, large energy infrastructures projects are often very complex. Their complexity lies in various aspects such as administration, regulation, technicality, and finances. Most Sub-Saharan African (SSA) countries, in the likes of the Democratic Republic of Congo (DRC), have very low electrification rate that is usually below 10%. As such, there are multiple communities that are still undeserved. These offgrid communities generally use diesel generators to obtain electricity despite the cost of fuel that is not affordable for everyone. For this reason, this paper sought to concisely present the biomass-solar photovoltaic (PV) hybrid mini-grid (BSPVHM) as a cost-effective solution to electrify disconnected communities that have untapped large farming potential. While referring to the DRC that has an average of 492,692 off-grid agricultural households, this paper demonstrated that multiple BSPVHM of capacities ranging from 5 to 15 MW could be implemented in localities of the 26 provinces of DRC that has an average energy deficit of 246 MW. The purpose of this research is to encourage the wide adoption of the BSPVHM to electrify undeserved SSA communities.
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Illegal dumping challenges in West Rand District Municipalities (WRDM), South Africa

  • Authors: Muzenda, E. , Belaid, M. , Nkosi, N.
  • Date: 2019
  • Subjects: Environment , Illegal Dumping , Landfill
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/404129 , uj:33878 , Citation: Muzenda, E., Belaid, M. & Nkosi, N. 2019. Illegal dumping challenges in West Rand District Municipalities (WRDM), South Africa.
  • Description: Abstract: Increased population and urban migration in the West Rand District Municipality (WRDM) have significantly contributed towards increased waste generation and associated challenges. Increased waste generation exerts pressure, difficulties and constraints in waste management in the district with regards to storage facilities, receptacles, removal services and transportation. The lack or absence of waste management services in addition to other factors are catalysts and drivers for illegal dumping. In WRDM, illegal dumping is a result of rising waste disposal tariffs, lack of storage facilities, disrupted waste collection schedules, unsafe and inaccessible dumbing sites particularly for in informal settlements. Illegal dumping is prevalent in low income and overpopulated areas. Ignorance, lack of minimum education and public awareness with regards to integrated waste management significantly contribute to illegal dumping which is threat to human life and the environment. Exploring energy and material recovery from waste opportunities plus recycling could contribute towards reduced illegal dumping.
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Impact of substrate composition in biomethane production under thermophilic conditions

  • Authors: Bambokela, Jonathan Empompo , Matheri, A. N. , Belaid, M. , Agbenyeku, E. E. , Muzenda, E.
  • Date: 2016
  • Subjects: Anaerobic digestion , Co-digestion , Substrate
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/215517 , uj:21426 , Citation: Bambokela, E.J. et al. 2016. Impact of substrate composition in biomethane production under thermophilic conditions.
  • Description: Abstract: In this investigation, the anaerobic digestion (AD) results from different substrates were evaluated. By means of two co-digestion processes with cow dung, it was observed a good performance in the first process and a poor production trend in the second one. NaOH was used as chemical absorbent in two different bottles in the CO2 fixing unit to compare the volume of biomethane produced. A batch anaerobic codigestion was carried out in 500 mL digesters which were placed into a water bath at 45°C and maintained at the initial pH of 7. Important AD factors such as pH, Carbon and Nitrogen ratio (C/N), concentration, substrate composition were observed. Through an ultimate analysis, amount of Carbon (C), Hydrogen (H), Nitrogen (N), and Sulphur (S) were also discussed. The toxicity of other elements found in substrates appeared higher in the second process than in the first. It was concluded that inhibitory elements identification and control before furthering any biogas production process were primordial.
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Incineration as a potential solution to Africa’s plastic waste challenges? A narrative review

