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This book gathers selected papers presented at the First International Conference on Renewable Energy and Climate Change (REC 2019), which was held at the Institute of Infrastructure Technology Research and Management (IITRAM) from 1 to 2 February 2019. The topics covered include renewable (green) energy and sources including wind power, hydropower, solar energy, biomass, biofuel, geothermal energy, wave energy, tidal energy, hydrogen & fuel cells, energy storage, new trends and technologies for renewable energies, policies and strategies for renewable energies, smart grids, batteries, and e-mobility, control techniques for renewable energies, hybrid renewable energies, renewable energy research and applications for industries, applications of renewable energies in electrical vehicles and other allied areas, artificial intelligence and machine learning studies for renewable energies, renewable energy systems in smart cities, climate change mitigation, carbon trading, carbon capture and utilization, and carbon dioxide refrigeration systems.

### Rare Earth Oxides Based Composites for High Voltage Supercapacitors Applications: A Short Review

Abstract
Supercapacitors (SCs) are energy storage devices with high power density and robust charge/discharge life cycles. The high power density of these energy storage devices makes them attractive storage devices in conjunction with other reversible electrical energy storage devices such as batteries and conventional capacitors. The common SCs are made of nanostructured carbonous electrode materials, which are limited with their relatively lower operating window and specific energy densities. Nanostructured metal oxide based carbonous composites are widely explored to overcome carbonous SCs. Rare earth (RE) oxides such as Nd2O3, Y2O3, and Eu2O3 are used in conjunction with carbonous/conducting polymers matrix for high specific density and operating voltage supercapacitors. The high band gap of RE oxides assists in achieving higher operating voltage window. The article will review the current status of RE oxide based supercapacitors and their physical properties in conjunction with underlying physical principles.
Ajay Tiwari, Ambesh Dixit

### Wind Farm Layout Optimization Using Teaching Learning Based Optimization Technique Considering Power and Cost

Abstract
Wind farm layout optimization has become one of the deciding approaches to increase power output and decrease total cost of a wind farm. In recent year, for capturing maximum energy from wind turbines, wind farmers are installing the wind turbines having bigger rotors and highly efficient turbine components. Even though they are unable to get the achievable output from the wind farm due to wake effect. The heart of our research study is to analyse and optimize the wind farm layout problem. The focus of wind farm layout optimization problem is to find the best placement of wind turbine in the area of wind farm such a way that there is no wake or minimal wake condition of downstream turbine. For that purpose study of wake, model is more important and find out the best optimal solution of placement of wind turbine. Teaching learning based optimization method is used for optimizing the positioning of wind turbines. It is considered that wind is coming from 36 rotational directions with 10° increment from 0 to 360° and velocity is uniform throughout 12 m/s.
Yash D. Modi, Jaydeep Patel, Garlapati Nagababu, Hardik K. Jani

### Performance Analysis of Fractional-Order PI-Based Controller for Variable Speed Hybrid Standalone WECS

Abstract
The presented work in the paper shows a comprehensive analysis of fractional-order PI (FOPI) controller based voltage and frequency (VF) control of variable speed hybrid-standalone wind-energy-conversion-system (WECS). The system comprises of two major components: (1) permanent-magnet-synchronous-generator (PMSG), (2) battery-energy-storage-system (BESS). For standalone operation, the frequency and magnitude of voltage need to be controlled at the load terminals. DSOGI-PLL (Dual-second-order-generalized-integral based phase-locked-loop) is designed to track the frequency of the system. Fractional-order (FO) controllers provide robustness to Voltage Source Converter (VSC) due to their fractional characteristic. FOPI (PIλ) controller has an extra degree-of-freedom λ (order of integral) with its proportional gain (Kp) and integral gain (Ki). Simulation analysis is carried out in MATLAB/Simulink for PMSG-BESS based WECS. Proposed controller’s performance is evaluated for varied conditions of operation. FOPI based controller is significantly minimizing the peak overshoot and settling time for the terminal voltage, also it improves the transient response of the system.
Anjana Jain, R. Saravanakumar

