Initial Investment Cost Research Articles

Insights into different marine aquaculture infrastructures from a life cycle perspective

Aquaculture facilities represent an often-neglected process in environmental impact studies. This study focus on the environmental impact assessment of alternative net materials in Mediterranean marine aquaculture. A Life Cycle Assessment was conducted using primary and secondary data from specific databases and literature. Three baseline scenarios were compared: copper alloy net cages with 100 % of recycled material (CAN100), 75 % of recycled material (CAN75), and polyethylene net (PEN) System boundaries include manufacturing and disposal of cages, nets, and mooring system. The use and emissions of antifouling paints and CAN were considered. Sensitivity analysis of the most impacting sub-processes and Uncertainty analysis were also conducted. The use of CAN is advantageous in terms of environmental impact, but only considering a complete recyclability of the net at the end of its service life. Moreover, when considering a reduced service life of the PEN due to the detrimental effect of biofouling, the advantage of the CAN is even more evident. To counteract the negative effect of biofouling, copper-based antifouling paints are generally used in marine aquaculture. These products are a main environmental hotspot in PEN systems. Therefore, a higher consumption of such products could determine an environmental burden shifting from CAN to PEN ones. So far, CAN are not widespread in the aquaculture industry, mainly due to the high cost of initial investment compared to traditional PEN. Considering operational and environmental advantages, CAN cages could represent an affordable and resilient solution for aquaculture enhancing environmental, economic, and social performances of this industry.

Solar energy generation from residential buildings, transition of the energy sector from fossils to carbon-free energy and meeting UN SDG

Purpose This study aims to focus on the transition of Kosovo’s energy generation sector from fossil fuels (94%), to renewable sources. The installation of 10 kW photovoltaic (PV) panels in individual houses will mitigate CO2 emissions from electrical energy generation and contribute meeting the sustainable development goals (SDGs; 7, 11 and 13) set by United Nations General Assembly. This study case is based on the installation of PV panels on the roofs, and where possible on the facades of the private residential buildings in seven, the most populated towns of Kosovo (Prishtina, Prizren, Mitrovica, Peja, Gjakova, Ferizaj and Gjilan). Design/methodology/approach This study used the data, in regard to direct normal irradiation, altitude, coordinates, PV system configurations, specific PV power output and optimum tilt of PV panels specific for the selected locations,retrieved from Global Solar Atlas, which is a web-based-tool, as provided by “Solargis,”a company that provides online and commercial solar data resources, selected by The World Bank and the International Finance Corporation. The second software was RETScreen Expert, which is more sophisticated and allows input of more variables with regard to the proposed 10 kW PV system. With the use of RETScreen Expert software, the financial viability of the project, the equity payback period, and the reduction in greenhouse gas (GHG) emissions compared to the base case were assessed. Based on the gained data, the feasibility and outcome of the study case were assessed in terms of power generation, cost and comparison with the present PV installed capacities in Kosovo. Findings Small-scale solar energy generated from individual buildings can make great impact of country’s policies toward lowering CO2 emission as one most influential greenhouse gas in rising average global temperature, improving air quality in towns by lowering emission of harmful gases and particulate matter (PM). As the study foresees installation of 10 kW of PV in residential houses, the calculated yearly energy generation would be around 15 MWh, which is twice of the average of real consumption of a household in Kosovo. This calculated energy generation from private houses is equal in capacity with generation of present PV parks that are connected on grid as reported from Transmission, System and Market Operator of the Republic of Kosovo. This proves that, if implemented, the study outcome would make Kosovo to meet the goal for a carbon free energy and meeting targets of at least three out of 17 SDG set by UNSC. Originality/value This paper’s model provides a ground for a transition of national energy sector from 90% fossils dependence to renewable energy sources (RES). Despite of some barriers such as cost of initial investment, energy storage, lack of government’s incentives and legislative base for households to become prosumer or at best energy self-sufficient buildings, this solution will make Kosovo harness its unused RES and meet targets of Paris Climate Agreement for net zero CO2 emissions from energy production by 2050 and SDG targets.

