Carbon Dioxide Research Articles

Regulating the interaction between Bi metal and Bi24O31Br10 nanosheets for efficient photoreduction of CO2

Artificial photosynthesis converting CO2 into valuable compounds has garnered significant interest. However, the insufficient surface activity sites, weak adsorption capacity of CO2 and poor electron-hole separation capability hinder CO2 photoreduction used for practical implementation. Herein, Bi nanoparticles/Bi24O31Br10 composite photocatalyst (Bi/BOB) was designed constructed through in-situ reduction of bismuth metal on the surface of ultra-thin Bi24O31Br10 nanosheets. Bi/BOB exhibits an excellent ability to reduce CO2 to CO. The CO2 reduction rate of the optimized Bi/BOB composite catalyst is 43.07 μmol·g−1·h−1, which is significantly superior to other reported bismuth-based photocatalysts. Experimental characterization and Theoretical simulation calculation reveal that the in-situ reduction of bismuth metal causes significant local lattice distortion and uneven charge distribution, thereby producing a strong interaction between Bi nanoparticles and BOB support. So, it enhances the adsorption and activation of carbon dioxide molecules and reduces the Gibbs free energy barrier during the catalytic reaction. Moreover, the strong interaction helps to enhance the separation of photogenerated charge carriers and stability of catalysts. This study offers research suggestions for the interaction between metal and support to enhance CO2 reduction.

Enhanced CO2 capture by functionalization of SBA-15 with APTES and l-lysine

In this study, amine-based CO2 sorbents were synthesized after functionalizing SBA-15 mesoporous materials. Mesoporous SBA-15 was characterized and functionalized by APTES as an alkanolamine, L-lysine as an amino acid and a combination of both. CO2 adsorption tests were performed at 1.6 and 2 bar to estimate the carbon dioxide (CO2) uptake on the sorbents. As expected, CO2 adsorption capacity (mmol/g) increases with pressure. Based on the elemental analysis of the sorbents and the results of Fourier transform infrared spectroscopy (FTIR), a proposal was made of the possible chemical reactions that may occur in order to describe the experimental results. It is important to mention that the pretreatment prior to the CO2 adsorption tests plays a key role for the application of amine-functionalized mesoporous silica. The presence of water conditions the formation of carbonic acid and carbonate adsorbed on the surface and, consequently, the CO2 adsorption capacity of the sorbent. APTES and l-lysine loaded onto mesoporous SBA-15 exhibited the highest CO2 adsorption capacity (4.53 mmol/g) at 2 bar and room temperature. After reloading the sorbents with APTES and Lysine, no improvements in the CO2 absorption capacity were observed.

Magnetic Solid-Phase Extraction with Dispersion of Magnetic Hypercrosslinked Polystyrene by Carbon Dioxide for the Extraction of Amphenicols from Honey and Milk in Their Determination by HPLC–MS/MS

Magnetic Solid-Phase Extraction with Dispersion of Magnetic Hypercrosslinked Polystyrene by Carbon Dioxide for the Extraction of Amphenicols from Honey and Milk in Their Determination by HPLC–MS/MS

Carbon dioxide emission equivalent calculation and inter-sectoral transfer pattern of different water use terminals in China

In the context of global climate change, all industries have put forward the requirements for carbon emission reduction. The effective use of water resources is the key to achieving carbon emission reduction, so it is particularly important to review the carbon dioxide emission equivalents of water resource utilization behaviors (CEE-WRUBs) of water users. However, existing research on CEE-WRUBs across various water sectors remains inadequate. Therefore, this study integrates the enhanced CEEA method, LMDI decomposition model, and IOA method to analyze CEE-WRUBs across diverse water use terminals. Then seeks their main driving factors and their transfer pattern among different industries, which are crucial to the realization of the global carbon neutrality objective. The results showed that: (1) China's CEE-WRUBs show a significant downward trend. Industrial water use emerges as the primary source of CEE, but the CEE-WRUBs of most industrial water terminals show a fluctuating downward trend. Grains' water use behavior (WRUBs) absorbed the largest CEE, reaching 14,698 Mt in 2020. (2) the water efficiency effect emerges as the predominant driver behind the increase in CEE-WRUBs most of the time, and holding a prominent position. The carbon emission intensity effect primarily steers the reduction of CEE-WRUBs. (3) the largest net outflow sector of WRUBs embodied carbon in 2007-2020 was transformed from basic material heavy industry (-153.54 Mt in 2007) to agriculture (-128.26 Mt in 2020). Most of the WRUBs embodied carbon of agriculture flows into light industry, while most of the WRUBs embodied carbon of basic material heavy industry flows into finishing heavy industry and construction. The methods and results of this study provide a potential reference for investigating the regional water-carbon relationship and advancing the global carbon neutrality objective.

