The present study focuses on optimizing the design and performance of natural draft mud-based cookstove (MBC) using the CFD tool ANSYS Fluent. The study simulates the performance of the MBC over different levels of three key factors, i.e. grate height, pot gap, and secondary hole diameter, against the targeted response parameters, which include average flame temperature, thermal efficiency, and combustion efficiency. Two-dimensional (2D) simulations of a real-world prototype of MBC were performed using ANSYS Fluent, solving governing equations for mass, momentum, energy, and species transport throughout the computational domain and employing a pseudo-transient accelerated solver approach to achieve a steady state. Grid independence was established to ensure reliable simulation results. It was observed that an optimized response was obtained at the grate height of 30 mm, pot gap of 30 mm, and secondary hole diameter of 8 mm, wherein the average flame temperature of 887 K, thermal efficiency of 27.64%, and a modified combustion efficiency of 98.97% was observed. The achieved thermal efficiency complied with the BIS IS 13,152:2013 standard for natural draft cookstoves, classifying it as a Tier 2 cookstove according to the performance targets outlined in ISO/TR 19,867-3:2018. The combustion efficiency exceeded 0.97, indicating pure flaming combustion. A full-scale field prototype was fabricated and successfully validated through laboratory and field experiments.

Carbon Capture and Utilization (CCU) technologies offer a promising avenue for transforming captured CO2 into valuable products, serving as renewable fuels or precursors for high-value synthesis. This study explores the dry reforming of methane (DRM) as a viable pathway to convert captured CO2 and CH4 into syngas, achieving high equilibrium conversion through the use of suitable catalysts. Conventional nickel-based catalysts are susceptible to carbon deposition, necessitating innovative approaches to enhance their performance. A tubular microreactor was employed to conduct the reforming process at 800 °C, utilizing Cs-promoted Ni catalysts supported on 90 % Al2O3 and 10 % ZrO2-based support composition. Catalyst preparation involved the impregnation technique, and subsequent characterization employed N2-physisorption, XRD, H2-TPR, TGA, TPD, and Raman spectroscopy. The DRM reaction was systematically investigated using the Ni/ ZrO2- Al2O3 catalysts, with a specific focus on the catalytic effects of Cs promotion. Observations revealed that Cs incorporation onto the ZrO2- Al2O3 matrix led to a substantial increase in hydrogen yield and selectivity across all catalyst compositions, accompanied by a significant reduction in carbon deposition on the catalyst surface. The optimal Cs loading, determined to be 3 wt% over Ni/ ZrO2- Al2O3 catalyst, exhibited CO2 and CH4 conversions of 90 % and 87 %, respectively, with an H2/CO yield approaching 1 (0.95). This research underscores the potential of Cs-modified catalysts in enhancing the efficiency of DRM for CCU applications, providing valuable insights into optimizing catalyst formulations for improved performance in carbon transformation processes.

Water hyacinth (WH), scientifically known as Eichhornia crassipes, is an invasive free-floating perennial hydrophyte that poses a significant threat to the environment and the economy. This study aims to systematically address the management challenges associated with WH by conversion into a potential solid fuel specifically targeted for rural cooking energy applications and estimate the potential of WH waste in India using GIS analysis. WH was collected, and various physical pre-treatment approaches were explored. Four shaping methods (unprocessed, chopping, roll pressing, and roll pressing + chopping) and four drying methods (open sun, multi-tray solar-small, multi-tray solar-large, and solar still) were attempted to identify the most efficient approach for rapid drying. The dried WH samples were pelletised, and characterized for calorific value ultimate analysis, proximate analysis, and heavy-metal content. The pellets, when utilised with a forced-draft cookstove, adhered to the BIS IS:13152 cookstove testing limits for thermal efficiency and emissions of PM2.5 and CO. The blending of WH with locally available agricultural waste (sawdust, cotton straw, and bagasse) in different ratios improved the calorific value by 10–15

