Industrial Process Heat Research Articles

Electrification potential of U.S. industrial boilers and assessment of the GHG emissions impact

Electrification is a key strategy for decarbonizing the industrial sector. Industrial process heating, which still relies heavily on fossil fuel combustion and accounts for the majority of sector wide GHG emissions, is a particularly attractive electrification target. Electrifying industrial boilers represents a cross-cutting opportunity for GHG emissions reductions, given their widespread use in most manufacturing industries. Yet, there are gaps in the understanding of the current population of conventional industrial boilers in the United States that preclude a characterization of boiler electrification's technical potential to reduce fuel consumption and GHG emissions. In this study, we develop an up-to-date dataset of the industrial boiler population in the U.S. and quantify the county-level electricity requirements and net changes in fuel use and GHG emissions under the current electric grid and theoretical future grid scenarios. Our results show an increase of 105 MMmtCO2e and 73 MMmtCO2e in GHG emissions from boiler electrification, with and without the replacement of byproduct fuels, respectively, under the current electric grid, and a reduction of 19 MMmtCO2e and 7 MMmtCO2e in GHG emissions under a future high renewables electric grid. GHG emissions savings are currently possible only in certain regions of the U.S. unless future grids are decarbonized. We also provide discussion that could be useful for policy makers and manufacturing facilities for advancing the electrification of industrial boilers in locations and industries toward fuel savings and GHG emissions reductions.

A Real-Time Capable PDE Model for an Industrial Heating Process

This paper presents a modeling approach of an industrial heating process where a stripe-shaped workpiece is heated up to a specific temperature by applying hot air through a nozzle. The workpiece is moving through the heating zone and is considered to be of infinite length. The speed of the substrate is varying over time. The derived model is supposed to be computationally cheap to enable its use in a model-based control setting. We start by formulating the governing PDE and the corresponding boundary conditions. The PDE is then discretized on a spatial grid using finite differences and two different integration schemes, explicit and implicit, are derived. The two models are evaluated in terms of computational effort and accuracy. It turns out that the implicit approach is favorable for the regarded process. We optimize the grid of the model to achieve a low number of grid nodes while maintaining a sufficient amount of accuracy. Finally, the thermodynamical parameters are optimized in order to fit the model's output to real-world data that was obtained by experiments.

About common but avoidable faults during planning, installation, and operation of solar heating plants in industrial applications

In the BEsoPro research project, multi-year measured solar yields of 13 solar heat for industrial processes (SHIP) plants in Germany are compared with planned values. The data come from plants installed between 2012 and 2019, with three collector technologies supplying heat to different industrial processes in the low-temperature range, below 100°C for all but one plant. The average collector area of the plants studied is 327 m²gr. With a high certainty, seven of the SHIP systems achieve a lower energetic performance than predicted and four systems reach the expectations. For the last two systems no conclusive quantitative assessment is made due to insufficient measurement data. A list of ten common faults and problems in SHIP plants is then defined based on the analysis of additional detailed measurement data available for eight of the 13 plants, combined with the authors’ long experience with SHIP plants. Particularly common faults are the undersizing of the solar heat exchanger and the undersizing of the pump(s) in the solar collector loop. No critical problems or major component or system defects are found. Overall, most faults could be avoided relatively easily with better system planning and installation. These findings should be urgently addressed by the branch to avoid long-term damaging effects on the image of SHIP systems.

Solar Heat for Industrial Processes in Jordan

Solar Heat for Industrial Processes in Jordan

Solar fractions of SHIP plants considering the availability of roof area based on OpenStreetMap data

Solar heat for industrial processes (SHIP) can be a key technology to decarbonize the industrial heat demand world-wide. Several national studies use either a bottom-up or a top-down-approach to assess the potential of solar process heat using estimated fixed solar fractions. Due to limited area available for the installation of solar collectors and the seasonality of the load profile, this solar fraction cannot be achieved in all cases. To address this limitation, another estimated factor is used in those studies. However, the impact of the lack of free area on solar fractions and overall solar potential has not been studied in detail so far. Thus, a dataset with load profiles and roof areas from OpenStreetMap GIS data from 489 German companies from secondary and tertiary sector is set up in this study. Based on the standardized pre-design methodology of the VDI 3988 guideline, the evaluations show that one third of the regarded companies lack sufficient roof area whereas two thirds can provide their summer heat demand with solar collectors. Furthermore, the study shows that an ambient temperature dependent heat demand limits the solar potential in terms of solar fraction even more than the available roof area.