Innovative Utilization of Information and Communication Technology in Hotels: Perspectives of Managers of Star-Rated Hotels in the Kumasi Metropolitan Area

Even though information and communication technology provide an important role in hotel service and aid service efficacy in customer satisfaction, little literature exists on it in the study area. The study assessed managers’ perception of innovative utilization of ICT in star-rated hotels in the Kumasi metropolitan area. Emphasis was laid on the relevance and reasons for the innovative use of ICT in hotels. A qualitative approach was adopted for the study and 50 hotel managers were sampled. Thematic analysis was used to analyze the data solicited. Results of the study established that managers were of the view that the innovative use of ICT in hotel service was relevant and reasons for which the hotels have innovatively used ICT in their service delivery were achieved. However, the innovative use of ICT in hotels may create problems such as high cost of initial investment, cost of training employees and poor employer-employee relations. The study discovered that the hotels have made good use of ICT innovatively to sustain their business. The study unearthed that hotels must be abreast with ICT use as it has become a tool for attracting guests to hotels.

A real options approach to renewable energy module end-of-life decisions under multiple uncertainties: Application to PV and wind in China

The issue of large-scale retirements of renewable energy modules has attracted considerable attention from governments and the public worldwide. Using the Chinese wind and photovoltaic industries as examples, this paper, for the first time, employs a real options approach to explore the optimal time for energy firms to retire their power plants and to predict the future trend of renewable energy wastage from a bottom-up perspective. The results show that the optimal retirement time for the four subdivided categories ranges from 16 to 23 years. The later the investments are made, the earlier the decommissioning time comes and the lower the project returns. Furthermore, wind projects have been found to generate more revenue than PV projects for the same size, and the gap continues to widen. Offshore wind technology always has the longest optimal service life (18.62 years in 2022) and the greatest project returns (10.84 million CNY in 2022). Annual utilization hours, the renewable electricity price and the waste price can accelerate the retirement of plants and generate more revenue for energy companies, while the initial investment cost has a completely opposite effect. The first wave of PV retirements will occur in 2035 at 305.82 GW, while onshore wind will be in 2036 at 530.77 GW and offshore wind will not explode until 2040 at 65.84 GW. An assessment of potential policies suggests that for every 100 CNY increase in incentive strength, the retirement wave arrives 1 year earlier. In contrast, for every 100 CNY increase in the strength of penalties, the retirement wave is delayed by 1 year. In addition, we verify that the size of the plants does not affect the forecast of the retirement trend, indicating that the assumptions about installed capacity do not cause bias.

LEVERAGING PROJECT MANAGEMENT TOOLS FOR ENERGY EFFICIENCY IN HVAC OPERATIONS: A PATH TO CLIMATE RESILIENCE

Efficient management of heating, ventilation, and air conditioning (HVAC) systems is paramount for mitigating energy consumption and enhancing climate resilience in modern infrastructure. This review explores the significance of leveraging project management tools to optimize energy efficiency within HVAC operations, thus fostering a pathway towards climate resilience. The integration of project management methodologies offers a systematic approach to address challenges associated with energy consumption in HVAC systems, thereby facilitating informed decision-making processes. Firstly, the review delves into the pressing need for energy conservation in HVAC operations amidst escalating concerns over climate change and its adverse impacts. The imperative to minimize energy consumption in buildings, particularly through HVAC systems, is highlighted as a pivotal step towards achieving climate resilience and sustainability goals. Subsequently, the review outlines the role of project management tools in orchestrating effective strategies to enhance energy efficiency within HVAC operations. By employing techniques such as project scheduling, risk management, and resource allocation, project managers can streamline the implementation of energy-efficient measures, thereby optimizing HVAC system performance and reducing carbon emissions. Moreover, the review underscores the importance of data analytics and technological advancements in augmenting the efficacy of project management tools for energy efficiency in HVAC operations. Leveraging real-time data monitoring, predictive analytics, and IoT-enabled devices enables proactive maintenance and continuous optimization of HVAC systems, thereby maximizing energy savings and bolstering climate resilience. Furthermore, the review elucidates the potential benefits and challenges associated with the adoption of project management tools for energy efficiency in HVAC operations. While improved cost-effectiveness, environmental sustainability, and operational performance emerge as primary benefits, challenges such as initial investment costs, technological complexities, and organizational inertia necessitate careful consideration. This review advocates for the integration of project management tools as a viable approach to foster energy efficiency in HVAC operations, thereby paving the way towards enhanced climate resilience and sustainability in built environments. By embracing innovative methodologies and technological solutions, stakeholders can mitigate energy consumption, reduce greenhouse gas emissions, and fortify infrastructure against the impacts of climate change.
 Keywords: HVAC, Climate Resilience, Project Management, Energy, Review.

