Volume 21, Issue 12 - Special Issue Dedicated to the “International Conference on Energy Sustainability and Advanced Materials – 2022 (ICESAM-2022)”

Day by day as the population increases, food waste keeps on growing. This waste needs to be managed in order to reduce the number of landfills and to use food waste efficiently. Among the various processes available, Anaerobic Digestion (AD) of food waste is one of the alternatives for processing food waste. The two biggest obstacles to anaerobic digestion of food waste are high biodegradability and high C/N ratio. The C/N ratio determines the ratio between substrate and nutrients; the latter is essential for microbial synthesis and for providing alkalinity through ammonia metabolism. Biogas, a product of the anaerobic digestion process, is a clean and renewable form of energy that can replace conventional energy sources that cause ecological-environmental problems and at the same time are depleted more quickly. The aim of this work was to increase the nitrogen content to enhance the production of biogas from canteen waste. During the process, two digesters of the same capacity were operated. Anaerobic digestion of canteen waste along with addition of ammonium chloride was carried out in Digester 1 while AD of only canteen waste was carried out in Digester 2. The amount of biogas produced in Digester 1 was in the range of 0.04 m 3 /kg–0.075 m 3 /kg, while in Digester 2 the volume range was 0.02 m 3 /kg–0.04 m 3 /kg. The average biogas produced in digester 1 consisting of canteen waste and nitrogen source was 0.053 m 3 /kg while biogas production in digester 2 with only canteen waste was 0.030 m 3 /kg. So, biogas produced by addition of nitrogen source was 77 % higher than that of only canteen waste. From this study we obtained a higher amount of biogas by addition of ammonium chloride as an external nitrogen source. Nitrogen demand of methanogens was fulfilled by additional supply of nitrogen resulting in increased quantity of biogas. Therefore, in anaerobic digestion addition of ammonium chloride was beneficial for food waste digestion. Hence, nitrogen content in canteen waste turned out to be the main parameter affecting anaerobic digestion of canteen waste which is justified in this research.

The present work details the development of a compositional model to replicate the heavy hydrocarbon flow in porous reservoir systems under non-isothermal conditions. The mathematical model considers mass and energy conservation equations describing the reactive of natural variables distributed in a multiphase hydrocarbon system. Such natural variable based compositional models better suit fully implicit numerical schemes with inexpensive Jacobian matrix computations. Further, the model accommodates a switch of primary variables for the disappearance and reappearance of a phase. The resulting nonlinear conservation equations are numerically discretized using a block-centered finite-difference scheme and solved with a quasi-Newton based implicit iterative solver. The present model is validated with the thermal profiles presented in the literature for the multiphase flow during the combustion of heavy crude oil in petroleum reservoir system with performance coefficient ( R 2 ), mean absolute error (MBE), and maximum absolute percentage error (MAPE) of about 0.954, 0.37, and 0.01 respectively. The developed compositional model projected 26 and 72 % of light and heavy oil recoveries respectively in about 160 days with a maximum or peak temperature of about 798 K. Further, the thermal and production profiles projected by the sensitivity analysis on various operating parameters are presented. It is noteworthy that the present works aid in providing an economical numerical based tool in evaluating the flow and transport during underground or in-situ combustion process for efficient energy exploration.

Carbon capture and storage (CCS) technology is regarded as the feasible solution to mitigate CO 2 emissions from the burning of fossil fuels in large-scale industries to meet energy demand. The storage of CCS requires the injection of CO 2 gas captured from bulk sources into geological formations. Deep saline aquifers are the largest identified storage potential formations for injecting high volumes of gas. The safe storage of CO 2 gas requires a better understanding of the gas migration and pore pressure buildup in the aquifer. In the present work, a numerical has been developed to study the various factors impacting the CO 2 gas migration in the formation of both homogeneous and multi-layered deep saline aquifers. The numerical model has been history matched with an analytical solution and the plume thickness data reported by Nordbotten, J. M., M. A. Celia, and S. Bachu. (2005). “Injection and Storage of CO 2 in Deep Saline Aquifers: Analytical Solution for CO 2 Plume Evolution during Injection.” Transport in Porous Media 58 (3): 339–60. The saturation distribution and pressure buildup in the aquifer are different for each case. The relative permeability of gas increases in the homogeneous case. The drainage efficiency increases along with injection time in any formation. However, the drainage process is less in layered formation compared with homogeneous formation. The parameterized storage efficiency factor ( Ɛ ) is calculated to understand the storage capacity of the aquifer along the lateral direction near to injection well. The formations having low permeability in the top and below layers of the aquifer, the storage efficiency factor is high indicating more amount of gas is stored.

