Conference Papers
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Item Investigation on Tire Pyrolysis Oil (Tpo) as a Fuel for Cook Stove and Lamps(Institute of Physics Publishing helen.craven@iop.org, 2018) Mohan, A.; Prajeeth Kumar, K.P.; Madav, V.Pyrolysis is an technology to derive value added products like pyrolytic oil, steel wire and carbon black, which works on the principle of thermo-chemical conversion of any carbonaceous feed stocks. The major factors affecting the pyrolysis are temperature, reactor configurations, residence time, heating source etc. A pilot plant study was conducted in a tire pyrolysis oil production industry located in Oyalapathy, Kerala for collecting the oil samples for the analysis. Tire pyrolysis oil (TPO) is a brownish colored, freely flowing liquid, medium viscosity with complex chemical composition. Due to its complex aromatic structure, presence of acids, aldehydes, oxygenated compounds hinders to apply in engine and stove as a fuel. Upgrading of hydrocarbons are necessary to obtain value added products and to derive thermally stable products. There are limited number of studies are carried out in the field of stove fuel production from hydrocarbon derived waste. An attempt was carried out to find the suitability of pyrolysis oil as a fuel in cook stove and oil lamps. The water boiling test was carried out to examine the boiling time for specific volume of water. The study shows that the TPO boils water in shorter time than kerosene and a clear comparison of two brand of fuels. The present study mainly includes the characterization like FTIR, GC-MS to investigate the components present in the oil and compare with diesel and kerosene. The commercialization and economic feasibility studies will be planned in future. © Published under licence by IOP Publishing Ltd.Item Co-pyrolysis of scrap tire and plastic using coal derived fly-ash(ETA-Florence Renewable Energies, 2019) Mohan, A.; Dutta, S.; Madav, V.; Bhushnoor, S.S.; Fernandez-Garcia, J.F.; Williams, P.T.Used automobile tires and thermoplastics (e.g. polypropylene) have become liability of modern societies and several avenues have been explored for their suitable disposal. Pyrolytic liquefaction of tires and plastics have attracted significant attention since the process can provide value-added products such as liquid transportation fuels and chemicals while mitigating the waste disposal issues. Pyrolysis can be done both in absence (thermal) or presence (catalytic) of a catalyst. Catalytic pyrolysis is favored by less demanding reaction conditions and better quality of product. Catalytic copyrolysis has the additional advantage in using a wider feedstock and a possible synergistic effects from different feeds during molecular transformations. This work investigates the effect of untreated fly-ash (class F) as catalyst for the copyrolysis of scrap tire and polypropylene at 300o C and atmospheric pressure using batch type pyrolysis reactor and also studied the effect of fly-ash during pyrolysis of scrap tire using Pyro-GC/MS. Copyrolysis was carried out using various ratio of scrap tire and polypropylene at 300o C, whereas the pyrolysis of scrap tire in pyro-GC/MS was carried out at 500o C. The maximum yield (23.33%) of oil was obtained at a ratio of 60:40 (w/w) of scrap tire and polypropylene in presence of 20wt% of fly ash catalyst. The oils were characterized by NMR, GC-MS, FT-IR and elemental analysis. © 2019 ETA-Florence Renewable Energies.Item Modeling and design validation of fluidized bed reactors for co-gasification of coal and biomass to study hydrodynamics and conversion(ETA-Florence Renewable Energies, 2019) Manu, J.; Dev, R.; Madav, V.The gasifier was designed with reaction chamber of 65mm diameter and 500 mm height. The study of gas-solid hydrodynamics is essential in designing of fluidized bed gasifier. Drag force plays a critical role in modeling fluidization behavior for gas-solid flow. This paper aims to study the effect of drag force on the fluidization parameter for the presently designed gasifier using CFD approach. The Eulerian-Eulerian model, coupled with different drag models was employed for this purpose. Time-averaged solid volume fraction, granular temperature, axial velocity of the solid particle in a lateral direction, and a central axis of the reactor were examined for different drag models like Syamlal O’Brien, Gidaspow, Mckeen and Representative unit cell. Effects of laminar and turbulent models on flow behavior were also studied. The study concluded that the McKeen model shows a relatively flat profile while estimating solid volume fraction while the RUC model overestimated the axial velocity of particles. There was relatively no change in flow behavior for the laminar and turbulent model while predicting the axial velocity of the solid particle in the lateral direction. The axial velocity of particles at a different packing factor was studied and showed no such observable difference in predicting hydrodynamics flow behavior. © 2019 ETA-Florence Renewable Energies.Item Hydrodynamic effect of elastic and inelastic collisions in fluidized bubbling bed reactor(American Institute of Physics Inc. subs@aip.org, 2020) Manu, J.; Madav, V.Collison of sand particles in fluidized bed plays a very important role in determining hydrodynamics of fluidized bed. Effect of coefficient of restitution on hydrodynamics on 300?