### Selection Criteria for Algae Biodiesel Production Using Slow Pyrolysis

Abstract
Biodiesel derived from non-edible oil feedstock may one of the most emerging fields of energy production. Biodiesel, as a fuel, can be used for power production in transport, automobiles and for power generation sector without adversely affecting nature. Major objectives of current research are the effect of various forms of algae on production of green crude, comparison of methods for algae to biofuel conversion, selection of various parameters for green crude production. Algae biodiesel satisfied BS-IV emission norms. Green crude derived using slow pyrolyser gives 19 ml/100 g of green crude with 2500 °C flask temperature and with 50 °C cooling water temperature.
Alpesh Mehta, Nirvesh Mehta

### Performance Analysis of 4-Leg IB APF for 3-Phase 4-Wire System with Renewable Energy Interface Fuzzy Control DC-Bus Capacitor

Abstract
This paper proposes the 4-leg active power filter (APF), which consists of interleaved buck inverter interfaced with the photovoltaic (PV) renewable energy source. The photovoltaic renewable energy system along with the boost converter associated with the 4-leg interleaved buck active power filter (4L IB APF) is not only for harmonic compensation but can well handle the active power requirement during the load hike. The most perilous shoot-through phenomenon associated with the conventional 4-leg inverter is fully eliminated by this 4-leg interleaved buck inverter enhancing the reliability. The id-iq control strategy is used for the reference compensating current generation. Along with this, Mamdani-based fuzzy logic controller (MFLC) is implemented for the well control of inverter dc-bus capacitor voltage for having more sensitivity to harmonics, unbalancing and dynamic condition. The detail analysis of harmonic, neutral current, load unbalancing and active power compensation has depicted for nonlinear three-phase and single-phase unbalanced load for different voltage condition during steady and dynamic state. MATLAB/Simulation and OPAL real-time simulator results verify the efficacy and feasibility of the photovoltaic renewable energy-based 4L IB APF.
Ranjeeta Patel, Anup Kumar Panda, Josep M. Guerrero

### Evaluation of Dynamic Amplification of Conventional and Mono-Lattice Structural System for Tall Wind Mill Towers

Abstract
Wind energy is a renewable source of energy and as it provides clean and green energy and is vigorously pursued in the last few years in the world as well as in India. A country like India has approximately 102,790 MW wind power generation capacity. Wind structures are tall and characterized by slender structural geometry. The height of wind mill plays an important role in wind power generation. One can extract more energy from wind by increasing height of tower, the major obstacle in height increase is the slenderness of the wind mill towers. To extract more energy various researcher has tried steel-concrete tower and octagonal shape tower to overcome slenderness effect. To avoid the slenderness effect on tall towers a combination of lattice-monopole structural system is proposed and investigated. A finite element model of 125 m tall tower is developed for comparison of conventional and proposed mono-lattice supporting structural systems. Detailed dynamic analysis under working loads of wind turbines and nonlinear seismic loads are carried out. The response of both structural systems is quantified in terms of dynamic amplification, displacement, and base shear. It is observed that mono-lattice structural system is less sensitive to dynamic forces and system proves economical for tall towers compared to conventional systems and can be used for tall towers to extract more power at low and unsteady wind sites.
Hemal J. Shah, Atul K. Desai

### Thermo-economic Comparison of Solar Heat Driven NH3–LiNO3 and NH3–H2O Absorption Refrigeration System

Abstract
The objective of this paper is to compare the thermal performance and evaluation of critical parameters for single effect ammonia/lithium nitrate (NH3–LiNO3) and aqua-ammonia (NH3–H2O) based absorption chiller coupled with various collectors at Ahmedabad city in India. Linear Fresnel reflector (LFR), Parabolic trough collector (PTC) and evacuated tube collector (ETC) are attached through thermally insulated storage tank to produce three ton of refrigeration (TR) at −4 °C evaporator temperature. The effect of heat source temperature on the performance parameters such as coefficient of performance (COP) and exergetic efficiency has been investigated for each chiller. Furthermore, the required optimum area and associated cost for each collector type have been determined. Thermo-economic comparison between various solar coupled absorption chillers depicted that maximum solar COP (SCOP) of ETC based system is 31.37% higher compared to that of LFR based system, whereas the cost of ETC based system is only 10.13% higher compared to LFR based system. Moreover, LFR occupies the 94% more land area for installation of solar field compared to ETC, which altogether recommended ETC coupled NH3–LiNO3 absorption refrigeration system.
Nishant Modi, Bhargav Pandya, Jatin Patel