Investigating the energy storage performance in optimal design of a solar hybrid multi‐generation system with distillatory

AbstractIn this study, a cogeneration system of heating, cooling and power used with the solar flat plate collectors (FPCs) and photovoltaic panels (PVs) integrates with a multi‐effect distillation through thermal vapor compression (MEE‐TVC), investigated as the first system to meet the loads of heating, cooling, electricity and fresh water. As an innovation, the combination of the first system with cooling and thermal storage tanks have been investigated. The systems are optimized with MATLAB and single‐objective genetic algorithm. The total annual cost considered as the objective function to compare the two systems and 36 and 61 design variables are obtained for the first and second systems, respectively. The design parameters considered for optimization included the capacity of the diesel engine as the prime mover, electrical chiller capacity, absorption chiller capacity, size of the boiler, partial loads of the diesel engine for each hour of the 2 days (1 day for hot months and 1 day for cold months), partial loads of the chillers for each hour of the first days (second day has no cooling load), number of FPCs and PVs, number of effects in the desalination unit, driving steam pressure, feed water flow rate, driving steam flow rate, and electric cooling ratio. The optimization aimed to fulfill the heating, cooling, electricity, and fresh water requirements of a residential town situated in Bandar Abbas, Hormozgan province, Iran. The second system's optimization results were compared with first system. The results have shown that the objective function for the first system was and the initial investment cost was , and for the second system the objective function was and the initial investment cost was . Therefore, by using energy storage, the objective function was reduced by 11.30%.

Evaluating strategies for developing renewable energies considering economic, social, and environmental aspects: a case study.

Due to fast industrial expansion and the increasing population in Vietnam, this country is confronting a mounting lack of energy. While this country has considerable renewable energy (RE) potentials, including wind, solar, biomass, and hydropower sources, it has yet to exploit them entirely because of a lack of proper planning. This research aimed to find and assess solutions for encouraging RE growth in Vietnam. RE development solutions were formulated through SWOT analysis and evaluated in terms of their social, economic, and environmental dimensions. The SWARA approach weighed the strategy evaluation criteria. The most influential sub-criteria were initial investment cost, reduction of adverse environmental impacts, and natural capacity of the region, with weights of 0.155, 0.127, and 0.114, respectively. Strategy evaluation was performed using the Gray ARAS, and the results were validated with the Gray COPRAS, the Gray TOPSIS-G, and the Gray MABAC. In the strategy ranking, the top strategy is to reduce the cost of renewable power generation. This can be achieved by using advanced technologies and promoting cooperation between domestic and foreign industries and companies. Increasing domestic and foreign investment in RE infrastructure by providing financial facilities for investors, developing domestic and international cooperation, and creating a competitive environment between different companies to reduce electricity production costs were the most suitable strategies.

Advancing Solar Rooftop Power Generation: A Review on the Integration of Concentrated Solar Technology and Advanced Materials with Economic Perspectives

Abstract: This review paper offers a thorough analysis of the integration of concentrated solar technology and advanced materials in solar rooftop power generation, with a primary emphasis on optimizing efficiency and economic viability. As the demand for sustainable energy solutions intensifies, harnessing concentrated solar energy on rooftops presents a promising avenue for meeting these challenges. The paper explores current advancements in concentrated solar technologies, including solar concentrators, parabolic troughs, and solar towers, elucidating their working principles and efficiency gains. Concurrently, the integration of advanced materials, such as high-efficiency photovoltaic materials, thermal storage materials, and coatings, is discussed for their role in enhancing the overall performance and durability of rooftop solar systems. A critical examination of the economic aspects associated with these technologies forms a pivotal aspect of this review, encompassing an evaluation of initial investment costs, operational expenses, and potential returns on investment. Economic models and case studies are presented, offering valuable insights into the financial implications and feasibility of widespread adoption.

