Food waste-to-energy conversion technologies: Current status and future directions

https://www.econstor.eu/bitstream/10419/243593/1/1666085774.pdf

Renewable energy consumption and economic growth nexus: A fresh evidence from West Africa

Anaerobic digestion (AD) is an established organic waste management technology, producing biogas and organic fertiliser as end-products. Despite being an established technology, AD still faces key challenges, including process inefficiencies due to substrate-induced instability and product quality assurance; inability to digest highly lignocellulosic biomass without pre-treatment; and management of effluents and emissions. Commercial grade carbon-based materials have been employed as stabilising agent to improve process efficiency. Biochar, a by-product from biomass pyrolysis, has recently been identified as a sustainable alternative material to commercial grade carbon-based adsorbent used in AD. This review highlights the challenges with the AD process and the limitations of the various conventional approaches in its management. An exposition of the characteristics of biochar and the physico-chemical properties of biochar, that can simultaneously promote AD process stability, increase biomethane yield rate and the agronomic quality of digestate, are presented and discussed.

A review of biochar properties and their roles in mitigating challenges with anaerobic digestion

Current updates on waste to energy (WtE) technologies: a review

Life cycle assessment of waste-to-energy (WtE) technologies for electricity generation using municipal solid waste in Nigeria

The continued concerns over energy prices, increase in population, and climate change issues have led towards a need for alternative and new energy sources. Municipal solid waste (MSW) is generally accepted as a renewable energy resource. This research study presents a techno-economic assessment potential to utilize the energy obtainable from MSW for the generation of electrical power. The assessment was carried out for energy generation by thermochemical (incineration or combustion) and biochemical (landfilling and anaerobic digestion) processes and based on the available data from seven selected municipalities. Due to the broad scope of this topic, life cycle impact of waste management, social acceptance, policy aspects, and emission reduction or fossil fuel offset are not considered and are not part of the assessment. Results presented in tabular form indicate, for example, that the price of steam generated by a fluidized steam generator is in the range of US$0.018/kWht (Lagos) to US$0.044/kWh (Nsukka) and compares favorably with the typical cost of steam at US$0.015/kWh. Electrical power generation using a combined heat and power plant provides electricity at a cost that is in the range of US$0.017/kWhe (Lagos) to US$0.040/kWhe (Nsukka) and also compares well with the typical cost of electricity in Nigeria at US$0.14/kWhe (as of 2012).

/pdf/renewable-municipal-solid-waste-pathways-for-energy-42se49n0c9.pdf

Renewable municipal solid waste pathways for energy generation and sustainable development in the Nigerian context

The global supplies of petroleum are on the decline and the dwindling resource has become increasingly difficult to access. Improved technology is increasingly been required to access petroleum that is in hard to reach geographical environments and has chemical composition that is not entirely compatible with existing processing techniques. Alternative energy involves energy from renewable and non-depleting sources such as wind and solar, offer many opportunities for research and development and are been widely developed globally. These sources of energy are expected to reduce the threat of a changing climate, air pollution and oil dependence caused by the automobile industry. There are many economic, environmental and societal benefits of employing various alternative energy sources or options in the passenger automobile industry for motive power. Transitioning from a monoculture of hydrocarbon-based transportation will be just as signify- cant as investments in research and development needed to develop a portfolio of cost-competitive and safe alternative powertrain technologies that can effectively retire the fossil fueled internal combustion engine, without much of any economic stress. In this work, we couple energy and environmental issues to obtain a realistic indication of the future of alternative powertrain technologies for the future of the passenger automobile industry.

