Pakistan
Advances and Challenges of MOF Derived Carbon-based Electrocatalysts and Photocatalyst for Water Splitting: A Review
Apr 2022
Publication
Environmental pollution and energy shortage are substantial fears to the modern world's long-term sustainability. Water splitting is an essential technique for eco - friendly and sustainable energy storage as well as a pollution-free method to produce hydrogen. In this regards Metal–organic frameworks have emerged as the most competent multifunctional materials in recent times due to its large surface areas adjustable permeability easy compositional alteration and capability for usage as precursors with a wide range of morphological forms. Further MOF-derived carbon-based nanomaterials also offer significant benefits in terms of tunable morphological features and hierarchical permeability as well as ease of functionalization making them extremely effective as catalysts or catalysts supports for a wide variety of important reactions. Recent developments in carbon-based MOFs as catalysts for overall water splitting are discussed in this review. We explore how MOFs and carbon-based MOFs might well be beneficial as well as which methods should be explored for future development. We divided our review into two sections: photocatalytic and electrocatalytic water splitting and we gathered published literature on carbon-based MOFs materials for their outstanding activity offers helpful methods for catalysts design and analysis as well as difficulties This study highlights the developments in MOF derived materials as photo and electro catalysts by explaining respective approaches for their use in overall water splitting.
Single-catalyst High-weight% Hydrogen Storage in an N-heterocycle Synthesized from Lignin Hydrogenolysis Products and Ammonia
Oct 2016
Publication
Large-scale energy storage and the utilization of biomass as a sustainable carbon source are global challenges of this century. The reversible storage of hydrogen covalently bound in chemical compounds is a particularly promising energy storage technology. For this compounds that can be sustainably synthesized and that permit high-weight% hydrogen storage would be highly desirable. Herein we report that catalytically modified lignin an indigestible abundantly available and hitherto barely used biomass can be harnessed to reversibly store hydrogen. A novel reusable bimetallic catalyst has been developed which is able to hydrogenate and dehydrogenate N-heterocycles most efficiently. Furthermore a particular N-heterocycle has been identified that can be synthesized catalytically in one step from the main lignin hydrogenolysis product and ammonia and in which the new bimetallic catalyst allows multiple cycles of high-weight% hydrogen storage.
Power Generation Analysis of Terrestrial Ultraviolet-Assisted Solid Oxide Electrolyzer Cell
Jan 2022
Publication
This paper presents a novel system design that considerably improves the entrapment of terrestrial ultraviolet (UV) irradiance in a customized honeycomb structure to produce hydrogen at a standard rate of 7.57 slpm for places with a UV index > 11. Thermolysis of high salinity water is done by employing a solid oxide electrolyzer cell (SOEC) which comprises three customized novel active optical subsystems to filter track and concentrate terrestrial UV solar irradiance by Fresnel lenses. The output of systems is fed to a desalinator a photovoltaic system to produce electrical energy and a steam generator with modified surface morphology to generate the required superheated steam for the SOEC. A simulation in COMSOL Multiphysics ver. 5.6 has shown that a customized honeycomb structure when incorporated on the copper–nickel surface of a steam generator improves its absorptance coefficient up to 93.43% (48.98%—flat case). This results in generating the required superheated steam of 650 ◦C with a designed active optical system comprising nine Fresnel lenses (7 m2 ) that offer the concentration of 36 suns on the honeycomb structure of the steam generator as input. The required 1.27 kW of electrical power is obtained by concentrating the photovoltaic system using In0.33Ga0.67N/Si/InN solar cells. This production of hydrogen is sustainable and cost effective as the estimated cost over 5 years by the proposed system is 0.51 USD/kg compared to the commercially available system which costs 3.18 USD/kg.