Real options analysis for regional investment decisions of household PV-ESS in China

This paper takes 30 provinces in China as the research subjects and constructs a real options model to explore the impact of carbon emissions trading market, energy storage subsidies, and their synergy on the optimal investment decision of household PV-ESS projects. The results show that a single factor has a catalytic effect on project investment, and both together have a better effect. And, project investment benefits are better in areas with abundant light resources and higher than average electricity prices. In addition, a sensitivity analysis is conducted on the initial investment cost, CO2 price, and energy storage subsidies. The results show that immediate investment in all provincial projects can be achieved when the initial investment cost is reduced by 50%, or the CO2 price is increased by about 33 times, indicating that the current environment is insufficient to attract investors. The results provide a reference framework for investment in household PV-ESS projects.

The Impact of Blockchain Technology Adoption on an E-Commerce Closed-Loop Supply Chain Considering Consumer Trust

This paper analytically explores the value of blockchain technology in building consumer trust in recyclers. We focus on an e-commerce closed-loop supply chain composed of an online platform and a manufacturer. In the forward chain, the platform selects a reselling or marketplace model to sell products. In the reverse chain, the platform collects used products, and the unknown whereabouts of the used products will cause consumer mistrust and be detrimental to the corporate image. Blockchain technology can address these challenges by improving the visibility of the recycling chain. By constructing differential game models, we specify the conditions for blockchain implementation and explore its impact on the online sales model choice and the E-CLSC performance. The findings show that the manufacturer consistently benefits from blockchain technology, while the platform decides to adopt it when the long-term profits outweigh the initial investment costs. Interestingly, the sales model selection will not change with the advent of blockchain technology. We further show the benefits of blockchain-enabled recycling and provide tangible insights for related practitioners.

Optimisation of Small-Scale Aquaponics Systems Using Artificial Intelligence and the IoT: Current Status, Challenges, and Opportunities

Environment changes, water scarcity, soil depletion, and urbanisation are making it harder to produce food using traditional methods in various regions and countries. Aquaponics is emerging as a sustainable food production system that produces fish and plants in a closed-loop system. Aquaponics is not dependent on soil or external environmental factors. It uses fish waste to fertilise plants and can save up to 90–95% water. Aquaponics is an innovative system for growing food and is expected to be very promising, but it has its challenges. It is a complex ecosystem that requires multidisciplinary knowledge, proper monitoring of all crucial parameters, and high maintenance and initial investment costs to build the system. Artificial intelligence (AI) and the Internet of Things (IoT) are key technologies that can overcome these challenges. Numerous recent studies focus on the use of AI and the IoT to automate the process, improve efficiency and reliability, provide better management, and reduce operating costs. However, these studies often focus on limited aspects of the system, each considering different domains and parameters of the aquaponics system. This paper aims to consolidate the existing work, identify the state-of-the-art use of the IoT and AI, explore the key parameters affecting growth, analyse the sensing and communication technologies employed, highlight the research gaps in this field, and suggest future research directions. Based on the reviewed research, energy efficiency and economic viability were found to be a major bottleneck of current systems. Moreover, inconsistencies in sensor selection, lack of publicly available data, and the reproducibility of existing work were common issues among the studies.

Are we really addressing the roadblocks to adoption of renewable and sustainable energy technologies? Total interpretive structural modeling approach.

Urban areas serve as a vital contribution to the global structural change towards renewable and sustainable energy technologies which also influence climate change. The aim of this paper is to identify the adoption roadblocks to renewable and sustainable urban energy technologies. This research has three parts: a mini-systematic literature study was conducted to identify the most prevalent roadblocks. Using total interpretive structural modeling (ISM), the relationships between the roadblocks and the source of causation were then examined. The roadblocks are classified based on their dependence and driving powers using MICMAC analysis in the third part of this research. The principal results and major conclusions demonstrate that all roadblocks are necessary for renewable and sustainable urban energy technologies. The roadblocks at level I are insufficient infrastructure, lack of coordination among authorities, lack of quality and reliable data and information, and competition with non-renewable technologies; roadblocks in level II are lack of skilled and trained personnel, limited public participation, awareness, and consumer interest, and lack of standardized technology; roadblock in level III is high initial investment cost; and lastly, roadblocks in level IV are lack of subsidies and financial support programs and absence of coherent related policies. Furthermore, as a result of theMICMAC analysis, none of the aforementioned roadblocks are classified as autonomous variables, implying that they are all required. The dependent roadblocks to renewable and sustainable energy technologies are defined as lack of coordination among authorities, lack of information, and competition with non-renewable technologies. Moreover, linkage roadblocks have high dependence and driving powers which are insufficient infrastructure, limited awareness and consumer interest, and lack of standardized technology. Lastly, high initial investment costs, lack of subsidies and financial support programs, absence of coherent related policies, and lack of skilled and trained personnel are the driving roadblocks with high driving power however not dependent.

