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Research Article
Luminescence Properties of Single-Component Broadband White Light Phosphors Based on Eu2+-Doped Ba7F12Cl2 Host
Issue:
Volume 14, Issue 5, October 2026
Pages:
156-162
Received:
12 July 2026
Accepted:
24 August 2026
Published:
4 September 2026
Abstract: With the continuous advancement of lighting technology, people’s pursuit of lighting quality has gradually shifted from simple power and brightness indicators to high-quality, healthy lighting and solar-like illumination. White light phosphors co-doped with multiple ions suffer from drawbacks including complicated ratio regulation, energy transfer loss, and thermally induced color drift, while single-component luminescent materials activated by a single rare-earth ion can effectively avoid the above deficiencies. In this work, a series of Ba7-xF12Cl2: xEu2+ fluorochloride phosphors were successfully synthesized via a high-temperature solid-state reaction method. Their crystal structures, fluorescence spectra, thermal stability, and CIE chromaticity coordinates were systematically characterized. X-ray diffraction (XRD) results confirm that all as-prepared samples are pure phases, and Eu2+ doping does not destroy the crystal structure of the host matrix. Under excitation by near-ultraviolet light, the samples exhibit broad-band white light emission centered at 430 nm with a full width at half maximum (FWHM) of approximately 90 nm, which originates from the characteristic 4f65d1 → 4f7 transition of Eu2+. Thermal stability measurements reveal that the luminescence intensity of the samples remains above 95% of the room-temperature value at 85°C. The obtained results demonstrate that Ba7F12Cl2: Eu2+ phosphors are promising single-component white light-emitting materials excited by near-ultraviolet light.
Abstract: With the continuous advancement of lighting technology, people’s pursuit of lighting quality has gradually shifted from simple power and brightness indicators to high-quality, healthy lighting and solar-like illumination. White light phosphors co-doped with multiple ions suffer from drawbacks including complicated ratio regulation, energy transfer ...
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Research Article
Unsupported Hydrogenation Catalysts in Liquid-phase Oil Hydroprocessing Research
Yuandong Hou*,
Rongguan Li,
Zihao Li,
Shaohui Ge
Issue:
Volume 14, Issue 5, October 2026
Pages:
163-168
Received:
13 July 2026
Accepted:
27 August 2026
Published:
4 September 2026
Abstract: To meet stringent commercial fuel specifications, direct coal liquefied oil (DCL oil) must undergo comprehensive hydrotreating prior to utilization. However, conventional hydrotreating technologies and catalysts adapted from petroleum refining are often inadequate due to the distinct compositional and structural characteristics of DCL oil—namely, high concentrations of heteroatoms (S, N, O), elevated aromaticity, abundant polycyclic aromatic hydrocarbons (PAHs), and significant levels of unstable olefins and phenolic compounds. Compared to tradition impregnation process, unsupported catalyst is prepared by forming process. For realizing the consistency of active phase before and after forming, active phase should maintains chemical inertness and dispersibility at forming condition. Herein, these active phase property is named as modularized property. The advantage of modularized property is studied by the comparation between unsupported and supported catalyst, which prepared by catalyst forming process and impregnation process, respectively. In catalysts sulfide slab investigation, forming process enhances the distribution ratio of more than two stack layers, which benefit to catalytic activity. Its ratio is 1.5 times of the catalyst prepared by impregnation process. In catalytic activity evaluation, catalyst prepared by forming process maintains a higher catalytic activity.
Abstract: To meet stringent commercial fuel specifications, direct coal liquefied oil (DCL oil) must undergo comprehensive hydrotreating prior to utilization. However, conventional hydrotreating technologies and catalysts adapted from petroleum refining are often inadequate due to the distinct compositional and structural characteristics of DCL oil—namely, h...
