ORCID Profile
0000-0003-2127-4206
Current Organisations
Technical University of Munich
,
University of Engineering and Technology
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Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JENVMAN.2019.109924
Abstract: Sustainability in power generation mainly depends on the transition from fossils to sustainable energy resources. Biomass from the crop residue has huge potential for renewable power generation, but it is still not utilized to its full potential. This study presents a comprehensive methodology to evaluate and forecast the current and future availability of selective crop residue to generate renewable energy. A forecast model incorporating historical trends in the crop yield has been developed in MATLAB and implemented for crop residue based biomass resource assessment of five primary crops (wheat straw, rice husk, rice straw, cotton straw, corn stover, and bagasse) in order to estimate the energy generation potential for Pakistan from 2018 till 2035. It was found that about 40 million tonnes of crop residue was available in Pakistan for power generation in the year 2018 considering a residue removal (availability) factor of 50%. This translates to an estimated potential of about 11,000 MW of electricity generation capacity using crop residue derived biomass for 2018. This capacity is predicted to gradually increase up to 16,000 MW by the year 2035 based on the trends in the growth of crop production since 2001. The suitability of a potential region for the installation of 100 MW biomass-fired power plants was also assessed by calculating crop residue density and an equivalent collection radius (R
Publisher: MDPI AG
Date: 19-05-2023
DOI: 10.3390/SU15108291
Abstract: The brick kiln industry is one of the largest and most highly unregulated industrial sectors in developing countries. Most of the kilns use low-quality coal as primary fuel along with small quantities of bagasse, rice husk, and wooden chips. As a result of inefficient methods of combustion in conventional brick kilns, such as fixed chimney Bull’s trench kilns (FCBTKs), harmful pollutants are emitted in high quantities, which ultimately deteriorate the environment and are widely in operation in Pakistan. The most prominent harmful pollutants include carbon dioxide (CO2), carbon monoxide (CO), sulphur dioxide (SO2), black carbon (BC), and particulate matter less than 2.5 microns (PM2.5). Over the years, new technologies have been adopted by developed countries for the reduction of environmental burdens. One of these technologies is induced draught zigzag kilns (IDZKs), or zigzag kilns (ZZKs), technology, which effectively improves the combustion across the path of bricks stacked in a zigzag pattern. For the mass adoption of this technology, environmental assessment and comparison of both technologies is a crucial step. Both types of kiln sites are investigated for the analysis of their emissions and their environmental impact in this work. Carbon mass balance equations are used for the calculation of emission factors. Collected inventory data is then used for the life cycle assessment of both types of kilns using open LCA (version 1.10.3) and the Eco-invent database. According to the study, ZZK technology outperforms FCBTK in all aspects. The analysis of the specific energy consumption (SEC) of fired bricks for each kiln type reveals that ZZKs require 30% less energy than the conventional FCBTK. This implies that ZZKs demand lesser fuel than FCBTKs. The zigzag technology adoption scenario, in particular, can lead to approximately 30% lower CO2 emissions, which can be further reduced by up to 80% when taking into account black carbon (BC) emissions. Additionally, the adoption of zigzag technology can result in a 35% decrease in PM2.5 emissions. The study shows that adopting ZZK technology significantly reduces impact categories, such as particulate matter formation (PMF), photochemical oxidant formation (POF), and terrestrial acidification (TA) by 63%, 93%, and 95%, respectively.
Publisher: MDPI AG
Date: 13-11-2020
DOI: 10.3390/EN13225941
Abstract: In this study, waste cooking oil (WCO) was used as a feedstock for biodiesel production, where the pretreatment of WCO was performed using mineral acids to reduce the acid value. The response surface methodology (RSM) was used to create an interaction for different operating parameters that affect biodiesel yield. The optimised biodiesel yield was 93% at a reaction temperature of 57.50 °C, catalyst concentration 0.25 w/w, methanol to oil ratio 8.50:1, reaction stirring speed 600 rpm, and a reaction time of 3 h. Physicochemical properties, including lower heating value, density, viscosity, cloud point, and flash point of biodiesel blends, were determined using American Society for Testing and Materials (ASTM) standards. Biodiesel blends B10, B20, B30, B40, and B50 were tested on a compression ignition engine. Engine performance parameters, including brake torque (BT), brake power (BP), brake thermal efficiency (BTE), and brake specific fuel consumption (BSFC) were determined using biodiesel blends and compared to that of high-speed diesel. The average BT reduction for biodiesel blends compared to HSD at 3000 rpm were found to be 1.45%, 2%, 2.2%, 3.09%, and 3.5% for B10, B20, B30, B40, and B50, respectively. The average increase in BSFC for biodiesel blends compared to HSD at 3500 rpm were found to be 1.61%, 5.73%, 8.8%, 12.76%, and 18% for B10, B20, B30, B40, and B50, respectively.
