High-temperature Process Research Articles

Intrinsic Poly-Si layer thickness: Its role in pinhole contact formation and interface passivation in poly-silicon on oxide solar cells

Tunnel oxide passivating contact (TOPCon) solar cells are characterized by high surface passivation and electrical transport efficiency due to the chemical passivation and field effect of the tunnel oxide and doped poly-silicon layers, respectively. Nevertheless, the passivation quality, implied open-circuit voltage (iVoc), and device lifetime are adversely affected by high-temperature processing, leading to Auger recombination and pinhole defects in the tunnel oxide layer. This study aimed to explore the introduction of intrinsic poly-silicon as an interlayer to improve thermal stability and assesses its effect on the passivation of the tunnel oxide interface. Findings indicate that an intrinsic poly-silicon interlayer with a minimum thickness of 18 nm prevents passivation degradation at elevated temperatures. Additionally, the incorporation of this interlayer facilitates the tuning of the doping profile in crystalline silicon, resulting in a diminished pinhole density and an enhanced iVoc of 714.9 mV. These results advance our understanding of TOPCon solar cell performance and provide a foundation for their further optimization.

Intelligent Optimization and Impact Analysis of Energy Efficiency and Carbon Reduction in the High-Temperature Sintered Ore Production Process

The coordinated optimization of energy conservation, efficiency improvement, and pollution reduction in the sintering production process is vital for the efficient and sustainable development of the sintering department. However, previous studies have shown shortcomings in the multi-objective collaborative optimization of sintering systems and the quantification of pollutant impacts. To address these, this paper proposes a multi-objective optimization method integrated with the NSGA-III algorithm and establishes an integrated system optimization model for sintered ore production and high-temperature waste heat recovery. The results demonstrate significant improvements: energy utilization efficiency increased by 0.67%, energy consumption decreased by 17.3 MJ/t, production costs were reduced by 11.45 CNY/t, and the emissions of CO2, SO2, and NOx were reduced by 0.464 kg/t, 0.034 kg/t, and 0.008 kg/t, respectively. Additionally, the study identified optimal configuration parameters and analyzed the quantitative impact of several key factors on multiple indicators. The results also show that reducing the water content of the mixture, decreasing the middling coal content in the fuel, and increasing the thickness of the material layer are effective strategies to reduce energy consumption and pollutant emissions in the sintering process. Overall, implementing these optimizations can bring significant economic and environmental benefits to the steel industry.

Phenolics in soymilk manufactured from black and Proto soybeans by two continuous-ultrahigh-temperature-processing technologies inhibit DU145-prostate cancer cell proliferation through apoptosis.

Plant genotypes and processing technologies affect health properties of foods. How thermal processes with different sterilization values influence polyphenols in soymilk manufactured from different genotypes, particularly black soybean has not been well characterized. This study's aims were to investigate how one- and two-phase ultrahigh temperature (UHT) processing technologies, with wide differences of lethality (F0 158.5 and 6.35, respectively), affected anti-prostate cancer DU145-cell properties of black soymilk compared to light-yellow-Proto soymilk. Phenolics were extracted from soymilk and used for chemical, cell cycle and apoptosis analyses. Total isoflavones and genistein in black soymilk were significantly higher than Proto soymilk by either processing methods. Compared to one-phase processing, two-phase produced higher gallic acid in both soybeans, and higher oxygen radical absorbance capacity (ORAC) in black soymilk. Soymilk processed from both genotypes by both UHT methods inhibited DU145 cells. Two-phase-UHT processed black soymilk was more effective than one-phase UHT-processed soymilk. IC50 values (mg/mL) of black and yellow soy extracts against prostate cancer cells differed only by 11%-25%, which were lower than the differences of total isoflavone (29%-33%) or genistein (>50% between two beans). The mechanism by which soymilk inhibited DU145 cell proliferation was through apoptosis as evidenced by cell cycle analyses and expressions of caspase-3, Bcl-2, and PARP-1 proteins. Antioxidant properties, isoflavones, and phenolic acids were negatively correlated with prostate-cancer-cell inhibition IC50 (p<0.05) with ORAC having the highest coefficient (r=-0.98). Overall, two-phase-UHT processing of soybean would produce soymilk products with a higher health benefit than a one-phase UHT method. PRACTICAL APPLICATION: This study characterized the potential prostate cancer prevention effect of soymilk's phenolic extract in black soybean and compared with yellow soybean. The crude extract can be prepared much less costly than purified isoflavones and has potential to be developed into a dietary supplement. This study shows differences of soymilks made by continuous high-temperature processing of two soybean types and can serve as a scientific foundation for future clinical research and commercialization.

