Solid Products Research Articles

Experimental study and prediction method of solid destabilization and production in deep carbonate reservoir during mining

Wellbore instability is one of the significant challenges in the drilling engineering and during the development of carbonate reservoirs, especially with open-hole completion. The problems of wellbore instability such as downhole collapse and silt deposit in the fractured carbonate reservoir of Tarim Basin (Ordovician) are severe. Solid destabilization and production (SDP) was proposed to describe this engineering problem of carbonate reservoirs. To clarify the mechanism and mitigate potential borehole instability problems, we conducted particle size distribution (PSD) analysis, X-ray diffraction (XRD) analysis, triaxial compression tests, and micro-scale sand production tests based on data analysis. We found that the rock fragments and silt in the wellbore came from two sources: one from the wellbore collapse in the upper unplugged layers and the other from the production of sand particles carried by the fluid in the productive layers. Based on the experimental study, a novel method combining a geomechanical model and microscopic sand production model was proposed to predict wellbore instability and analyze its influencing factors. The critical condition and failure zone predicted by the prediction model fit well with the field observations. According to the prediction results, the management and prevention measures of wellbore instability in carbonate reservoirs were proposed. It is suggested to optimize the well track in new drilling wells while upgrading the production system in old wells. This study is of great guiding significance for the optimization of carbonate solid control and it improves the understanding of the sand production problems in carbonate reservoirs.

Thermal reactivity and gas–solid product evolution during coal catalytic combustion: An experimental study

To achieve efficient and clean coal combustion, catalytic combustion technology has received widespread attention. This paper systematically studied the influence of calcium-based compounds on the thermal reactivity and gas–solid two-phase product evolution behavior of different coal using TG-MS and FTIR analysis, combining kinetics and thermodynamics methods, the catalytic coal mechanism was discussed. Results demonstrated that both catalysts improved the combustion reactivity, the burnout temperatures of lignite, bituminous coal and anthracite were reduced by 30.75 °C, 53 °C and 25.5 °C respectively with CaO, as well as decreased by 24.75 °C, 55.5 °C and 29 °C respectively with CaCl2. Meanwhile, it was worth noting that the activation energy of three coals was also reduced. CaCl2 was more likely to bind with the C = O functional group on the surface of coal, forming CO-Ca2+ complexes, resulting in a decrease in the content of C = O and C-O. While CaO tended to absorb volatile matter, causing local overheating and promoting the breakage of side chains and bridge bonds. Besides, the calcium-based compounds advanced the gas evolution peak of combustion and the emissions of CO2, NO2 and SO2 were effectively controlled. These results aimed at providing a new reference direction for further industrial development of clean coal combustion technology.

Biochar and syngas from wet torrefaction of oil palm empty fruit bunches and palm oil mill effluent: A renewable energy approach

Abstract Palm oil mill effluent (POME) and oil palm empty fruit bunches (EFB) constitute the highest waste generated in the mill. This study investigates thermochemical approaches, specifically wet torrefaction and gasification, aiming to transform these wastes into higher-value products such as biochar. Wet torrefaction was initially applied to EFB and POME at 200 °C, with a heating rate of 5 °C/min for 30-min residence time under nitrogen-inert conditions, resulting in a solid yield of 82%. This process led to a notable increase in the heating value of raw EFB by 30.6%, from 17.3 to 22.6 MJ/kg. Subsequently, the product underwent gasification at various temperatures ranging from 600 to 800 °C, with a constant heating rate of 10 °C/min, gas flow rate of 20 ml/min, and a retention time of 30 min. The gasification reaction improved the solid yield and resulted in the generation of liquid products and syngas. The results indicated that 45-59% of biochar, 12-17% of bio-oil, and 30-39% of syngas were produced. The syngas composition, determined using gas chromatography, revealed the presence of CO2, H2, CH4, and CO. The solid product, characterised by a higher heating value, is a viable alternative for solid fuel. The findings suggested that both wet torrefaction and the gasification process have the potential to address the abundance of palm mill waste issues and offer an alternative approach for utilising and generating energy within the mill.