### Thermo-economic Analysis of Biomass-Powered Single Effect LiBr/H2O Absorption Refrigeration System

Abstract
This work presents thermo-economic performance analyses of the absorption refrigeration system (ARS) having a capacity of 1 TR. The present ARS uses different types of biomass (wheat straw, rice straw, and soybean stalk) and produces a cooling effect at a temperature of 8 °C. The thermo-economic optimum generator temperature about 93.5 °C is obtained for the present ARS. In addition, the coefficient of performance (COP) is obtained about 0.678. The break-even point for the ARS is calculated about 10.8 years using wheat straw biomass. Further, the break-even point and biomass consumption are found the maximum for soybean stalk due to its higher cost and lower calorific value compared to wheat straw biomass.
Bhaumik Modi, Bhavesh Patel, Anurag Mudgal

### Issue and Challenges with High-Temperature Solar Selective Material for Solar Thermal Application

Abstract
Solar selective coatings (SSC) are integral part of the receiver in any concentrated solar thermal system for efficient conversion of incident solar energy into thermal energy. The most common solar thermal systems are based on parabolic trough collectors, which are operating at 350 °C. Thus, the absorber coating should be robust and efficient to operate at such temperatures without any degradation. There are limited such solar selective coatings and very few are commercially available. These are cermet based structure and are stable at high temperature in vacuum. These structures are prone to chemical reaction in open-air condition, which results in degraded optical performance of SSC structures. Thus, there are issues and challenges in SSCs, especially for higher operating temperatures, which is essential to realize the higher efficiency of solar thermal systems. The work is focusing on such constraints towards realizing high temperature solar selective coatings.
Rajesh Kumar, Ambesh Dixit

### Investigation on the Relative Influence of Absorber Layer Defect States Over Performance of Pb-Based and Sn-Based Perovskite Solar Cells

Abstract
Currently, the research in third-generation solar cells is proliferating in an exponential manner. Among these, the Perovskite solar cell has been the preferred research matter among the researchers. This study consists of numerical simulation-based comparison between various standard parameters of the lead-free perovskite solar cell and tin-based (lead-based) perovskite solar cell using SCAPS-1D. The comparison is performed based on performance parameters viz. open-circuit voltage, short circuit current density, fill factor and efficiency. We observed that despite the presence of severe order of defect states the performance of tin-based perovskite solar cell was superior which could be critical from the perspective of lead-free perovskite solar cell manufacturing and commercialization.
Piyush Baldha, Krunal Patel, Kshitij Bhargava

### Application of Fuzzy Linguistic Modeling Aggregated with VIKOR for Optimal Selection of Solar Power Plant Site: An Empirical Study

Abstract
Fast development of the economies and technology leads a tremendous increase in the demand for electrical energy. The primary energy sources viz. coal, natural gas, petroleum, etc. replenished day by day as they require millions of years for their formation. To address this issue, utilization of renewable energy sources such as wind energy, solar energy, hydropower, marine energy, etc. have been considered as one of the vital solutions to meet the energy demand. But they require huge investment; hence, feasible studies are essentially needed for finding the large systems associated with aforesaid resources. Therefore, this work highlights the several suggestions for selection of site which is an important stage in the establishment of solar power plant. Moreover, a hierarchy multi-criteria decision-making (MCDM) approach based on fuzzy logic and VIKOR method has been adopted for the selection of site in the Gujarat state of India.
Bhavin Shah, Harsh Lakhani, Kumar Abhishek, Soni Kumari

