Solar Industrial Process Heat Research Articles

Greenhouse Gas Mitigation Potential Through Clean Energy for Cement Production in India

Abstract A preliminary approach has been made to assess the concentrated solar energy applications in cement production as well as greenhouse gas mitigation potential. The work starts with identification of processes that utilize thermal energy in cement production. Then, a cluster of cement plants located at different locations in the country has been made. Also, the availability of solar radiation and wind speed at each plant location have been identified. Subsequently, the solar industrial process heating systems have been developed for different locations in the country. Further, solar reactor output, number of heliostats, total land area and mirror surface have been estimated. All these estimations are done by considering three types of thermal losses in solar reactors, i.e., 15, 30 and 45%, respectively. Solar energy can provide a total of 738.11 PJ of thermal energy, which is needed to fulfill the process heating requirement of the calcination process for the manufacturing of cement in India. Solar industrial process heating systems for cement production in India can reduce yearly CO2 emissions by 2457–7648 thousand tons.

Impact of Temperature and Optical Error on the Combined Optical and Thermal Efficiency of Solar Tower Systems for Industrial Process Heat

Concentrating solar thermal (CST) power towers can provide high flux concentrations at commercial scale. As a result, CST towers exhibit potential for high-temperature solar industrial process heat (SIPH) applications. However, at higher operating temperatures, thermal radiation losses can be significant. This study explores the trade-off between thermal and optical losses for SIPH applications using a collection of three case studies at operating temperatures that range from 900-1,550 °C. We assume blackbody radiation to represent the thermal losses at the receiver and we use ray tracing to estimate the optical losses. The results show the impact of process temperature on the maximum attainable system efficiency, as well as the higher flux concentration requirements as the temperature increases.

Molecular insights into thermal conductivity enhancement and interfacial heat transfer of molten salt/porous ceramic skeleton composite phase change materials

Molten salt has been considered as one of the most promising candidate materials for thermal energy storage (TES) systems owing to its remarkable energy density and consistent thermal performance. These properties render it particularly advantageous for the applications in concentrated solar power (CSP) and industrial process heat utilization. Nonetheless, their practical applications still face nonnegligible challenges such as the low thermal conductivity and risk of leakage. Packing molten salts into porous skeletons could be an effective way for addressing these issues. In the present work, the heat transfer characteristics of a composite phase change material (CPCM) consisting of binary chloride salt and a porous ceramic skeleton, are investigated at the microscale level using molecular dynamics (MD) simulations. Simulation results indicate that the integration of a porous SiC skeleton can substantially enhance the thermal conductivity of binary molten salt NaCl/KCl. At the temperature of 1000 K, a notable enhancement of 625.74 % in thermal conductivity has been observed. Moreover, the underlying mechanism of heat conduction enhancement has been revealed from the microscopic perspective. The results demonstrate that auxiliary thermal conductivity paths and interfacial heat transfer play primary roles in determining the thermal conductivity of CPCMs. The method of surface charge modification can effectively improve the interfacial heat transfer and the reason can be attributed to the additional thermal conductivity paths and the large number of particles involved in the interfacial heat transfer. The results gained in this work may provide insights into the heat transfer mechanism of composite molten salt/porous skeleton as well as practical guidance for designing CPCM for thermal storage applications.

Enhanced monitoring and dynamic analysis of a concentrated solar thermal experimental plant for steam production

Solar heat for industrial processes (SHIP) is an increasingly interest option as a key strategy to decarbonise the industrial sector. Linear Fresnel Collectors are a promising technology due to their cost-effectiveness and efficiency. As part of the SOLPINVAP project, an experimental facility was constructed to prove the use of modular Linear Fresnel collectors for steam production in industrial processes. SHIP plants commonly use standard industrial sensors, which can result in high uncertainty when measuring absorbed and produced heat. This can be problematic when selling energy to customers through an energy purchase agreement. To address this issue, an uncertainty analysis was conducted in the experimental plant, and more precise instrumentation was added to the installation. This reduced the uncertainty in the absorbed energy in the solar field from 12 % to 3 % and obtaining an uncertainty of 3 % in the generated energy. Additionally, the operation of the plant was studied through experimental tests conducted during the summer of 2022, and the system dynamics were analysed during the period of peak heat absorption.

