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Biogas use as fuel in spark ignition engines

- Kukoyi, T.O., Muzenda, E., Akinlabi, Esther Titilayo, Mashamba, A., Mbohwa, Charles, Mahlatsi, T.

Value addition of coal fines and sawdust to briquettes using molasses as a binder

- Manyuchi, M. M., Mbohwa, Charles, Muzenda, E.

Economic analysis of biogas upgrading and utilization as vehicular fuel in South Africa

- Masebinu, S. O., Aboyade, A. O., Muzenda, E.

  • Authors: Masebinu, S. O. , Aboyade, A. O. , Muzenda, E.
  • Date: 2015
  • Subjects: Biomethane , Economics , Gas processing cost
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/72861 , uj:18338 , Citation: Masebinu, S.O., Aboyade, A.O. & Muzenda, E. 2015. Economic analysis of biogas upgrading and utilization as vehicular fuel in South Africa.
  • Description: Abstract: Economic and sensitivity analysis of a simulated biogas upgrading plant using a gas permeation software has been presented in this study. The effect of three process conditions on gas processing cost (GPC) were simulated. An increase in CO2 increased the GPC from $0.73 to $1.39/m3 of biomethane while an increase in feed pressure increased GPC from $0.65 to $1.16/m3 of biomethane. As the feed flow rate increased from 80-140 m3/h, the product flow rate increased from 46-100 m3/h while the GPC decreases from $0.79 to $0.39/m3 of biomethane. At optimized condition, the calculated GPC was $0.46/m3 of biomethane. The NPV, IRR and BCR for producing biomethane was R15,240,343, 22.41% and 2.05 respectively with a break-even in the 5th year. Using CBG over gasoline, the end user saves 34% of annual fuel cost which is approximately R47,255 with a payback period of one year and three months for vehicle retrofitting. The fuel prices differential between gasoline and CBG as well as the overall savings, makes CBG attractive to the producer and end user.
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Removal and recovery of heavy metal from multi-component metal effluent by reduction crystallization

- Phetla, P.T., Ntuli, F., Muzenda, E.

Electrolytic deposition of manganese dioxide from Nigerian manganese ore using graphite electrodes

- Muriana, R. A., Omeye, L. U., Abubakre, O. K., Muzenda, E., Ndlovu, S., Abdulkareem, A. S.

  • Authors: Muriana, R. A. , Omeye, L. U. , Abubakre, O. K. , Muzenda, E. , Ndlovu, S. , Abdulkareem, A. S.
  • Date: 2017
  • Subjects: Driving potential , Electrolytic deposition , Electrolytic manganese dioxide
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/250364 , uj:26088 , Citation: Muriana, R.A. et al. 2017. Electrolytic deposition of manganese dioxide from Nigerian manganese ore using graphite electrodes. 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria.
  • Description: Abstract: Super rich manganese dioxide got deposited at the anode when manganese sulphate solution was electrolytically decomposed, and the deposits called Electrolytic Manganese Dioxide (EMD). Manganese ore containing about 35.79% manganese from Ka’oje (Kebbi State, Nigeria) with pyrolusite (MnO2) as the major manganese mineral alongside iron mineral present as hematite, was the resource material. Some 1973.31g of beneficiated ore sample (75 to 600μm) was isothermally reduced with charcoal (52.17% carbon) at 6000C for one hour. The paramagnetic high oxide ore got reduced to a ferromagnetic lower oxide containing 38.90% manganese. Some 610g portions of the reduced ore were leached in varied concentrations of sulphuric acid (1.0M, 1.5M and 2.0M) at 500C for one hour and 42.36% leaching efficiency was achieved with 2.0M acid. Calculated elemental mass balance revealed that 2.0M acid dissolved 100.52g of manganese into the leach liquor as manganese sulphate along with 13.83g of iron and 7.47g of aluminium as the major elements. Each leach filtrate was purified with aqueous sodium hydroxide except some 600ml of filtrate from 2.0M acid leaching which was decomposed unpurified for comparison. The filtrates were respectively electrolyzed at 2.5V, 3.0V and 4.0V driving potentials for five hours using graphite electrodes. Analyses showed that the purified liquor extracted with 2.0M acid and electrolysed at 4.0V deposited the best quantity and quality of EMD, containing 98% MnO2. This high grade EMD is a principal precursor in Ferro-alloy production for steel making and also an important raw material for electrochemical cells and other allied manganese-based chemicals.
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Parametric study of single and double stage membrane configuration in methane enrichment process

- Masebinu, S. O., Aboyade, A. O., Muzenda, E.