### Controller Design for Buck–Boost Converter Using State-Space Analysis

Abstract
In this paper, the small-signal model of buck–boost DC–DC Converter is presented. The final model is obtained in terms of state matrix ($$A$$), input matrix ($$B$$), output matrix ($$C$$) and feedforward matrix ($$D$$). The small-signal modelling for buck–boost converter is done in order to construct a robust controller for it by using state-space analysis and root-locus technique. The entire system is analyzed by giving a step-input to the system, which is modelled in Laplace domain. This paper primarily focuses on reduction of steady-state error for the dynamic model of buck–boost converter. The controller, comprising of lag compensator, is designed with the help of root-locus technique according to the need of the designed parameters such as settling time, peak overshoot, steady-state error, relative stability, etc. By taking various values of zeros and poles of compensator, the unit step response is analyzed in detail. The presented system also has an inherent characteristic of inverse time response generally exhibited by non-minimum phase system.
Dhrumil Daftary, Chirag H. Raval

### Optimal Utilization of Reactive Power Capability of Renewable Energy Based Distributed Generation for Improved Performance of Distribution Network

Abstract
Increasing penetration of distributed generation (DG) in distribution networks (DNs) may increase the voltage level beyond the statutory permit. Normally, DGs operate at unity power factor (UPF) and does not contribute to reactive power generation. In this work, the reactive power capability of DGs has been assessed to mitigate the overvoltage problem in DN due to increased penetration of DGs. Two objective functions, minimization of energy loss of a DN and minimization of average voltage deviation of all bus bars, are proposed by optimizing reactive power of DGs as control variables. It is shown that DGs with reactive power support can enhance the performance of DN. Particle swarm optimization with time series power flow solution is used to optimize the control variables of wind- and solar-based DGs.
Praghnesh Bhatt, Chao Long, Bhinal Mehta, Nilay Patel

### Voltage Control of Wind and Diesel-Based Distributed Generating System Using PSO and CSA

Abstract
The power sector worldwide promotes more penetration of distributed generation (DG) at distribution network (DN) as a cost-effective solution to supply ever increasing power demand. DG is one of the promising solutions to supply smaller isolated system where diesel- and wind-based generating units operate in parallel to achieve greater reliability. In this work, transient performance of such hybrid power system has been analyzed using its state-space model in the event of reactive power load perturbations. The performances of three types of static var compensators (SVC) are compared to ascertain their capabilities to quickly damp out the terminal voltage deviations. Two evolutionary optimization techniques, namely cuckoo search algorithm (CSA) and particle swarm optimization (PSO), are presented for the tuning of SVCs controller gains. It is revealed that gains tuned with CSA and PSO present significant improvement in the dynamic behavior of the system as compared to conventional optimization technique.
Pankita Mehta, Praghnesh Bhatt, Vivek Pandya

### Harmonic Current Signal Injection-Based Grid Impedance Measurement Technique for Active Harmonic Filter

Abstract
At present, the main issue faced in practical application of active harmonic filter with LCL filter is the protection of AHF due to the resonance condition which is attained unintentionally in the process of removing harmonic and improving power quality. At resonance condition, voltage or current magnification takes place which results in failure of components connected in active harmonic filters. In addition to this, voltage fluctuation occurs for parallel-connected appliances, which results in poor power quality and makes system less reliable. In this work, a noninvasive signal injection method known as harmonic current signal injection method is implemented. The method determines grid impedance in order to avoid resonance conditions in the AHF application. The method uses the existing setup of AHF for measurement of impedance of the grid, thus eliminating the need of additional hardware for determination of impedance. This method is simulated in PSIM and validated under different values of grid impedance.
Bhargav Nashikkar, Rajendrasinh Jadeja, Vinod Patel, Tapankumar Trivedi, Uvesh Sipai

### Experimental Investigation of Dehumidifier Hybrid Air Conditioner Integrated Zeotropic Refrigerant Blend R-407C Air Source Water Heat Pump

Abstract
Air gets heated while passing through the desiccant wheel in a hybrid air conditioning system and needs to be cooled before passing to cooling coil. This hot air can be an effective heat source for the air source heat pump to heat the water. The present work includes experimental investigation of the dehumidifier integrated hybrid R-407C air source water heat pump under different air temperature to achieve hot water. The results exhibit that heating capacity increases by 15% by increasing the air-source temperature from 30 to 45 °C. End loop COP of the system is reduced by 25%.
Juned R. Kazi, Neeraj Agrawal