Modeling of a Solar Thermal Plant to Produce Hot Water and Steam for a Brewery Factory

The environmental impact caused by the intensive exploitation of fossil fuels to generate heat and electricity has already reached a critical level. Also, as the industrial sector is the largest energy consumer, mainly in the form of heat, it has then become compulsive to implement the use of renewable solar heat in industrial processes, such as those found in the food processing and beverages industries, which do not require high temperatures. Consequently, this study examines the viability of supplying heat as hot water at 80 °C and saturated steam at 160 °C to a medium-sized brewery factory through a hybrid solar plant composed of flat plate and parabolic trough collectors and sensible thermal energy storage. The study was conducted numerically using the meteorological conditions of a city different from that where the factory is located because it benefits from higher insolation levels. The mean annual solar fractions achieved were 49.9% for hot water production and 37.3% for steam generation, at a levelized cost of heat of 0.032 USD/kWh, which can be considered competitive if compared against the values reported in other similar solar projects. Also, the decrease in fossil fuel consumption allowed an annual reduction of 252 tons of carbon dioxide emissions.

Integration of Solar Thermal Process Heat

Varying conditions for heat integration still make individual designs and planning for the Balance of Plant (BoP) necessary and slow down the market integration of solar heat for industrial processes (SHIP). In addition to increased costs for planning, this also leads to higher technical and project management risks due to the lack of standardized engineering procedures. Therefore, the goal of the MODULUS project is to design a modular standardization concept, which is developed during the planning and engineering phase of three commercial SHIP projects. For testing the functionality, test plans have been drawn up which are intended to provide initial guidance for tests and their criteria to be carried out in each case prior to delivery, cold and hot commissioning. The BoP of the plant in Turnhout (Belgium) has already been installed and commissioned on site. Its example will be used to discuss the procedure for commissioning in the present work. Furthermore, a survey was sent to 80 companies to evaluate the trends of the SHIP world market. Several trends are discussed that will have a significant impact on market developments in the coming years.

Alternative Approach for Thermo-Hydraulic Modeling of Direct Steam Generation in Parabolic Trough Solar Collectors

Abstract The implementation of direct steam generation in linear concentrators is limited mainly by the complexity and the high demand for computational resources of the models developed to predict the installation behavior. With this in mind, we introduce an innovative methodology to characterize the thermo-hydraulic behavior of direct steam generation in parabolic trough solar collectors, with a strong focus on two-phase flow phenomena. Our proposed approach has resulted in a generalized function that eliminates the need for the convective coefficient h and enables accurate prediction of the flow pattern within the receiver. By comparing our model with experimental data from the literature, we achieved relative squared errors (RSEs) values of less than 3% for temperature and pressure calculations, thus validating the robustness of our methodology. The Taitel and Dukler diagram confirms an appropriate flow pattern, while intermittent flow is observed initially during boiling; the pressure drop, although slightly elevated compared to direct solar steam (DISS) loop results, remains within acceptable limits; and the model demonstrates suitability for assessing liquid water, phase change, and superheated steam temperature evolution along the loop. Moreover, we further showcased the practical application of our developed model by applying it to a specific case study conducted in Agua Prieta, Sonora (Northwest México). The validated model exhibits versatility and is applicable to various cases, including both concentrating systems for electricity production and solar heat for industrial processes.

Low-Pressure Steam Generation with Concentrating Solar Energy and Different Heat Upgrade Technologies: Potential in the European Industry

The industry is currently responsible for around 21% of the total CO2 emissions, mainly due to heat production with fossil fuel burners. There are already different technologies on the market that can potentially reduce CO2 emissions. Nevertheless, the first step for their introduction is to analyze their potential on a global scale by detecting in which countries each of them is more attractive, given their energy prices and resources. The present work involves a techno-economic analysis of different alternatives to replace industrial gas boilers for low-pressure steam production at 120 °C and 150 °C. Solar Heat for Industrial Processes (SHIP) was compared with Electric Boilers (EBs), High-Temperature Heat Pumps (HTHPs), and Absorption Heat Transformers (AHTs). SHIP systems have the potential to reach payback periods in the range of 4 to 5 years in countries with Direct Normal Irradiance (DNI) values above 1400 kWh/m2/year, which is reached in Spain, Italy, Greece, Portugal, and Romania. HTHPs and AHTs lead to the lowest payback periods, Levelized Cost of Heat (LCOH), and highest CO2 emission savings. For both AHTs and HTHPs, payback periods of below 1.5 years can be reached, particularly in countries with electricity-to-gas price ratios below 2.0.

