Catalytic effect of ash on bio-oil thermal conversion

This paper investigated the catalytic effect of inorganic elements in ash on bio-oil thermal conversion process (pyrolysis and gasification). Bio-oil with a natural ash contents of 0.05 wt.% and bio-oil added with 3 wt.% of ash were explored. The influence of ash content of the bio-oil conversion on char, tar and gas yields were investigated over a wide range of temperature from 500°C to 1200°C.A Horizontal Tubular Reactor (HTR) is used for pyrolysis process and an Entrained Flow Reactor (EFR) is used for gasification process.The experimental results showed that ash seems to favor re-polymerization reactions that lead to an increase in char yield and causing a decrease in the yield of gas while an increase was a priori expected.

Synthesis and characterization of vanadium pentoxide on different metal oxides by the sol-gel process for application in the conversion of the SO2 to SO3

Sulfuric acid is the largest volume chemical currently produced in the world. Is manufactured by the contact process, it involves three stages: combustion, conversion and absorption. The SO2 conversion reaction is the key step in the process, it uses catalysis. The objective of this work is to synthesize a series of mixed vanadium oxides X% / MO2 with M (Si, Al and Ti) by sol-gel process followed by calcination at 400 ° C, in order to study their reactivity in the catalytic oxidation of SO2 to SO3. Characterization of those materials was carried out by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) with energy dispersive X-ray (EDX), X-ray diffraction, thermal analysis (TDA/TGA) and N2 adsorption at 77 K. Their acid-base properties are studied by the decomposition reaction of isopropanol (propan-2-ol). In this work, we have studied the reactivity of the catalysts prepared in the conversion of SO2 to SO3 by an iodometric as dosage which consists in assaying the iode with sodium thiosulfate

Removal of cationic dye by high surface activated carbon prepared from biomass (date pits) by carbonization and activation processes

In this work,we investigated the capacity of activated carbon (AC) to adsorb Methylene Blue (MB) from aqueous solution. AC-H3PO4 and AC-ZnCl2was obtained from date pits via a one-step chemical method using H3PO4 and ZnCl2 as activating agents. The performance of AC was characterized by different analyses techniques: proximate analysis, SEM, XRD and FT- IR and TGA. The experiments results showed that the MB removal increased by increasing each of AC-H3PO4 and AC-ZnCl2 concentration, contact time and temperature. The efficiency of the adsorption tests are evaluated by the Langmuir and Freundlich isotherm models. Equilibrium data fitted well by Freundlich modelwith a maximum of the adsorption capacity of 95 mg/g at 333 K for AC-ZnCl2, However, the adsorption was well adapted to the Langmuir isotherm with a maximum of the adsorption capacity of 125 mg/g at 298 K for AC-H3PO4. The kinetics data was explained by the pseudo second-order model, and the intra-particle diffusion with some other rate controlling steps has been suggested as the adsorption mechanism. The pseudo-second-order model described better the adsorption process. The thermodynamic study suggested that MB adsorption on AC-ZnCl2 was endothermic, spontaneous and non-spontaneous for AC-H3PO4.         

Removal of organic matter and polyphenols in the olive oil mill wastewater by coagulation-flocculation using aluminum sulfate and lime.

This work aims to treat the liquid discharges from the olive oil crushing units to protect the receiving environments by the coagulation-flocculation process using lime and aluminum sulfate as chemical coagulants. We proceed by studying the effectiveness of the coagulation-flocculation technique in eliminating organic matter and polyphenols that characterize our samples and the possibility of reusing the treated wastewater in irrigation.Analysis shows that adding 1.7 g/l aluminum sulfate can eliminate 58% of COD, 23% of TSS, and 24% of polyphenols, producing 21g/l of sludge, and eliminating 52% of COD, 48% of TSS, and 72% Of polyphenols requires the addition of 20 g/l of lime, but 25 g/l of sludge is produced. Combining two coagulants (1.7 g/l of aluminum sulfate and 20 g/l of lime) reduces 64 % of COD, 72 % of TSS, and 62 % of polyphenols, with the sludge is 29g/l. The germination test by cucumber seeds showed the validity of the use of treated olive oil wastewater in agricultural irrigation