TINGKAT PENCEMARAN LOGAM Cd, Fe, Cr DAN Cu AIR SUMUR GALI DI Eks-TPA TALANG GULO KOTA JAMBI

Former solid waste disposal at Talang Gulo TPA Jambi City implements a waste management system using a controlled landfill. Leachate and rainwater absorb into the soil and accumulate to become polluted groundwater. Furthermore, the polluted water flows into the dug well water and can reduce the quality of the dug well water. The aim of this study is to determine the heavy metal pollution index of residents' dug well water and the influence of the distance between the ex-TPA and dug well water. This research method is purposive sampling based on the distance of heavy metal sample points, namely 70 m, 230 m and 300 m. Sample analysis used an Atomic Absorption Spectrophometer (AAS) in the laboratory. The results were classed and indexed (C/P), the groundwater was very lightly contaminated with Cd (<0.1), heavily contaminated with Fe (0.51-0.75), very lightly contaminated with Cr (<0.1), and moderately contaminated with Cu (0.26-0.50). Based on the R value of the four metals, it shows that there was a very high influence between the distance between the well water sample and the former solid waste disposal leachate product.

Solid household waste production in the city of Niamey (Niger)

Solid household waste production in the city of Niamey (Niger)

Glossary of terms used in biochar research (IUPAC Technical Report)

Abstract Biochar is the solid carbonaceous product of biomass pyrolysis. The properties of biochar depend on the biomass feedstock as well as the pyrolysis temperature and time. Therefore, biochars with different properties and functionalities can be produced. Biochar research has been intensive in the past 15 years, focusing mainly on soil applications, wastewater treatment, and contaminant remediation. However, a formal definition of biochar and related terms is missing, which hinders the standardization of scientific results worldwide and the scaling-up of research at the industrial level. Furthermore, an official terminology may promote the development of a harmonized legal framework for biochar production and applications, both at regional and national levels. This glossary of terms consists of 178 scientifically sound definitions of the most commonly used terms in biochar research. The definitions of this glossary are interconnected, allowing the reader to further explore the synergies between terms. The distribution of terms reflects the multidisciplinarity of biochar research: chemistry, material science and engineering, and soil science are the main disciplines represented here. The list of terms is by no means exhaustive and the strategic objective of this effort is to develop a dynamic document in which more terms will be added in the future, and the existing ones will be refined, as biochar research evolves.

Liquid-phase pulse discharge cracking of n-hexadecane: An efficient method for generating light and valuable fuels

The conversion of low-grade heavy oil into value-added chemicals has garnered significant attention. Plasma is a potentially cleaner, environmentally friendly, and faster method of cracking heavy oil. In this work, ethanol-assisted cracking of hexadecane, a model compound of heavy oil, to produce valuable light fuels such as syngas, C2 hydrocarbons, and gasoline was investigated under ambient conditions using liquid-phase pulsed-discharge plasma. The gas, liquid, and solid products formed by cracking were analyzed in detail. Single discharge energy and discharge time were the key influences on the cracking reaction. The increase in single discharge energy improved gas and light hydrocarbon yields and inhibited the production of heavy materials, with the maximum gas generation flow rate of 96.1 mL/min. Prolonging the discharge time did not significantly affect the light product selectivity (>97 %). The energy consumption of the reaction was also evaluated and showed a low level of energy consumption. At a single discharge energy of 2.28 mJ and a discharge of 15 min, it obtained 129.9 mg of light hydrocarbons, 13.6 % n-hexadecane conversion, 9.2 kWh/kg energy consumption for n-hexadecane conversion, and 4.0 kWh/m3 energy consumption for gas generation, and the mass balance of the product was determined.