Green investment and its transformative impact on energy use in agriculture: A holistic approach towards carbon dioxide emissions

The extensive use of non-renewable energy sources in agriculture and associated unsustainable practices have contributed greatly to climate change issues. Africa's lack of green initiatives has exacerbated environmental pollution in the last decade. In that regard, this study investigates the transformative impact of green investment on carbon emissions in agriculture fueled by dependency on non-renewable energy use in the sector. It utilizes advanced econometric techniques, including dynamic ordinary least squares, fully modified ordinary least squares, and the causality tests to conduct a rigorous analysis. The findings reveal a concerning rise in agricultural pollution via crop and livestock production. However, green investment is found to have a positive impact on carbon dioxide emissions, hence a potent tool for significantly reducing carbon emissions. The causality analysis unveils a bidirectional causal relationship between green investment and agricultural pollution and a unidirectional causality between green investment and carbon emissions, shedding light on the complex interplay between these variables. Also, non-renewable energy is found to increase carbon emissions in the region. The outcomes of this research contribute valuable insights and lay a foundation for future research and policymakers to enhance the future of agricultural research and sustainability. It also offers a roadmap for developing effective policies that balance the immediate needs of the agricultural sector with the imperative of long-term environmental sustainability. Finally, it has a global significance on the relevance of green initiatives to boost sustainable agriculture and reduce pollution.

The Impact of Economic Growth, Energy and Electricity Consumption Usage on CO2 Emissions: A Case Study of Morocco

Given the uncontrolled increase in environmental pollution and degradation of environmental quality worldwide, the environmental impact of economic growth has become a major focus in recent decades the most important question is: How does economic growth affect environmental quality? This study addressed this issue, examining the nature of the long-run relationship between economic growth per capita and pollutant emissions in Morocco. For this reason, the ARDL (Autoregressive Distributed Lag) modeling approach was used from 1990 to 2020. This approach mainly includes time series analysis and cointegration. The relationship tested introduces four variables: carbon dioxide (CO2), energy consumption per capita, electricity consumption per capita and GDP per capita. The main results indicate a long-term relationship between economic growth, energy consumption and CO2 emissions, indicating that a 1% increase in electricity consumption increases CO2 emissions by 0.36%. On the other hand, a 1% increase in GDP per capita increases CO2 emissions by 0.76%, and a 1% increase in energy consumption increases emissions by 2.06%. Thus, all variables show a significant effect. In conclusion, the strategy that Morocco needs to follow to solve our problems is to prioritize investment in research, development and artificial intelligence, while providing adequate training in energy-related fields.

The Role of Organic Farming for Climate Change Mitigation and Sustainable Development: A Review

Climate Change, exacerbated by human activities such as fossil fuel combustion and greenhouse gas emissions like carbon dioxide (CO2), is a pressing global crisis that disrupts long-term weather patterns, ecosystems, and human well-being. Organic agriculture offers a viable solution to mitigate these effects. By lowering greenhouse gas emissions and enhancing soil carbon sequestration, organic farming strengthens ecosystem resilience. Practices such as eliminating synthetic fertilizers and pesticides, rotating crops, and utilizing organic waste foster robust agricultural systems capable of enduring extreme weather and water scarcity. This paper provides an in-depth analysis of how organic farming contributes to climate change mitigation, detailing practices that support soil carbon sequestration, reduce nitrogen oxide (N2O) emissions, and boost biodiversity. It also addresses challenges such as emissions measurement and consumer behaviour, emphasizing the need for further research and supportive policies. Organic agriculture not only advances sustainable development but also promotes food security and environmental sustainability in the face of climate change.