Thermo-Economic Analysis of a Solar-Assisted Industrial Process Heating System

Thermo-Economic Analysis of a Solar-Assisted Industrial Process Heating System

Techno-Economic Assessment of Evacuated Flat Plate Solar Collector System for Industrial Process Heat

Techno-Economic Assessment of Evacuated Flat Plate Solar Collector System for Industrial Process Heat

Influence of heat storage materials in a concentrated solar absorber for space heating

Industrial process-heating is usually counting on fossil fuels. It’s preferred for using solar power due to its free availability and eco friendliness compared to fossil fuels. This experimental study of solar absorber crammed with metal chips is tested outdoor with a dish collector. The metal chips are aluminum, copper, and steel scraps, and therefore the selected mass is one kg. During the outdoor trials, the absorber with integrated materials undergoes sensible heating to store concentrated solar power. Using sensible and heat of transformation materials within the absorber improves heat storage capacity. While passing atmospheric air through solar absorber with a velocity of two 0.45 m/s and therefore the hot air is useful for process-heating. Absorber with aluminum fillings was observed effective in heat storage and warmth output of air. The general heat retention inside the absorber was maximum when integrating aluminum chips inside.

Hybrid energy system optimization model: Electrification of Ontario's residential space and water heating case study

Energy systems are becoming more complex as new energy sources are introduced in support of clean energy goals. These hybrid energy systems can be configured for cogeneration to account for multiple energy uses, including not only electricity but also space heating, water heating, and industrial process heat. Variable renewable energy systems are increasingly being added to hybrid systems to mitigate climate change and reduce greenhouse gas (GHG) emissions. This often creates additional challenges to meet energy demands due to variability associated with renewable generation. In support of energy planning for the new clean economy, the Hybrid Energy System Optimization (HESO) model has been developed to study the feasibility and benefits of nuclear-renewable hybrid energy systems. The model is formulated, as a mixed-integer linear programming (MILP) algorithm, to determine the best energy mix by minimizing annual cost. Because electrification will play a significant role in realizing a clean economy, this study explores the potential economic viability of electrification of residential water and space heating in Ontario. Different energy scenarios have been analyzed to understand the challenges associated with electrification and determine which energy sources will significantly reduce greenhouse gas emissions, while also maintaining competitive energy costs. The results show that electrification of residential water heating can be a viable alternative to natural gas heaters; reducing GHG emissions and energy cost. However, electrification of residential space heating is more challenging due to the large seasonal temperature variations that create significant energy demand fluctuations. Additional nuclear and wind generating capacity, as well as storage systems, are all important elements to support Ontario's transition to a low carbon economy through electrification.

Development of a current source resonant inverter for high current MHz induction heating

High frequency industrial induction heating processes typically employ resonant inverters to reach high efficiency at high power levels. Advancements in wide band gap (WBG) device technology has made it feasible to push the possible frequency of these processes into the MHz regime using solid state technology. Several topologies can be applied, each with advantages and drawbacks. This paper presents a current source resonant inverter (CSRI) employing a custom designed power module utilizing 1700V SiC MOSFETs for MHz operation of a high-Q resonant tank for induction heating, which presents new challenges in the inverter module design. An integrated gate driver structure is demonstrated driving four MOSFETs in parallel in MHz operation. Theoretical analysis predicts substantial parasitic influence on inverter operation, and thus an inverter is constructed to provide experimental verification of MHz operation, while the challenges associated with high frequency CSRI operation are discussed. In the experimental inverter setup, the fabricated power module achieves > 90 % efficiency for a calculated reactive power of 170 kVA and 2.3 kW output power during unloaded operation, validating the inverter design for extension to higher power loaded operation.

A design tool for a parabolic trough collector system for industrial process heat based on dynamic simulation

The industrial sector is one of the biggest oil consumers in Cyprus, corresponding to 20% of the fuel consumption. A parabolic trough collector (PTC) system seems the best option to produce clean thermal energy at higher temperatures than those that can be achieved from the already widely used flat plate collectors on the island. This paper presents a simulation model built to investigate the performance of the first industrial PTC system in Cyprus, installed at the Cyprus biggest soft drinks factory. The simulation model is built in TRNSYS and is validated using data from the real PTC system installed at the factory. The results show a very good fitting between the operating parameters and the power output of the Solar Field (SF), Concrete Thermal Storage System (CTES), and the Steam Generator (SG). The average percentage relative error of the system's contribution to the process is less than 6.32% for the daily steam production and during a week did not exceed 6.45%. The novelty of this study is the development of a design tool that can be used by potential interested industries to identify the suitable system that fits their needs. All data are provided in the form of graphs and allow anyone to use as input data the thermal energy demand and required steam temperature of the industry to retrieve information about the size of a suitable system which satisfies these requirements depending on each case. The payback period for all cases examined varies from 2 to 6 years, depending on the size of the system.

