Minimize CO2 Emissions Research Articles

Improving the Thermal Performance and Energy Efficiency of Buildings by Incorporating Biomass Waste into Clay Bricks

Excessive urban construction is primarily driven by uncontrolled population growth, which has serious consequences for the environment, energy, cost, and human life in general when building materials are massively used. In terms of energy and economic efficiency, buildings that make use of sustainable construction materials and technologies perform better. This is because building in an eco-friendly way results in less waste. Agro-industrial by-products and insulating materials are two examples of sustainable materials that have been put to good use in the climate change mitigation effort and to preserve the environment. Precast components are emphasized as a viable option that is suitable for this purpose and may potentially fulfill the need for housing units. Thus, this study investigated the viability of employing agricultural waste consisting of pomegranate peel waste to produce fired clay bricks. Results demonstrated that the optimum amount of pomegranate peel waste was determined to be 15%, and the optimal firing temperature was determined to be 900 °C. The thermal conductivity of all test samples was lower than that of conventional brick. Furthermore, when compared to conventional wall brick, all the tested samples of manufactured brick reduced energy consumption by 17.55% to 33.13% and carbon dioxide emissions by 7.50% to 24.50%. In addition, the economic feasibility of employing each synthetic sample was evaluated by computing the simple payback time (SPP). It was determined that 1.88-10.74 years were required for the brick samples to provide a return on their initial investment. Due to its ability to decrease heat gain, preserve energy, minimize CO2 emissions, and shorten the payback time, burned clay bricks manufactured from pomegranate peel waste are regarded as a feasible building material. Hence, manufactured bricks are usually considered an exceptional contribution to environmental sustainability.

Effect of ECAP process on mechanical properties and microstructure of AA-6061 recycled chips

The oxidation of aluminum machined chips makes successful recycling via the traditional re-melting technique difficult. A viable solution to this problem is to utilize solid-state recycling to transform aluminum machined chips directly into semi-finished goods, eliminating the costs of the re-melting process and minimizing CO2 emissions. In the present study, Al-6061 alloy chips have been recycled using hot extrusion followed by severe plastic deformation at ambient temperature to examine the material's mechanical properties and microstructures. The current study investigates the effects of equal channel angular pressing samples after (1, 2, and 4) cycles using a die with 90° and 20° angles, a strain of 1 was applied each pass for a maximum of four cycles at room temperature, through different routes (BC, C) on the mechanical properties of recycled specimens before and after the process. Observations showed a significant improvement in the characteristics of recycled chips exposed to hot extrusion followed by the ECAP technique. Maximum ultimate tensile strength (265, and 238 MPa) maximum yield strength (149, and 136 MPa), and elongation to failure (46 and 41%) for both routes were obtained. Moreover, each pass increases yield strength ultimate tensile strength, and micro-hardness while increasing elongation to failure. The mechanical characteristics of ECAPed specimens were higher than the extruded specimen. The mechanical properties and microstructures of solid-state recycled Al-6061 alloy chip samples were significantly influenced by the number of passes and route types.

Reducing CO2 emissions in the iron industry with green hydrogen

The different methods of producing Green Hydrogen have been discussed in detail in this article. The implications and significance of employing green hydrogen in the steel and iron industries have been brought to light. Carbon Dioxide (CO2) is a significant environmental gas pollutant which is released in large quantities by steel mills and other industrial facilities. It is hoped that the appropriate measures would be taken to minimize the emission of hazardous gases, such as CO2, from each facility. The green hydrogen idea is a new technology that is being used as an alternative energy source for the sectors listed above. The most important step in reducing CO2 emissions is to collect it and store it in a secure location. In this article, the main goal and scope is to analyse various methodologies to minimize CO2 emissions in Iron and Steel Industries as well as compare with noble green hydrogen technology. Here, the state of art for the emission of CO2 as well as the recommendations of Green Hydrogen Technology are emphasized which is the novelty of this article.