Experimental Study and Process Simulation on Pyrolysis Characteristics of Decommissioned Wind Turbine Blades

The development of wind power has brought about increasing challenges in decommissioning, among which DWTBs (decommissioned wind turbine blades) are the most difficult component to deal with. To enable the cost-effective, energy-efficient, and environmentally friendly large-scale utilization of DWTBs, an experimental study on thermogravimetric and pyrolysis characteristics of DWTBs was carried out. A new process involving recycling glass fiber with pyrolysis gas re-combustion and flue gas recirculation as the pyrolysis medium was innovatively proposed, and the simulation calculation was carried out. Thermogravimetric experiments indicated that glass fiber reinforced composite (GFRC) was the main heat-generating part in the heat utilization process of blades, and the blade material could basically complete pyrolysis at 600 °C. As the heating rate increased, the formation temperature, peak concentration, and proportion of combustible gas in the pyrolysis gas also increased. The highest peak concentration of CO gas was observed, with CO2 and C3H6 reaching their peaks at 700 °C. The solid product obtained from pyrolysis at 600 °C could be oxidized at 550 °C for 40 min to obtain clean glass fiber. And the pyrolysis temperature increased with the increase in the proportion of recirculation flue gas. When the proportion of recirculation flue gas was 66%, the pyrolysis temperature could reach 600 °C, meeting the necessary pyrolysis temperature for wind turbine blade materials. The above research provided fundamental data support for further exploration on high-value-added recycling of DWTBs.

Synergistic Catalytic Effects on Nitrogen Transformation during Biomass Pyrolysis: A Focus on Proline as a Model Compound.

To investigate the control mechanisms of NOx precursors and the synergistic effects of composite catalysts during proline pyrolysis, a systematic series of experiments was conducted utilizing composite catalysts with varying Fe-Ca ratios. Product distribution analysis was employed to elucidate the catalysts' mechanisms in reducing NOx precursor emissions. The synergistic interactions between Fe and Ca were quantitatively assessed through comparative theoretical and experimental release calculations. The results indicate that an increase in the Fe content in the catalyst led to a rise in amine concentrations from 0.9% to 2.95%, implying that Fe facilitates the generation of amine-N through ring-opening and substitution reactions. When the Fe to Ca ratio was balanced at 1:1, nitrogen predominantly participated in the formation of purines via cyclization and substitution reactions. Additionally, all composite catalysts exhibited a suppressive effect on the release of NOx precursors, attributed to their significant enhancement of solid product retention. Fe-Ca composite catalyst synergistically inhibits the release of gaseous nitrogen. Notably, the strongest synergistic effect was observed with a 1:3 Fe to Ca ratio, which reduced the release of NH3 by 38.7% and HCN by 53.6% during proline pyrolysis. This study offers valuable insights into the control of NOx precursors and the optimization of nitrogen-rich biomass pyrolysis processes.

Exploring the biorefinery potential of sweet potato crop residues through torrefaction and pyrolysis: Processing of leaves, stems, and peel

The utilization of neglected agro-industrial waste is essential for mitigating environmental impacts. This study aims to characterize the products of using sweet potato peels, leaves and stems via pyrolysis and torrefaction techniques. Additionally, the study examined the impact of the torrefaction pre-treatment on pyrolysis products. Solid, liquid, and gaseous products were characterized. Results indicated that torrefaction pre-treatment increased biochar yield but diminished bio-oil and gas yields. Thermal treatments had minimal impact on the specific surface area of formed solids and biochars. Bio-oils showed a proclivity towards basicity with increasing temperature. Phenols predominated in the organic fraction of bio-oils, with torrefaction pre-treatment resulting in reduced alcohol and increased hydrocarbon concentration. Gas composition revealed elevated CO2 levels during torrefaction, while torrefaction pre-treatment amplified CH4 concentration. These findings suggest potential for extracting chemical inputs like phenolic resins and biocides from sweet potato waste bio-oils, though further treatments are required for effective solid adsorption.

Green low-cost synthesis of zero-valent iron nanoparticles from Palm Petiole Extract for Cr(VI) removal from water.