Influence of Aeration, Introduction of Probiotics, and Supply of Water on Landfill Gas Production—Study of Models

When municipal solid waste (MSW) is placed in a landfill, it undergoes anaerobic decomposition, leading to the production of landfill gas, which primarily consists of methane (CH4) and carbon dioxide (CO2). Reducing methane emissions is essential in the fight against climate change. It must be implemented at global and European levels, as set out in 2030 in the impact assessment of the climate goal plan. This assessment states that to achieve the goal by 2030 and to reduce greenhouse gas emissions by at least 55%, the methane emissions must be reduced, considering the goals of the Paris Agreement. The Glasgow Climate Pact includes a global mitigation target of the year 2030: to reduce CO2 emissions by 45%, and the emissions of methane and other greenhouse gasses. For that purpose, looking for new, more advanced ways of managing such waste is necessary. The main objective of this experimental study was to evaluate the influence of aeration, probiotic introduction, and water supply on the production of landfill gasses (CO2, CH4, N2, H2, etc.) in five different landfill models during the management of MSW and to propose the best solutions for reducing environmental pollution. The results of the research showed that the first and second models of landfills, using only anaerobic conditions, can be used for the treatment of MSW for the production of biogas (CH4, CO2), as up to 40–60% of it was released during the 120-experiment period. The third landfill model can be applied in old, already closed landfills, where the rapid stabilization and aeration of MSW are required to minimize pollutant emissions (N2, etc.) and unwanted odors and shorten biodegradation processes. The results of the fourth and fifth landfill models, in which aerobic–anaerobic conditions were applied, showed that the developing nitrification–denitrification processes resulted in complete nitrogen removal (from 20% to 0%), and overall waste stabilization improved the biodegradation of the MSW. Later, relatively good (on average, 30%) results of biogas (CH4, CO2) emissions are achieved during anaerobic condition formation results. Summarizing all experiment results of all landfill models for the further evaluation of the processes, all models can be applied in real practice depending on where they will be used and what result they want to achieve.

Assessment of the benefits and risks of sewage sludge application as soil amendment for agriculture in Eswatini

Sewage sludge is an important soil conditioner, and source of nutrients with a potential for use in agriculture. However, such benefit needs to be weighed against the risks due to the presence of heavy metals, and other substances that may endanger human health, plants, soil and the ecosystem. This research had the objective of evaluating the agricultural potential of sewage sludge together with the risks that may be present in use. Samples of sewage sludge from seven wastewater treatment plants in Eswatini were analyzed for selected physical and chemical parameters, and heavy metal concentrations using commonly established laboratory procedures. The analysis results indicated that, sludge samples exhibited high organic matter content, cation exchange capacity, macro nutrients such as nitrogen and phosphorus and micro nutrients (trace metal elements) needed for plant growth. Anaerobically digested sludge samples showed higher carbon to nitrogen ratio because of biomass loss in the form of methane and carbon dioxide. The heavy metal concentrations are all within safe limits except the sludge from Matsapha area that had levels of chromium, and nickel above regulatory limits. With respect to their heavy metal contents, most of the sludge samples would qualify as Class A sludge ready to be used as organic fertilizer for agriculture without regular monitoring of heavy metals in the soil to which they are applied. The study results indicated the importance of sewage sludge for their agricultural potential through supplementation of both micro and macro nutrients needed for plant growth, for improving the soil properties such as water holding capacity and permeability, through the increase of organic matter content, and retention of nutrients due to the high cation exchange capacity. All these benefits are realized with sewage sludge being a lower cost alternative to commercial fertilizers. Moreover, the low concentration of heavy metals present in the sludge presents lower risk that may arise in the course of utilizing the sludge as agricultural supplement. Key words: Agriculture, fertilizer, heavy metals, nutrient, sewage, sludge, nitrogen, phosphorous