RNN-Based Time Series Analysis for Wind Turbine Energy Forecasting

One significant source of renewable energy is wind power, which has the potential to generate sustainable energy. However, wind turbines have many challenges, such as high initial investment costs, the dynamic nature of wind speed, and the challenge of locating wind-efficient energy regions. Wind power predicting is crucial for effective planning of wind power generation, optimization of power generation, grid integration, and security of supply. Therefore, highly accurate forecasts ensure the efficient and sustainable operation of the wind energy sector and contribute to energy security, economic stability, and environmental sustainability. This study proposes a deep learning (DL) approach based on recurrent neural networks (RNNs) for long-term wind power forecasting utilizing climatic data. The input data that forms the basis of this study is obtained directly from a wind turbine system operating under real-world conditions. The proposed model in this study is based on a multilayer back-propagation neural network (RNN) architecture specifically designed to effectively handle complex data sets and time-dependent series. The architecture of the model is built on an RNN consisting of four separate layers, each with 50 hidden neurons, carefully structured to increase its capacity to capture complex features. To improve the robustness of the model and avoid overlearning, each RNN layer is followed by a dropout (regularizing) layer that randomly deactivates 20% of the neurons to enhance the generalization ability of the network. To finalize the prediction capability of the model, a linear function was chosen in the last layer to directly match the actual values. Evaluating the model performance metrics, the proposed architecture achieved a prediction accuracy of 91% R2 on the test dataset. The findings indicate that proposed method based on multilayer RNN can successfully capture the relationships between the sequential data of the wind turbine.

Economic analysis of hybrid solar-wind power system for application in Heipang community

Economic feasibility is one of the major criteria for selecting energy options for application in any location. One of the main drawbacks of renewable energy technology is its initial cost of investment which results in high energy tariffs making it unaffordable for low-income earners. The cost of renewable energy depends on many factors such as the potential of the renewable resources of the site and government policies on renewable energy technology. This paper aimed to determine the annualized cost of a designed hybrid solar-wind power system for the Heipang community to meet a load demand of 158.3kW and the sensitivity analysis of bank loan interest rate, inflation rate, day of autonomy, depth of battery discharge, and wind turbine rated velocity on the investment payback time. The cost of the components of the designed system was obtained from vendors and a techno-economic analysis was done using MATLAB software. Results show that the annualized cost of the hybrid solar-wind power system is ₦ 52,268,266.97, with battery, solar, and wind power systems taking 85%, 8%, and 7% of the total annualized cost respectively, and Levelized cost of energy ₦ 154.53/kWh. The analysis further shows that for ₦ 185.00, N 160.00, and ₦ 127.00 per kWh cost of energy at a 19% inflation rate and 20% bank interest rate, the investment payback times are 8.3, 9.5 and 11.9 years respectively, and 9.8, 11.4 and 14.3 years respectively. Information from this work may help policy-makers and would-be investors make informed decisions on renewable energy technology investment.

A study of supply chain relationship change and RFID IT adoption: Evidence from listed companies

RFID technology has developed rapidly over the last few decades. However, due to high initial investment costs and various security issues, the impact of RFID information adoption on a company's economic value remains ambiguous, and the application of this information technology is in a wait-and-see attitude. In this paper, using supply chain and financial information of A-share listed companies in Shanghai and Shenzhen from 2010 to 2022 as samples, we provide empirical evidence that the changes in supply chain relationships significantly affect the adoption of RFID information technology. Our findings provide timely policy implications for firms considering RFID adoption.