Economic Viability and Environmental Efficiency Analysis of Hydrogen Production Processes for the Decarbonization of Energy Systems
Aug 2019
Publication
The widespread penetration of hydrogen in mainstream energy systems requires hydrogen production processes to be economically competent and environmentally efficient. Hydrogen if produced efficiently can play a pivotal role in decarbonizing the global energy systems. Therefore this study develops a framework which evaluates hydrogen production processes and quantifies deficiencies for improvement. The framework integrates slack-based data envelopment analysis (DEA) with fuzzy analytical hierarchy process (FAHP) and fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS). The proposed framework is applied to prioritize the most efficient and sustainable hydrogen production in Pakistan. Eleven hydrogen production alternatives were analyzed under five criteria including capital cost feedstock cost O&M cost hydrogen production and CO2 emission. FAHP obtained the initial weights of criteria while FTOPSIS determined the ultimate weights of criteria for each alternative. Finally slack-based DEA computed the efficiency of alternatives. Among the 11 three alternatives (wind electrolysis PV electrolysis and biomass gasification) were found to be fully efficient and therefore can be considered as sustainable options for hydrogen production in Pakistan. The rest of the eight alternatives achieved poor efficiency scores and thus are not recommended.
Co-CoOx Supported onto TiO2 Coated with Carbon as a Catalyst for Efficient and Stable Hydrogen Generation from Ammonia Borane
Apr 2020
Publication
Ammonia borane (AB) can be catalytically hydrolyzed to provide hydrogen at room temperature due to its high potentaial for hydrogen storage. Non-precious metal heterogeneous catalysts have broad application in the field of energy catalysis. In this article catalysts precursor is obtained from Co-Ti-resorcinol-formaldehyde resin by sol–gel method. Co/TiO2@N-C (CTC) catalyst is prepared by calcining the precursor under high temperature conditions in nitrogen atmosphere. Co-CoOx/TiO2@N-C (COTC) is generated by the controllable oxidation reaction of CTC. The catalyst can effectively promote the release of hydrogen during the hydrolytic dehydrogenation of AB. High hydrogen generation at a specific rate of 5905 mL min−1 gCo−1 is achieved at room temperature. The catalyst retains its 85% initial catalytic activity even for its fifth time use in AB hydrolysis. The synergistic effect among Co Co3O4 and TiO2 promotes the rate limiting step with dissociation and activation of water molecules by reducing its activation energy. The applied method in this study promotes the development of non-precious metals in catalysis for utilization in clean energy sources.
Advanced Polymeric/inorganic Nanohybrids: An Integrated Platform for Gas Sensing Applications
Jan 2022
Publication
Rapid industrial development vehicles domestic activities and mishandling of garbage are the main sources of pollutants which are destroying the atmosphere. There is a need to continuously monitor these pollutants for the safety of the environment and human beings. Conventional instruments for monitoring of toxic gases are expensive bigger in size and time-consuming. Hybrid materials containing organic and inorganic components are considered potential candidates for diverse applications including gas sensing. Gas sensors convert the information regarding the analyte into signals. Various polymeric/inorganic nanohybrids have been used for the sensing of toxic gases. Composites of different polymeric materials like polyaniline (PANI) poly (4-styrene sulfonate) (PSS) poly (34-ethylene dioxythiophene) (PEDOT) etc. with various metal/metal oxide nanoparticles have been reported as sensing materials for gas sensors because of their unique redox features conductivity and facile operation at room temperature. Polymeric nanohybrids showed better performance because of the larger surface area of nanohybrids and the synergistic effect between polymeric and inorganic materials. This review article focuses on the recent developments of emerging polymeric/inorganic nanohybrids for sensing various toxic gases including ammonia hydrogen nitrogen dioxide carbon oxides and liquefied petroleum gas. Advantages disadvantages operating conditions and prospects of hybrid composites have also been discussed.