Insights into the degradation mechanism of Fe-40Ni-15Co superalloy exposed to marine atmospheric and high-temperature conditions

This study investigated the corrosion and oxidation mechanism of the Cr-free Fe-40Ni-15Co superalloy with exposure to a tropical marine atmosphere for one year and a subsequent high temperature of 650 °C for 300 h. The degradation behavior of the samples was evaluated based on surface characterization and analysis. In the tropical marine atmospheres, the corrosion process of the Fe-40Ni-15Co superalloy presented an initial localized type after one month of exposure and gradually developed into uniform. The corrosion products were mainly comprised of Fe2O3 and NiO, suppressing the pitting process. During the high-temperature oxidation process, all samples presented super-parabolic oxidation kinetics. Except for the initial active oxidation due to salt deposits, the corrosion products after atmospheric exposure could significantly enhance the oxidation resistance at 650 °C. An explanation for the degradation mechanism of the Fe-40Ni-15Co superalloy was developed based on the synergistic effects of atmospheric corrosion and high-temperature oxidation.

Multi-core–shell nanoboxes comprising polydopamine-derived C coated NiCo@C and FeCo@C nanohybrid for enhanced electrochemical quantification of nitrofurantoin

The development of a high-performance electrochemical sensing platform for monitoring nitrofurantoin (NFT) levels in various real samples plays an important role in the research community worldwide. To accomplish this objective, the crucial challenge is to construct sensing interfaces with outstanding electrocatalytic capabilities. In the present work, a highly efficient metal@carbon electrocatalyst with porous and multi-core–shell nanobox structure comprising polydopamine (PDA)-derived C coated NiCo@C and FeCo@C nanohybrid (named as NiCo@C/FeCo@C@C) was fabricated by simply pyrolyzing NiCo@FeCo Prussian blue analogues (PBA)@PDA. The carbonization of PDA into carbon shells protected the framework from collapsing during high-temperature pyrolysis process, thus enlarging the specific surface areas and porosity. The NiCo@C/FeCo@C@C composite attained an enhanced electrochemical capability, such as an outstanding electronic conductivity from the double carbon shell with porous structure, a large number of active sites and a high electrocatalytic activity from the metallic alloy nanoparticles, which exhibited a highly sensitive response to NFT. Under optimized experimental conditions, the established NiCo@C/FeCo@C@C electrochemical sensor displayed a wide linear range of 0.05–100 μM for NFT determination, coupled with a low detection limit of 14 nM. The practical feasibility of this sensor was also confirmed by the analysis of NFT in tablet and lake water samples with outstanding recovery rates. Moreover, the sustainability of the sensor was demonstrated through its prominent performance in high reproducibility, selectivity and long-term stability. This study thus introduces an innovative approach for the advance of highly efficient electrocatalysts in the area of electrochemical sensing.