### Experimental Investigation of the Solar Dryer Using Phase-Change Material

Abstract
The solar dryer is widely used to dry the agro-products for preservation during sunlight hours. A general drawback of conventional solar dryer system is the need for thermal energy storage in order to balance the supply and demand of heat during night hours. In the present work, experimental work has been carried out for an indirect type cabinet solar dryer using phase-change material (PCM) to investigate the possibility of utilizing thermal energy storage in the systems. The solar dryer consists of solar air collector with thermal storage unit consists of five numbers of aluminum tubes filled with a PCM (i.e., paraffin wax). Experiments were conducted for 2.7 kg of tomatoes with and without paraffin wax in the dryer during the month of April 2017. The result shows that by using PCM the drying time of the system is extended by 1 h 48 min after sunset. The moisture content of tomatoes was reduced by 94.4% in 12 h as compared to the open sun drying, which took 74 h, respectively. Moreover, the quality and texture of dried tomatoes produced from solar dryer are superior compared to that of open sun drying.
C. O. Yadav, P. V. Ramana

### Design and Optimization of Hybrid Electric Vehicle

Abstract
The key issues associated with the hybrid racing car are low starting torque, lower acceleration and more weight. In this research work, hybrid racing vehicle is optimally designed such that the overall weight is reduced and the starting torque is increased. This is achieved by designing sustainable and safe chassis with minimum members. Further, materials that have maximum strength with minimum weight is identified. The simulation study is performed in NX-CAD software. It can be observed from the results that the weight is reduced by around 11.4 %. Moreover, suitable motor, battery, steering, suspension and braking system are identified for a hybrid racing car. This shows feasibility of implementing the proposed design in practice for manufacturing the hybrid racing cars.
Tarang Varmora, Manish Kumar, Shah Krupa Rajendra

### Climate Control of Greenhouse System Using Neural Predictive Controller

Abstract
This paper presents the concept of neural predictive techniques for the modeling and controlling of the greenhouse system (GHS). Greenhouse system provides the favorable environment to the plants. The GHS is a class of nonlinear and complex systems. Initially, the dynamics of the GHS are precisely modeled in the presence of the uncertainties and disturbances using the system identification approaches based on the neural network (NN). To train the NN, Levenberg–Marquardt backpropagation algorithm is being utilized. This research uses the neural predictive control (NPC) approach to achieve stabilizing control and tracking control. The efficacy of the proposed scheme is validated for the various operating conditions under different initial conditions and enormous external disturbances. The superiority of the proposed research is also compared with the conventional PID control.
Shriji V. Gandhi, Manish T. Thakker

### Green Concrete by Replacing Coarse Aggregate with Cupola Slag for Environmental Protection

Abstract
Recently world leads to higher infrastructural growth including developing countries like India leads to higher consumption of construction material such as cement and concrete. For production/manufacturing of cement and concrete requires huge amount of natural resources that leads to rapid depletion of natural resources and emission of GHG’s and other harmful pollutants in environment which are responsible for quick climate changes and also create a perilous threat to human lives, ecology and environment. So to preserve the environment, one should preserve the natural resources. In this regards, authors attempted use of cupola slag aggregate (CSA) as replacement of naturally available coarse aggregates. A comparative study shows results for control mix and cupola slag aggregate concrete. From the study, one can conclude that, cupola slag can be used as coarse aggregate effectively in structural as well as in plain concrete and suggest such various other alternative materials prove very effective to slowing down of climate changes and preserving natural resources and environment.
Vishwash K. Mistry, Dipak J. Varia