One of the hottest research topics over the last decades was the valorization or/and recycling of agro-industrial wastes into different valuable liquid or solid products, which is considered a sustainable and low-cost approach. In this study, we developed zero-valent iron nanoparticles from Palm Petiole Extract (P-NZVI) using a green and straightforward approach. The as-synthesized P-NZVI was used to adsorb Cr(VI) in water. The physico-chemical characterizations of P-NZVI, including the particle size, crystalline structure, surface area, morphology, and functional groups, were investigated via several techniques such as UV-vis spectroscopy, SEM, TEM, XRD, FTIR, AFM, DLS, pHZPC measurement, and BET analysis. The adsorption performance of P-NZVI was studied under different operational parameters, including pollutant concentration, pH, temperature, and adsorbent mass. The adsorption rate was found to be 89.3% within 40 min, corresponding to the adsorption capacity of 44.47 mg/g under the following conditions: initial Cr(VI) concentration of 40 mg/L, pH 5, and a P-NZVI dosage of 1 g/L. It was found that the adsorption pattern follows the Langmuir and the pseudo-second-order kinetic models, indicating a combination of monolayer adsorption and chemisorption mechanisms. The thermodynamic study shows that the adsorption process is endothermic and spontaneous. The reusability of P-NZVI was carried out four times, showing a slight decrease from 89.3 to 87%. These findings highlight that P-NZVI's could be an effective green adsorbent for removing Cr(VI) or other types of toxic pollutants from water.

Continuous hydrothermal processing of poly(ethylene terephthalate) (PET) under subcritical water conditions: A proof-of-principle closed-loop study

Plastics have undeniably played a crucial role in the technological and societal advancements over the past decades. However, the current linear consumption model and the reliance of the plastic industry on fossil carbon pose pressing environmental and economic challenges that cannot be ignored. In this context, poly(ethylene terephthalate) (PET) has emerged as one of the most studied plastics in the field of chemical recycling, given its extensive use in packaging and textiles, and its susceptibility to undergo solvolysis into its constituent monomers, which facilitates closed-loop recycling of PET waste. This study presents the validation of a first-of-its-kind continuous flow system that utilizes subcritical water for neutral hydrothermal processing of PET at three different reaction temperatures 250, 280 and 310 °C. Regardless of the processing conditions, PET underwent full conversion into monomers and low molecular weight esters like mono(2-hydroxyethyl) terephthalate (MHET) and bis(2-hydroxyethyl) terephthalate (BHET), with an approximate carbon distribution of 20 % and 80 % between aqueous and solid products, respectively. The product composition is strongly related to the processing conditions, with 77.5 % ethylene glycol and 94.2 % terephthalic acid recovered as monomers at 310 °C. Furthermore, solid products were repolymerized to assess the potential of reusing the heterogeneous precursor mixture as starting material for PET production. Results reveal that the solid products obtained at 250 °C yielded polymer chains with decomposition temperature, melting temperature, crystallinity, and average molecular weight (50.4 kDa) closest to commercial PET. These results underscore the potential of neutral hydrothermal processing in a future circular PET value chain.

Structure and magnetism of DyIII2 based triple-stranded helicates derived from dinucleating Schiff base ligands

We report herein the synthesis of three dinuclear DyIII helicates, [DyIII2(H2LR)3](NO3)3·xH2O (1–3, R = Me, Cl, Br), by reacting Dy(NO3)3·5H2O and three closely related Schiff bases derived from 3-Hydroxy-2-naphthohydrazide and three different 2,6-diformylphenols. Single crystal X-ray structural characterization revealed that all these complexes are isostructural and composed of complex cations of general formula [DyIII2(H2LR)3]3+, in which three monoanionic Schiff base ligands are wrapped around two DyIII centers, leading to triple-stranded helical structures. Notably, the configuration of monoanionic H2LR ligands imparts a coordination-induced chirality on individual complex cation, and the presence of equivalent amounts of enantiopure Λ and Δ complex cations made the solid products as racemic mixtures, crystalizing in the centrosymmetrical space groups. Variable-temperature magnetic susceptibility measurements have been performed in the temperature range 2 − 300 K for a representative complex 2, and AC susceptibility studies further disclose the slow relaxation of magnetization in 2, characteristics for single-molecule magnets.

A comprehensive kinetic study on low-GHG hydrogen production from microwave-driven methane pyrolysis

The present study focuses on the cogeneration of hydrogen (H2) and solid carbon from microwave-driven methane pyrolysis in a fluidized bed of carbon pellets. Numerical simulations using a coupled gas-solid chemistry approach reveal that introducing microwave thermal effects improves methane conversion rate, H2 selectivity, and carbon deposition rate. The chemical pathways analysis divulges that once the leading reaction for decomposing CH4 into H2, i.e., CH4+H ↔ CH3+H2, is completed, the C2H2 deposition mechanism onto the carbon pellets is the dominant pathway for the solid carbon production, indicating almost no carbon black (i.e., nanoparticles) formation. Carbon pellets provide abundant surface area for the conversion of C2H2 to H2, enhancing H2 selectivity in the resulting products. More importantly, the importance of more complex molecules, such as polycyclic aromatic hydrocarbons, greatly diminishes when using carbon pellets in the pyrolysis process, implying that smaller kinetic mechanisms are equally effective and desirable.