Nano to micron-size combustion particles in smokers’ homes: magnetic properties of tobacco and cigarette ashes

Cigarette emission comprises high-temperature combustion processes producing diverse harmful compounds, gases, and particulate matter that are spread through the air and can be taken by smokers and passive smokers involuntarily. We determined the magnetic properties of tobacco cigarettes from six commercial brands. We also monitored the emission of particulate matter in some smokers’ homes using low-cost sensors and the PM2.5 dataset was studied through a time series analysis. In addition, compositional, morphological, and magnetic properties of cigarette ashes were studied and compared with available data. Unexpected positive mean values of specific magnetic susceptibility (χ = 3.7 ×10-8 m3kg-1) and saturation isothermal remanent magnetization (SIRM = 0.6 ×10-3 Am2kg-1) of tobacco cigarettes indicate the presence of “magnetic condiments” in this unburned material. In contrast, as a consequence of puff and smoldering burn, a magnetic increase of up to 35-fold the reference values of unburned material evidence an important neoformation of airborne tobacco-derived magnetic particle ToMP. Mixtures of these ToMPs with different sizes, from nano to micron-sized, comprise superparamagnetic SP, single-domain SD, and multidomain MD particles. This work provides new accurate information on specific tobacco product ingredients (not declared) and the unnoticed ToMP emission after smoking habits, which are needed for tobacco products, consumers and passive smokers (including vulnerable children) exposed to second-hand smoke. ToMPs and myriad other toxicants may be inhaled, escape from the inhalation system and penetrate biological barriers leading to long-term human health risks.

Cu2SnS3/rGO nanocomposites with optimized pore structure for high-performance lithium-ion batteries

Developing advanced anode materials is essential for enhancing the rate performance and stability of lithium-ion batteries (LIBs), which is critical for meeting the demands for next-generation energy storage solutions. In this research, Cu2SnS3/rGO nanocomposites were synthesized via a rapid microwave-assisted one-step method, followed by post-synthetic annealing. The incorporation of reduced graphene oxide (rGO) not only significantly improves its electrical conductivity, but also effectively inhibits the agglomeration of CTS nanoparticles. The nanocrystal size in the CTS/rGO nanocomposites has been dramatically downsized, transitioning from the pristine CTS dimensions of 0.9–1.5 μm to a mere 100 nm. This downsizing is a critical advancement in the electrode, as it enhances the surface area and reactivity of the composite. The subsequent high-temperature annealing process shrinks the pore size in the CTS/rGO nanocomposite, decreasing from an average of 42.13 nm to a more confined range of 7.81 to 8.77 nm, depending on the annealing temperatures. Electrochemical testing reveals that the CTS/rGO-A nanocomposite annealed at 300 °C exhibits superior electrochemical performance to the unmodified CTS and non-annealed CTS/rGO composite. The performance is evidenced by an initial capacity of 1856.97 mAh g−1 at a current density of 1 A g−1 and retains a capacity of 1250.32 mAh g−1 after 500 cycles. To elucidate the underlying mechanisms governing the lithium ion diffusion kinetics, capacitance and diffusion behavior of the CTS/rGO-A electrode, advanced techniques such as galvanostatic intermittent titration technique (GITT) and rate cyclic voltammetry (CV) were utilized. These analyses revealed that the synergistic effect of an increased Li+ diffusion coefficient (DLi+), coupled with a notable capacitive contribution, is demonstrated to the enhanced electrochemical performance observed. Furthermore, the COMSOL Multiphysics simulation also indicates improved structural stability of CTS/rGO-A, attributed to minimized stress from volume expansion during discharge. The CTS/rGO-A nanocomposites, featuring enhanced electrochemical performance, coupled with a straightforward and efficient fabrication method, emerge as a promising material for scalable and practical energy storage solutions.

Microstructure evolution process and multi-scale deterioration mechanism model of graphite tailings cement-based materials subjected to high temperature

This manuscript investigated the thermal stability, crystal reconstruction and microstructure evolution of graphite tailing cement mortar subjected to high temperature. Simultaneously, a computational model for heat transfer and degradation considering chemical transformations had been developed by combining multiscale mechanics with the laws of thermodynamics. The results show that 20% graphite tailings can increase the tobermorite crystal content under high temperature and inhibit its transformation into disordered form. Furthermore, the dormant active SiOx in graphite tailing is gradually activated under the action of high temperature, which catalyzes and induces the formation of more belite crystal in graphite tailing cement mortar. Additionally, 40% graphite tailing can promote the generation of anorthite by the induction of high temperature. Finally, a new multi-scale model considering the chemical transformation is established to calculate the high-temperature degradation process of graphite tailing cement mortar.