  • Authors: Masebinu, S. O. , Aboyade, A. O. , Muzenda, E.
  • Date: 2014
  • Subjects: Biogas , Methane enrichment , Membrane configuration
  • Type: Article
  • Identifier: uj:5003 , http://hdl.handle.net/10210/13143
  • Description: Operational study of a biogas upgrading plant with cleaning and methane (CH4) enrichment has been presented in this study. Parametric study was conducted to investigate the effect of variation of process conditions for single stage without recycle (SSWR) and double stage with permeate recycle (DSPR) on product purity, CH4 recovery and compression power requirement. In the study, achieving high CH4 recovery and product purity simultaneously could not be attained in SSWR configuration. The performance of DSPR yielded a better result but with higher membrane area and compression power. DSPR configuration achieved high CH4 recovery and purity at increasing feed pressure, selectivity and feed flow. The CH4 losses increased in both configurations as %CO2 increased in the feed. DSPR configuration is considered the best configuration due to the end use of the product, as vehicular fuel, which requires high product purity.
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Parametric effects on leaching behavior of nickel-copper matte in ammonia

- Muzenda, E., Ramatsa, I. M., Ntuli, F., Abdulkareem, A. S., Afolabi, A. S.

Modeling of the mechanical responses of nanocrystalline metals and alloys

- Sanusi, K. O., Afolabi, A. S., Muzenda, E., Akinlabi, Esther Titilayo

Chemical absorption of carbon dioxide in biogas purification

- Maile, O. I., Muzenda, E., Tesfagiorgis, H.

Environmental sustainability : multi-criteria decision analysis for resource recovery from organic fraction of municipal solid waste

- Masebinu, S. O., Akinlabi, Esther Titilayo, Muzenda, E., Mbohwa, Charles, Aboyade, A. O., Mahlatsi, T.

Effect of chemicals treatment and fiber loading on mechanical properties of borassus (Toddy palm) fiber/epoxy composites

- Reddy, K. Obi, Maheswari, C. Uma, Reddy, K. Ramakrishna, Shukla, M., Muzenda, E., Rajulu, A. Varada

  • Authors: Reddy, K. Obi , Maheswari, C. Uma , Reddy, K. Ramakrishna , Shukla, M. , Muzenda, E. , Rajulu, A. Varada
  • Date: 2015
  • Subjects: Borassus fruit fiber , Chemical treatments , Spectroscopy
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/73565 , uj:18426 , Citation: Reddy, K.O. et al. 2015. Effect of chemicals treatment and fiber loading on mechanical properties of borassus (Toddy palm) fiber/epoxy composites.
  • Description: Abstract: The aim of the present study was to investigate and compare the mechanical properties of untreated and chemically modified Borassus fiber reinforced epoxy composites. Composites were prepared by hand lay-up process by reinforcing Borassus fibers with epoxy matrix. To improve the fiber-matrix adhesion properties, alkali (NaOH), and alkali combined with silane (3- aminopropyltriethoxysilane) treatments on the fibers surface were carried out. Examinations through Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were conducted to investigate the structural and physical properties of the Borassus fibers. Tensile properties such as modulus and strength of the composites made by chemically modified and untreated Borassus fibers were studied using a Universal Testing Machine (UTM). Based on the experimental results, it was found that the tensile properties of the Borassus reinforced epoxy composites were significantly improved, as compared with the neat epoxy. It was also found that the fiber treated with combination of alkali and silane exhibited superior mechanical properties as compared with alkali and untreated fiber composites. The nature of fiber/matrix interface was examined through SEM of cryo-fractured samples. Chemical resistance of composites was also found to be improved with chemically modified fiber composites.
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Tyre derived fuel as an alternative fuel for CI engines

- Pilusa, T.J, Shukla, M., Muzenda, E.