Hybrid Vehicle CO2 Emissions Reduction Strategy Based on Model Predictive Control

This work proposes a hybrid drive controlled configuration, using a minimum emissions search algorithm, which ensures the operation of the Internal Combustion Engine (ICE) in its fuel efficiency range, minimizing CO2 emissions by controlling the power flow direction of the Electric Machine (EM). This action is achieved by means of Power Converters, in this case a bi-directional DC-DC Buck-Boost Converter in the DC-side and a DC-AC T-type Converter as the inverting stage. Power flow is controlled by means of a bi-directional Model Predictive Control (MPC) scheme, based on an emissions optimization algorithm. A novel drivetrain configuration is presented where both, the ICE and the EM are in tandem arrangement. The EM is driven depending on the traction requirements and the emissions of the ICE. The EM is capable of operates in motor and generator mode ensuring the Minimum Emission Operating Point (MEOP) of the ICE regardless of the mechanical demand at the drivetrain. Simulation and validation results using a Hardware in the Loop (HIL) virtual prototype under different operation conditions are presented in order to validate the proposed overall optimization strategy.

Battery-H2 storage system for self-sufficiency in residential buildings under different electric heating system scenarios

An H2 storage system (i.e., an electrolyzer, H2 tank, and a fuel cell) has received attention for seasonal storage. The H2 storage system can improve energy conversion efficiency by utilizing recovered heat from the fuel cell in a residential application. This study investigated the potential of a battery-H2 storage system using the recovered heat to maximize energy self-sufficiency in residential buildings. The entire energy supply network consisted of a photovoltaic, electric heating system, and energy storage systems (i.e., battery, H2 storage system, and heat tank). To investigate the self-sufficiency performance, four storage cases (i.e., no storage, battery-only, H2 storage system, and battery-H2 storage system cases) were introduced to the residential buildings under two electric heating system scenarios (i.e., electric boiler and heat pump system). In addition, these cases were evaluated in terms of economic and environmental performance, and the effects of battery efficiency uncertainty and battery types on energy network performance were analyzed. The findings showed that the battery-H2 storage system achieved the highest self-sufficiency while reducing the battery capacity because the H2 storage system compensated for a self-discharge loss of the battery for seasonal storage. Accordingly, the battery-H2 storage system was the most cost-effective option for minimizing CO2 emissions in residential buildings. When the battery was used with the H2 storage system, improving battery energy conversion efficiency was more effective than battery self-discharge rate in reducing CO2 emissions further. In addition, a lead-acid battery was more cost-effective than a lithium-ion battery but showed low potential to reduce CO2 emissions and was disadvantageous in terms of physical size.

Increasing RES penetration through H2 technologies on Flores island, Azores: A techno-economic analysis

On Flores island (Azores, Portugal), energy production depends up to 47% on fossil fuels, namely Diesel. To minimize CO2 emissions, the dependency on fuel prices, and to mitigate the consequences of variability and intermittency of renewable energy sources, a new energy system, based on H2 storage was analysed. To achieve the optimal size of the system, a computer model was developed and a multi-objective genetic algorithm function was used to minimize three objectives: the difference of levelised cost of energy (△LCOE), CO2 emissions and the percentage of renewable energy dumped (RRES, dump). From the set of solutions obtained, one that meets RRES, dump ≤ 1%, lowest CO2 emissions and lowest △LCOE is chosen and an economical and energetic analysis is performed. The newly proposed system reduces Diesel consumption by 68,7% (1057487 L/year) and CO2 emissions by 65,9% (2455,1 CO2 tons/year) achieving a renewable energy sources (RES) penetration of 89% (36% increase), but fails to decrease the levelised cost of energy (56,62 €/MWh increase). However, a way to make the project viable through financial support is presented and an alternative to reduce the levelised cost of energy by commercialising the products of electrolysis, hydrogen and oxygen, is proposed. Finally, it is expected that with further research and development of H2 technologies, economic and energetic results will get more advantageous, opening up new perspectives for the future.