Crystallization Control to Prepare Uniform CsPbI2Br Thin Films for High-Efficiency Perovskite Solar Cells.

All-inorganic perovskite solar cells (PSCs) face challenges related to film inhomogeneity, which arises from nonideal crystallization. This issue significantly impedes the advancement of all-inorganic PSCs. In this study, we observed that during the crystallization process of CsPbI2Br, the Br-rich intermediate phase is often preferentially deposited, leading to an uneven distribution in the out-of-plane direction of the perovskite film. To address this issue, crown ether molecules (dibenzo-18-crown-6) were introduced into the perovskite precursor solution. The complexation of crown ether with Cs cations and Br anions optimizes the crystallization sequence of the perovskite, ensuring that the intermediate phase closely conforms to the standard stoichiometric ratio. This adjustment significantly mitigates the problem of uneven halogen ion distribution along the out-of-plane direction. Furthermore, the crown ether thermally decomposes during the high-temperature annealing process, thereby not affecting the composition of the final perovskite film. Following crown ether treatment, the efficiency of the PSCs reached 14.08%, and the unpackaged devices maintained 80% of their initial efficiency after 1000 h of exposure to light in an atmospheric environment.

Effect of Mg on Plasticity and Microstructure of Al-Mg-Ga-Sn-In Soluble Aluminum Alloy

Soluble aluminum alloy materials used in underground operational tools are synthesized via a high-temperature smelting process. The microstructure and composition distribution of the alloy were analyzed using X-ray diffraction, metallographic microscopy, and scanning electron microscopy with energy-dispersive X-ray and electron backscatter diffraction techniques. The mechanical properties were evaluated using a universal testing machine and hardness tester, while solubility assessments were conducted in a constant-temperature water bath. This study focuses on the plasticity and dissolution characteristics of Al-Mg-Ga-Sn-In alloys with varying Mg contents. The tensile strength (σb) of the alloy was 181.99 MPa, with an elongation (δ) of 27.49% and cross-sectional shrinkage (φ) of 11.67% at a magnesium content of 3.0 wt.%. Additionally, in the compressive test, the compressive yield strength (σsc) was recorded at 188.32 MPa, while the compression rate (δ) was 27.06% and the section expansion rate (φ) was 138.66%. Furthermore, the alloy demonstrated the ability to dissolve spontaneously in water at 90 °C, exhibiting an average dissolution rate of 1.0 g·h−1cm−2 and a maximum dissolution rate of 3.25 g·h−1cm−2 after 12.0 h. Consequently, this alloy composition not only satisfies the requirements for rapid solubility but also exhibits favorable plasticity, providing a novel reference for the selection of soluble aluminum alloy materials.

Flexibilizing Mechanisms of Spinel-, Hercynite-, Galaxite-, and Chromite-Containing Basic Refractories for Cement Rotary Kilns

Background: Refractory linings of cement rotary kilns are subjected to severe thermomechanical stresses of cranking, ovality, tyre hooping/migration, and uneven thermal distribution. An insistent demand is to discover the significance of spinel, hercynite, galaxite, and chromite in magnesia refractories, as well as their flexibilizing mechanisms. Objectives: The objectives are to compare the fracture behavior of magnesia–spinel, – hercynite, -galaxite, and -chromite refractories and to unveil the flexibilizing mechanisms of different spinels. Methods: The wedge-splitting test is carried out to produce various fracture parameters. Their flexibilizing mechanisms are unveiled by performing microstructural observations and analyses. Results: Various fracture parameters are obtained, including specific fracture energy, brittleness number, characteristic crack length, and thermal-shock resistance parameter. Generally, magnesia–hercynite bricks and magnesia–galaxite bricks have demonstrated the obvious advantages of fracture resistance, which are more flexible than magnesia–spinel bricks and magnesia–chromite bricks. Conclusion: The flexibility of magnesia–spinel bricks is attributed to microcracks generated from the thermal mismatch between spinel grains and surrounding periclase, which is recognized as the thermal-expansion mismatch mechanism. In magnesia–hercynite and magnesia-galaxite refractories, the active-ion-diffusion mechanism is predominant beyond similar microcracks, to drive the flexibility by the continuous diffusion of Fe2+, Mn2+, and Mg2+ during high-temperature processes. In magnesia–chromite bricks, the pore rims contribute to the flexibility as a silicate-migration mechanism, after silicate envelopes first arise around chromite grains and then vanish into the surrounding magnesia by the suction of capillary force during the burning process.