Performance Analysis of Hydrogen Fuel Cell with Two-stage Turbo Compressor for Automotive Applications
May 2021
Publication
This paper discusses the numerical modeling of an automobile fuel cell system using a two-stage turbo-compressor for air supply. The numerical model incorporates essential input parameters for air and hydrogen flow. The model also performed mass and energy balances across different components such as pump fan heat-exchanger air compressor and keeps in consideration the pressure losses across flow pipes and various mechanical parts. The compressor design process initiates with numerical analysis of the preliminary design of a highly efficient two-stage turbo compressor with an expander as a single-stage compressor has several limitations in terms of efficiency and pressure ratio. The compressor’s design parameters were carefully studied and analyzed with respect to the highly efficient fuel cell stack (FCS) used in modern hydrogen vehicles. The model is solved to evaluate the overall performance of PEM FCS. The final compressor has a total pressure and temperature of 4.2 bar and 149.3°C whereas the required power is 20.08kW with 3.18kW power losses and having a combined efficiency of 70.8%. According to the FC model with and without expander the net-power outputs are 98.15kW and 88.27kW respectively and the maximum efficiencies are 65.1% and 59.1% respectively. Therefore it can be concluded that a two-stage turbo compressor with a turbo-expander can have significant effects on overall system power and efficiency. The model can be used to predict and optimize system performance for PEM FCS at different operating conditions.
Water Removal from LOHC Systems
Oct 2020
Publication
Liquid organic hydrogen carriers (LOHC) store hydrogen by reversible hydrogenation of a carrier material. Water can enter the system via wet hydrogen coming from electrolysis as well as via moisture on the catalyst. Removing this water is important for reliable operation of the LOHC system. Different approaches for doing this have been evaluated on three stages of the process. Drying of the hydrogen before entering the LOHC system itself is preferable. A membrane drying process turns out to be the most efficient way. If the water content in the LOHC system is still so high that liquid–liquid demixing occurs it is crucial for water removal to enhance the slow settling. Introduction of an appropriate packing can help to separate the two phases as long as the volume flow is not too high. Further drying below the rather low solubility limit is challenging. Introduction of zeolites into the system is a possible option. Water adsorbs on the surface of the zeolite and moisture content is therefore decreased.
Dynamic Model to Expand Energy Storage in Form of Battery and Hydrogen Production Using Solar Powered Water Electrolysis for Off Grid Communities
Feb 2022
Publication
In this model we used a 50 WP photovoltaic panel to produce electrical energy. This electricity production was used directly and stored in a battery. In this design we coupled batteries and hydrogen as a means of storing energy. In case of overcharging the battery it will be attached with water electrolysis to convert the excess amount of chemical energy of the battery into hydrogen energy storage. Hydrogen will be stored as a compacted gas and in chemical storage. We used PEM (proton exchange membrane) electrolysis technologies to breakdown water molecules into hydrogen and oxygen which were then stored in the designed tanks. Different supply voltages were used in our practical readings with an average gaining of 22.8 mL/min on a voltage supply of 2. While using Ansys simulation software we extrapolated hydrogen production until reaching 300 mL/min on 12 V of supply (which represents 220% higher production). By using the second phase of this model hydrogen energy was converted back into electrical energy with the help of a PEM (proton exchange membrane) fuel cell when needed. This model explores the feasibility of energy storage in the form of hydrogen and chemical energy for off-grid communities and remote areas comprising batteries water electrolysis and fuel cells. The main purpose of hydrogen storage in this system is to store and handle the extra energy of system produced through PV panel and utilize it for any desired requirements.
Environmental Assessment of Hydrogen Utilization in Various Applications and Alternative Renewable Sources for Hydrogen Production: A Review
May 2023
Publication
Rapid industrialization is consuming too much energy and non-renewable energy resources are currently supplying the world’s majority of energy requirements. As a result the global energy mix is being pushed towards renewable and sustainable energy sources by the world’s future energy plan and climate change. Thus hydrogen has been suggested as a potential energy source for sustainable development. Currently the production of hydrogen from fossil fuels is dominant in the world and its utilization is increasing daily. As discussed in the paper a large amount of hydrogen is used in rocket engines oil refining ammonia production and many other processes. This paper also analyzes the environmental impacts of hydrogen utilization in various applications such as iron and steel production rocket engines ammonia production and hydrogenation. It is predicted that all of our fossil fuels will run out soon if we continue to consume them at our current pace of consumption. Hydrogen is only ecologically friendly when it is produced from renewable energy. Therefore a transition towards hydrogen production from renewable energy resources such as solar geothermal and wind is necessary. However many things need to be achieved before we can transition from a fossil-fuel-driven economy to one based on renewable energy
Energy and Exergy Analysis of a Geothermal Sourced Multigeneration System for Sustainable City
Feb 2023
Publication
The issue of depleting fossil fuels has emphasized the use of renewable energy. Multigeneration systems fueled by renewables such as geothermal biomass solar etc. have proven to be cutting-edge technologies for the production of different valuable by-products. This study proposes a multigeneration system using a geothermal source of energy. The main outputs include power space heating cooling fresh and hot water dry air and hydrogen. The system includes a regenerative Rankine cycle a double effect absorption cycle and a double flash desalination cycle. A significant amount of electrical power hydrogen and fresh water is generated which can be used for commercial or domestic purposes. The power output is 103 MW. The thermal efficiency is 24.42% while energetic and exergetic efficiencies are 54.22% and 38.96% respectively. The COPen is found to be 1.836 and the COPex is found to be 1.678. The hydrogen and fresh water are produced at a rate of 0.1266 kg/s and 37.6 kg/s respectively.