Thermo-economic optimization of a novel hybrid structure for power generation and portable hydrogen and ammonia storage based on magnesium–chloride thermochemical process and liquefied natural gas cryogenic energy

Storage and transfer of hydrogen (H2) from production sites/plants to large-scale demanding industries are one of the most challenging obstacles to hydrogen adoption. Hydrogen liquefaction and its chemical storage in the form of ammonia (NH3) can be used for safe and economic transportation. High energy consumption and carbon dioxide (CO2) emissions to supply the utility of these systems can limit the production of liquid H2 and liquid NH3. Therefore, efficient design and practical strategies to store hydrogen at a large scale with minimal energy consumption and CO2 emissions are necessary. In this research, an innovative hybrid system for portable hydrogen storage and power generation with zero CO2 emission through liquefied natural gas (LNG) regasification is developed. The proposed structure includes a cryogenic air separation unit, magnesium–chloride hydrogen production process, ammonia production system, hydrogen liquefaction cycle, and Rankine/oxy-fuel power plants. The heat loss of the proposed structure is utilized to supply the required heat load for the thermo-electrochemical unit. The LNG regasification operation is utilized for pre-cooling the hydrogen liquefaction system and the necessary refrigeration of the air separation process and the final products. The developed structure is fed by 1883 kmol/h LNG, which is converted to 120 kmol/h liquid NH3, 180 kmol/h liquid H2, 924.5 liquid CO2, and 16.09 MW power. The thermal and exergy efficiencies for the designed system are 20.33% and 22.76%, respectively. The results of the exergy investigation reveal that the largest contribution of exergy destruction occurs in heat exchangers (31.27%), combustion chamber (34.65%), and turbines (8.12%). The economic evaluation indicates that the net annual profit, added value, and payback period are 15.93 US$/yr, 0.0779 US$/kWh, and 5.646 yr, respectively, based on the energy potential of Newfoundland and Labrador in Canada. Three-objective optimization approach using the combination of genetic algorithm and neural network exhibits that the energy efficiency and net annual profit based on the Bellman-Zadeh approach increase up to 27.04% and 45.20 US$/MMBTU, respectively, and the irreversibility reduces to 99.4 MW.

Directing the pore size of rigid polyurethane foam via controlled air entrainment

The interest in polyurethane rigid (PUR) foams as potent thermally insulating materials for a wide range of applications continues to grow as the minimization of CO2 emissions has become a global issue. Controlling the thermal insulation efficiency of PUR foams starts with the control of their morphology. Although the presence of micrometric air bubbles originating from air entrainment during the blending of the PU reactive mixture has been shown to influence the final PUR foam morphology, detailed experimental investigations on how exactly they affect the final PUR foam pore size are still lacking. To fill this gap, we use a double-syringe mixing device, which allows to control the number of air bubbles generated during a first air entrainment step, before using the same device to blend the reactive components in a sealed environment, avoiding further air entrainment. Keeping all experimental parameters constant except for the air bubble density in the reactive mixture, we can correlate changes of the final PUR foam morphology with the variation of the air bubble density in the initially liquid reactive mixture. Our results confirm recent findings which suggest the presence of two different regimes of bubble nucleation and growth depending on the presence or absence of dispersed air bubbles in the liquid reactive mixture. Our study pushes those insights further by demonstrating an inverse relation between the air bubble density in the liquid reactive mixture and the final pore volume of the PUR foam. For example, at constant chemical formulation and blending conditions, we could vary the final pore size between 400–1600 μm simply by controlling the amount of pre-dispersed air bubbles within the system. We are confident that the presented approach may not only provide a valuable model experiment to scan formulations in R&D laboratories, but it may also provide suggestions for the optimization of industrial processes.