Effect of High Processing Temperature on the Rheological and Morphological Properties of Recycled Polypropylene

Effect of High Processing Temperature on the Rheological and Morphological Properties of Recycled Polypropylene

Electrification or Hydrogen? The Challenge of Decarbonizing Industrial (High-Temperature) Process Heat

The decarbonization of industrial process heat is one of the bigger challenges of the global energy transition. Process heating accounts for about 20% of final energy demand in Germany, and the situation is similar in other industrialized nations around the globe. Process heating is indispensable in the manufacturing processes of products and materials encountered every day, ranging from food, beverages, paper and textiles, to metals, ceramics, glass and cement. At the same time, process heating is also responsible for significant greenhouse gas emissions, as it is heavily dependent on fossil fuels such as natural gas and coal. Thus, process heating needs to be decarbonized. This review article explores the challenges of decarbonizing industrial process heat and then discusses two of the most promising options, the use of electric heating technologies and the substitution of fossil fuels with low-carbon hydrogen, in more detail. Both energy carriers have their specific benefits and drawbacks that have to be considered in the context of industrial decarbonization, but also in terms of necessary energy infrastructures. The focus is on high-temperature process heat (&gt;400 °C) in energy-intensive basic materials industries, with examples from the metal and glass industries. Given the heterogeneity of industrial process heating, both electricity and hydrogen will likely be the most prominent energy carriers for decarbonized high-temperature process heat, each with their respective advantages and disadvantages.

Thermosensitive polymer/nanosilica hybrid as a multifunctional additive in water-based drilling fluid: Rheologicalproperties and lubrication performance as well as filtration loss reduction capacity

In previous studies, for obtaining a flat rheological drilling fluid, binary and ternary thermosensitive silica (SiO2) nanohybrids as rheological modifiers were synthesized using N-isopropylacrylamide with a thermal association temperatureof 32–33 °C as the thermosensitive monomer [J. Petrol. Sci. Eng. 219 (2022), 111096; Geoenergy Science and Engineering 228 (2023), 211934]. However, the as-synthesized SiO2 nanohybrids exhibited limited performance and low thermal transition temperature. Thus surface initiated atom transfer radical polymerization was utilized to graft hydrophilic poly(ethylene glycol) methyl ether methacrylate (PEGMA) onto SiO2 surface to obtain PEGMA/SiO2 nanohybrids with an elevated thermal association temperature of 75 °C. The morphology and structure of the as-synthesized PEGMA/SiO2nanohybrid were characterized by infrared spectroscopy and transmission electron microscopy; and its effects as a thermosensitive multifunctional additive on the rheological properties and lubrication performance as well as filtration loss reduction capacity of a water-based drilling fluid were investigated. Results indicate that the drilling fluids with 1.0% PEGMA/SiO2 nanohybrids exhibited obvious thermal thickening behavior in the temperature range of 70–80 °C; at low temperatures, however, they had a significant viscosity reduction effect therein. At room temperature, the apparent viscosity and plastic viscosity were reduced by 68% and 50%, respectively. Besides, due to the tightly packed plugging layer formed by PEGMA/SiO2 nanohybrids and bentonite, the filtration loss of the drilling fluids containing 1.0% PEGMA/SiO2 nanohybrid was reduced by 37% as compared with that of the base slurry; and the lubrication coefficient was decreased by up to 50%. Moreover, the high-temperature aging process promoted the intermolecular interactions of the nanohybrids and their interaction with bentonite flakes, thereby further improving the rheological behavior, filtration reduction ability, and lubricity of the drilling fluids. The as-synthesized thermosensitive PEGMA/SiO2 nanohybrids with excellent multifunctionality could find promising application in water-based drilling fluids.