### Potential Study of Atmospheric Water Generator (AWG) for Humid Climatic Conditions of Eastern States in India

Abstract
Water scarcity is one of the major issues which India is currently facing. About 600 million Indian population is facing high to extreme stress over water. Despite water resources, India’s eastern states are actually water poor as households and individuals remain inadequate of water supply. These eastern states are blessed with humid climates where average yearly relative humidity and dry-bulb temperature range from 75 to 85% and from 20 to 30 °C, respectively, which clearly indicates that these regions have high water extraction potential from the atmosphere. Atmospheric water generator is a reliable technology to harvest water from the atmosphere. In this paper, an analytical investigation is presented to analyse the potential of atmospheric water generator (AWG) for eastern Indian states. Amount of water yield was calculated for different major cities and towns of eastern states around the year. Monthly condensate extraction remained in the range from 1800 to 2100 kg. Per kg cost of condensate for different evaporator temperatures was investigated. For evaporator temperature at 5 °C, the cost varied from 0.95 INR to 1.30 INR. It was noticeable that condensate extraction was clearly a function of air humidity ratio and temperature. The condensate yield follows a similar trend of relative humidity.
Krunal Patel, Jatin Patel, Harshil Raval

### Exergy Analysis—A Useful Concept of Sustainability for Air Source Heat Pump System

Abstract
Due to increasing energy demand, exergy analysis becomes necessary to use energy-efficient systems by minimizing losses. India is one of the largest markets of air source heat pump system. Taking this criterion into consideration, this study aims to investigate the performance of air source heat pump system. To identify the losses, exergy destruction in each component was determined. It was noticeable that exergy destruction of compressor was highest (40.76%) because of its non-isentropic compression and friction losses, followed by the expansion valve (36.03%), evaporator (15.72%) and condenser (7.5%). Effect of condenser temperature on second law efficiency varied linearly with decreasing nature. Effect of evaporator temperature on overall efficiency was studied. Coefficient of performance of the actual system (4.28) deviated from the theoretical COP (5.23) because of pressure loss in condenser and evaporator.
Nidhi Trapasia, Krunal Patel, Rajesh Patel

### Role of Algae in CO2 Sequestration Addressing Climate Change: A Review

Abstract
Climate change is the change in average conditions of weather during a long time period, due to increased addition of greenhouse gases (GHG) to earth’s atmosphere. Industrialization and deforestation have been identified as primary causes of increased GHG in which carbon dioxide (CO2) is the major factor, accounting for over half of the warming potential. Increase in CO2 level in atmosphere needs to be addressed by effective and sustainable carbon sequestration technologies. Out of numerous CO2 sequestration technologies, biological methods using algae could be one of the most efficient and economical ways. Algae can be extensively used for utilizing CO2 and the resulting biomass may be used for producing biofuel and multiple value-added products. Many countries have started implementing carbon credits with a fiscal value as price of polluting the air. This has spread awareness worldwide and attracted investments in carbon sequestration via microalgae cultivation. This review summarizes the global research status of utilizing microalgae in CO2 sequestration.
Vishal Paul, P. S. Chandra Shekharaiah, Shivbachan Kushwaha, Ajit Sapre, Santanu Dasgupta, Debanjan Sanyal

### Chemical Looping Reforming (CLR) System for H2 Production—A Review

Abstract
Nowadays, world’s rising energy demand is satisfied by coal and petroleum based non-renewable fuels. But these fuels have some major drawbacks that these processes generate harmful oxidise like CO2, NOx. Out of these CO2 affects climate change of the whole world by producing global warming effect. Hydrogen can be use alternative to these energy sources due to its high energy generation per unit mass and low environmental impact compare to other fossil fuels. But the H2 is very less in nature. The steam reforming of methane is wildly used to harvest hydrogen from different fuels. It also produces CO2 and NOx. And the process cost of separating these gases from flue gases is consuming very high energy. The alternative to this technology is chemical looping reforming, that doesn’t produce NOx and CO2 can be easily separate. In this work authors try to compare different types of oxygen carriers used in many literatures by investigating their reactivity, crushing strength, and stability at different temperature. Also authors try to find most capable oxygen carrier (OC) for this system by considering OCs stability at higher temperatures and reactivity.
Mit Pujara, Mit Sheth, Nikunj Rachchh, Rameshkumar Bhoraniya, Atal Bihari Harichandan

### Commitment for a Cleaner India: Utilization of CO2 and Sewage Wastewater by Green Algae Scenedesmus sp. Under Laboratory Conditions