Impacts, Barriers, and Future Prospective of Metal Hydride‐Based Thermochemical Energy Storage System for High‐Temperature Applications: A Comprehensive Review

This article summarizes various thermochemical energy storage (TCES) systems based on their thermochemical properties, operating temperature, and storage density. Metal hydride (MH)‐based TCES is a potential energy storage system due to its higher energy storage density (>100 kWh m−3), higher operating temperature (>500 °C), relatively better reaction kinetics, and minimal or no energy losses (theoretically). MHs operate at various temperature ranges, and based on temperature, they are classified as low‐temperature MH and high‐temperature MH. This article highlights potential metal alloys operating above 300 °C, with an energy storage density of more than 100 kWh m−3, suitable for concentrated solar thermal power generation and industrial process heating applications. Magnesium (Mg) alloy‐based hydrides have shown good cyclic stability (up to 1500 cycles) at a temperature above 400 °C. The lower cost of material, higher energy storage capacity, better reversibility, and higher thermal stability of Mg‐based alloys have been explored in several small‐scale experimental investigations. The thermal energy storage (TES) efficiency of MH‐based TCES systems is reported ≈ 90%, which is significantly higher than sensible and latent TES systems. Challenges associated with MH‐based TES systems, such as heat transfer enhancement, cost reduction, and chemical and thermal stability, have been discussed in detail.

Potential for Solar Industrial Process Heat Systems for Tea Drying Applications – A Case Study

Abstract An increase in energy consumption especially for industrial applications enhances the uptake of fossil fuels since, they are currently the major sources of industrial process heat and electricity. The need for clean energy technologies is therefore critical, in order to meet the rising energy demand using sustainable energy sources. Solar thermal energy technologies have attracted much attention in terms of research and developmental activities worldwide. The present study seeks to explore the viability of adopting solar thermal technologies at Tingamira - Tanganda Tea estate, Zimbabwe. Data on current sources of heat, daily consumption of process heat and required process temperatures was gathered. Systems advisor model (SAM, version-2021.12.2) was applied to analyse feasibility of linear Fresnel (LF) and Parabolic trough (PT) solar thermal technologies for industrial tea drying. LF system is potentially a better option for producing process heat for low temperature applications. It requires smaller aperture area (360 m2) and a lower initial capital cost of $ 112 860 which is about 8 % cheaper. Also, it yields more energy at lower levelized cost of heat as compared to PT technology when solar multiple is increased up to 2. Replacing wood fuel would reduce the factory carbon footprint by 114 tonnes CO2 annually. Also, potential for sensible rock-bed heat storage systems in the tea factory was assessed. Rock bed sensible TES using natural rocks can avail a viable option for heat storage and about 16 m3 of storage volume would be needed to meet a daily heat demand of 1 MWh.

Defocus Controller for a Rotatory Fresnel Collector

Solar heat for industrial processes (SHIP) is becoming one of the most attractive solutions for industry decarbonisation. Solar plants require a complex control system to manage the fluctuation of their source, solar radiation. One of the problems of this system is the possibility of overheating when solar production is greater than consumption. The main objective of this study was to design a defocus controller for the SunDial, the rotatory Fresnel collector. A dynamic simulation was carried out for a SHIP system with the defocus controller. Finally, a solution to satisfy the accuracy needed for the SunDial was presented.

Türkiye’deki Organize Sanayi Bölgelerinde Termal Güneş Enerjisi Uygulamalarına Yönelik Olanaklar ve Engeller: Kayseri Organize Sanayi Bölgesi Örneği