Performance Evaluation of Solar Air Collector in Sensible Heat Storage by Forced Convection with Cherry Powder

In practice different kinds of solar air heaters are available for domestic heating and industrial air heating purposes, space heating, process heating and agricultural applications. Advantage of this system is to use of renewable energy source that is free in cost and an eco-friendly, economical and simple device. There are so many researcher who focuses to improve the efficiency and to maintain the continuous heat supply of the double pass solar air heater using sensible storage material. The heat transfer and friction characteristics due to the sensible storage material of solar air heaters have been reviewed in this research. A double pass solar air heater was fabricated and integrated with thermal storage system and powdered cherry pits are used as a thermal storage medium. The performance of this heater was studied for different configurations. The solar heater integrated with thermal storage delivered comparatively high temperature. The efficiency of the air heater integrated with thermal storage was also higher than the air heater without thermal storage system. The study concluded that the presence of the thermal storage medium at the absorber plate is the best configuration.

Optimum Torrefaction Range for Macaw Husks Aiming Its Use as a Solid Biofuel

Abstract Biomass feedstock is broadly available in many countries, and a significant amount of residual biomass comes from agriculture and forest crops. This study aims to identify a consistent criteria for optimize Macaw husks torrefaction process maximizing the energy content and minimizing the mass loss. The optimization criteria is based on the severity factor (SF), HHVTorrefied, and ηSolid-Yield. The energy density (ρEnergy) does not provide consistent and indisputable evidence as an optimization criteria; the same applies to energy-mass co-benefit index (EMCI) and ηEnergy-Yield. This investigation combined few temperatures (180 °C, 220 °C, and 260 °C) with different residence times (20, 40, and 60 min) and found that the optimum torrefaction range for Macaw husk is 220 < T (°C) < 240 and 10 < t (min) < 40. The best experimental result was 220-40 (dry torrefaction at T = 220 °C and t = 40 min) corresponding to SF ∼ 5.14 and HHVTorrefied ∼ 21.71 MJ/kg (ηSolid-Yield ∼ 0.86 and HHVRatio ∼ 1.14). As the raw material has small ρBulk or ρEnergy, the authors suggest the use of a densification process previously to torrefaction. The obtained solid final product had high-quality biofuel following properties: FCdb, H/C, and O/C ratios, high heating value (HHV). The gain and loss optimization method seems promising to identify the optimum torrefaction parameters for any biomass species and the obtained optimum temperature is not far from the ones available as waste heat in industrial processes.

Review on Process Development and Challenges in Biomass Pyrolysis

In recent times, the escalation of greenhouse gases, air pollution and depletion of the ozone layer has enforced the researchers to renovate the regular use of fossil fuels into alternate methods which are non-toxic, eco-friendly, and cost-effective. Biomass is one of the traditions to swap fossil fuels. Biomass can be transmogrified into beneficial and eco-friendly forms of energy under various conversion processes. The obtained energy can be used for heating water, industrial heating process, and generating electricity. Pyrolysis is a method to alter biomass into useful products, as the final yields of this process include bio-oil, char, methane (CH4), hydrogen (H2), carbon monoxide (CO) and carbon dioxide (CO2). It is well known for its high efficiency and environmental performance. In this method even the agricultural residues, waste woods, solid municipal waste, plant wastes can be utilized. This review comprehends the various concepts on products of biomass pyrolysis, mechanisms, and several pre-treatment processes used for efficient pyrolysis of biomass have been analysed. The impact of various fundamental constraints such as temperature, heating rate, particle size was studied and their influence on yield and composition were studied.

Supporting Visualization Analysis in Industrial Process Tomography by Using Augmented Reality-A Case Study of an Industrial Microwave Drying System.