Perovskite-based catalysts have been explored as low-cost substitutes for platinum (Pt)- based catalysts for diesel particulate matter (DPM) oxidation. In this work, manganese (Mn)-substituted strontium ferrite (SrFeMnO3-δ) (SFM) as a catalyst was coated on the honeycomb structure of cordierite support and tested for its catalytic performance for DPM oxidation using a real-world engine. The characteristic diffraction peaks due to the presence of the perovskite structure of SFM were observed for the cordierite-supported SFM. Mn was substituted in the lattice of un-substituted strontium ferrite and no other impurities were formed upon the Mn-substitution. Highly agglomerated SFM particles were formed solely due to the perovskite phase formation temperature (900 °C). The SFM catalyst enhanced catalytic Printex-V oxidation performance compared to its oxidation without the catalyst, where Printex V was used as the model DPM. The SFM catalyst showed high CO2 selectivity upon the oxidation of DPM. These results infer that the SFM catalyst possesses promise as an alternative to commercially available DOC catalysts based on PGM for DPM oxidation. SFM-coated cordierite support performed much better in terms of particle number, mass and surface area than commercial diesel oxidation catalyst (DOC) or without DOC at no engine load. The performance is substantially higher even at moderate engine loads of up to 40% and comparable at very high engine loads of 100%. Detailed investigations on a real engine exhaust and measurement of crucial parameters like particle number, mass and surface area suggest convincing and relatively rare evidence for its potential as a catalyst for diesel exhaust emission control catalyst.

In the present work, copper molybdenum mixed oxide phase Cu 3 Mo 2 O 9 was synthesized and studied for catalytic diesel soot oxidation reaction. The impregnation of silver and potassium over copper molybdenum mixed oxide was also studied for further improvement in soot oxidation activity under the both tight and loose contact modes. The soot oxidation temperature ( T max ) decreased from 602 °C in the absence of catalyst to 376 °C with copper molybdenum mixed oxide under tight contact mode, while this was observed at 434 °C for loose contact condition, which suggest high activity of the present catalyst for soot oxidation reaction. There was only slight improvement in the catalytic activity of silver and potassium promoted catalysts. From the detailed structural characterization of the as-prepared catalyst, it was inferred that the synthesized copper molybdenum mixed oxide phase was Cu 3 Mo 2 O 9 . The catalyst structure is highly defective with structural oxygen vacancies responsible for rapid soot oxidation at lowered temperature. These findings were also corroborated by XPS and other studies.

The Coronavirus disease 2019 (COVID-19) pandemic has severely crippled the economy on a global scale. Effective and accurate forecasting models are essential for proper management and preparedness of the healthcare system and resources, eventually aiding in preventing the rapid spread of the disease. With the intention to provide better forecasting tools for the management of the pandemic, the current research work analyzes the effect of the inclusion of environmental parameters in the forecasting of daily COVID-19 cases. Three univariate variants of the long short-term memory (LSTM) model (basic/vanilla, stacked, and bi-directional) were employed for the prediction of daily cases in 9 cities across 3 countries with varying climatic zones (tropical, sub-tropical, and frigid), namely India (New Delhi and Nagpur), USA (Yuma and Los Angeles) and Sweden (Stockholm, Skane, Uppsala and Vastra Gotaland). The results were compared to a basic multivariate LSTM model with environmental parameters (temperature (T) and relative humidity (RH)) as additional inputs. Periods with no or minimal lockdown were chosen specifically in these cities to observe the uninhibited spread of COVID-19 and explore its dependence on daily environmental parameters. The multivariate LSTM model showed the best overall performance; the mean absolute percentage error (MAPE) showed an average of 64% improvement from other univariate models upon the inclusion of the above environmental parameters. Correlation with temperature was generally positive for the cold regions and negative for the warm regions. RH showed mixed correlations, most likely driven by its temperature dependence and effect of allied local factors. The results suggest that the inclusion of environmental parameters could significantly improve the performance of LSTMs for predicting daily cases of COVID-19, although other positive and negative confounding factors can affect the forecasting power.