  • Authors: Pilusa, T.J , Shukla, M. , Muzenda, E.
  • Date: 2013
  • Subjects: Tyre derived fuel-diesel , Waste tyre pyrolysis , Alternative fuel , Crude oil
  • Type: Article
  • Identifier: uj:4957 , http://hdl.handle.net/10210/13058
  • Description: The study presented in this article investigated the potential use of tyre derived fuel-diesel blends as an alternative low cost fuel for compression ignition engines. A short review was conducted on waste tyre pyrolysis technology and its benefits in addressing the waste tyre management while providing an alternative usable fuel for diesel engines. Crude oil obtained from slow pyrolysis of waste tyres was distillated and its respective fractions were characterized and blended with low sulphur diesel fuel for fuelling a stationery truck engine linked to a hydraulic dynamometer. The test results revealed that fuel fraction blends with low sulphur diesel can be used to fuel a conventional compression ignition engine, however special attention is required to manage the exhausts emission due to high concentration of sulphur dioxide. There is no doubt that tyre derived fuel has a potential as future alternative fuel for compression ignition engines.
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Factors influencing chemical absorption of CO2 and H2S in biogas : a review

- Maile, O.I., Tesfagiorgis, H., Muzenda, E.

  • Authors: Maile, O.I. , Tesfagiorgis, H. , Muzenda, E.
  • Date: 2015
  • Subjects: Absorption rate , Efficiency , Solvent
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/72927 , uj:18345 , Citation: Maile, O.I., Tesfagiorgis, H. & Muzenda, E. 2015. Factors influencing chemical absorption of CO2 and H2S in biogas : a review.
  • Description: Abstract: Absorption is a process in which a substance (solute) is brought into contact with a solvent normally for a purpose of separation, which can be either physical or chemical. pH and concentration of the solvent, temperature of both the gas and the solvent, and absorbing surface area influence the absorption process. pH affect the absorption rate and if an acid or base is added into the system the absorption rate is lowered. Concentration of carbon dioxide in the gas stream and the loading rate influence the rate of absorption. MEA has an optimum absorption rate at liquid temperature of 35 °C. Ammonia has high removal efficiency at ambient temperature and there exists a direct relationship between absorption rate and temperature. Absorption of CO2 with sodium hydroxide is normally done at a temperature range of - 1-16 °C (30-60 °F). Calcium oxide requires high temperature for absorption ranging from 300-390 °C, while 22-80 °C is used for H2S absorption with K2CO3. A linear increase results from heating the CO2 gas stream prior to absorption. The rate of absorption is influenced by the contact area between the absorbing fluid and the gas.
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An investigation into the effect of temperature on the leaching of copper-matte

- Muzenda, E., Ramatsa, I.M., Ntuli, F., Belaid, M., Tshwabi, P.M

Renewable energy: deployment and the roles of energy storage

- Masebinu, S. O., Akinlabi, Esther Titilayo, Muzenda, E., Aboyade, A. O.

  • Authors: Masebinu, S. O. , Akinlabi, Esther Titilayo , Muzenda, E. , Aboyade, A. O.
  • Date: 2016
  • Subjects: Energy storage , Environment , Renewable energy , Sustainability
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/93707 , uj:20381 , Citation: Masebinu, S.O. et al. 2016. Renewable energy: deployment and the roles of energy storage.
  • Description: Abstract: Hydro energy still remains the highest RE contributor to electricity generation globally, nevertheless, trends in solar and wind energy has shown increasing investment in RE. Though a decline in investment was observed between 2012 and 2013, yet investment in RE exceeded that of non-RE in the excess of $80 billion dollar. In 2014, investment increased by 16%. As developed countries get saturated with RE technologies, developing countries are now the focus for investment. Wistfully, path dependency problem, lack of adequate infrastructure and policy framework have been highlighted as the major barrier to RE deployment in developing countries. Also, lack of harmonised government agency for RE implementation, incentives and educational gap are the institutional and social barriers. Energy Storage (ES) is being promoted as the “game changer” with capability of smoothening the variability associated with the two RE technologies, wind and solar, with the highest deployment rate. Recent developments are indicative of cost reduction for ES. This paper therefore presents a concise and holistic review of renewable energy (RE) technologies for electricity generation and assess the roles of ES in mitigating intermittency associated with their generation profile.
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Technology selection and siting of a biogas plant for OFMSW via multi-criteria decision analysis

- Kigozi, R., Aboyade, A. O., Muzenda, E.