Turkiye's industrial parks (IP) represent more than one-third of the country's exports and employ 2.1 million people, almost one-third of the country's total industrial employment. As an effective means of implementing macro policies, IPs are essential for inclusive and sustainable industrialisation by improving efficiency and lowering costs. Given Turkiye's vulnerability to climate change and natural disasters, investments in renewable energy (RE) are poised on the national climate change agenda for a steady and reliable energy supply. As an upper-middle-income country, Turkiye has a good start transitioning to RE mainly. Although one of the top 5 countries with total solar capacity, solar heat for industrial processes (SHIP) is one of the not-fully discovered areas for energy generation. With this background, this study examines drivers and barriers to adopting SHIP technologies. The method uses the lessons from prosumer experience in developing and applying SHIP technologies. For this purpose, the field research was conducted in two phases, and the two different data sets were collected by the methods of 'Semi-structured in-depth interviews with prosumers' and 'Survey on solar energy usage with members of IP'. The current barriers and drivers in decision-making for investment and installation of photovoltaics implications and their maintenance were identified. Then, a survey built on the lessons learned from the analysis of the interviews was made to determine why there is no improvement in the deployment of SHIP implications. Finally, essential barriers and sub-barriers are listed under the headings of ‘legal, regulatory, procedural, economic, financial, Social, and technical'. The results of the data analysis show that 'insufficient government support, lack of financial support, inadequate capacity and expertise with modern technologies, and inefficient infrastructure' are identified as significant barriers to the diffusion of SHIP technologies in the IP context in Turkiye.

Developing optical and thermal models with experimental validation of parabolic trough collector for moroccan industrial heat applications

This work presents the development of advanced optical and thermal models for parabolic trough collector systems (PTCs) through an extensive experimental study utilizing a PTMx-24 collector from Soltigua company, installed at Green Energy Park (GEP) research facility. The optical model leverages Tonatiuh software, employing the Monte Carlo Ray Tracing (MCRT) method. Moreover, a MATLAB script was adjusted to account for Incidence Angle Modifier (IAM) fluctuations in the optical analysis, while incorporating receiver thermal parameters for the thermal analysis. This study assesses the potential of PTCs in the territory of Solar Heat for Industrial Processes (SHIP) over various seasons within a semi-arid climate, offering invaluable insights for sustainable energy utilization. The validation of the models was conducted across four distinct days characterized by diverse meteorological conditions. The optical model demonstrates a remarkable correlation of 97.04 % between the MATLAB script and experimental results. Additionally, results from Tonatiuh software exhibited an important accuracy of 95.92 %. The thermal model showcased outstanding precision, revealing a correlation of 98.5 % compared to experimental results, signifying its adaptability to collectors of varying geometries and parameters. These findings highlight the predictive potential of these models, aiding in the decision-making process to determine the system's performance on specific days with specific meteorological conditions.

Potential assessment of solar industrial process heating and CO2 emission reduction for Indian cement industry

For the Indian cement sector, a simple approach is presented to evaluate the potential of solar industrial process heating (SIPH) and the resulting decrease in CO2 emissions. The first step was to identify the locations of cement plants with their annual installed capacity and their annual actual cement production. After that, the yearly process heating requirement for the calcination process at each cement plant has been estimated using the actual annual cement production value. Finally, using the concept of a top-of-tower (TT) solar plant design, the total thermal energy that could be saved has been estimated as 771.35 Petajoule (PJ) /annum. Finally, the adoption of the SIPH system with storage is expected to mitigate CO2 emissions by 45.2 MT (Megatons) annually. By utilizing renewable energy sources in the cement manufacturing process, energy consumption and CO2 emissions will be reduced.

Proposal of a microchannel receiver for Fresnel technology to supply solar heat for industrial processes

This work is focused on the linear Fresnel technology to supply solar heat for industrial processes, proposing a new microchannel receiver design for pressurised gases. This design consists of two absorber panels converging at the focal line of the Fresnel system; each of these panels consists of a compact core fin structure attached to both front and back plates. The fluid flows through the receiver along its length in several passes, so that the compactness is constant and greater than in the previous pass. This arrangement improves heat transfer and, therefore, the cooling of the more thermally stressed areas of the panel, without over penalising the pressure drop.A thermal resistance model has been formulated to quantify the fluid heating along the panel length and the thermal gradient along the panel thickness. This model has been used to perform a thermo-exergy optimisation based on several characteristic parameters: the aperture half-angle of the cavity shaped by the two converging panels; and the channels dimensions in each pass of the panel. For each of these parameters, a maximum exergy efficiency has been obtained accounting for the receiver heat losses, the fluid pressure drop and the optical performance of the primary mirror field.