Assessment of Wind Energy Potential for the Production of Renewable Hydrogen in Sindh Province of Pakistan
Apr 2019
Publication
In this study we developed a new hybrid mathematical model that combines wind-speed range with the log law to derive the wind energy potential for wind-generated hydrogen production in Pakistan. In addition we electrolyzed wind-generated power in order to assess the generation capacity of wind-generated renewable hydrogen. The advantage of the Weibull model is that it more accurately reflects power generation potential (i.e. the capacity factor). When applied to selected sites we have found commercially viable hydrogen production capacity in all locations. All sites considered had the potential to produce an excess amount of wind-generated renewable hydrogen. If the total national capacity of wind-generated was used Pakistan could conceivably produce 51917000.39 kg per day of renewable hydrogen. Based on our results we suggest that cars and other forms of transport could be fueled with hydrogen to conserve oil and gas resources which can reduce the energy shortfall and contribute to the fight against climate change and global warming. Also hydrogen could be used to supplement urban energy needs (e.g. for Sindh province Pakistan) again reducing energy shortage effects and supporting green city programs.
Development and Mechanistic Studies of Ternary Nanocomposites for Hydrogen Production from Water Splitting to Yield Sustainable/Green Energy and Environmental Remediation
Mar 2022
Publication
Photocatalysts lead vitally to water purifications and decarbonise environment each by wastewater treatment and hydrogen (H2 ) production as a renewable energy source from waterphotolysis. This work deals with the photocatalytic degradation of ciprofloxacin (CIP) and H2 production by novel silver-nanoparticle (AgNPs) based ternary-nanocomposites of thiolated reducegraphene oxide graphitic carbon nitride (AgNPs-S-rGO2%@g-C3N4 ) material. Herein the optimised balanced ratio of thiolated reduce-graphene oxide in prepared ternary-nanocomposites played matchlessly to enhance activity by increasing the charge carriers’ movements via slowing down charge-recombination ratios. Reduced graphene oxide (rGO) >2 wt.% or < 10 nm. Therefore AgNPs-S-rGO2%@g-C3N4 has 3772.5 µmolg−1 h −1 H2 production which is 6.43-fold higher than g-C3N4 having cyclic stability of 96% even after four consecutive cycles. The proposed mechanism for AgNPs-S-rGO2%@g-C3N4 revealed that the photo-excited electrons in the conduction-band of g-C3N4 react with the adhered water moieties to generate H2 .
Synthesis and Characterization of Carbon-Based Composites for Hydrogen Storage Application
Dec 2021
Publication
Recent development shows that carbon-based composites are proving to be the most promising materials in hydrogen energy production storage and conversion applications. In this study composites of the copper-based metal-organic framework with different ratios of graphite oxide have been prepared for hydrogen storage application. The developed materials are characterized by X-ray diffraction (XRD) gravimetric thermal analysis (TGA) scanning electron microscopy (SEM) and BET. The newly developed composites have an improved crystalline structure and an increased surface area. The results of the experiment showed that the composite material MOF/GO 20% can store 6.12% of hydrogen at −40 ◦C.
