Abstract/Overview Tea, produced from the evergreen plant, Camellia Sinensis, is the most widely consumed beverage in the world after water. Although tea processing has now diversified into various speciality end products such as instant, white, oolong, iced, flavoured, and various blends, the most abundantly produced tea product in the world is fermented black tea. Black tea production is essentially a “dry” process, as no water is used at any of the production process steps. However ...
Abstract: Fossil fuels, particularly crude oil, have proven to be a source of energy to households, transportation and power industries over the past decades. This natural reserve is diminishing at an alarming rate with crude oil having reserves to last the earth for the next half a century. As a result, researchers are constantly seeking remedial technologies to close this gap. Thermochemical conversion processes such as pyrolysis, gasification and liquefaction (PGL) offer an alternative so...
Abstract: Al2O3.TiO2 ceramic composites exhibit versatile properties such as high hardness and excellent wear, chemical, thermal and corrosion resistance. As such, they have been used in various applications such as optical and electronic, gas separation, biomedical processes, and support for transition metal catalysts, wear resistant coatings in machinery, textile and printing industries. However, alumina and alumina-based composites often exhibit high brittleness which limits their potenti...
Abstract: Coal due to its relatively large quantities and wide distribution worldwide has generated renewed interest in research and development with the aim of establishing coal conversion technologies that are technically reliable, environmentally and economically feasible. It has proved to be a prominent energy source in emerging markets with increasing energy demand by accounting for the largest increase in the demand of energy amongst all other energy sources. Furthermore, with its high...
Abstract: The research presents a comparative study on the effectiveness of blending plant based natural coagulants (Cactus Opuntia and Moringa Oleifera extracts) and a synthetic coagulant (aluminium sulphate or alum) in treatment of raw water. The low production rates of natural coagulants has derailed their commercialization this has driven the idea of blending synthetic coagulants which is envisaged to be the more appropriate means of application in this study. To measure the effectivenes...
Abstract: In this review, the role of surface modification of nanoparticles to enhance their performance as adsorbents was explored. Performance was assessed by comparisons on adsorption capacities of differently modified nanoparticles (silica, iron, and alumina based nanoparticles) on different heavy metal ions (Cu, Cd, Co, Ni, Pb, As, Cr, Zn, Mn, and Hg). A comparison of pure and modified materials revealed that the modified materials gave superior adsorption capacities. A close relationsh...
Abstract: The disposal of sludge processes accounts for 60% of the total operation and 40% of total emissions of greenhouse gas from wastewater treatment plants operations. Moreover, sludge contains pathogenic microorganisms, organics, inorganics, trace metals and emerging micropollutants, which can be a public health menace. To comply with the Environmental Protection Agency standards, sludge must be stabilized and detoxified before being disposed or reused. This study focuses on the use of...
Abstract: In this study, the co-briquetting of coal fines saw dust and molasses as a binder is explored as an option for value addition of the wastes generated in the various industries. The effect of the saw dust concentration and the molasses concentration was investigated through measuring the briquette's calorific value, fixed carbon, compressive strength and shatter index. Addition of Ca(OH)2 was done to effect removal of sulphur from the briquette. Measurements of the briquettes physio...
Abstract: A green prospective based on the reuse of waste materials such as beef tallow and waste cooking vegetable oils to manufacture soap is presented. Beef tallow and waste cooking oils that is discarded as waste from households and restaurants after frying is reviewed for the production of toilet (bath) soap. The discarded oil is purified with a brine solution and bleached with Hydrogen Peroxide (H2O2.) Purified waste cooking oils and beef tallow is mixed with coconut oil commonly used ...
Abstract: Pyrolysis is one of the prospective processes that can be utilized to obtain high value chemicals and energy from coal and biomass. Coal-biomass co-pyrolysis presents a green, low-risk, cheap, sustainable, renewable energy source with low carbon emissions. Co-pyrolysis offers the highest yield of liquid fuels and gas compared to the individual feedstocks. It has been illustrated that the production yields experimentally usually exceed the calculated and this can be explained by the...
Abstract: There are a number of factors that affect the output of the Fischer Tropsch process, change in the process parameters like catalyst used, residence time, temperature, pressure, particle size, bed height, flowrate and even the type of reactor used. A small manipulation of the parameters is enough to change completely the conversion, selectivity; therefore, these parameters have to be monitored. This paper presents the effect of the operation parameters on the Fischer Tropsch synthes...
Abstract: Biogas has been exploited as one of the alternative sources of renewable energy having the potential to replace fossil fuels. It contains impurities when raw, as it consists of 50e70% methane (CH4), 30e50% carbon dioxide (CO2) and trace gases such as hydrogen sulfide (H2S). Chemical absorption is often a preferred purification technique in industrial applications because it has high efficiencies, removes H2S completely, operates at low pressures, and has higher reaction rates. The ...
Abstract: Biodiesel has emerged as a promising alternative fuel to replace dwindling fossil-based resources, particularly in view of its added environmental merit of reducing additional air pollution. Its specific attraction stems from the similarity of its physical properties to fossil fuel-derived diesel. Although the production of biodiesel is a relatively straightforward process, reaction progress monitoring and product analysis require costly specialist equipment, such as gas chromatogr...
Abstract: This simulation study explores sustainable improvements that could be made to a pine dust pyrolysis system to eliminate total dependence on external electrical energy supply and improve the yield of high-quality dry bio-oil. The components, stoichiometric yield and composition of oil, char and gas were modeled in ChemCAD using data from literature and results from biomass characterization and pyrolysis. A fast pyrolysis regime was used to increase the overall yield of dry oil fract...
Abstract: Botswana high-ash semi-bituminous coal produced by Morupule mine is under-utilized due to a lack of knowledge in possible applications of derivative products such as tar, syngas, and charcoal. This study is aimed to determine the possibility of producing tar as the main product via stage condensation in a semi-batch pyrolysis plant. A conventional process that incorporates fractional distillation to refine tar makes the low-quality coal uneconomical for coal to tar application beca...