Segmentation and Classification of Fission as Pores in Reactor Iirradiated Annular U[sbnd]10Zr Metallic Fuel Using Machine Learning Models

Metallic fuels, particularly U10Zr, are promising candidates for next-generation sodium-cooled fast reactors. Irradiation of nuclear fuels in reactors can lead to the formation of solid and gas fission product which subsequently forms microstructural pores, deteriorating fuel performance. Due to the massive amount of pores and complex phases formed, a quantitative description of fission gas pores is not yet available, preventing the development of microstructure-informed fuel performance modeling for fuel qualification. This paper applied a pre-trained deep learning model to ∼10,260 high magnification scanning electron microscopy images. This method increased the accuracy of fission gas pore segmentation and allows statistical features to be extracted which cannot be achieved manually. A pre-trained decision tree model worked on the segemenation resutls and further classified the pores into different categories to produce a correlation between the pores, movement of lanthanides, and temperature gradient during irradiation. This paper emphasizes the potentials of machine learning models to accelerate fuel research, development, and qualification for advanced reactors.

Research on Carbon Dioxide-Assisted Electrocoagulation Technology for Treatment of Divalent Cations in Water

In the external drainage water of Xinjiang Karamay Petrochemical Company, the calcium and magnesium ion contents are as high as 630 mg/L and 1170 mg/L, respectively. These ions are subsequently scaled at large quantities in water treatment equipment, which greatly reduces the efficiency of the process. This study used a coupled chemical precipitation (CP) and electrocoagulation (EC) method to deal with external drainage water. The results show that the removal rates of calcium and magnesium were 94.71% and 96.33%, respectively, when the pH was adjusted with sodium silicate and EC was introduced after saturating the water samples with CO2. In this study, a quadratic polynomial equation was developed for predicting the removal of calcium and magnesium ions using this coupled technique under three factors of current density (CD) (15, 20 and 25 mA/cm2), reaction time (RT) (30, 40 and 50 min) and pH (10.0, 10.5 and 11.0). It was found that these three variables have a significant effect on the removal of both the abovementioned ions. The response surface method based on a Box–Behnken design showed that the average removal rates of calcium and magnesium ions could be 96.57% and 98.66% at a CD of 22 mA/cm2, RT of 46 min and pH of 11. This study confirmed the presence of calcium carbonate in the solid product through XRD and SEM analysis. The results indicate that this study is promising, and the developed technique can also be used to remove the high concentrations of calcium and magnesium ions from different wastewaters.

Unlocking Sustainability: A Comprehensive Review of Up-Recycling Biomass Waste into Biochar for Environmental Solutions

From the perspective of converting waste into valuable products and reducing environmental pollution, the up-recycling of biomass waste into carbon-rich materials is attracting widespread attention. This literature review presents the possibilities of using the solid product of one-stage carbonization (char) of plant-origin waste biomass. Several applications are discussed, including the production of sorbents, energy storage materials, catalyst carriers, and agricultural applications.

Large-area, low-cost, highly durable solar evaporators for sustainable solarizing seawater