  • Authors: Mazhandu, Z. S. M. , Muzenda, E. , Belaid, M. , Mamvura, T. A. , Nhubu, T.
  • Date: 2020
  • Subjects: Incineration , Life Cycle Assessment , Plastic waste
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/458865 , uj:40776 , Citation: Mazhandu, Z.S.M. et al. 2020. Incineration as a potential solution to Africa’s plastic waste challenges? A narrative review.
  • Description: Abstract: Africa is considered the second most polluted continent and it will contribute the highest amount of waste into the world’s oceans by 2035. A paltry 4% of the total municipal solid waste (MSW) generated in Africa is recycled and yet 70-80% of the MSW is recyclable. In addition, 90% of the waste that is generated is dumped at uncontrolled landfills while 10% is illegally burnt. Africa has accumulated over 130 million tonnes of plastic waste on its landfills. The poor recycling statistics of the continent means that Africa is missing out on the benefits that plastic waste can yield such as job creation and energy generation; both which are lacking in Africa. The objectives of this review are therefore to assess whether incineration can be considered in the management of plastic waste in Africa based on past life cycle assessment studies; to determine the risks associated with incineration as well as evaluate threats to its success. Data was sourced using keywords and phrases in academic databases and grey literature. The results show that opportunities exist for Africa to manage its plastic waste sustainably and therefore, landfilling of plastic wastes is not the solution due to the risk of spontaneous fires that release harmful toxins. In conclusion, as the continent navigates the path to “zero waste to landfills” in line with circular economy principles; it is time for waste to energy technologies such as incineration to be considered in waste management systems. Life cycle assessments (LCAs) within the African context need to be carried out as they are lacking, in order to determine how incineration or other treatment methods such as pyrolysis and use of plastic wastes in cement kilns and blast furnaces can be successfully implemented without increasing eco-toxicological and human toxicological impacts.
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Measurement of infinite dilution activity coefficients of selected environmentally important volatile organic compounds in polydimethylsiloxane using gas – liquid chromatography

  • Authors: Muzenda, Edison , Belaid, M. , Ntuli, Freeman
  • Date: 2010
  • Subjects: Thermodynamics , Polydimethylsiloxane , Activity coefficients , Volatile organic compounds absorption
  • Type: Article
  • Identifier: uj:5306 , http://hdl.handle.net/10210/5284
  • Description: Silicon oil chemically known as polydimethylsiloxane (PDMS) is a high boiling point solvent highly suitable for volatile organic compounds (VOCs) absorption. In order to use PDMS as an absorption solvent for a specific waste gas problem, it is important to determine the infinite dilution activity coefficients of the VOCs to be separated with PDMS. This work reports activity coefficients at infinite dilution of 13 VOCs in polydimethysiloxane determined by the dynamic gas liquid chromatographic technique. The measurements were carried out at various temperatures (i.e, 303.15, 313.15, 323.15., 333.15, 353.15, 373.15, 393.15 and 423.15K). Four PDMS polymers with average molecular weight ranging from 760 to 13 000 were used as solvents. A control column packed by Perkin Elmer to our specifications was used to validate the coating and packing methods. Flow rate dependence of the elution peaks was also investigated by varying it from 10 – 50 ml/min. Precision was improved by reproducing the results using columns with different liquid loading, thus also studying the retention mechanism. The results compare well with the data from previous work using simple headspace and UNIFAC predictions and literature values. The successful comparison gives an indication of the GLC as a rapid, simple and accurate method for studying the thermodynamics of the interaction of a volatile solute with a non volatile solvent.
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Microwave-assisted extraction of castor oil

Optimising biogas production from anaerobic co-digestion of chicken manure and organic fraction of municipal solid waste

  • Authors: Matheri, A. N. , Ndiweni, S. N. , Belaid, M. , Muzenda, E. , Hubert, R.
  • Date: 2017
  • Subjects: Anaerobic , Biogas , Co-digestion
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/241017 , uj:24803 , Citation: Matheri, A.N. et al. 2017. Optimising biogas production from anaerobic co-digestion of chicken manure and organic fraction of municipal solid waste.
  • Description: Abstract: In this study, it was observed that in experimental work under laboratory scale using conventional biochemical methane potential (BMP) assay, the loading rate ratio 4:1 had optimum biodegradability rate than other ratios which were investigated, while the loading rate ratio of 1:1 had optimum biogas and methane yield after 15 days hydraulic retention time. It was concluded that chicken waste (CM) monodigestion has higher biodegradability rate compare to organic fraction municipality solid waste (OFMSW) mono-digestion. Co-digestion of OFMSW and CM stabilizes conditions in digestion process such as carbon to nitrogen (C:N) ratio in the substrate mixtures as well as macro and micronutrients, pH, inhibitors or toxic compounds, dry matter and thus increasing biogas production. It was concluded that the organic waste generated in the municipal landfills could be co-digested with CM to produce methane which can be used as a source of environmentally friendly and clean energy for the transport sector, industries and residential homes.
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Parametric optimization route of oil extraction from seed : a review