An Insight into Carbon Nanomaterial-Based Photocatalytic Water Splitting for Green Hydrogen Production
Dec 2022
Publication
At present the energy shortage and environmental pollution are the burning global issues. For centuries fossil fuels have been used to meet worldwide energy demand. However thousands of tons of greenhouse gases are released into the atmosphere when fossil fuels are burned contributing to global warming. Therefore green energy must replace fossil fuels and hydrogen is a prime choice. Photocatalytic water splitting (PWS) under solar irradiation could address energy and environmental problems. In the past decade solar photocatalysts have been used to manufacture sustainable fuels. Scientists are working to synthesize a reliable affordable and light-efficient photocatalyst. Developing efficient photocatalysts for water redox reactions in suspension is a key to solar energy conversion. Semiconductor nanoparticles can be used as photocatalysts to accelerate redox reactions to generate chemical fuel or electricity. Carbon materials are substantial photocatalysts for total WS under solar irradiation due to their high activity high stability low cost easy production and structural diversity. Carbon-based materials such as graphene graphene oxide graphitic carbon nitride fullerenes carbon nanotubes and carbon quantum dots can be used as semiconductors photosensitizers cocatalysts and support materials. This review comprehensively explains how carbon-based composite materials function as photocatalytic semiconductors for hydrogen production the water-splitting mechanism and the chemistry of redox reactions. Also how heteroatom doping defects and surface functionalities etc. can influence the efficiency of carbon photocatalysts in H2 production. The challenges faced in the PWS process and future prospects are briefly discussed.
International Experience of Carbon Neutrality and Prospects of Key Technologies: Lessons for China
Feb 2023
Publication
Carbon neutrality (or climate neutrality) has been a global consensus and international experience exchange is essential. Given the differences in the degree of social development resource endowment and technological level each country should build a carbon-neutral plan based on its national conditions. Compared with other major developed countries (e.g. Germany the United States and Japan) China's carbon neutrality has much bigger challenges including a heavy and time-pressured carbon reduction task and the current energy structure that is over-dependent on fossil fuels. Here we provide a comprehensive review of the status and prospects of the key technologies for low-carbon near-zero carbon and negative carbon emissions. Technological innovations associated with coal oil-gas and hydrogen industries and their future potential in reducing carbon emissions are particularly explained and assessed. Based on integrated analysis of international experience from the world's major developed countries in-depth knowledge of the current and future technologies and China's energy and ecological resources potential five lessons for the implementation of China's carbon neutrality are proposed: (1) transformation of energy production pattern from a coal-dominated pattern to a diversified renewable energy pattern; (2) renewable power-to-X and large-scale underground energy storage; (3) integration of green hydrogen production storage transport and utilization; (4) construction of clean energy systems based on smart sector coupling (ENSYSCO); (5) improvement of ecosystem carbon sinks both in nationwide forest land and potential desert in Northwest China. This paper provides an international perspective for a better understanding of the challenges and opportunities of carbon neutrality in China and can serve as a theoretical foundation for medium-long term carbon neutral policy formulation.
Forecasting Hydrogen Production from Wind Energy in a Suburban Environment Using Machine Learning
Nov 2022
Publication
The environment is seriously threatened by the rising energy demand and the use of conventional energy sources. Renewable energy sources including hydro solar and wind have been the focus of extensive research due to the proliferation of energy demands and technological advancement. Wind energy is mostly harvested in coastal areas and little work has been done on energy extraction from winds in a suburban environment. The fickle behavior of wind makes it a less attractive renewable energy source. However an energy storage method may be added to store harvested wind energy. The purpose of this study is to evaluate the feasibility of extracting wind energy in terms of hydrogen energy in a suburban environment incorporating artificial intelligence techniques. To this end a site was selected latitude 33.64◦ N longitude 72.98◦ N and elevation 500 m above mean sea level in proximity to hills. One year of wind data consisting of wind speed wind direction and wind gust was collected at 10 min intervals. Subsequently long short-term memory (LSTM) support vector regression (SVR) and linear regression models were trained on the empirically collected data to estimate daily hydrogen production. The results reveal that the overall prediction performance of LSTM was best compared to that of SVR and linear regression models. Furthermore we found that an average of 6.76 kg/day of hydrogen can be produced by a 1.5 MW wind turbine with the help of an artificial intelligence method (LSTM) that is well suited for time-series data to classify process and predict.