Conventional solarizing seawater technology faces significant challenges including a large footprint, time-consuming processes, and inefficient energy utilization. Solar-driven interfacial water evaporation (SIWE) technology, offers a promising approach for sustainable solarizing seawater, facilitating the production of solid salt with reduced time and land requirements. Nevertheless, the urgent challenge lies in the development of low-cost, large-area solar evaporators that are highly salt-resistant and adaptable, enabling efficient and sustainable solar desalination for solid salt production. As such, a large-area, affordable, and highly durable melamine foam/reduced graphene oxide/sodium alginate (MGS) solar evaporator is proposed for continuous solarizing seawater using a simple method of “immersion-crosslinking-reduction”. Among them, hydrophilic melamine foam serves as the supportive framework, immersed with graphene as light absorption material, and hydrophilic sodium alginate polymeric network for fixing graphene sheets and regulating water evaporation enthalpy. As such, MGS solar evaporator can be prepared in a large-area of 0.5 m × 0.5 m at the cost prices as low as $2.91 m−2. The optimized MGS solar evaporator achieves a high water evaporation rate of 2.30 kg m−2h−1 with the photothermal conversion efficiency of 89.2 % under one sun irradiation. In outdoor environments, MGS allows for timely convective/diffusive salt discharge through its macropores, thus allowing for prolonged seawater solarization without obvious solid salt accumulation. Notably, the original seawater can be highly concentrated until all the water evaporates and solid salt precipitates. This developed MGS solar evaporator offers a novel perspective on efficient seawater solarization, conserving both time and land.

Study on Effects of Hydrothermal Heat Treatment Method on Fertilizer Efficiency of Biomass Waste

This study explores a new way of utilizing biomass waste as fertilizer based on the hydrothermal heat treatment method. Hydrothermal heat treatment was carried out on common biomass waste, including corn stalks, livestock manure, and vegetable waste. by heating them to 120°C and then to 240°C respectively, while measuring the contents of organic matter, total nutrients, and humus in hydrothermal solid products. The experimental results are as follows. With the increase in temperature, the pH of three kinds of biomass waste hydrothermal products is reduced to different degrees. The content of organic matter in the solid products of corn stalk increased with the increase of temperature, the content of organic matter in the hydrothermal products of vegetable waste was opposite to that of corn stalk, and the content of organic matter in the hydrothermal solid products of pig manure was higher than 30% at different temperatures. The total nutrient content of the hydrothermal product of corn stalk decreased first and then increased with the increase of temperature, and reached the minimum value of 10.12 g/L at 180°C. The total nutrient content of the solid product of vegetable waste showed a negative correlation with temperature, and the total nutrient content of the raw material of pig manure was 60.55 g/kg. The total nutrient content of solid products after different hydrothermal temperature treatments was 41.8–59.03 g/kg, which was lower than that of raw materials. With the increase of temperature, the humic acid content of the solid product of corn stalk first increased and then decreased, the humic acid content of hydrothermal product of pig manure continued to increase with the increase of temperature, and the humic acid content of hydrothermal product of vegetable continued to increase with the increase of temperature. At 210°C, the contents of humic acid and fulvic acid reached the maximum, and the humification rate reached the maximum of 0.856.

Consumer reactions to packaging-free product dispensers: a variety of buyers' profiles to consider

PurposeThis study investigates consumer reactions to dispensers offering solid packaging-free products (e.g. pasta, lentils, cereals) integrated in a delimitated area in a grocery store. More specifically, the research examines the impacts of the overall appeal of packaging-free solid food product dispensers and their perceived ease of use on consumers' intention to use these dispensers and purchase packaging-free products. Moreover, using a set of variables, different buyer profiles are highlighted.Design/methodology/approachThe field study for this research was conducted in a delimitated area (i.e. a shop within a shop) dedicated to solid packaging-free products (e.g. pasta, lentils, cereals) in a university cooperative store in the province of Quebec, Canada. A total of 456 buyers and consumers of packaging-free products from this store took part in the field study and completed our survey.FindingsThis study shows packaging-free dispensers' overall appeal and perceived ease of use to be determinants of consumers' intention to use these dispensers and purchase packaging-free products. The Rebus (response-based procedure for detecting unit segments) method highlights the need to consider three buyer profiles (enthusiastic, pragmatic, and sceptical) with different reactions to the specific dispensers used by retailers for packaging-free products.Originality/valueThis study focuses on buyers' reactions to packaging-free dispensers in stores, during the purchase process, whereas previous ones highlighted the drivers of and barriers to consumer adoption of packaging-free products (before the purchasing process starts). It also points to the need to fine-tune the segmentation of consumers of packaging-free products, which must be based not only on consumers' previous experience or familiarity with these products but also on the integration of their drivers and barriers.