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This research paper focuses on effectiveness of process hazard analysis (PHA) and safety instrumented systems (SIS) interventions during process design and implementation which prevents accident and loss in chemical process industries. An initial preview was conducted to analyze the accidents and incidents in case of industrial and chemical process industries which enabled to define the research question in a scientific way. The research was conducted using a survey questionnaire developed with the help of focus group and was based on theoretical and conceptual framework developed for the study. The survey received responses from 36 participants who met the inclusion and exclusion criteria. The validity and reliability were established using confirmatory factor analysis, convergent validity, and Cronbach’s Alpha. The data analysis methods were used to answer the research questions to test the hypotheses. From the results it is observed that PHA and SIS were in an agreeable range. However, the performance factors grouped based on barrier controls and organizational behavior were have moderate positive relationship. This showed there exists a gap in the PHA and SIS contributing factors which may directly or indirectly cause industrial accidents in the chemical process industries.Article Highlights: Investigates the effectiveness of Process Hazard Analysis (PHA) and Safety Instrumented Systems (SIS) in averting accidents within chemical process industries. Utilizes a robust methodology combining theoretical frameworks and survey-based empirical data from 36 respondents, validated through rigorous statistical analyses. Reveals a generally favorable assessment of PHA and SIS efficacy, yet underscores potential gaps in contributory factors, particularly in barrier controls and organizational behavior, highlighting the need for targeted safety interventions. [ABSTRACT FROM AUTHOR]

Abstract This research paper focuses on effectiveness of process hazard analysis (PHA) and safety instrumented systems (SIS) interventions during process design and implementation which prevents accident and loss in chemical process industries. An initial preview was conducted to analyze the accidents and incidents in case of industrial and chemical process industries which enabled to define the research question in a scientific way. The research was conducted using a survey questionnaire developed with the help of focus group and was based on theoretical and conceptual framework developed for the study. The survey received responses from 36 participants who met the inclusion and exclusion criteria. The validity and reliability were established using confirmatory factor analysis, convergent validity, and Cronbach’s Alpha. The data analysis methods were used to answer the research questions to test the hypotheses. From the results it is observed that PHA and SIS were in an agreeable range. However, the performance factors grouped based on barrier controls and organizational behavior were have moderate positive relationship. This showed there exists a gap in the PHA and SIS contributing factors which may directly or indirectly cause industrial accidents in the chemical process industries.

This study analyzes the consequences of first-order chemical reactions, radiation, and viscous dissipation on the unsteady magnetohydrodynamic natural convective flow of a viscous incompressible fluid over a vertically positioned semi-boundless oscillating plate with uniform mass diffusion and temperature. An implicit finite-difference technique is employed to solve a set of dimensionless, coupled, nonlinear partial differential equations. The numerical results for fluid velocity, concentration, and temperature at the plate under different dimensionless parameters are graphically displayed. Due to first-order homogeneous chemical reactions, it has been discovered that the velocity rises at the time of a generative reaction and drops during a destructive reaction. A decline in velocity is observed with an increase in the phase angle, radiation parameter, and chemical reaction parameter. Further, it has been revealed that plate oscillation, radiation, chemical reactions, and the magnetic field significantly influence the flow behavior.

In this study, temozolomide (TMZ), a drug used in the treatment of anaplastic astrocytoma and glioblastoma multiforme, was incorporated in multiwalled carbon nanotubes (MWCNTs) and hybrid carbon nanotubes with graphene (MWCNTs-G) functionalized by polyethylene glycol (PEG). The aim was to evaluate the potential of these nanocarriers for targeted delivery and sustained release of TMZ in brain tumor cells. Oxidized MWCNTs and MWCNTs-G were noncovalently functionalized with PEGs of different molecular weights and subsequently loaded with TMZ following standard procedures. Thorough physicochemical and biopharmaceutical characterization of the TMZ-loaded carbon nanocarriers pointed to high encapsulation efficacy (up to 67%) and drug loading (up to 18% out of 25% theoretical value) and homogeneous particle size distribution, with z-average (160 to 300 nm) and zeta potential (–31 to –21 mV) of the particles adequate for crossing the blood-brain-tumor-barrier (BBTB) and entering into the tumor cells. Successful functionalization and TMZ loading were confirmed by SEM and TEM images, UV-Vis absorption, infrared and Raman spectroscopy, and TGA analyses. Sustained release of TMZ from the carbon nanocarriers was observed in vitro. The presented findings form a fundamental platform for further investigation of these formulations against different types of glioma cells and in adequate animal models.