Optimization of without SCM concrete exposed to seawater according to minimum cost and CO2 emissions: Sustainable design with ABC algorithm

The service life of marine concrete structures is relatively shorter due to various salts in seawater. In this context, assistance is obtained from the exposure classes in standards such as EN 206. In this study, an ABC-based (artificial bee colony) algorithm was developed that considers the CO2 emissions and cost analysis of concrete designed according to EN 206 standards. The number of studies involving algorithms in designs according to regulations and standards is very few in the literature. In addition, Supplementary Cementitious Materials (SCMs) are generally used in concretes exposed to sea water. This study investigated the physical, mechanical, durability, microstructure, cost and sustainability properties of concretes without SCM. This study produced nine concrete mixes with different cement dosages (260–300–340 kg/m3) and a water/cement ratio (0.45,0.55, and 0.65). The mixes were cured in normal water (NWC) and seawater (SWC). As the cement mixes’ cement dosage increased, the water absorption and apparent porosity values decreased. Since the increase in the w/c ratio increased the capillary void content of the mixes, it enhanced the porosity and sorptivity values. While the 28d compressive strength of NWC-applied concretes varies between 31.3 and 39.8 MPa, the compressive strength of SWC-applied concrete varies between 30.7 and 36.8 MPa. After 80 wetting-drying cycles, the compressive strength of the concretes decreased below 20 MPa. The CO2 emission values of the concrete vary between 270 and 343 kg and their costs range between 17.9 and 21.5 $/m3. According to the ABC algorithm, it was determined that cement dosage should be 260 kg/m3, w/c ratio should be 0.45 for high compressive strength, low cost, and CO2 emission. As a result, it has been determined that a lower cost and more durable concrete design can be made if methods such as the ABC algorithm are combined with EN 206 standards.

Redox MoO3/CaMnO3 catalysts for chemical-looping oxidative dehydrogenation of propane: A greener approach of propylene production

A redox catalyst with MoO3 loaded on CaMnO3 perovskite was evaluated for chemical-looping oxidative dehydrogenation (ODH) of propane to produce propylene. This approach requires less energy for the production per unit of propylene with minimum CO2 emission, which is highly desirable from an environmental perspective. H2-TPR indicates that the incorporation of MoO3 minimizes the release of surface oxygen, which is favorable for high propylene selectivity. XRD reveals the presence of active sites, while scanning SEM-EDX show uniform dispersion of deposited MoO3 on CaMnO3. XPS analysis demonstrates that MoO3 addition promotes the formation of lattice oxygen which improves the propylene selectivity. The highest propylene yield of 30.6% with a propylene selectivity of 59% was achieved at 550 ℃ with 10% MoO3/CaMnO3. The catalysts also show stable activity in successive redox cycles. The addition of MoO3 enhances propylene yield and selectivity, due to free lattice oxygen, as revealed by XPS and H2-TPR.

Exploring the hybrid route of bio-ethanol production via biomass co-gasification and syngas fermentation from wheat straw and sugarcane bagasse: Model development and multi-objective optimization

Biomass co-gasification and syngas fermentation is one of the least trotted paths in the Indian biofuel production scenario. The aim of the research here is to develop an equilibrium model of biomass co-gasification and syngas fermentation in Aspen plus. Two Indian lignocellulosic biomass namely wheat straw and sugarcane bagasse have been selected as feedstock for this co-gasification process followed by the syngas fermentation. The process shows promising results in terms of ethanol production and energy usage. The effects of gasification process parameters on overall process performance have been analysed. Empirical regression equations were constructed to account for the effects of biomass ratio, which is the ratio of the masses of wheat straw and sugarcane bagasse, gasification temperature and equivalence ratio over ethanol yield, lower heating value of syngas, cold gas efficiency, overall system efficiency, and CO2 emission using response surface methodology. Finally, a multi-objective optimization has been conducted to maximize the ethanol production and overall system efficiency, and to minimize the CO2 emission of the system. Results suggest that the wheat straw and sugarcane bagasse ratio of 4:1, 919.5oC temperature and 0.15 equivalence ratio is the optimum point with an ethanol production rate of 20.917 tonnes/hr, overall efficiency of 52.184%, and a minimum CO2emission of 32669.862 kg/h.