Mechanisms and advancements in microwave-enhanced CO2 mineralization of lightweight porous concrete

Lightweight porous concrete (LPC) typically exhibits low early strength, which can be addressed by enhancing early strength through carbon dioxide (CO2) mineralization curing while achieving permanent CO2 sequestration. The efficacy of this process relies on maintaining optimal moisture levels. This study investigates the influence of moisture content on the performance of solid waste-based lightweight porous concrete blocks (RSFAC) subjected to microwave heating pretreatment. Moisture levels were adjusted to 10%, 20%, 30%, and 40% (initial water-to-cement ratio of 45.4%) before undergoing mineralization curing within an environment set at a temperature of 20 °C, relative humidity 75%, and a CO2 concentration of 40% for a duration of 0.5 h. The impact of moisture content on RSFAC's compressive strength, carbon sequestration rate, mineralization products, and microstructure was evaluated. Results indicate that compared to conventional oven pretreatment methods requiring nearly 10 h, microwave pretreatment technology achieves equivalent water content within just 50 min, significantly reducing the time needed for mineralization pretreatment. RSFAC, when pretreated with microwave heating, outperforms untreated samples (Ref-0 and Ref-1) in terms of compressive strength and carbon sequestration efficiency. Optimal performance was observed at a moisture content level of 30%, with the highest recorded compressive strength achieved at 1, 3, and 7 d respectively. At the curing age of 7 d, the compressive strength reached up to 2.32 MPa while the carbon sequestration rate reached approximately 11.61%. Furthermore, aragonite and calcite (tetrahedral and hexahedral), without poorly crystalline spherulites, were identified as the main crystalline CaCO3 generated by RSFAC under this specific moisture content condition; pores larger than 50 nm served as primary reaction sites for RSFAC mineralization curing, whereas there was a significant increase in pore proportion with sizes less than 20 nm after filling with mineralization products.

Oesophageal intubations in anaesthetic practice across Australia and New Zealand: A webAIRS analysis of 109 incidents.

Oesophageal intubations are more common than may be realised and can potentially cause significant patient harm even if promptly identified and corrected. Reports of morbidity due to unrecognised oesophageal intubation continue to present in coroner and media reports. Therefore, it would be helpful to identify mechanisms to prevent these events and implement strategies to avoid and identify incorrect endotracheal tube placement. This analysis of oesophageal intubations reported to webAIRS aims to provide an in-depth analysis of all events in which oesophageal intubation occurred. WebAIRS is a web-based, bi-national incident reporting system collecting voluntarily reported anaesthetic events across Australia and New Zealand, with more than 10,500 incidents registered. A structured search through the webAIRS database identified 109 reports of oesophageal intubation reported between July 2009 and September 2022. A common cause of oesophageal intubation was the misidentification of the larynx due to a poor laryngeal view. Desaturation directly attributed to the misplaced endotracheal tube occurred in 43% of all reports. The authors precisely defined early recognised oesophageal intubation and delayed or unrecognised oesophageal intubation. Most reports (74%) described early recognition of the misplaced intubation, of which 27% led to directly contributed to hypoxia. Cardiovascular collapse as a direct consequence of the late recognition of oesophageal intubation was described in five (18%) of these events. There was inconsistency in end-tidal carbon dioxide monitoring and interpretation of the resulting waveform. Findings show that oesophageal intubation continues to be an issue in anaesthesia. Incidents described confusion in diagnosis, human factors issues and cognitive bias. Clear diagnostic guidance and treatment strategies are required to be developed, tested and implemented.