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Research Article
Remediation of Hydrocarbon Impacted Soil Using Clogen
Issue:
Volume 14, Issue 5, October 2026
Pages:
169-177
Received:
15 September 2026
Accepted:
4 October 2026
Published:
23 October 2026
Abstract: Hydrocarbon pollution of soil remains one of the most critical environmental challenges in oil-producing regions such as the Niger Delta, where crude oil exploration, transportation, and refining activities frequently result in environmental contamination. This study investigated the remediation of hydrocarbon-impacted soil using CLOGEN, a locally developed electro-ionic biopolymer formulated by Andelsta Ltd. and approved by the Federal Government of Nigeria under Patent No. R.16273. Laboratory and field investigations were conducted to evaluate the efficiency of CLOGEN in reducing Total Petroleum Hydrocarbons (TPH) in contaminated soils. Site characterization revealed that the soil lithology consisted of sand, sandy clay, silty clay, coarse sand, and fine sand, with the site predominantly classified as a clay-based soil. The fine-grained clay structure exhibited low effective porosity and a high affinity for petroleum hydrocarbons due to strong adsorption characteristics. The nitrate concentration in the soil ranged from 10.06 mg/kg to 27.42 mg/kg, while ammonium concentration reached a maximum value of 11.018 mg/kg, indicating low nitrogen availability and the need for nutrient supplementation during remediation to maintain an optimum carbon: nitrogen: phosphorus (C:N:P) ratio for microbial activity. Initial TPH concentrations ranged from 454 mg/kg to 8,528 mg/kg, exceeding the permissible limit of 1,000 mg/kg established by the Hydrocarbon Pollution Remediation Project (HYPREP) and the National Oil Spill Detection and Response Agency (NOSDRA). Soil samples were analyzed before and after treatment to determine changes in physicochemical properties and microbiological activity. The results revealed a substantial reduction in TPH concentrations, with remediation efficiency reaching up to 96%, thereby reducing contamination levels to within regulatory standards. Furthermore, the remediation process enhanced microbial population density and improved soil nutrient balance, indicating the capability of CLOGEN to restore ecological functionality in hydrocarbon-impacted soils. Overall, the findings demonstrate that CLOGEN is an effective and environmentally sustainable remediation agent for petroleum-polluted environments in the Niger Delta.
Abstract: Hydrocarbon pollution of soil remains one of the most critical environmental challenges in oil-producing regions such as the Niger Delta, where crude oil exploration, transportation, and refining activities frequently result in environmental contamination. This study investigated the remediation of hydrocarbon-impacted soil using CLOGEN, a locally ...
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Research Article
Simulation of Waste to Energy Plant Using Flue Gas from Fluid Catalytic Cracking Regenerator
Issue:
Volume 14, Issue 5, October 2026
Pages:
178-194
Received:
4 October 2026
Accepted:
16 October 2026
Published:
31 October 2026
DOI:
10.11648/j.ajche.20261405.14
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Abstract: This study presents the simulation, performance analysis, economic evaluation, and validation of a waste-to-energy plant integrated with a fluid catalytic cracking (FCC) regenerator using Aspen HYSYS. The system comprises a gas expander, a heat recovery steam generator (economizer, evaporator, and superheater), a steam turbine–generator, and a condenser for recovering thermal energy from FCC regenerator flue gas. Material and energy balances were performed to establish thermodynamic consistency across the process units. The flue gas entered the system at 700°C and 250 kPa, with a mass flow rate of 3 x 105 kg/h and a heat flow of approximately -5.45 x 108 kJ/h. The gas expander reduced the gas temperature to 585.3°C and pressure to 120 kPa, generating approximately 11.50 MW of mechanical power at a polytropic efficiency of 85%. Heat recovery through the economizer, evaporator, and superheater produced superheated steam at 442.4°C and 4000 kPa, while the flue gas exited the stack at 251°C. The steam turbine expanded the steam to 10 kPa and 46.01°C, generating approximately 9.35 MW at a polytropic efficiency of 86%. Sensitivity analysis revealed that expander power output increased from 5.96 to 34.79 MW with increasing flue gas temperature, while increasing mass flow rate from 1 x 105 to 1 x 106 kg/h raised power output from 3.83 to 38.34 MW. Steam turbine–generator power output also increased with flue gas temperature and mass flow rate. Economic analysis estimated a total capital cost of USD 2.82 million, annual operating costs of USD 1.51 million, and annual utility costs of USD 180,182. Validation against plant data showed deviations generally below 6% for key performance parameters. The findings demonstrate the potential of FCC regenerator flue gas recovery to improve refinery energy efficiency, generate electricity, and reduce waste heat losses.
Abstract: This study presents the simulation, performance analysis, economic evaluation, and validation of a waste-to-energy plant integrated with a fluid catalytic cracking (FCC) regenerator using Aspen HYSYS. The system comprises a gas expander, a heat recovery steam generator (economizer, evaporator, and superheater), a steam turbine–generator, and a cond...
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Qingfeng Tu