Minimizing energy consumption is often a grave challenge in many industrial energy-intensive process units such as Multiple Stage Evaporator (MSE). Integration of Energy Reduction Schemes (ERSs) is a common technique to resume a countable amount of energy. Hence, the present work proposes a hybrid (h-) ERSs integrated MSE placed in the paper industry, used to increase the solid content of the black liquor. The h-ERSs Integrated MSE comprises several ERSs such as Thermo-Vapor Compressor, Steam-, Feed-split, and Feed Preheater to improve the energy efficiency significantly, and its energy performance is compared with base (b-) MSE. For this purpose, nonlinear mathematical models have been developed and transformed into a constrained optimization problem to search for the optimum energy efficiency obtained as Steam Economy (SE). A state-of-art metaheuristic approach, Equilibrium Optimizer (EO), along with some well-acquainted solution approaches (Interior Point OPTimizer, Interior Point Method, and Particle Swarm Optimization) has been simulated in different platforms to estimate the maximum SE to check their competitiveness for this industrial optimization problem. It is observed that EO outperformed all the algorithms with a 66 % higher SE for h-MSE than b-MSE. Eventually, the steady state parameters are applied as the initial conditions to analyze the nonlinear enthalpy dynamics of the b-and h-MSE. A neural base solution has been adopted to rigorously study the open-loop process dynamics that meet the desired product quality.

This work presents a study on the separation of model compounds representative of mustard husk pyrolysis oil, through a combination of experimental and modelling approaches. Atmospheric and vacuum distillation were used to perform the separation, and the obtained results were validated by means of an Aspen simulation model. To simulate the pyrolysis oil, different fractions present in mustard husk pyrolysis oil were used. Atmospheric distillation was performed at temperatures ranging from 50 to 180 °C, while vacuum distillation was conducted at varying temperatures and pressures. The composition of the distillate and residue was analysed, and it was found that coking occurred due to polymerization reactions, even at moderate temperatures up to ∼100 °C during atmospheric distillation. Therefore, vacuum rotary evaporation was employed to carry out further studies at lower temperatures (50 °C) and pressures (50 mbar), resulting in a recovery percentage of 56 % for lighter fractions and 36 % for heavier fractions, with complete water (62 %) collected in the distillate phase. The simulated feed mixture, which consisted of Guaiacols, furfurals and furan methanols, was distributed equally in both the distillate and residue phases, and the experimental recoveries in distillate and residue phases were found to be similar with simulation values. Further studies are needed to comprehend the separation behaviour of real pyrolysis oil and to minimize polymerization reactions in the column.

In this study Ochrobactrum intermedium (Alhpa-22) was isolated from petroleum refinery sludge and characterized by using 16rRNA. In experimentation, for decolrization of methyl orange dye an indigenous noble bacterial ochrobactrum intermedium (Alhpa-22) at 35 °C has been used in a bioreactor. The ochrobactrum bacterial decolorized methyl orange dye having the concentration of 50 mgL −1 by 87 % within 9 days, which is a very encouraging result. decolorization of methyl orange dye by the isolated bacteria was elucidated using a UV–Vis spectrophotometer. The experimental data were fitted first and zero order kinetics models which show degradation of dye follows first order kinetics in presence of Lysinibacillus fusiformis KLm1, bacterial ochrobactrum intermedium (Alhpa-22) and mix consortia of Lysinibacillus fusiformis KLm1 and ochrobactrum intermedium (Alhpa-22). The rate constant were estimated to be 0.017 h −1 , 0.020 h −1 and 0.014 h −1 respectively. Due to its higher decolorizing capability these may be used for the bioremediation of methyl orange dye (azo dye).