SYNTHESIS OF PRECIPITATED CALCIUM CARBONATE IN THE FORM OF CALCITE CRYSTALS AS A VALORIZATION OF LIME CARBIDE SLAG WASTE

The presence of high level of calcium oxide (CaO) has been detected in lime carbide (LC) slag waste generated form the acetylene gas industry. There is untapped potential for the valorization of LC-slag waste, where the calcium oxide content can be converted into Precipitated Calcium Carbonate (PCC/CaCO3) which is valuable and can contribute to carbon dioxide sequestration. Calcium carbonate has unique advantages as a carrier, but some critical problems need to be addressed, such as low productivity, disordered structure, and weak adsorption ability. In this study, the desired type of crystal is calcite which has the most stable characteristics from the other types of crystals. Micro-bubble reactor is used as a method of dispersing CO2 in converting CaO to PCC/CaCO3. This method has the advantage of being able to maintain CO2 gas bubbles longer in solution so that the reaction time that occurs can also be optimize. The LC-Slag valorization process was carried out by varying the LC-slag concentration between 3-7% w/w and the reaction time between 15 - 35 minutes. The dispersion of CO2 gas is fixed at a flow rate of 2.5 L/m. From the yield, it can be seen that the longer the reaction time, the yield of PCC/CaCO3 produced is also greater. At 35 minute reaction time and concentration LC-Slag Waste varied 3, 5, and 7% w/w, the produced yields were 89.44, 95.00, and 93.76%, respectively. This is evidenced by the results of SEM and XRD analysis. In the future, this treatment method is expected to provide more insight and guidance for the valorization of LC-slag waste and CO2 mineralization in the acetylene gas industry.

Carbon footprints and health security: A comparative assessment of the Sustainable Development Goals 3 and 13 in East Asian countries.

In East Asia, where several countries are among the top emitters of carbon dioxide globally, the need to address the dual challenges of reducing carbon footprints and ensuring health security is paramount. Against this backdrop, this study used a descriptive analysis to provide a comparative assessment of the carbon footprints and the level of health security in East Asia using secondary data, sourced from the World Development Indicators. The findings from the study show that it is only North Korea that its average carbon footprint of every person is less than 2.3 tons. However, China, Japan, Mongolia and South Korea are currently lagging behind in meeting the SDG 13 target. Meanwhile, North Korea recorded the highest incidence of tuberculosis in the region. Despite the fact that South Korea and Japan were the highest emitter of CO2, the duo had the lowest under five mortality, infant mortality, incidence of TB alongside the highest life expectancies which surpassed the regional performance. In view of the above, the policymakers in Asia and the rest of the countries with health insecurity should emulate the policymakers in Japan and South Korea by making adequate investment in health, education, and standard of living of their citizens.

Characterization of Depleted Hydrocarbon Reservoir AA-01 of KOKA Field in the Niger Delta Basin for Sustainable Sub-Sea Carbon Dioxide Storage

Characterization of Depleted Hydrocarbon Reservoir AA-01 of KOKA Field in the Niger Delta Basin for Sustainable Sub-Sea Carbon Dioxide Storage

Quantifying carbon footprint of salmon fillet processed in Vietnam: impact of transportation and improvement opportunities.

The carbon footprint of a product represents the amount of greenhouse gas (GHG) emissions released during its production, transportation, and consumption and is calculated as carbon dioxide equivalent (CO2-eq). It should be integrated into different existing and future seafood awareness campaigns to create more holistic yardsticks by which consumers, retail businesses, and producers can assess the environmental impacts of seafood. This study used the life cycle assessment (LCA) method for the first time to quantify the carbon footprint of salmon fillet products processed in Vietnam for export. The carbon footprint of 1-kg salmon fillet at the factory gate ranges between 7.20 and 15.05kg CO2-eq, depending on transportation modes of head-on-gutted (HOG) salmon from Norway to Vietnam. Transportatiton by airfreight doubled carbon footprint of salmon fillet products processed in Vietnam compared to sea freight. Feed and electricity were identified as the two most respective contributing factors during the stage of cultivation, processing fresh salmon in Norway, and the stage of salmon fillet processing in Vietnam. They accounted for about 95% and 50% of the total carbon footprint in these stages of the production chain, respectively. To reduce the carbon footprint of the salmon fillet products processed in Vietnam, the company should (i) make a careful production plan to use sea freight transportation instead of airfreight and (ii) use more electricity from renewable energy sources. Furthermore, the carbon footprint of these products can be reduced by improving the cultivation process via changing feed ingredients and enhancing the feed conversion ratio (FCR).

