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Olive mill solid waste (OMSW) is a significant agricultural byproduct from olive cultivation and related productions. Recognized as a valuable energy resource in countries such as Jordan, Syria, and Tunisia, this study focuses on the comprehensive characterization of Jordanian OMSW (J-OMSW) and RTC coal. Utilizing analytical tools such as thermogravimetric analysis (TGA), bomb calorimetry, FLASH organic elemental analyzer, x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), the research also includes a comparative analysis with river trading company (RTC) coal to assess the co-gasification feasibility of the two feedstocks. Equilibrium-based analysis explores optimal co-gasification conditions for RTC coal and J-OMSW, assessing reaction, energy, and elemental balances. J-OMSW is characterized by higher volatiles (73.26%) and lower fixed carbon (20.59%) than RTC coal, which has 39.09% volatiles and 54.31% fixed carbon, enhancing co-gasification compatibility. Ultimate analysis indicates J-OMSW has significant carbon (47.53%) and oxygen (40.14%), contrasting with RTC coal’s higher carbon (76.39%) and lower oxygen (8.15%), supporting synergistic co-gasification processes. RTC coal’s higher heating value (HHV) at 30.44 ± 0.2 MJ/kg complements J-OMSW’s HHV (23.75 ± 0.2 MJ/kg), enhancing the blend’s energy potential. Both materials share similar functional groups of C-H, C = O, C-O-C, and C-OH, minimal mineral matter, and predominantly amorphous structures, underscoring their co-gasification suitability. J-OMSW displays a more porous microstructure compared to RTC coal, further enhancing gasification potential. The equilibrium model identifies optimal gasifier temperatures of 1,150 °C, 1,200 °C, 1,200 °C, 1,200 °C, and 1,250 °C for 100%, 90%, 75%, 50%, and 25% RTC coal blends, respectively, achieving peak CGEs ranging from 66.90 to 82.83%. Higher pressures (above 30 bars) and temperatures negatively affect CGE, particularly in blends. The model favors a 50% blend for its efficiency and environmental benefits, demonstrating technical viability. The lowest actual oxidizer moles result in CGE deviations between 0.01% and 1.27%, suggesting an optimal equivalence ratio (ER) of 0.5–0.65. Comprehensive characterization of J-OMSW and RTC coal, alongside equilibrium analysis, confirms the feasibility of co-gasification, providing insights into efficient energy recovery from J-OMSW.

Commercial activated carbon (AC) was selected and impregnated with sodium hydroxide. The carbons were characterized for their surface area, morphology, and functional groups. BET surface area analysis illustrates an average surface area of ca. 1000 m2/g with an average pore radius of 1.5 nm. SEM analysis provided agglomerated particles with sizes of sub-micrometer. The surface acidity of the impregnated AC showed an increase in pHzpc on the raw AC. Both carbons illustrated several functional groups with an increase in the hydroxyl group with impregnation. Adsorption capacities for both carbons against CO2, N2O, and 10% CO2in an N2O gas mixture were studied by volumetric analysis and using a newly developed apparatus. The corresponding saturation capacities are 101, 60.39, and 90 mg/g, respectively. The gas mixture was chosen to simulate the exhaust CO2gas from mobile sources. Both carbons demonstrated saturation capacities for gas mixtures with values higher than those of pure gases. This AC might be used as a support for catalytic conversion of CO2to hydrocarbons from mobile sources where N2O exists as a major interference.

ABSTRACT Oil fly ash (OFA) is generated in large quantities from power generation plants through combustion of fuel oil. Waste OFA contains more than 80% carbon and can be used [...]