Industrial Waste Gases as a Resource for Sustainable Hydrogen Production: Resource Availability, Production Potential, Challenges, and Prospects
May 2024
Publication
Industrial sectors pivotal for the economic prosperity of nations rely heavily on affordable reliable and environmentally friendly energy sources. Industries like iron and steel oil refineries and coal-fired power plants while instrumental to national economies are also the most significant contributors to waste gases that contain substantial volumes of carbon monoxide (CO). CO can be converted to a highly efficient and carbon free fuel hydrogen (H2) through a well-known water gas shift reaction. However the untapped potential of H2 from waste industrial streams is yet to be explored. This is the first article that investigates the potential of H2 production from industrial waste gases. The available resource (i.e. CO) and its H2 production potential are estimated. The article also provides insights into the principal challenges and potential avenues for long-term adoption. The results showed that 249.14 MTPY of CO are available to produce 17.44 MTPY of H2 annually. This suggests a significant potential for H2 production from waste gases to revolutionize industrial waste management and contribute significantly towards Sustainable Development Goals 7 9 and 13ensuring access to affordable reliable sustainable and modern energy for all and taking decisive climate action respectively.
Towards a Sustainable Future: Bio-hydrogen Production from Food Waste for Clean Energy Generation
Jan 2024
Publication
To address climate change energy security and waste management new sustainable energy sources must be developed. This study uses Aspen Plus software to extract bio-H2 from food waste with the goal of efficiency and environmental sustainability. Anaerobic digestion optimised to operate at 20-25°C and keep ammonia at 3% greatly boosted biogas production. The solvent [Emim][FAP] which is based on imidazolium had excellent performance in purifying biogas. It achieved a high level of methane purity while consuming a minimal amount of energy with a solvent flow rate of 13.415 m³/h. Moreover the utilization of higher temperatures (600-700°C) during the bio-H2 generation phase significantly enhanced both the amount and quality of hydrogen produced. Parametric and sensitivity assessments were methodically performed at every stage. This integrated method was practicable and environmentally friendly according to the economic assessment. H2 generation using steam reforming results in a TCC of 1.92×106 USD. The CO2 separation step has higher costs (TCC of 2.15×107 USD) due to ionic liquid washing and CO2 liquefaction. Compressor electricity consumption significantly impacts total operating cost (TOC) totaling 4.73×108 USD. showing its ability to reduce greenhouse gas emissions optimize resource utilization and promote energy sustainability. This study presents a sustainable energy solution that addresses climate and waste challenges.
Techno-economic Analysis of Stand-alone Hybrid PV-Hydrogen-Based Plug-in Electric Vehicle Charging Station
Sep 2024
Publication
The increase in the feasibility of hydrogen-based generation makes it a promising addition to the realm of renewable energies that are being employed to address the issue of electric vehicle charging. This paper presents technical and an economical approach to evaluate a newer off-grid hybrid PV-hydrogen energy-based recharging station in the city of Jamshoro Pakistan to meet the everyday charging needs of plug-in electric vehicles. The concept is designed and simulated by employing HOMER software. Hybrid PV-hydrogen and PV-hydrogenbattery are the two different scenarios that are carried out and compared based on their both technical as well as financial standpoints. The simulation results are evident that the hybrid PV- hydrogen-battery energy system has much more financial and economic benefits as compared with the PV-hydrogen energy system. Moreover it is also seen that costs of energy from earlier from hybrid PV-hydrogen-battery is more appealing i.e. 0.358 $/kWh from 0.412 $/kWh cost of energy from hybrid PV-hydrogen. The power produced by the hybrid PV- hydrogen - battery energy for the daily load demand of 1700 kWh /day consists of two powers produced independently by the PV and fuel cells of 87.4 % and 12.6 % respectively.
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