Publisher: MDPI AG
Date: 06-06-2022
DOI: 10.3390/SU14116930
Abstract: This research study presents an approach for analysis of pico hydro waterwheels by both experimental and numerical methods. The purpose of this research is to harness the energy efficiently from flowing water of irrigation channels and other shallow water sources in rural areas because the electrification of rural areas through connection to grid electricity is very costly. The novelty of this research work lies in testing of the waterwheel as a high-speed device, which is not usually explored. The review of existing literature reveals that pico waterwheels have been extensively studied but without changing the blade profile immersed in the water stream ot the inclination angle of the water stream. In this study, a pico scale waterwheel was tested with three different types of blade profiles, namely a C-shape blade, V-shape blade and straight blade, through computational fluid dynamics (CFD) simulations for different tip speed ratios (TSR), varying the immersed depth of the blade in the stream and changing the angle of the water conduit while keeping the number of blades and the diameter of the wheel constant. The numerical and experimental results were validated for the C-shape blade profile. A substantial improvement in performance is observed with a C-shape blade profile at a TSR of 0.88. The results show that by varying the angle of the water conduit, the maximum performance is achieved at inclination φ = 45°, with an overall improvement of 4.87% in the efficiency.
Publisher: Frontiers Media SA
Date: 28-09-2022
DOI: 10.3389/FENRG.2022.880064
Abstract: The utilization of biomass for cooking and heating is old, occurring from the early stages of human evolution because of its wide and easy availability. In Asia, a majority of the population is dependent on solid biomass for cooking and heating applications. Biomass cookstove produces emissions like carbon monoxide (CO), and particulate matter with aerodynamic diameter ≤2.5 μm (PM 2.5 ) which are dependent on the classifications and characteristics of fuel used in stoves. These emissions trigger many health risks because of the utilization of traditional cookstoves (TCS) which have less thermal efficiency. The literature contains a considerable amount of information on biomass cookstoves however, it is dispersed particularly in Asian countries. In this principle, this paper gives an overview of available literature on biomass cookstoves for cooking and heating in Asian countries which are involving Bangladesh, China, India, Mongolia, Nepal, Pakistan, Sri Lanka, and Laos. This paper covers a detailed discussion on various aspects of biomass cookstoves: history, classification, fuel characteristics, health risks, design criteria, the scenario in selected Asian countries, thermal efficiency and emission comparison, and barriers to dissemination of improved biomass cookstoves (ICS). Learning from the review and comparison made conclude that the ICS has better thermal efficiency, and lesser emissions, as well as health risks but, have some potential barriers to dissemination.
Publisher: MDPI AG
Date: 17-05-2023
DOI: 10.3390/SU15108125
Abstract: Highly concentrated triple-junction solar cells (HCTJSCs) are cells that have erse applications for power generation. Their electrical efficiency is almost 45%, which may be increased to 50% by the end of the year 2030. Despite their overwhelming ability to generate power, their efficiency is lower when utilized in a concentrated manner, which introduces a high-temperature surge, leading to a sudden drop in output power. In this study, the efficiency of a 10 mm × 10 mm multijunction solar cell (MJSC) was increased to almost 42% under the climatic conditions in Lahore, Pakistan. Active cooling was selected, where SiO2–water- and Al2O3–water-based nanofluids with varying volume fractions, ranging from 5% to 15% by volume, were used with a 0.001 kg/s mass flow rate. In addition, two- and three-layer microchannel heat sinks (MCHSs) with squared microchannels were designed to perform thermal management. Regarding the concentration ratio, 1500 suns were considered for 15 August at noon, with 805 W/m2 and 110 W/m2 direct and indirect radiation, respectively. A complete model including a triple-junction solar cell and allied assemblies was modeled in Solidworks software, followed by temperature profile generation in steady-state thermal analyses (SSTA). Thereafter, a coupling of SSTA and Ansys Fluent was made, in combination with the thermal management of the entire model, where the temperature of the TJSC was found to be 991 °C without active cooling, resulting in a decrease in electrical output. At 0.001 kg/s, the optimum average surface temperature (44.5 °C), electrical efficiency (41.97%), and temperature uniformity (16.47 °C) were achieved in the of MJSC with SiO2–water nanofluid with three layers of MCHS at a 15% volume fraction. Furthermore, the average outlet temperature of the Al2O3–water nanofluid at all volume fractions was high, between 29.53 °C and 31.83 °C, using the two-layer configuration. For the three-layer arrangement, the input and output temperatures of the working fluid were found to be the same at 25 °C.
Publisher: MDPI AG
Date: 12-09-2023
DOI: 10.3390/SU151813604
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Muhammad Amjad.