Industrial process tomography (IPT) based process control is an advisable approach in industrial heating processes for improving system efficiency and quality. When using it, appropriate dataflow pipelines and visualizations are key for domain users to implement precise data acquisition and analysis. In this article, we propose a complete data processing and visualizing workflow regarding a specific case—microwave tomography (MWT) controlled industrial microwave drying system. Furthermore, we present the up-to-date augmented reality (AR) technique to support the corresponding data visualization and on-site analysis. As a pioneering study of using AR to benefit IPT systems, the proposed AR module provides straightforward and comprehensible visualizations pertaining to the process data to the related users. Inside the dataflow of the case, a time reversal imaging algorithm, a post-imaging segmentation, and a volumetric visualization module are included. For the time reversal algorithm, we exhaustively introduce each step for MWT image reconstruction and then present the simulated results. For the post-imaging segmentation, an automatic tomographic segmentation algorithm is utilized to reveal the significant information contained in the reconstructed images. For volumetric visualization, the 3D generated information is displayed. Finally, the proposed AR system is integrated with the on-going process data, including reconstructed, segmented, and volumetric images, which are used for facilitating interactive on-site data analysis for domain users. The central part of the AR system is implemented by a mobile app that is currently supported on iOS/Android platforms.

Economic solution for low carbon process heat: A horizontal, compact high temperature gas reactor

In 2018, nuclear energy generated 55% of United States’ and one third of the world’s carbon free electricity, making nuclear energy a key tool in efforts to mitigate climate change before 2050. However, the current nuclear technology, light water reactors (LWRs), is limited to 300°C, so it cannot be used to decarbonize industrial process heat which accounts for 12% of US greenhouse gas emissions. High temperature gas reactors (HTGRs) can meet the high temperature demand with carbon free nuclear heat. The estimated cost of HTGRs, such as the Next Generation Nuclear Plant (NGNP), are even higher than state-of-the-art LWRs. In this paper, we expanded our nuclear cost estimating tool to include HTGRs and find that the NGNP overnight capital costs were 32% higher than an advanced LWR per unit capacity. The higher cost will naturally result in larger risk to cost overrun as recently experienced by larger LWRs in western nations. With a design-to-build mindset to minimize cost and construction risk, we introduce the horizontal, compact HTGR (HC-HTGR). The reactor core and steam generator are mounted horizontally on rails and in-line with one another, decreasing the size of the reactor building relative to the power capacity four times when compared to traditional HTGRs. The HC-HTGR reduced overnight civil structure costs by 42%, indirect costs by 38%, and total capital costs by 20% from NGNP. We discussed the required engineering of new systems for the HC-HTGR including vessel supports, the reactor cavity cooling system, and steam generator design. Finally, we estimated the fuel and operations costs of the HC-HTGR, and a survey of low-carbon industrial process heat technology showed the HC-HTGR can deliver a highly competitive levelized cost of heat in the range of $6.13–12.48/GJ.

Heat Transfer and Friction Factor Characteristics of Turbulent Flow through a Conical Heat Exchanger

In this present energy demand scenario, the use of a waste heat recovery device like regenerator, recuperator, reheaters in the industrial processes is gaining much more importance due to improvement in thermal efficiency, and consequently reduction in thermal pollution. In the power plant, the waste heat carried by hot flue gases through the chimney remains untapped which can be recovered through the use of a conical heat exchanger at the inner portion of the chimney. Also, few customized designs of the conical coil heat exchanger can have the potential to be used to recover the waste heat in other industrial processes like chemical reactors, electrical contractors, HVAC applications, condenser, boiler, and evaporator, etc. In the present study, different arrangements of the conical coil heat exchanger are analyzed using a numerical technique. A conical coil of different geometrical configurations viz. at three different cone angles 45°, 90°and 135°, and at three different pitches 20 mm, 25 mm, and 30 mm are considered. The results for heat transfer and friction factor are presented for the flow of fluid of different Reynolds numbers. The impact of geometrical parameters as well as flow parameters on pressure drop and heat transfer under constant wall heat flux conditions are presented. The average heat transfer and pressure drop values are observed to be 175 to 225% more than the smooth tube values with increased pressure drop. Also, the results indicate that there is a nonlinear increase in both Nusselt number and friction factor with the increase in cone angle and pitch of conical coil.