In the search for environmentally acceptable alternative fuels for diesel engines, biodiesel is a tempting option. Still, the long-term repercussions are excessive noise and vibration, as well as irregular and unpredictable combustion, which leads to knocking. In this study, an attempt was made to study the vibrational behavior of diesel engines fuelled with neat diesel and jatropha biodiesel blends (BJ0, BJ10, BJ20, BJ30, and BJ40) and lubrication oil degradation at different operating time periods (40, 60, 80 and 100 h). Vibration analysis is done through the measurement of horizontal and vertical frequencies and physical characteristics of lubrication are done through the determination of viscosity and density. Observation shows that there is a definite relationship between the degradation of oil and the vibration signatures of the engine. It is observed that BJ20 is the best-suited fuel for optimized performance. The highest frequency of vibration is reported in the frequency range of 1039–1041 Hz. The present study provides the guidelines for condition monitoring of bio fuelled engines for proper maintenance and scheduling change of oil.

Biodiesel, an important sustainable fuel used in the transportation sector, demands a stable, recyclable and green catalyst for its economical and environmentally benign production. A novel green heterogeneous acid catalyst was developed by extracting sodium silicate from bamboo leaf ash (BLA), using which SBA-16 (BLA) was synthesized and then impregnated with 10 wt% each of WO 3 and ZrO 2 , characterized and evaluated for the transesterification of Ankol seed oil with methanol to biodiesel. XRD, SEM, TEM and pore size characterization indicated that impregnated WO 3 and ZrO 2 were present outside the mesopores of SBA-16 (BLA) as monoclinic phases, thus 3D cubic cage-like Im3m mesopores of SBA-16 were unaltered. NH 3 -TPD indicated the presence of acid sites of two distinct strengths, attributed to the Lewis and Brønsted acidity of WO 3 –ZrO 2 impregnated into SBA-16 (BLA) and hence gave the highest biodiesel yield of 98 %. In contrast 10 wt% of WO 3 and 10 wt% of ZrO 2 separately impregnated into SBA-16 gave 65  and 57 % of biodiesel yield respectively, possibly due to the presence of Lewis acidity alone in them. Among the WO 3 (10 %)–ZrO 2 (10 %) impregnated mesoporous supports viz. SBA-16 (BLA), SBA-16 (synthesized using tetraethyl orthosilicate), SBA-15, MCM-41, MCM-48, KIT-6, FDU-5, and TUD-1, the highest biodiesel yield of 98 % was given by SBA-16 (BLA), attributed to its spherical morphology and strong interaction with WO 3 –ZrO 2 as inferred from SEM and XPS characterizations respectively. From the effect of process parameters on the WO 3 (10 %)–ZrO 2 (10 %)/SBA-16 (BLA) catalyst, maximum biodiesel yield was obtained at the temperature of 65 °C, catalyst amount of 200 mg, methanol:oil weight ratio of 10:1 and reaction time of 3 h. Under these reaction conditions, it retained the same biodiesel yield for six recycles after regeneration every time, confirmed its catalytic stability and recyclability.

A methodology based on sound non-equilibrium thermodynamics principles is developed to estimate the extremum dissipation point for steady-state incompressible flow past a sphere at low Reynolds numbers. It is shown, that the extremum dissipation point appears at the point when both the shear stress and the pressure at the surface of the sphere are equal to zero. The Reynolds number and the position of the extremum dissipation flow past a sphere were further estimated with the aid of a mathematical model for pressure distribution on the sphere surface, accounting for both creeping and ideal flow. The parameters of the model were determined by comparison of the calculated pressure distribution at the surface with the available literature data. The conditions at which the separation angle and the extremum dissipation angle coincide were also investigated. It is believed that this work could be used to further elucidate the flow past a sphere.

In the present work jatropha, palm, and karanja-based biodiesel and diesel blends, as well as biodiesel diesel and butanol blends, were studied. 112 density data for biodiesel-diesel blends in the temperature range of 30–65 °C were generated. 651 data for viscosity for these blends were generated in the temperature range of 25–65 °C. Blends with butanol were studied only at room temperature. The addition of butanol has not made much of a difference in the density or viscosity of the blends. Empirical models available in the literature were fitted to the data. The linear model in volume fraction and temperature was accurate for density. A generalized model was proposed representing the density for the biodiesel/diesel blend comprising all three biodiesels. A new empirical model for viscosity was also proposed in the study. The proposed model performed well compared to other models, with % an OARD of 3.74 %. A generalized model for viscosity was also proposed. The generalized models could estimate the density and viscosity with % OARD of 0.673  and 5.25 %, respectively.