Determination of optimal technological conditions for the manufacture of semi-finished products from gooseberry fruit

The quality of pureed berries products is determined by many factors. The purpose of the study was to determine the optimal technological conditions for the manufacture of semi-finished products from gooseberries, providing for the use of equipment with a rotary machine (MAG‑50) and ensuring the required quality characteristics. The objects of research were semi-finished products from gooseberries. The manufacturing technology involved high-temperature processing or the use of the rotary machine MAG‑50. The research methods were standard. It has been found that in order to obtain products with the required quality characteristics, the duration of processing in MAG‑50 had the greatest influence. The optimal technological conditions for the manufacture of products in MAG‑50 have been determined: processing for 14–20 minutes at a temperature of 59–65°C of at least 72% of fresh berries or 58–65°C of at least 66% of quick-frozen ones. It has been established that the technology involving the use of rotary machine MAG‑50, compared with the high-temperature one, made it possible to obtain products with a lower content of mesophilic aerobic and facultative anaerobic microorganisms, molds (by 97.7 and 69.8%, respectively), better appearance characteristics (by 1.7%), color, texture and odor (by 2.3%), taste and aftertaste (by 3.6%). The state of the raw materials had the greatest impact on the content of yeast in semi-finished products — products made from fresh berries contained 48.7% more of them on average than products from quick-frozen ones. Compared with the Senator variety, gooseberry fruits of the Pink 2 variety made it possible to obtain products with a high content of soluble solids, sugars, minerals and ascorbic acid (by 18.2, 58.9, 7.7 and 61.8%, respectively), less titrated acids and dietary fibers (by 21.2 and 20.3%, respectively). The study demonstrates the potential of obtaining semi-finished products from gooseberries, regardless of their variety and condition by using the technology involving the use of MAG‑50.

Enhanced Stability of Melt-Processable Organic-Inorganic Hybrid Manganese Halides for X-Ray Imaging.

Mn-based metal halides scintillators with high photoluminescence quantum yield (PLQY) have recently emerged as promising large-size candidates for X-ray imaging but still remains as difficult challenge in stability and high processing temperatures. Here, three manganese halides are designed by introducing branched chains into organic cations and extending the carbon chains, namely (i-PrTPP)2MnBr4, (i-BuTPP)2MnBr4 and (i-AmTPP)2MnBr4, successfully lowered the melting point of manganese halides to 120.2 °C. Three materials show striking light yields of 59000, 40000, and 52000 photons MeV-1, respectively. The lowest detection limits are 42.30, 50.92, and 45.71 nGy s-1, respectively. Meanwhile, compared to their counterparts with linear carbon chains, the introduction of branched chains has significantly enhanced the stability of the scintillators in the glass state. A transparent glass has been prepared using a melt-quenching method, which exhibited 80% transmittance at 400-700nm. The glass is utilized for X-ray imaging, achieving a high spatial resolution up to 46.6 lp mm-1. This result provides a new approach to enhancing the performance of such scintillator materials.