Design and research of multi-information fusion RFID sensor for fruit and vegetable quality detection.

With the increasing demand for fruits and vegetables in the market, the development of cold chain logistics has put forward higher requirements for the quality of fruits and vegetables in storage. To ensure the freshness of fruits and vegetables during storage and transportation and avoid unnecessary loss, it is necessary to conduct real-time detection of their odor to ensure their quality. Therefore, based on nano-composite materials combined with Radio Frequency Identification (RFID) technology, this paper designs an integrated RFID sensor that can simultaneously detect temperature, carbon dioxide, and ethanol concentrations. The test results show that the sensor has a high sensitivity of 0.25dB/°C, 0.011dB/ppm, and 0.65MHz/ppm for detecting temperature, carbon dioxide, and ethanol concentration, respectively. The sensor also uses Printed Circuit Board (PCB) technology to make the sensor base, which has the advantages of low cost, easy portability, and mass production capability. The results obtained evidencethat the system meets the requirements of environmental monitoring for fruit and vegetable storage, runs stably, and has a high use value.

Electrocatalytic formate synthesis from polyethylene terephthalate and carbon dioxide through sulfide-and-reconstruct engineering of catalyst

The global issue of plastic pollution and carbon emission have significantly impacted the survival of both ecosystems and human beings. Electrochemical coupling of polyethylene terephthalate plastic (PET) and CO2 into fine chemicals provides a potential approach to achieve waste resource utilization and carbon neutrality. Herein, we reported an innovative electrocatalytic system for concurrently upgrading PET hydrolysate and CO2 into value-added formic acid. Through a sulfide-and-reconstruct strategy, Ni3Bi2S2 and Bi2S3 were synthesized as pre-catalysts, which can undergo in situ reconstruction to form NiOOH/Ni3Bi2S2 at the anode and Bi (1.5 S) at the cathode during electrolysis. The exceptional electrocatalytic performance (96 % and 97 % at the anode and cathode, respectively) and stabilities (>30 h) of the anodic NiOOH/Ni3Bi2S2 and cathodic Bi (1.5 S) was attributed to the exposure of the true active site after reconstruction. By coupling PET hydrolysate oxidation reaction (POR) with CO2 reduction reaction (CO2RR), the assembled zero-gap MEA electrolyzer realized a total Faradaic efficiency of 175 % for formate. This study provided a concept for upcycling of PET.

Optimizing Vertical Farm Cultivation of Cichorium spinosum L.: White Light's Influence and Nutrition Management

The objective of this study was to examine the integration of a wild leafy vegetable, Cichorium spinosum L., in vertical farms. This research comprises two experiments focusing on different “white” light products and nutrient solutions. During both experiments, the temperature varied between 25-28°C, relative humidity ranged from 50-70%, carbon dioxide was at 450 ppm, and light intensity was set at 300 μmol m−2 s−1 respectively. In the lighting experiment, the three spectra used had the commercial names Neutral, Full and a SunLike™, and their spectral composition (blue:green:red:far-red) were 14:32:43:10, 16:36:40:8, and 21:34:36:7 respectively. The photoperiod was set to 12 hours and the plant density was 50 plants m−2. Results showed no significant impact on agronomical parameters and leaf anatomy. The stomatal length and width decreased as the red:blue ratio of the light sources decreased, being greater in the Neutral treatment (red:blue ratio of 3.1) compared to the Full and SunLike™ (red:blue ratios of 2.5 and 1.7 respectively). Based on these results the preferable “white light” product was the one with the highest efficiency and lowest market price at the time of the experiment. In the nutrient solution experiment, the agronomical and nutritional attributes of stamnagathi plants supplied with a control nutrient solution, “N10-Fe15” were compared to plants cultivated under limited nitrogen, “N4-Fe15” and elevated iron, “N10-Fe48”, EC was 1.5 ds m−1, and pH was 5.6-6.5. The experiment simulated commercial practices by increasing the photoperiod to 15 hours and plant density to 100 plants per square meter. The results did not demonstrate significant effect of the nutrient solution differences on the agronomical characteristics except from a decrease in total Kjeldahl nitrogen under limited nitrogen conditions. Notably, leaf tissue phosphorus content increased under elevated iron conditions. The nitrate content remained within safe for consumption thresholds for all treatments. Based on these results, stamnagathi can be integrated in vertical farms under limited nitrogen conditions. Stamnagathi’s resilience to elevated iron in the nutrient solution demonstrated its potential for future biofortification experiments.