Wind energy potential assessment for co-generation of electricity and hydrogen in the far North region of Cameroon

The fast increase of Cameroon population growth rate and the actual shortage of electricity plaguing the country, particularly in remote areas, give rise to great challenges in the energy generation sector. Nowadays, renewable and clean energy sources are used to foster and improve electricity production via hydrogen generation with water electrolysis. This paper therefore scrutinizes the wind energy potential alongside the electricity and hydrogen generation from wind energy for the cities of Kousseri, Kaele, Maroua, Mokolo, Mora and Yagoua in the Far North Region of Cameroon using wind speed data recorded at 10 m, 40 m and 70 m heights for the years 2011–2021. Several performance indicators including the wind power density, wind turbines power output, wind turbines capacity factor, hydrogen production, cost of produced electricity and hydrogen and payback period are utilized to evaluate the techno-economic viability of the system. This assessment was carried out employing twenty-two commercially accessible wind turbines. Our findings revealed that, Kousseri displays the best hydrogen output with yearly hydrogen production ranging from 3.5054 to 53.232 tons of hydrogen. The annual compressed hydrogen to be saved in this region was found to be in the range of 92.5049 to 1404.70 m3. Enercon E-48/800 turbine records the highest capacity factor in all the chosen locations with the lowest cost of energy varying from 0.0578 $/kWh at Kousseri to 0.0838 $/kWh at Mora. The lowest cost of hydrogen was found to be 4.3865 $/kg for Kousseri, 5.5284 $/kg for Kaele, 5.7160 $/kg for Maroua, 5.9439 $/kg for Mokolo, 6.5065 $/kg for Mora and 6.3354 $/kg for Yagoua employing GE 1.5SL turbine. The highest annual energy output of 3193.9, 2738.1, 2488.4, 2393.9, 2153.3 and 2323.1 MWh was acquired at Kousseri, Kaele, Maroua, Mokolo, Mora and Yagoua, respectively. The shortest payback period was found to be 2.9 years which was related to the case where Enercon E-48/800 wind turbine was assumed to be installed at Kousseri. Finally, the maximum CO2 emission minimization to be achieved if electricity produced by wind turbine is utilized in place of oil burning power plant and power plant that burns natural gas as fuel was 885.36 tons of CO2 and 641.60 tons of CO2, respectively.

Assessing the adequacy of transportation overall vehicle effectiveness for sustainable road transportation

Organizations in today’s supply chains strive for transportation activities optimization. However, transportation is a significant environmental impact activity. Particularly, road transportation is the highest emission rate source and the most widespread modality for last-mile delivery. In this context, the use of performance management tools, such as key performance indicators (KPIs), is a strategy to reach both economic-operative and environmental benefits. Among all KPIs, overall equipment effectiveness (OEE) is one of the most suitable KPIs to measure the utilization of an industrial asset. In the transportation sector, a variant of the OEE, known as the transportation overall vehicle effectiveness (TOVE), is used to define the performance of vehicle distribution activities, such as road transportation for last-mile delivery and urban logistics. Although TOVE is effective for evaluating vehicle performance in terms of administrative availability, operating availability, performance, and quality, the indicator does not take into the environmental impact related to road transportation activities. Literature has proposed several formulations to quantify transport carbon emissions, most of which are linear relationships to the distance travelled. However, these models are not suitable for assessing the TOVE performance of road transportation activities. This paper aims to compare the performance of last-mile delivery in terms of TOVE and carbon emissions evaluated with a distance travelled formulation in two different scenario systems. The comparison shows the inadequacy of TOVE in terms of environmental sustainability, as maximizing road transport performance while ignoring the environmental dimension excludes the minimization of CO2 emissions. Therefore, the foundation for future developments of TOVE for sustainable road transportation can be established from this divergence.