Waste to energy technologies from organics fraction of municipal solid waste

- Matheri, A.N., Mbohwa, Charles, Belaid, M., Seodigeng, T., Ngila, J.C., Muzenda, E.

  • 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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Diffusion in saturated clayey barrier medium

- Agbenyeku, E. E., Muzenda, E., Msibi, M. I.

  • Authors: Agbenyeku, E. E. , Muzenda, E. , Msibi, M. I.
  • Date: 2017
  • Subjects: Leachate , Percolation , Earthen barrier
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/223036 , uj:22415 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2017. Diffusion in saturated clayey barrier medium. International Conference on Sustainable Materials Processing and Manufacturing, SMPM 2017, 23-25 January 2017, Kruger National Park.
  • Description: Abstract: The design of clay/clayey barriers for the containment of buried wastes conventionally has been based on the assumption that the hydraulic conductivity controls the rate of leachate percolation. However, recent studies show that diffusion is a controlling mechanism of solute transport in many fine-grained soils. Although the measurement of the hydraulic conductivity of finegrained soils is comparatively a common practice in soil engineering, the measurement of diffusion coefficients is not. As such, it is becoming increasingly essential to assess the movement of chemicals through soil barriers due to diffusion. Studies indicate that diffusion may be an important, if not dominant mechanism of contaminant transport through waste containment barriers. This paper is therefore in line with the efforts made in the measurement of diffusion coefficients of inorganic chemicals passing through saturated soils. Herein, both steady-state and transient equations relating to the diffusive transport of inorganic chemicals are presented. A number of factors affecting diffusion coefficients are identified and a simple method for measuring diffusion coefficients for a compacted barrier is defined. The definition for the diffusion coefficient of soil called the effective diffusion coefficient, D* is seen to vary widely. Generally, the variations are due to the different factors affecting diffusion of solutes in soil and the various ways of including the volumetric water content in the governing equations. Hence, errors in interpretation and comparison of D* values can occur if the appropriate definition is not used. In a nutshell, the concept of diffusion may be unfamiliar to many soil specialists, worsened by the myriad terminologies linked to the study of diffusion in soils. Thus the study attempts to acquaint soil engineers with vital information for the measurement of diffusion coefficients for barrier designs.
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Reduction crystallization of Ni, Cu, Fe and Co from a mixed metal effluent

- Phetla, T.P., Ntuli, F., Muzenda, E.

Effect of blending coal with torrefied biomass for possible application in energy production

- Mamvura, T., Muzenda, E.

  • Authors: Mamvura, T. , Muzenda, E.
  • Date: 2016
  • Subjects: Coal , Biomass , Blending , Torrefaction
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/93696 , uj:20382 , Citation: Mamvura, T. & Muzenda, E. 2016. Effect of blending coal with torrefied biomass for possible application in energy production.
  • Description: Abstract: Emissions of greenhouse gases mostly from fossil fuels are responsible for global warming and climatic changes. This has led to research in bioenergy to reduce greenhouse emissions because bioenergy is part of the carbon cycle, and can only emit greenhouse gases that are part of the carbon cycle. The drawback is its low calorific value when it is in its raw form. Torrefaction improves its energy content to values that are comparable to coal. In this study, marula seeds and blue gum wood, two of South Africa most abundant biomass, were blended with coal both raw and torrefied to see the impact of the torrefaction process on energy density. Blending was done at different ratios to see the optimum results. Results showed that highest calorific value was obtained at 100% marula seeds and 0 % coal, and it was recommended for further studies. Blue gum wood due to its high moisture had slightly higher heating value than the reference coal but from an economical point of view it was not attractive for further studies. This showed the significance of the torrefaction process in increasing heating value of selected biomass in the hope of reducing effects of greenhouse gas emissions.
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