Performance Analysis of Precooling Systems for Cryogenic Carbon Capture: A Comparative Study of Theoretical, Numerical, and Experimental Methods

The urgency of addressing climate change has necessitated innovative and practical approaches to reducing greenhouse gas emissions. Cryogenic Carbon Capture (CCC) technology has emerged as a promising solution for capturing CO2 from industrial emissions. This study investigates a simplified design for a precooling system within CCC technology, focusing on optimizing the efficiency and reliability of the system while minimizing energy consumption. The research examines the effects of CO2 concentration in a gas mixture (simulated flue gas, nitrogen and carbon dioxide), cooling bath temperature, and gas mixture flow rate on the performance of heat exchangers in the precooling system. Theoretical, numerical, and experimental analyses were conducted to assess the system’s performance. The use of liquid nitrogen at -196°C in the cooling bath was found unsuitable due to CO2 freezing within the pipes. Instead, a mixture of dry ice and isopropyl alcohol at -78.5°C proved effective in maintaining consistent temperature and pressure conditions without causing CO2 blockages. Numerical simulations highlighted the importance of optimizing pipe length to balance temperature control and pressure dynamics, with a 140 cm pipe length identified as optimal for heat exchanger design. Experimental results revealed that longer pipes enhance cooling performance due to increased heat exchange surface area, while higher CO2 compositions and flow rates result in higher outlet temperatures and pressures. The study emphasizes the need for further research and simulation work to refine heat exchanger designs for industrial applications, aiming to develop systems that maximize cooling efficiency while ensuring reliable operation.

Greenhouse farming: Hydroponic vertical farming- Internet of Things (IOT) Technologies: An updated review

This review paper of literature highlights the importance of greenhouse urban farming technology, hydroponics, aeroponics, aquaponics, vertical farming and applications of Internet of Things (IOT) technologies. The greenhouse farming is a well known modern agriculture technology for optimal plant growth. Hydroponics, a soilless cultivation technique using nutrient solutions under controlled conditions, is used for growing vegetables, high-value crops, and flowers. Vertical farming is a popular trend in hydroponics that involves stacking multiple layers of plants in a vertical arrangement. This farming method saves space, reduces water usage, and increases yields per square foot of growing area. In comparison to conventional greenhouse cultivation, hydroponics requires less fertilizer, pesticides, and water due to the precise control over their distribution. The term “Internet of Things (IOT)” is a system of interconnected computing devices, sensors, objects, microcontrollers, and cloud servers that can transmit data across a network and control other devices remotely without human intervention. A better management of nutrient solution in hydroponic systems requires optimum pH, electrical conductivity (EC), or ions concentration. The three main greenhouse farming gases (GHGs) emissions in hydroponics hi-tech urban farming are nitrous oxide, methane and carbon dioxide (CO2). To measure the levels of CO2 in hydroponics, the more intermediate to advanced grower can use a CO2 monitoring and controllers system. Hydroponic vertical farming is in infancy in India. Although hydroponic vertical farming units for production of crops like strawberry, lettuce and other leafy vegetables, foliage and flowers are functioning in major metros of India. However, the organized hydroponic vertical farms for production of food crops are not available in India. Therefore, only a few successful hydroponic vertical farms have been built in India mainly due to the initial high price tag on construction and the cost of maintaining them afterwards. Another disadvantage is carbon footprint of hydroponic vertical farming is very high, and discourages its applications.