A hybrid solar–biogas system for post-COVID-19 rural energy access

Abstract Solar home systems for rural electrification are often designed with a limited energy supply, which presents a drawback for the technology. Furthermore, uncontrolled livestock faeces in rural communities constitute environmental sanitation and health risks. Livestock excrement can be used through a biogas digester to supplement solar energy to provide adequate and sustainable electricity access to underserved rural communities while achieving waste management. Therefore, this study presents a hybrid solar–biogas system for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities. A parametric research approach that involves the use of the Integrated Environment Solution Virtual Environment software application and mathematical models to design the desired household load and the hybrid system sizing is used in the study. The findings show that the daily household energy consumption was 6.6 kWh, equivalent to 206.40 kWh/month. A 1.2-kWp and 1.2-m3 hybrid solar–biogas system was found to adequately power the house. Financially, the total initial investment cost of the system was $5777.20 with a net present value of $6566.78, net profit of $4443.6, a payback period of 14 years and 8 months, and a levelized cost of energy of $0.21/kWh; these include a 60% initial investment and maintenance costs subsidy. Energy performance contracting and energy-as-a-service were recommended to effectively run and operate the system. The study successfully revealed the design, specifications and upscaling mechanism of the proposed hybrid solar–biogas system. More research is required to unveil the efficacy of the system, the performance gap and the perception of the technology by the beneficiaries.

A novel cryogenic air separation unit with energy storage: Recovering waste heat and reusing storage media

The combination of the air separation unit and cryogenic energy storage enhances system efficiency; however, there are still significant irreversible losses in the energy conversion process and high investment costs. This paper explored the potential for deep integration of these two process and proposed a novel air separation with liquid nitrogen energy storage process recovering waste heat and reusing storage media process. The proposed process improved the liquefaction and power generation processes and recovered the compression heat for air purification processes. Taking an actual plant as a research case, the integrated system was simulated using Aspen Plus software. The round-trip efficiency, exergy efficiency, and power generation of the proposed process are 0.537, 0.722, and 10.52 MWh respectively, which are 6.2 %, 20.9 %, and 68.3 % higher than those of conventional process. By reusing storage nitrogen and recovering compression heat, the proposed process reduces the initial investment cost by half while achieving a dynamic payback period of 6 years with a levelized cost of electricity at $82.8/MWh. Furthermore, it is worth noting that media reuse operations have a greater impact on economy when off-peak electricity cost is low; whereas utilization of compression heat has a greater impact when off-peak electricity cost is high.

New Generation Sustainable Technologies for Soilless Vegetable Production

This review article conducts an in-depth analysis of the role of next-generation technologies in soilless vegetable production, highlighting their groundbreaking potential to revolutionize yield, efficiency, and sustainability. These technologies, such as AI-driven monitoring systems and precision farming methods, offer unparalleled accuracy in monitoring critical variables such as nutrient concentrations and pH levels. However, the paper also addresses the multifaceted challenges that hinder the widespread adoption of these technologies. The high initial investment costs pose a significant barrier, particularly for small- and medium-scale farmers, thereby risking the creation of a technological divide in the industry. Additionally, the technical complexity of these systems demands specialized expertise, potentially exacerbating knowledge gaps among farmers. Other considerations are scrutinized, including data privacy concerns and potential job displacement due to automation. Regulatory challenges, such as international trade regulations and policy frameworks, are discussed, as they may need revision to accommodate these new technologies. The paper concludes by emphasizing that while these sustainable technologies offer transformative benefits, their potential for broad adoption is constrained by a complex interplay of financial, technical, regulatory, and social factors.

The Economic Viability of Smart Home Investments: A Cost-Benefit Analysis

This study report performed a thorough data-driven analysis to evaluate the economic sustainability of smart home investments in the quickly changing residential living scene. The research provided a comprehensive view of the financial ramifications of implementing smart home technology by taking into account initial investment costs, energy savings, maintenance and operating expenditures, and user satisfaction. The results show a considerable potential for improved user happiness and energy savings, which supports the financial viability of smart home investments. The findings highlight the multifarious significance of these technologies in establishing more practical and efficient living environments and provide insightful information for policymakers, industry stakeholders, and homeowners.

Flue Gas Desulfurization Scrubbers in Heavy Diesel Combustion Plants

Through the purification technology of flue gas desulfurization, ultralow emissions of SO2 flue gas in industrial flue gas can be achieved. In this article, wet flue gas desulphurization (FGD) processes using limestone (calcium carbonate CaCO3) and caustic (sodium hydroxide NaOH) as absorption solution are introduced in terms of fluid mechanics and mass transfer phenomena as well as absorption unit processes. Also initial investment and operation costs are compared for wet flue gas desulphurization processes using limestone and and caustic.