Abstract
Carbon dioxide (CO2) emission is globally increasing every year accelerating the issue of climate change. Conversion of CO2 into biomass by photosynthesis helps to overcome the challenges of global warming while producing fuel, feed, and value-added products. Green microalgae Scenedesmus sp. was studied for the biomass generation potential utilizing CO2 without adding any other carbon (C) source. Optical density (OD), cell count, elemental C, and total organic carbon (TOC) were determined for the produced biomass. The results demonstrated that the OD and TOC increased from 0.4 to 2.6 and from 51 to 380 ppm, respectively. The elemental C was found to be 47% of the produced biomass. It was also of interest to determine the possibility of using sewage wastewater for growing Scenedesmus sp. without additional nutrient. The growth of Scenedesmus sp. was evaluated in BBM media and in sewage wastewater. The results indicate that the OD of Scenedesmus cultures was similar in control and primary sewage wastewater. TOC of the pellet in primary wastewater was around 91% of the culture grown in control. This study confirmed that Scenedesmus sp. can effectively utilize atmospheric CO2 and can grow in sewage wastewater as well.
Debanjan Sanyal, Santosh Kodgire, Dishant Desai, Nishant Saxena, Sunita Singh, Santanu Dasgupta

### A Design Framework for Portable Artificial Photosynthesizer: A Future Reality

Abstract
Global warming due to the addition of carbon dioxide (CO2) emissions is creating a threat to the environment and techniques to reduce the impact of CO2 gains importance and attention of researchers to equip a new technology paradigm to reduce the emissions. Even though naturally available, petroleum products are advised to consume less, unlike any other commodities that are available in the market. This is due to the negative effects of the petroleum products as they emit carbon dioxide due to partial combustion. Source correction is the best solution to any problem. Reducing the utilization of the petroleum products in the transportation sector may not be possible immediately. So, there is an immediate need to solve the problem which can add value to the environment by consuming the petroleum products. Photosynthesis places an important role in the balancing of oxygen and carbon dioxide ratios. The process of artificial photosynthesis through catalytic reactions still stands a complex nature. This work aims to develop a design model for portable artificial photosynthesizer through catalytic reactions which can be easily fixed to an exhaust unit for automobiles. Converting CO2 to O2 through artificial photosynthesis through this portable device is the prime aim of this design which helps to add oxygen to the environment instead of contributing to CO2 emissions. A supported catalyst and a catalytic process have been developed for the conversion of CO2 + H2O (in the form of steam) to some efficient carbon product. The catalyst simultaneously splits water into hydrogen and oxygen, and conversion of carbon dioxide into hydrocarbon under very mild reaction conditions and at atmospheric pressure. Artificial photosynthesis portable device once tested experimentally for the desired efficiency can be a breakthrough in the environmental technology with the demand to consume more petroleum products giving thrust to both economy and environment.
Raja Sekhar Mamillapalli, V. Vishnu Namboodiri

### Thermodynamic Analysis of Transcritical CO2 Booster Systems with Flooded Evaporator for Supermarket Application

Abstract
The paper presents the thermodynamic modeling and analysis of a CO2 booster system operating in a transcritical cycle with flooded evaporator for the supermarket application. In present scenario, the HVAC sector is facing challenge due to the implementation of various protocols, i.e., Montreal and Kyoto protocols, which leads to explore the long-term and eco-friendly solutions. CO2 is considered as one of the rediscover and ecologically safe refrigerant, however, the performance of the overall systems is low as compared to the existing and conventional systems, especially in warm climatic conditions like India. Therefore, these systems need to be modified and improved. There are many modifications proposed, in which CO2 booster system is one of them. In this paper, an attempt has been made to further improve the standard CO2 booster system by including flooded evaporator at low temperature (LT), medium temperature (MT), and simultaneously both LT and MT. The results show that addition of flooded evaporator improve the COP, however, improvement is higher in case of MT and LT-MT flooded evaporator as compare to only LT flooded. Further, the degree of improvement is more as the climatic temperature increases.
Manju Lata, Ashish Kumar Yadav, Dileep Kumar Gupta