Techno-economic and environmental feasibility analysis of solar industrial process heating systems in textile industries of Bangladesh

Taking into account the energy crisis and concerns about the effect of burning fossil fuels on the environment, the utilization of renewable energy technologies is being promoted extensively. Despite having significant potential, the feasibility of utilizing solar thermal energy as industrial process heat in Bangladesh is yet to be assessed and this paper aims to fill this research gap. In current work, the viability of utilizing solar thermal energy in Bangladesh for industrial process heating is investigated by parametric analysis considering thermal, economic, and environmental factors. Effect of mass flow rate and inlet temperature on overall heat loss coefficient is studied. The heat gain with respect to the available area for different mass flow rates is presented which can be used as a guideline to determine the capacity of an installed system. A case study is presented for an operational textile factory in Mymensingh to realize the potential of solar industrial process heat using flat plate solar collectors. Energy savings might reach up to 14.7% in summer and around 9% in winter which also leads to reduction of CO2 emission to the same percentage. The payback period has been found to be 13.58 years.

Evaluation of using solar energy in Iran's textile industry towards cleaner production: Sustainable planning and feasibility analysis

The use of solar thermal energy is a suitable alternative to fossil fuels, but due to the lack of sufficient information on the implementation of thermal plants, solar industrial process heat (SIPH) was not implemented. The goal of this study is to assess SIPH in the textile industry of Iran. For this purpose, the suitable province for developing SIPH projects is determined from five dimensions using multicriteria decision-making (MCDM) methods. The step-wise weight assessment ratio analysis (SWARA) is used for weighting and the grey measurement alternatives and ranking according to compromise solution (MARCOS-G) is used for prioritizing the provinces. Then, at the optimum site, the performance of a 5 MW power plant with solar parabolic trough collectors along with the storage system is optimized, and dynamic modeling is done. MCDM results showed that Isfahan is the most suitable province for developing SIPH in Iran's textile industry. The feasibility assessment showed that the levelized cost of heat in the optimal condition is equal to 20.9 $/MWh-t. Also, it has led to the reduction of 4 kt of CO2 emissions. Although the price of natural gas is very cheap in Iran, if the pollution tax policies are applied in Iran, SIPH will be cost-effective in the textile industry.

Pre-Feasibility Assessment Tool for Solar Industrial Process Heating

The industrial sector demands 25% of global energy as heat, where one-third is used at temperatures below 150 °C. Nevertheless, the installed solar heating capacity in the industry is only 0.02%, even though the integration of solar heating systems into production processes could significantly reduce fossil fuel consumption at a competitive cost. Among other reasons, this low penetration is due to the final users’ lack of knowledge of solar heating technologies. As a result, a free pre-feasibility assessment tool was developed for non-specialised users to evaluate the possibility of integrating solar heat into their processes using basic information. This tool uses transient simulation to estimate a feasible solar heating system through the parametric optimisation of the solar collection area, thermal storage volume, heat exchange capacity, and solar integration schemes at the supply level and costs. A commercial facility in Mexico was analysed using the developed tool as a case study. However, even when this is not a design tool, the calculated solar collector area, storage tank volume, and investment were only 2.1%, 9.0%, and 2.3% higher than reported by the solar designer. Pre-feasibility assessment tools are essential to overcome the certainty gap between end users and solar designers, thus enhancing the possibility of implementing solar heating systems in various commercial and industrial processes.

Pathways to the use of concentrated solar heat for high temperature industrial processes

Pathways to the use of concentrated solar heat for high temperature industrial processes

Analysis of the thermal inertia of pipelines in SHIP

Solar Heat for Industrial Processes (SHIP) is one of the most promising alternatives to decarbonize the industry. The present work aims to analyze the influence of thermal pipelines inertia on a small-scale solar concentrator of 20 kW with a phase-change material thermal storage. Two dynamic simulations for this SHIP system integrated into a tube steel factory in Romania were developed with Dymola software: one of them considered the thermal inertia of the pipelines and the other did not. By comparing the simulation results, we have found that the pipeline inertia conveyed delays in the start-up sequence of the system and decreased the temperatures of heat transfer fluids until the steady state is reached. Furthermore, the thermal inertia decreased the total energy produced. Other researchers have also found delays due to the inertia of the pipelines, but the delays were lower than ours. The difference in the delays may be due to the small scale of the SHIP system analyzed in the present work. Finally, we can conclude that dynamic simulation became important in SHIP systems because of the difference found with the non-inertia simulation.