Community kitchen tandoor (CKT) is a clay-based hollow cylindrical device commonly used in South Asian and Middle Eastern countries for baking flatbreads and cooking meat. These CKTs, generally fuelled by charcoal or wood, contribute significantly to the pollution loads in ambient air along with occupational exposure hazards. CKTs, being a part of the informal sector, lack emissions and safety guidelines. This study surveys 139 restaurants in CKT hotspots of New Delhi, India, to understand tandoor design and operational parameters and to assess PM2.5 and CO exposure concentrations at representative field restaurants. PM2.5 and CO exposure concentrations from traditional CKT was found to be several-folds higher than safe indoor air quality levels. Further, the traditional CKT was evaluated for different improved fuels (like briquettes and pellets) in the laboratory for PM2.5 and CO microenvironment concentrations. It was found that the fuel improvements in traditional CKT could not improve microenvironment concentrations to the desired levels; hence, an automated pellet-fed forced-draft improved tandoor with an improved combustion chamber design is demonstrated. The results of the laboratory trial of improved tandoor were compared with traditional tandoor (using pellets) and have shown 84

The present work assesses the real-world performance of novel improved mud-based cookstoves (MBC) - Pavak 1 (P1) and Pavak 2 (P2) in a remote community in Khandwa, Madhya Pradesh, India. These MBC's were designed using multi-parameter optimization based on extensive laboratory testing. These MBCs are affordable and durable, and can be locally manufactured without compromising cooking quality, taste, or convenience while still meeting the Indian cookstove performance standards (BIS IS 13152 (Part 1): 2013) for emissions and efficiency. MBC's performance was compared to traditional stoves (TS) in accordance with the ISO 19869:2019 cookstove field testing protocol. 45 cooking sessions were captured (22 P1; 13 P2; 10 TS). Fuel-based emission factors (EF) for PM2.5 and CO were estimated using the carbon balance method. Results indicate reductions in PM2.5 (56% for P1 and 46% for P2) and CO emissions (15% for P1 and 0.85% for P2) compared to TS. Analysis of real-time modified combustion efficiencies showed that MBCs exhibited prolonged periods in pure flaming conditions compared to TS. A user perception survey was conducted in the intervention households to understand community acceptability. Our results demonstrate the potential for increased adoption rates, emphasizing the importance of information, education, and communication (IEC) programs to maximize health and climate benefits.

The ferrihydrite and modified ferrihydrite-based adsorbents were explored in the present study to remove selenate and bacterial contamination from drinking water. All the zinc-modified absorbents show >80 % bacterial count reduction, contrary to the unmodified adsorbents (30-40 % reduction). Ferrihydrite-based adsorbent modified with zinc (FH2-10) was the most efficient for selenate adsorption and exhibited the highest bactericidal activity. Sorption experiments showed that for Se (VI) concentration of 400 mu g L-1, a sorbent dose of 0.5 g L(-1 )was sufficient to meet drinking water guidelines within the first 10 min. The maximum adsorption capacity of 40.984 mg/ g was obtained for FH2-10. The regeneration and reuse studies show that the selenium removal efficiency retained was >85 % even after three consecutive adsorption-desorption cycles. Column adsorption studies were performed to assess the adsorbent's field applicability, which inferred the adsorption capacity of 1.3 mg/ g. The FH2-10 adsorbent also showed >95 % bacterial growth reduction against E. coli. Hence the present detailed studies infer that FH2-10 is an efficient material for the simultaneous removal of selenium and bacterial contamination from drinking water, with potential for field application if the sulfate co-ions are not present in higher concentrations.