Plastic waste use in the blast furnace as a reducing agent

  • Authors: Mazhandu, Z. S. M. , Muzenda, E. , Belaid, M. , Mamvura, T. A. , Nhubu, T.
  • Date: 2020
  • Subjects: Blast Furnace , Coke , Landfill
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/458868 , uj:40778 , Citation: Mazhandu, Z.S.M. et al. 2020. Plastic waste use in the blast furnace as a reducing agent.
  • Description: Abstract: Steel is among the most essential materials in construction, making its manufacture equally important. Steel is manufactured either via an integrated iron and steel making route characterised by the Blast Furnace (BF) and a Basic Oxygen Furnace (BOF), smelting followed by a BOF or in an electric arc furnace. The objective of this paper explores the possibility of using plastic waste in Africa as an alternative reducing agent to coke in the Blast Furnace; a recycling practice that is commonly done in Japan and Europe. There are many benefits that can be accrued environmentally, operationally and economically when using waste plastics in the BF. The hydrogen content in waste plastics is almost three times more than that in pulverised coal making it a better reducing agent environmentally and economically. Plastic waste has a higher calorific value and less impurities, which results in energy savings and less dioxins and furans in the process. In addition, bearing in mind that over 130 million of tonnes of plastic waste are currently in Africa’s landfills, utilising waste plastics in the BF will result in savings in landfills airspace, prevent financial losses incurred through dumping valuable recyclables, protect the environment and the public because if spontaneous fires start in landfills then toxic fumes such as furans and dioxins, cannot be generated if the landfills are plastic free. With such evidence on hand, plastic waste use in the BF presents an untapped beneficial opportunity not only for the continent of Africa but other continents such as North America where landfilling is rife.
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Preliminary design of a biogas-solar PV hybrid mini-grid system for off- grid agricultural communities

  • Authors: Bambokela, J.E. , Belaid, M. , Muzenda, E.
  • Date: 2020
  • Subjects: Agricultural , Biogas , Hybrid
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/475292 , uj:42870 , Citation: Bambokela, J.E., Belaid, M. & Muzenda, E. 2020. Preliminary design of a biogas-solar PV hybrid mini-grid system for off- grid agricultural communities.
  • Description: Abstract: Mini-grid technologies are rapidly growing and occupying predominant place in Sub-Saharan Africa (SSA). Rural electrification rate is drastically rising because of the wide adoption of mini-grid systems in off-grid communities. However, there is still a lot of efforts needed from a regulatory, technological, and financial point of view. The mini-grid concept is currently being reviewed by African energy stakeholders to be integrated in their national and regional energy plan. To achieve an effective integration, the design of mini-grid set-ups must be understood. To understand its design, various factors such as the system components, the sizing and optimization tools and major implementation phases must be considered carefully. For this reason, this paper seeks to define the concept of mini-grid and propose a biogas-solar Photovoltaic (PV) hybrid mini-grid (BSPVHM) as a power solution for underserved agricultural communities.
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The potential for a sustainable biodiesel production by modified biobased catalyst : a review

Waste to energy technologies from organics fraction of municipal solid waste

  • Authors: Matheri, A.N. , Mbohwa, Charles , Belaid, M. , Seodigeng, T. , Ngila, J.C. , Muzenda, E.
  • Date: 2016
  • Subjects: Anaerobic , Co-digestion , Digesters
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/214143 , uj:21243 , Citation: Matheri, A.N. et al. 2016. Waste to energy technologies from organics fraction of municipal solid waste.
  • Description: Abstract: With rapid economic growth and increased urbanization, South Africa faces the problem of municipal solid waste (MSW) disposal and pressing the need for waste to energy recovery. Nowadays, renewable energy is the key consideration in the discussion of the sustainable worldwide energy system that reduces global climate change, human health problems, and environmental degradation. Sustainable development requires the sustainable supply of clean and affordable renewable energy. The renewable energy source such as bioenergy, solar energy, wind energy, hydropower, geothermal is usually viewed as sustainable energy sources that drive economic development. Wastes are convertible to useful energy through waste to energy (WtE) technologies. In this study, renewable energy technologies from the organic fraction of municipal solid waste (OFMSW) and their relation to sustainable development are discussed. Via the application of the simple multi-attribute rating (SMART) technique of multiple-criteria decision analysis (MCDA) and analytical hierarchy process (AHP) as a decision support tool, the most preferred model option for WtE technology was selected from a list of potential alternatives available in the market base on environmental, sociocultural, technical and economical consideration. From our investigation into the City of Johannesburg Landfill, the OFMSW had the highest fraction that comprises of 34% in portion. From MCDA-AHP results, anaerobic digestion was the most preferred technology of choice, taking into consideration environmental preservation as the ultimate goal.
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