Real-Time Experimental Performance Assessment of a Photovoltaic Thermal System Cascaded With Flat Plate and Heat Pipe Evacuated Tube Collector

Abstract In response to the global quest for a sustainable and environmentally friendly source of energy, most scientists’ discretion is solar energy, especially solar thermal. However, successful deployment of solar thermal technologies such as solar-assisted process heating (SAPH) systems in medium- to large-scale industries is still in quandary due to their inefficacy in raising ample temperatures. Cascaded SAPH system, which is essentially a series combination of two same or different types of thermal collectors, may provide a worthwhile solution to this problem. In this article, performance assessment and comparison of two cascaded SAPH systems have been presented: photovoltaic thermal (PVT) cascaded with flat-plate collector (PVT-FPC) and PVT coupled with heat pipe evacuated tube collector (PVT-HPETC). Simulation models have been presented for individual FPC, HPETC, and PVT as well as PVT cascaded with FPC and HPETC systems in TRNSYS and validated through outdoor experimentation. Both the first and the second laws of thermodynamics have been employed to reveal veritable performance of the systems. Results show that PVT-HPETC delivers better performance with 1625 W thermal energy, 81.59% energy efficiency, and 13.22% exergy efficiency. It cuts 1.37 kg of CO2 on an hourly basis. Cascaded systems can be effective in sustaining industrial process heat requirements.

Multiobjective Optimization of a Novel Solar Tower-Based Gas Turbine-Driven Multi-Generation Plant With Energy, Exergy, Economic, and Environmental Impact Analysis

AbstractIn this study, a novel solar tower-based gas turbine-driven multi-generation plant is proposed and analyzed in detail with energy, exergy, economic, and environmental impact analysis. A multiobjective optimization is performed by incorporating all performance indicators simultaneously. The proposed plant consists of an intercooling-regenerative-reheat solarized gas turbine cycle as the primary power cycle of a multi-generation plant for the first time. Two organic Rankine cycles are used to utilize waste heat of intercooling section and exhaust of gas turbine. To produce the multi-generation products of power, cooling, industrial process heating, fresh water, floor heating, green hydrogen, domestic hot water, hot air for food drying, and greenhouse heating, power cycles are integrated with a multi-effect desalination, a double-effect absorption refrigeration cycle, an electrolyzer, a drying hot air unit, a greenhouse heater, and an industrial process heater. A rigorous parametric analysis is performed to reveal the effects of variations of decision variables on the plant performance. At the optimum conditions, energy efficiency, exergy efficiency, average unit product exergy cost, and emission savings values are determined as 57.23%, 40.7%, 0.08315 $/kWh, and 948.7 kg CO2/h, respectively. Moreover, proposed plant can produce 1962 kW power and 3.353 kg/h hydrogen in addition to other utilities with a system cost rate of 0.05134 $/s and 3226 kW exergy destruction rate.

The Key Techno-Economic and Manufacturing Drivers for Reducing the Cost of Power-to-Gas and a Hydrogen-Enabled Energy System

Water electrolysis is a process which converts electricity into hydrogen and is seen as a key technology in enabling a net-zero compatible energy system. It will enable the scale-up of renewable electricity as a primary energy source for heating, transport, and industry. However, displacing the role currently met by fossil fuels might require a price of hydrogen as low as 1 $/kg, whereas renewable hydrogen produced using electrolysis is currently 10 $/kg. This article explores how mass manufacturing of proton exchange membrane (PEM) electrolysers can reduce the capital cost and, thus, make the production of renewable power to hydrogen gas (PtG) more economically viable. A bottom up direct manufacturing model was developed to determine how economies of scale can reduce the capital cost of electrolysis. The results demonstrated that (assuming an annual production rate of 5000 units of 200 kW PEM electrolysis systems) the capital cost of a PEM electrolysis system can reduce from 1990 $/kW to 590 $/kW based on current technology and then on to 431 $/kW and 300 $/kW based on the an installed capacity scale-up of ten- and one-hundred-fold, respectively. A life-cycle costing analysis was then completed to determine the importance of the capital cost of an electrolysis system to the price of hydrogen. It was observed that, based on current technology, mass manufacturing has a large impact on the price of hydrogen, reducing it from 6.40 $/kg (at 10 units units per year) to 4.16 $/kg (at 5000 units per year). Further analysis was undertaken to determine the cost at different installed capacities and found that the cost could reduce further to 2.63 $/kg and 1.37 $/kg, based on technology scale-up by ten- and one hundred-fold, respectively. Based on the 2030 (and beyond) baseline assumptions, it is expected that hydrogen production from PEM electrolysis could be used as an industrial process feed stock, provide power and heat to buildings and as a fuel for heavy good vehicles (HGVs). In the cases of retrofitted gas networks for residential or industrial heating solutions, or for long distance transport, it represents a more economically attractive and mass-scale compatible solution when compared to electrified heating or transport solutions.