With the advancement in urbanization and industrialization, there’s sharp resource exhaustion along with instability in the global economy. Currently, most of the economies and industries follow a take-make-disposal pattern of production and consumption. This linear pattern magnifies the constraints on the availability of the resources and subsequently leads to hiked prices, unsustainable overuse, and economic volatility. Considering the circumstances, developed and developing nations are in lust after new, sustainable and carbon-free economic models to make the planet liveable. In pursuit of feasible advancements, the scientific community has already started exploring approaches to re-use or re-cycle different components across the production-consumption succession and put back the residue into the cycle of product generation, commonly conceptualized as a zero waste biorefinery. The researcher's expertise in this domain emphasis integrating the bioeconomy into a closed and re-circulating loop system to compensate for the burgeoning demands of humans. Biomass wastes from various industrial and agricultural operations have pushed the shortcomings into circular bioeconomy that not only adds auxiliary value but articulate social and environmental concerns as well. Henceforth, the present chapter provides a comprehensive outlook on various aspects of zero waste bio-refinery as a sustainable technology to process lignocellulosic wastes, algal waste, and residues into value-added products.

This book is a compilation of processes, technologies & value-added products like high-value biochemicals & biofuels produced from waste biorefineries.

Rapid economic growth, especially in developing countries, directly impacts transport fuel demand, waste generation and greenhouse gas (GHG) emissions. Hence, there is an increasing need to supplement fossil fuel demand with sustainable alternative options while also addressing solid waste and GHG emissions. India generates the highest amount of annual municipal solid waste (MSW) (277 million tonnes out of the global 2.01 billion tonnes); this is estimated to double by 2050. This high MSW generation rate, inadequate management, unscientific landfilling and inefficient disposal practices is a serious concern to health and the environment. The organic fraction of MSW generated in India is estimated to be in the range of 40–60% and contains huge potential fuel value for waste to energy (WtE) options. Owning to the large availability of MSW and its associated environmental and social burdens, MSW for fuel production to support the nations’ sustainability commitments looks attractive, if done scientifically. Considering India as the case study, this chapter reviews the possible routes for converting MSW to useful automobile fuels. Additionally, through life cycle assessment (LCA), this chapter discusses the amount of fossil fuel substitution in the total mobility fuel mix by the MSW derived fuel. LCA evaluation revealed a net 85.03 kg CO2 eq. global warming potential, 0.184 mol H+ eq. acidification potential, 7.794 × 10–3 mol of N eq. eutrophication potential and 4.873 CTUh human toxicity potential, respectively, for ethanol production from 1 tonne of organic fraction of MSW. The findings can help assess the MSW utilization in a more scientific way wherein the benefits are assessed in terms of mitigation of GHG and environmental costs averted, in addition to foreign savings through the reduced import of fossil fuels. Few successful pilot projects as case studies will help getting several stakeholders together, which will be essential for taking this waste utilization option to a useful scale.

Selenium contamination of water resources has become a potential health risk issue. The application of aluminium-iron (Al-Fe) mixed oxide for the rapid adsorption of both selenite (IV) and selenate (VI) ions from water was studied. The synthesized Al-Fe mixed oxide was characterized to understand the morphological and structural properties. Batch adsorption experiments were performed to understand the adsorption performance with variable parameters. Al-Fe mixed oxide was found as efficient for both selenite (IV) and selenate (VI) ion adsorption over a wide pH range up to pH < 9. Adsorption experiments revealed that the dose of 0.1 g L-1 with an initial selenium concentration of 500 mu g L-1 is sufficient to meet the WHO guideline value within the first 30 min of contact time. Langmuir, Temkin and Dubinin-Radushkevich (DR) adsorption isotherm and pseudo-second order kinetics presented better fitting for selenite (IV) and selenate (VI) ions with maximum adsorption capacity for Se(VI) and Se(IV) as 33.1 mg g(-1) and 6.188 mg g(-1) respectively. Column adsorption and regeneration were also studied to understand the practical applicability of the adsorbent. The adsorbent was regenerated using mild alkali and can further be reused without any significant decrease in adsorption efficiency.