μm particles in gas-solid fluidized bed was investigated. Eulerian-Eulerian model was used for simulating hydrodynamics of fluidized bed. For investigation, different values of coefficient of restitution which correspond to different values of elasticity of particles were used. No bubbles were found for perfectly elastic collisions. With decrease in the value of coefficient of restitution from 1 to 0.8, bubble formation shows a positive effect. © 2020 Author(s).Item High temperature corrosion behaviour of stainless steels and Inconel 625 in hydroxide salt(Elsevier Ltd, 2021) Pooja, M.; Ravishankar, K.S.; Madav, V.Biomass gasification had proven to be an alternative source of energy to coal gasification. However, it requires high temperatures of about 1000°C for biomass drying and reduction. On the other hand, to reduce the oxidation and corrosion of gasifier structural materials it is important to keep the gasifier working temperature as low as possible. One effective way of keeping the reduction temperature low is to use molten salts as catalyst during biomass gasification. However, by virtue, molten salts cause several corrosion issues in ferrous alloys. In this context, the present study investigates the effect of hydroxide molten salt on the corrosion behaviour of stainless steels such as 316 and 310 and Inconel 625. The samples exposed to the salt at 700°C for about 48 h was analysed for corrosion using weight loss method. A scanning electron microscopy analysis of the exposed samples revealed the depth of corrosion and change in microstructure due to molten salt attack. Although all the selected materials suffered severe corrosion, among all, Inconel 625 show higher corrosion resistance. © 2021 Elsevier Ltd. All rights reserved.Item Capture and Characterization of Particulates from a Single-Cylinder Diesel Engine Fuelled with Refined Tire Pyrolysis Oil(Springer Science and Business Media Deutschland GmbH, 2023) Mohan, A.; Madav, V.Crude tire pyrolysis oil (CTPO) was refined using the principle of selective adsorption and preferential solubility using silica gel as an adsorbent and petroleum ether as a diluent and combusted in a single-cylinder diesel engine. Particulate analysis was conducted in a single-cylinder diesel engine to understand the carbonaceous deposition in piston crowns and surfaces using various analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Further, lubricating oil analysis was performed using a combination of ICP-AES, viscosity, flash, and fire point tests. The results showed that carbon deposition from upgraded tire pyrolysis oil is observed to be higher than diesel due to its high aromatic content. The high amount of carbon deposits from upgraded tire pyrolysis oil was attributed to the high amount of oxygenates in StTPO, which leads to increased polymerization and subsequent condensation on piston crown surfaces, which was then carbonized. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item The experimental analysis of heat transfer characteristics of a hot surface impinged by a lateral air jet(American Institute of Physics, 2025) Kumar, C.; Madav, V.This experimental investigation explores the heat transfer dynamics caused by lateral air jet impingement on a hot, thin stainless steel foil. The aim is to understand the heat transfer characteristics of air jet impinging laterally on the top surface. This setup is relevant to industrial cooling applications where space is limited. Using a thermal imaging camera, the study captures the steady-state temperature distribution across the foil surface. The experiment was conducted by varying the jet exit to stagnation point-to-diameter (S/d) ratios for the lateral jet (2 to 20). The study was carried out for Reynolds number 3000. Keeping electronic chip temperatures below a critical threshold is crucial, as excessive heat can cause performance issues, chip damage, and even pose safety risks in extreme cases. To address the substantial cooling needs of heat-generating chips, a variety of methods and technologies have been explored, including heat pipes, pool boiling, microchannel heat sinks, spray cooling, and jet impingement, among others. The findings show that the lateral jets is good choice for electronic cooling applications when the localized cooling is necessary, and by keeping specific S/d value wider area cooling can also be achieved. It is observed that at S/d=8 maximum Nu is achieved and as S/d is increased further cooling area coverage is widening even though the maximum Nu achieved is comparatively less. This study offers valuable insights into optimizing air jet impingement techniques for enhanced thermal management in various technological domains. © 2025 Author(s).