Predicting the Stability of Organic Matter Originating from Different Waste Treatment Procedures.

Recycling organic wastes into farmland faces a double challenge: increasing the carbon storage of soil while mitigating CO2 emission from soil. Predicting the stability of organic matter (OM) in wastes and treatment products can be helpful in dealing with this contradiction. This work proposed a modeling approach integrating an OM characterization protocol into partial least squares (PLS) regression. A total of 31 organic wastes, and their products issued from anaerobic digestion, composting, and digestion-composting treatment were characterized using sequential extraction and three-dimension (3D) fluorescence spectroscopy. The apportionment of carbon in different fractions and fluorescence spectra revealed that the OM became less accessible and biodegradable after treatments, especially the composting. This was proven by the decrease in CO2 emission from soil incubation. The PLS model successfully predicted the stability of solid digestate, compost, and compost of solid digestate in the soil by using only the characterized variables of non-treated wastes. The results suggested that it would be possible to predict the stability of OM from organic wastes after different treatment procedures. It is helpful to choose the most suitable and economic treatment procedure to stabilize labile organic carbon in wastes and hence minimize CO2 emission after the application of treatment products to the soil.

Optimal design and operation of solar energy system with heat storage for agricultural greenhouse heating

A significant challenge of agricultural greenhouses is their high energy demand which is mainly satisfied by fossil fuels resulting in climate change impacts. In this paper, a joint design-operation linear optimization framework for a solar energy system with heat storage is developed to fulfill the agricultural greenhouse heating load. The energy system consists of solar collector, backup boiler, and short-long term heat storages. The developed framework is applied to reach minimum-cost solution. Then, the effects of emission reduction policies, greenhouse cultivation scheduling, natural gas price, and investment cost scenarios are investigated. Furthermore, a multi-objective optimization is performed in terms of minimizing CO2 emissions and total annual cost using epsilon-constraint method. The optimal energy system due to the minimum-cost solution includes a 1065 m2 solar collector and a 1265 kW boiler in combination with 967 kWh and 25 MWh short-term and long-term heat storages, respectively. The 30 % carbon reduction policy results in a 70.5 % increase in solar collector area. The selected optimal solution of the Pareto front, which is the closest solution to the ideal point, has 35.3 % more annual cost and 89.5 % less CO2 emissions compared to the minimum-cost solution.

Comparative techno-economic and energy analyses of integrated biorefinery processes of furfural and 5-hydroxymethylfurfural from biomass residue

For efficient feedstock and energy utilization, integrated biorefinery processes are applied to furfural production from bagasse to convert furfural residue into 5-hydroxymethylfurfural (HMF)—an important intermediate building block for the production of various biochemicals. Here, a techno-economic analysis of the integrated processes of furfural and HMF production combined with electricity generation under different scenarios was performed to identify the most suitable process design. Simulations revealed that using the whole bagasse in the biorefinery plant and recycling 50% waste from the HMF production to recover unreacted sugar (scenario 2) achieved the maximum furfural and HMF production with minimum CO2 emission, compared with integrated processes without sugar recycling (scenario 1), with 80% (scenario 3) and 60% biomass (scenario 4) bypassed to the biorefinery, and with a standalone combined heat and power system (scenario 5). Moreover, heat integration improved the efficiency of biorefinery plant (scenario 2), with an energy recovery potential of 71%, leading to the maximum profit at 11% internal rate of return. However, the high operating cost associated with the requirement of solvents and catalysts for HMF production represents the largest cost distribution in the proposed integrated processes. Sensitivity analysis revealed that solvent cost was the most important parameter for economic benefit. In addition, improving technological efficiency in the pretreatment and HMF production phases can enhance product yield, thereby benefiting the profitability of this process.