The level of air ions considers as an early detection tool for change in the environmental pollutants. The advancement in storage and transportation technology has increased the concentration of air ions in an urban environment. Significant literature reveals that if positive air ions are present in a large number, it has severe health impacts on the human body. This paper discusses the seasonal scanning of air ions at a traffic junction and green zone. The spot sampling methodology used in this study and assessment of air ions count (AIC) during both summer and winter seasons in 2019 at Nagpur city, India. The study reveals that the critically polluted regions are season invariable concerning air ions as a precursor of pollution. The observation of fewer values in negative ions for both the summer and winter season in traffic intersections grounded the fact that seasonal washout of pollutants is not there, which is observed for green zones. The vehicle counts and its density in the green zone play a critical role in the concentration of negative ions. The air ion ratio (-/+) of the morning, afternoon, and the evening was 1.030, 1.142, and 1.142, respectively in the green zone and having lowest values in the traffic location (morning, afternoon, and the evening was 0.92, 0.83, and 0.77, respectively). The increment or decrement in the ion ratio could help understand the prevailing air quality scenario in the urban macro-environment.

Biomass has historically been an indispensable and reliant energy source due to its renewable and carbon–neutral nature, globally accounting for nearly 10% of the total primary energy supply and around 70% of all renewable energy production. India being one of the major contributors to global bioenergy, has a yearly biomass availability of around 500 million metric tonnes, 30% of which is surplus. Around two-thirds of all bioenergy supplies in India are consumed by burning traditional biomass in the residential sector (e.g., cooking), resulting in negative environmental and health impacts. India’s target of producing 10 GW of installed capacity of biomass energy by 2022 has already been achieved in 2020. Moreover, it is estimated that the adoption of LPG and cleaner cookstoves could displace around 25% of the fuelwood, which could potentially be used for other purposes. Considering this huge biomass potential, replacing fossil fuel or oil with biomass as raw material for cleaner fuel and chemicals production presents an attractive option. This shift can become the driving force for the development of specially designed biorefineries to produce various useful value-added products, including biofuels and biochemicals, from a single source. This chapter looks into sustainable and close to zero-waste biorefineries to produce high-value products such as biochar, bio-oil and syngas from biomass waste.

The current work describes a simple and uncomplicated chemical process for the production of Nickel tartrate (NiT), proceeded by powder calcination in an air atmosphere to generate the Ni/NiO core-shell nanostructure. The synthesis technique is quick, energy-efficient, and toxic-free, with the potential for large manufacturing. The results show that the method of mixing reactant species has a significant impact on the chemistry of the reaction, the morphology of the particles, and the production rate. Differential Scanning Calorimeter (DSC) analysis of NiT powder was shown that the tartrate molecules dissociate at a temperature of similar to 393 degrees C, leading to the formation of Ni/NiO core/shell structure, which was confirmed by diffraction techniques, electron microscopes, optical and magnetic measurements. This synthesis protocol can be further generalized to create different metal/metal oxide core/shell nanostructures. The magnetic, dielectric and optical properties of the synthesized NiT and Ni/NiO Powder samples were also investigated. The dielectric constant of NiT samples was observed high and low loss factor (tans) in comparison with Ni/NiO samples. Magnetic experiments revealed that NiT samples had paramagnetic fields, whereas Ni/NiO samples have improved ferromagnetic nature dependent on the thickness of the oxide shell. Surprisingly, NiT is a stable powder under many circumstances, allowing us to securely handle, store, and move it, whereas Ni/NiO may be created by the calcination process at the site of application.