Multi-stage precipitation modeling for AA 7050 hole repairs in additive friction stir deposition

A multi-stage precipitation model is formulated to predict the microstructural evolution and explain the high performance of additive friction stir deposited aluminum alloy 7050 (AA 7050) for hole repair. The first stage is the heating process due to the high-temperature thermomechanical process of the stir. In this process, small η precipitates dissolve as they lose their stability with increasing temperature, and this causes the volume fraction of η precipitates to decrease and the concentration of Mg and Zn in the matrix to increase. The second stage is the cooling process at the end of the repair where material feeding ends and the tool is lifted away. Heterogeneous nucleation of η precipitates may occur and as the temperature cools below 250 °C, Guinier–Preston (GP) zones start to form. The final stage is the natural aging process, where the η′ precipitate starts to grow. The volume fraction and precipitate radius are predicted for each type of precipitate. Furthermore, the fine η′ precipitates and GP zones with a decent volume fraction improve the material strength and fatigue life.

Thermodynamic Study of the High-Temperature Partitioning Process of Carbon Elements in Intercritical Quenching and Partitioning High-Strength Steels

Thermodynamic Study of the High-Temperature Partitioning Process of Carbon Elements in Intercritical Quenching and Partitioning High-Strength Steels

General Synthesis of High-Entropy Oxides and Carbon-Supported High-Entropy Oxides by Mechanochemistry.

High-entropy oxides (HEOs) have been receiving a lot of attention due to their excellent properties. However, current common methods for preparing HEOs usually involve high-temperature processes. The development of green synthesis techniques remains an important issue. Carbon-supported HEOs have shown excellent performance in electrochemical energy storage in recent years. Crucially, the traditional methods cannot synthesize carbon-supported HEOs under N2 or air atmospheres. Toward this end, a universal method for preparing carbon-supported HEOs was proposed. During this process, without high-temperature post-treatment, high-entropy LaMnO3 could be synthesized in 2 hours using the mechanical ball-milling method. Furthermore, this method was universal and has been proved in the synthesis of a series of HEOs such as PrVO3, SmVO3, and MgAl2O4. The LaMnO3 species synthesized by this method exhibit excellent catalytic performance in CO combustion and could maintain a conversion rate of over 97 % for 350 hours. Subsequently, carbon-supported HEOs could be obtained with 0.5 hours of additional ball-milling, offering significant advantages over traditional methods. This process provides a potential method to synthesize carbon-supported HEOs.

The Role of Low-Carbon Fuels and Carbon Capture in Decarbonizing the U.S. Clinker Manufacturing for Cement Production: CO2 Emissions Reduction Potentials

Low-carbon fuels, feedstocks, and energy sources can play a vital role in the decarbonization of clinker production in cement manufacturing. Fuel switching with renewable natural gas, green hydrogen, and biomass can provide a low-carbon energy source for the high-temperature process heat during the pyroprocessing steps of clinker production. However, up to 60% of CO2 emissions from clinker production are attributable to process-related CO2 emissions, which will need the simultaneous implementation of other decarbonization technologies, such as carbon capture. To evaluate the potential of fuel switching and carbon capture technologies in decarbonizing the cement industry, a study of the facility-level CO2 emissions is necessary. This study evaluates the potential for using a single low-carbon fuel as an energy source in clinker production for cement manufacturing compared to conventional clinker production (which uses a range of fuel mixes). In addition, conventional carbon capture (operated with natural gas-based steam for solvent regeneration) and electrified carbon capture configurations were designed and assessed for net-zero emission targets. Carbon emissions reductions with and without biogenic emissions credits were analyzed to ascertain their impact on the overall carbon accounting. Results show that carbon emissions intensity of cement can vary from 571 to 784 kgCO2eq/metric ton of cement without carbon capture and from 166.33 to 438.66 kgCO2eq/metric ton of cement with carbon capture. We find that when biogenic carbon credits are considered, cement production with a sustainably grown biomass as fuel source coupled with conventional carbon capture can lead to a net-negative emission cement (−271 kgCO2eq/metric ton of cement), outperforming an electrified capture design (35 kgCO2eq/metric ton of cement). The carbon accounting for the Scope 1, 2, and biogenic emissions conducted in this study is aimed at helping researchers and industry partners in the cement and concrete sector make an informed decision on the choice of fuel and decarbonization strategy to adopt.