Artificial Neural Networks as Artificial Intelligence Technique for Energy Saving in Refrigeration Systems—A Review

The refrigeration industry is an energy-intensive sector. Increasing the efficiency of industrial refrigeration systems is crucial for reducing production costs and minimizing CO2 emissions. Optimization of refrigeration systems is often a complex and time-consuming problem. This is where technologies such as big data and artificial intelligence play an important role. Nowadays, smart sensorization and the development of IoT (Internet of Things) make the massive connection of all kinds of devices possible, thereby enabling a new way of data acquisition. In this scenario, refrigeration systems can be measured comprehensively by acquiring large volumes of data in real-time. Then, artificial neural network (ANN) models can use the data to drive autonomous decision-making to build more efficient refrigeration systems.

Improving the sustainability of porcelain tile manufacture by flowsheet simulation

Porcelain tiles manufacturing is energy-intensive since it contains several stages in which the product is subjected to thermal treatments. The energy used in the process mainly comes from the combustion of natural gas, pushing the industry to decrease its consumption to upkeep its competitiveness in the coming targets of modern sustainable policies. This work presents a simulation-based strategy for the holistic optimization of energy consumption in the tile manufacturing process. Mechanistic models for all involved processing units, describing the respective thermal and electrical energy consumptions, have been implemented in the Dyssol framework and validated against available experimental data. The energy consumption optimization procedure was performed using a coupled Dyssol-Matlab framework. The proposed cost function, which considered electric and thermal energies, was used as the main criterion to determine the optimal design set of process parameters. Various optimization approaches to minimize the overall cost function and the required computational time have been compared. The proposed strategy allows the computing of improved process parameters resulting in minimization of energy consumption and CO2 emissions while keeping product quality intact. Among the solutions, a reduction of 30.2% of fuel per ton of fired tile can be obtained with modification of the processing parameters.

Influence of fibres characteristics on the engineering properties of geopolymer concrete- a review

Growing environmental consciousness in the construction sector encourages the utilization of alternate binders to partially or completely replace ordinary Portland cement (OPC), as its manufacturing generates CO2, which pollutes the environment. Geopolymer concrete (GPC) have emerged as an environmentally acceptable construction material because it can be prepared using industrial wastes, thereby minimizing CO2 emissions and utilizing the wastes which would otherwise become sources of pollution. Apart from environmental benefits, GPC is more durable and shows better mechanical properties than OPC-based concrete. However, GPC exhibits quasi-brittle behavior. To address this shortcoming, numerous studies have been carried out on the development, evaluation, and deployment of fiber reinforcement in GPC. In this article, the state-of-the-art of fiber-reinforced GPC is addressed, with an emphasis on the influence of fiber type, dosage, aspect ratio, etc., on the engineering properties. Based on the literature review, challenges and future prospects have also been discussed. The goal of this research is to develop a solid scientific and conceptual understanding of fiber-reinforced GPC, which will aid in the selection of the most efficient fiber for various GPC construction applications.

Dekarbonizacija procesa proizvodnje margarina korišćenjem krovnih fotonaponskih panela i kogeneracije

he paper proposes a methodology for defining the optimal solution for the integrated usage of cogeneration and rooftop photovoltaics. The purpose is to minimize CO₂ emissions in industrial plants. The methodology is founded on the integral use of energy audit techniques (analyzing energy and material flows in a production process and the dependence of electricity and heat consumption on a production volume) and mathematical optimization (linear programming). In accordance with the obtained consumption profiles, technical limitations, and legal regulations, the potential for installing rooftop photovoltaic (PV) panels at appropriate locations and the implementation of appropriate cogeneration technologies were analysed. The proposed methodology was tested on a local margarine production facility. The integrated application of cogeneration (gas engines) and photovoltaics can reduce the current CO₂ emission by 56% if PV panels are installed on the entire accessible rooftop surface, i.e. up to 44.5% if 150 kW PV panels are installed as the new national regulation proposes.