Solids sag and formation damage are serious problems encountered while drilling with barite-weighted drilling fluids. The objective of this study is to investigate the effect of reducing barite particle size on rheological properties, fluid stability, and filter cake removal. Barite samples with different particle sizes were prepared using sieve analysis and ball milling technique. Micronized barite (8 μm) showed a moderate stability with zeta potential measurements for a pH range greater than 8. Solubility tests showed good enhancement in barite removal as the particle size was reduced, with a difference of around 11 g/L between the largest size (75-106 μm) and the micronized size of barite. HPHT filtration test results confirmed the solubility results with 5 wt.% enhancement in filter cake removal efficiency as barite particle size was reduced to micronized size. [Received: December 4, 2017; Accepted: December 17, 2018]

ABSTRACTWaste oil fly ash (OFA) collected from disposal of power generation plants was treated by physicochemical activation technique to improve the surface properties of OFA. This synthesized material was further used for potential hydrogen sulfide (H2S) adsorption from synthetic natural gas. The raw OFA was basically modified with a mixture of acids (20% nitric acid [HNO3] and 80% phosphoric acid [H3PO4]), and it was further treated with 2 M potassium hydroxide (KOH) to enhance the surface affinity as well as surface area of synthesized activated carbon. Correspondingly, it enhanced the adsorption of H2S. Crystallinity, surface morphology, and pore volume distribution of prepared activated carbon were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analyses. Fourier transform infrared (FTIR) study was also performed to identify the functional groups during different synthesis stages of modified activated carbon. The Langmuir, Freundlich, Sips, and dual-site Langmuir (DSL) models were used to study the kinetic and breakthrough behavior of H2S adsorption over alkali-modified activated carbon. Modeling results of isotherms indicated that OFA has dual sites with high and low affinity for H2S adsorption. The Clark model, Thomas model, and Yoon-Nelson model were used to examine the effects of flow rate and inlet concentration on the adsorption of H2S. Maximum uptake capacity of 8.5 mg/g was achieved at 100 ppm inlet concentration and flow rate of 0.2 L/min.Implications: Utilization of worthless oil fly ash from power plant is important not only for cleaning the environment but also for solid waste minimization. This research scope is to eradicate one pollutant by using another pollutant (waste ash) as a raw material. Chemical functionalization of synthesized activated carbon from oil fly ash would lead to attachment of functional groups of basic nature to attract the acidic H2S. Such type of treatment can enhance the uptake capacity of sorbent several times.

Enhanced gas recovery methods such as foamed CO2are recommended for depleted gas reservoirs. Viscoelastic surfactant (VES) is a form of a surfactant used for forming CO2foam. In this study, the impact of VES on CH4and CO2retention and adsorption in calcite rock samples was studied. Crushed samples of Indiana limestone rocks of average particle size (125–250 μm) were used in the static adsorption experiments. To study the effect of VES on CH4and CO2adsorption, 50% of the crushed samples were conditioned in a solution of NaCl of 0.1 vol % surfactant. X-ray diffraction shows that the rock samples are 99.99% calcite and traces of quartz. The gas adsorption experiments were performed at different temperatures; namely; 50, 100, and 150 °C and at a pressure of 45 bar. At 50 °C, the plain calcite samples adsorbed more CH4and CO2compared to that treated with VES. However, at 100 and 150 °C, the plain sample adsorbed much less CH4and CO2than the treated sample. This means that at higher temperatures (100 and 150 °C) VES enhanced the adsorption of both CO2and CH4on the rock surface. Thermodynamic investigations showed that the process of gas adsorption in the plain samples was exothermic with ΔHadsof −13.5 and −16.7 kJ/mol for CO2and CH4, respectively, and at 50 °C the adsorption was spontaneous with ΔGadsof −0.425 for CH4and −2.599 for CO2. In contrast, at higher temperatures (100 and 150 °C), the adsorption of CO2and CH4on surfactant treated sample was spontaneous and endothermic with corresponding ΔHadsof 36.2 and 60.1 kJ/mol and ΔGadsof −4.701 and −0.581 for CO2and CH4, respectively. The adsorption of CO2was three times that of CH4because of the high affinity of calcite to CO2. Because of the multilayer adsorption on both samples, Freundlich isotherm was found to be the best model that fits the experimental data of calcite with both CO2and CH4at different temperatures. Dynamic adsorption experiments were carried out using gas coreflooding system with the same calcite cores used in the static adsorption experiments. The results of this study showed that carbonate rock samples conditioned in the surfactant solution have great adsorption potential for CO2and are excellent candidates for CO2sequestration. However, surfactant promoted high CH4adsorption at 100 and 150 °C, and this will reduce the natural gas recovery. In contrast, using viscoelastic surfactant at low-temperature reservoirs (50 °C) reduced CH4adsorption by blocking the active adsorption sites in the carbonate rock samples, and this will increase the gas recovery.