The perovskites Nd1-xCexCo1-yCuyO3 (x = 0–0.05, y = 0–0.1) have been synthesized using PVP-assisted sol–gel method and applied for soot oxidation reactions. XRD technique reveals the formation of orthorhombic phase with crystal volume of around ~ 214 Å3 and crystal size of ~ 25–40 nm. The interconnected nanoparticles with hollow spherical network morphology of particles are observed for the samples NdCoO3 (NC1) and Nd0.98Ce0.02Co0.95Cu0.05O3 (NC2) with particle sizes of around 300–500 nm. The samples experienced a charge transfer from ligand (O2−) to cobalt cation in UV region (210–260 nm) and also observed broad absorption bands in the visible region (380–600 nm). In addition, the bandgap energy of NC2 showed the lowest value (4.21 eV); as well as surface morphological advantage promoted the transport of surface-chemisorbed oxygen species in the inner and outer surface of catalysts surface due to the reducibility of the catalyst with the soot $$\left( {\frac{{{\text{O}}_{2}^{{{\text{x}} - }} }}{{{\text{O}}_{2}^{{{\text{x}} - }} + {\text{O}}^{2 - } }} = 0.90} \right)$$ . Furthermore, XPS results evidenced the higher content of Co2+ cation upon substitution of Ce/Cu into NC1, which successively formed more amount of Oβ-oxygen species. Remarkably, the perovskite NC2 showed the lowest soot oxidation temperature (T50% = 434 °C) among the investigated perovskites. Besides, the spherically networked morphology of NC2/NC1 samples also decided the soot oxidation process.

The discrepancy in the performance of improved cookstoves (ICSs) in laboratory and field settings has been well demonstrated, with field results portraying considerable decrease in performance resulting in partial fulfilment of claims due to various factors. This study aims at determining possible discrepancy causing factors—categorised as controllable and uncontrollable. Additionally, performance discrepancy of various cookstoves was explored by testing them in both the settings, keeping the controllable factors consistent. The testing method was in line with Bureau of Indian Standards protocol for testing one traditional cookstove (TCS), three natural draft ICS and one forced-draft (FD) ICS; the cookstoves were evaluated for total particulate matter (TPM), carbon monoxide (CO) concentration measured in the proximity of the cookstove and thermal efficiency. Results reveal TCS to be the major TPM and CO emitter in both the settings, while FD stove was the cleanest. Average increase of TPM and CO in field was found 31% and 33%, respectively, with 10% decrease in thermal efficiency compared to laboratory. Statistical analysis shows substantially less laboratory and field performance variations as compared to previous studies. However, deviations in the results were attributed to uncontrollable factors like kitchen aspect ratio, air exchange rate and local weather among others which are dissimilar to laboratory conditions. Findings from the study are helpful in synchronising the laboratory and field performance by strictly adhering to the controllable factors and outlining the uncontrollable factors while testing before certifying stoves.

Sulphur modified nano zerovalent iron (S?nZVI) has shown considerable promise for removal of various aqueous contaminants. However studies utilizing S?nZVI for removal of aqueous inorganic arsenic (As) is relatively rare, which was studied in this work. Characterization of the synthesized S?nZVI showed typical core-shelled structure with distorted outer shell consisting of iron oxide and FeS. The removal rate of both As(III) and As(V) by S?nZVI was considerably enhanced compared to nZVI and highest As removal was observed at S/Fe ratio of 0.1 under acidic condition. Results showed slight decrease in As removal efficiencies for S?nZVI aged upto 48 h, with obvious drop in As removal efficiencies for longer aging time which although still exhibited higher reactivity than bare nZVI. Spectroscopic investigation showed sulphur amendment of nZVI completely altered the As sequestration mechanism compared to nZVI. While reduction of the adsorbed As(III) and As(V) was observed for bare nZVI, in contrast, uptake of As(III) and As(V) by S?nZVI involves adsorption as As(III) and As(V) oxyanion respectively with additional precipitation of As2S3. Overall, the study shows that incorporation of FeS on the surface of nZVI can be an effective modification strategy for efficient sequestration of As from contaminated water.