/pdf/overview-of-energy-and-environmental-issues-in-the-passenger-2qo7s2gn2o.pdf

Overview of Energy and Environmental Issues in the Passenger Automobile Industry

Internal combustion engines with application in automobiles and other relevant industries constitute significant environmental pollution via the release of toxic exhaust gasses like carbon monoxide (CO), hydrocarbons (HC), particulate matter (PM), and nitrogen oxide (NOx). Engine researchers and manufacturers are challenged to develop external and internal measures to ensure environmentally friendly solutions to accommodate and conform to the growing list of emission standards. Therefore, this work presents an experimental investigation of the NOx emission profile of a diesel engine that is fuelled and fitted with waste frying oil-based biodiesel and catalytic converter. Using a single-cylinder, four-stroke air-cooled CI engine at a constant speed of 1900 rpm and different loadings of 25%, 50%, 75%, and 100%; fitted with a catalytic converter at the exhaust outlet of the engine and linked to a dynamometer and a gas analyser, an experiment was conducted at biodiesel/diesel volume blends of B0 (0/10), B5 (5/95), B20 (20/80), B30 (30/70), B70 (70/30), B100 (100/0); and 30% concentration (v/v), 0.5 litre/hr flow rate of aqueous urea from the catalytic converter. The results show an increasing NOx emission as the biodiesel component increased in the blend. The catalytic converter showed a downward NOx reduction with a significant 68% reduction in efficiency at high exhaust gas temperatures. It is concluded that the combined utilisation of waste frying oil-based biodiesel and the catalytic converter yields substantial NOx emission reduction. 

/pdf/combined-effect-of-a-catalytic-reduction-device-with-waste-2ugaivyl.pdf

Combined Effect of a Catalytic Reduction Device with Waste Frying Oil-Based Biodiesel on NOx Emissions of Diesel Engines


 This research is a study assessing the performance of hybrid nanofluids in hybrid photovoltaic (PV)–thermal systems. This study addresses 10 hybrid nanofluids applied to hybrid PV–thermal systems. The transition to carbon-free energy can mitigate the worst effects of climate change, ensuring that global sustainability is addressed. Clean energy is now responsible for one-third of the global capacity, of which 20% is attributed to solar energy. Renewables continue to be economically viable, with declining costs driving growth. This study aims to compare the yearly performances of a model hybrid PV–thermal system using 10 different hybrid nanofluids. Hybrid nanofluids constitute two or more dissimilar materials stably suspended in a base fluid (e.g. water). MATLAB and COMSOL Multiphysics® computational fluid dynamics software are employed together for the benchmarking assessment with good agreement observed. Various fluid inlet temperatures (Tin ∈ [300, 360] K), nanofluid volume concentrations (φ ∈ [0, 4]%) and storage-tank volumes (V ∈ [50, 300] L) were simulated. The meteorological data applied were those for Lagos, Nigeria (6° 27’ 55.5192” N, 3° 24’ 23.2128” E). The assessment based on analytical-numerical solutions reveals that the thermal enhancement by hybrid nanofluids ranges from 6.7% (graphene oxide [GO]—multiwalled carbon nanotube [MWCNT]/water) to 7% (ZnO—Mn–ZnFe2O4/water) for φ = 2% and V = 300 L. The yearly exergy efficiency ranges from 2.8% (ZnO—Mn–ZnFe2O4/water) to 2.9% (GO—MWCNT/water), also for φ = 2% and V = 300 L. These findings have implications for a vast range of industrial processes, expanding the knowledge that is critical to a sustainable future.
 A combined solar PV-thermal system that stores thermal energy using nanofluids is modelled. Hybrid nanofluids (two or more dissimilar materials stably suspended in a base fluid) are shown to enhance the annual electrical, thermal and exergetic outputs of the system.

Olaleye Michael Amoo

Papers

Renewable municipal solid waste pathways for energy generation and sustainable development in the Nigerian context

Overview of Energy and Environmental Issues in the Passenger Automobile Industry

Combined Effect of a Catalytic Reduction Device with Waste Frying Oil-Based Biodiesel on NOx Emissions of Diesel Engines

Benchmark assessment of performance indices of a selection of hybrid nanofluids in a hybrid photovoltaic/thermal system