The objective of this research was to enhance adsorption capacity of Acacia nilotica(keekar) sawdust for the abatement of chromium bearing wastewater and to investigate the effect of process parameters on adsorption capacity. The sawdust was activated by acid wash and functionalized subsequently with formaldehyde. Functionalization of activated sawdust raised its chromium removal efficiency of almost 10% as compared to its adsorption removal efficiency of HCl treated sawdust in a batch adsorption study. Adsorption kinetic data provided better fitting with pseudo second order model. Maximum adsorption capacity calculated through the best fitting Langmuir model was 6.34mg·g−1and 8.2mg·g−1for HCl treated and formaldehyde functionalized sawdust adsorbents, respectively. The adsorption of Cr(VI) was endothermic when studied by varying temperature from 20°C to 50°C for both activated and functionalized adsorbents.

A Ca/Na-aluminosilicate was synthesized from kaolin and limestone via the hydrothermal reaction and was used for CO2capture from a gas stream. Synthesis was performed at several combinations of temperature, pressure, kaolinite to limestone mass ratio, and the reaction time. The products were characterized by determining the crystalinity, surface morphology, surface area, and the pore size distribution. When the reaction temperature and pressure are increased, the sodium hydroxide concentration has a significant effect on the formation of novel Ca/Na-aluminosilicate phases. X-ray diffraction shows that a mixture of Gehlenite Ca2Al(Al1.22Si0.78O6.78)OH0.22(43wt %) and Stilbite Na5.76Ca4.96(Al15.68Si56.32O144) (57 wt%) is produced in 36M NaOH at 200°C and 15bar. The adsorption capacity of the above product for CO2from a gas stream increased with temperature, reaching a CO2uptake of 294.7mg/g at an equilibrium pressure of 45bar and a temperature of 150°C. Thermodynamic studies show spontaneous and endothermic adsorption behavior with a ΔHadsof 4.64kJ/mol,ΔSadsof 25.25J/mol.K, and ΔGadsof −6.09kJ/mol obtained at 150°C. The CO2adsorption/cycling process were repeated and it was found that the capacity of the novel adsorbent decreases in the second cycle and remains constant after that. This suggests chemisorption process took place on the fresh adsorbent and physical adsorption occurred at higher cycles.

The solubility of hydrogen sulfide (H2S) is very high in different liquids such as water or liquid sulfur. The existence of H2S results in local corrosion and causes cracking to the steel even if the concentration of H2S is low. The objectives of this paper are to (1) evaluate copper nitrate as an H2S scavenger while drilling sour horizontal and multilateral wells and (2) investigate the effect of copper nitrate on the drilling fluid rheological properties and drill pipe corrosion. The obtained results showed that by adding the copper nitrate (1 lb/bbl) to the drilling mud there was no change in the shear stress–shear rate behavior, and the yield point (YP) plastic viscosity (PV) ratio was increased by 20% indicating good hole cleaning. In addition, the filtrate volume reduced by 26% and the filter cake thickness decreased by 50%. The new formulation of the drilling fluid with the copper nitrate is not corrosive (the corrosion rate was 0.00084 lb/ft2 after 24 h at 212 °F). Breakeven experiments showed that adding copper nitrate to the drilling fluid doubled the adsorption capacity when compared with triazine and tripled the capacity when compared with Scav1 when using I lb of the commercial H2S scavenger per bbl of the drilling fluid.

A new CO2 adsorbent is produced from waste oil fly ash (OFA). Ammonium hydroxide solution is used to convert OFA to activated carbon. Then, the product is used for the adsorption of CO2 from a nitrogen/carbon dioxide (N2/CO2) gas mixture. The OFA samples are characterized by several techniques. Chemical treatment of OFA considerably changed its surface morphology. In particular, its surface area, as determined by BET measurements, increased from 59 to 318 m2/g. The amine-functionalized ash had a monolayer adsorption capacity of 74.51 mg/g and was obtained at relative pressure, 0.05