Influence of acid–base properties of cobalt–molybdenum catalysts supported on magnesium orthophosphates in isomerization of 3,3-dimethylbut-1-ene

AbstractSynthesis and physico-chemical characterization of a pure magnesium phosphate (MgP) prepared by coprecipitation, and MgP modified by introduction of cobalt–molybdenum (4–12wt.% of MoO3 with the Co/Mo ratio fixed at 0.5) have been carried out. The structural properties of these catalysts were characterized by X-ray diffraction, their textural properties were determined by N2 adsorption–desorption isotherms and the dispersion of cobalt–molybdenum was studied by XPS spectroscopy. Their acid properties have been investigated by in situ FT-IR spectroscopy of adsorbed molecules, often, 2,6-dimethylpyridine (pKa=6.7), pyridine (pKa=5.3). Co–Mo incorporation leads to a modification in the MgP acid–base properties, especially on the acid sites type and number. Thus, lower loading of cobalt–molybdenum species decreased the number of strong Lewis acid sites whereas higher loading increased it. It was found that Lewis acid sites on magnesium phosphates play an important role in the isomerization of 3,3-dimethylbut-1-ene.The 3,3-dimethylbut-1-ene (33DMB1) conversion increases with the reaction temperature from 493 to 653K for MgP, but decreases after 573K for MgP supported by Co–Mo. A linear relationship between both types of acid sites and conversion values was found. The deactivation of the catalysts appears at high reaction temperature (>573K)

Groundwater Quality Monitoring in Response to Marine Intrusion: A Case Study in Northern Morocco

Water stress, resulting from a demand for water exceeding the available quantity, is a major global challenge. Groundwater usage is a commonly adopted strategy to address this situation, but it often leads to marine intrusion, threatening the quality of water in coastal aquifers. This phenomenon typically stems from overexploitation of aquifers, declining water table levels, and rising sea levels due to climate change. Our study aims to monitor the quality of groundwater intended for human consumption and provide a detailed assessment of its current state. We identified several physicochemical parameters, such as temperature, pH, and bicarbonates, with maximum electrical conductivity values reaching 2810 µs/cm, a total hardness of 21 meq/L, sulfate levels of 689 mg/L, and chloride levels of 628 mg/L, from six boreholes and one well located along the coastal area of the Al Hoceima region. These samples were also subjected to Principal component analysis (PCA) of the chemical parameters, revealing two factors that represent approximately 62.15% of the total variance in the groundwater quality dataset. Simulation results indicate signs of seawater intrusion in several areas, particularly near the coast, emphasizing the urgency of protecting groundwater resources and developing sustainable management strategies to ensure a safe and reliable supply of drinking water in the region

Assessment of Water Treatment Processes and Quality Parameters at the Al Hoceima Desalination Plant

Water is a vital resource essential for sustaining life and supporting human development. In the face of increasing population growth, urbanization, and environmental challenges, ensuring access to clean and safe drinking water remains a global priority. This study focuses on assessing the efficacy of water treatment processes at the Al Hoceima Desalination Plant in Morocco, examining various parameters to evaluate water quality improvement. Physicochemical parameters such as pH, conductivity, turbidity, total hardness, alkalinity, chloride, sulfate, calcium, magnesium, and dissolved oxygen, as well as bacteriological indicators including Escherichia coli, intestinal enterococci, coliforms, specific growth rates at 22°C and 37°C, and clostridia spores, were analyzed. The study aims to provide insights into the effectiveness of advanced treatment technologies in producing potable water and ensuring a sustainable water supply. Results indicate significant improvements in water quality following treatment processes, highlighting the importance of reverse osmosis in meeting water quality standards and addressing water scarcity challenges