The primary aim of this study is to alternate between conventional fossil fuels and reduce the emissions of greenhouse gases and sulfur dioxide from diesel engines. In the current study, to mitigate NOx emissions, the exhaust gas recirculation (EGR) technique was implemented utilizing hybrid alternate biodiesel at three varying proportions of 5%, 10%, and 15% at an optimum compression ratio of 20:1. The findings demonstrate that for hybrid alternative biodiesel at a compression ratio of 20:1 and fully loaded, the brake thermal efficiency (BTHE) is 31.8% with 10% EGR. With 15% EGR, the peak pressure for the hybrid biodiesel is lower than it would be without EGR by around 2.28%. When EGR is increased, the ignition delay and NOx emissions are reduced slightly. With only an increase in EGR rates of up to 10%, brake-specific fuel consumption (BSFC) values were reduced efficiently. The hybrid biodiesel with 10% EGR reduces exhaust gas temperature to 341°C.

To design and operate various equipment of the solids control system in offshore drilling platforms, it is important to establish how the moisture content influences the characteristics of drilled cuttings to form packed beds and flow over solid surfaces. The current study comprehensively analyzes how moisture content, primarily composed of water and representing water-based muds (WBMs), influences the bed packing properties and drilled cuttings' flowability. The particle aggregation/disaggregation dynamics, loose and tapped bulk densities and porosities, compaction dynamics of packed beds, Hausner ratio, and angle of repose of drilled cuttings with ten distinct moisture contents (1.4—44.0 wt%) were analyzed. It was noticed that the increment of moisture content up to 15.2% promoted the formation of looser interparticle structures. However, these structures were steadier, showing greater difficulty flowing and releasing air/liquid. The continuous increment of moisture content beyond 15.2% promoted a complete change in the material behavior. The interparticle structures became denser. The material could flow and release air/liquid more easily. In addition, it was possible to establish a classification of the different behaviors of drilled cuttings according to the moisture content. Predictive models were proposed to describe the influence of the moisture content on the bed packing and flowability properties of drilled cuttings.

A plate heat exchanger is one of the smallest and most efficient heat exchangers on the market. This experiment aims to assess the performance of methanol-water as a base fluid in a plate heat exchanger that affects the heat transfer performance. For this study, aluminum oxide (Al2O3) nanoparticle was used in various ratios (0.25, 0.5, and 0.75 vol. %) in a base fluid (10 vol.% methanol & 90 vol.% water) to prepare a nanofluid. At two different temperatures, such as 55°C and 60°C, with varying flow rates (2 to 8 L/min) and varying nanoparticle concentrations (0.25 to 0.75%), thermo physical characteristics and convective heat transfer studies were performed, and the results are presented. The overall inference was that there was a notable enhancement in the hot side, cold side, and overall heat transfer coefficient by the combination of Al2O3 nanoparticle and methanol-water-based fluid. It was noted that utilizing Al2O3/methanol-water nanofluid could significantly reduce the temperature gradient in the heat exchanger and improve its performance. Maximum hot fluid coefficient of 4300 W/m2°C, cold fluid coefficient of 4600 W/m2°C, and overall coefficient of 2200 W/m2°C were noted for 0.75 vol.% nanoparticle concentration and at a flow rate of 8 L/min.

The primary aim of this study is to alternate between conventional fossil fuels and reduce the emissions of greenhouse gases and smoke from diesel engines. The current study aimed to improve the performance and emission characteristics of a variable compression ratio (VCR) diesel engine operated with hybrid biodiesel. Experiments were done with the best hybrid biodiesel, which was made by mixing 20% rubber seed oil (RSO) with 80% waste plastic oil (WPO). The tests were done at four compression ratios (CRs): 16:1, 17:1, 18:1, and 20:1. Under a CR of 20:1 and at full load, the engine’s brake thermal efficiency went up by 30.5%, its brake-specific fuel consumption went down by 0.347 kg/kWh, and notably diminished emissions of carbon monoxide (0.43% volume), hydrocarbons (79 ppm), and smoke (22%). However, with increasing CRs, NOx emissions rose unfavourably (1092 ppm) compared to diesel (820 ppm). Also, diesel and clean (WPO) were compared to see how the CR values affected combustion, performance, and emissions. Compared to diesel, under maximum load and the CR of 20:1, hybrid biodiesel demonstrated approximately 3.7% higher brake thermal efficiency. The findings suggest potential applications for this hybrid biodiesel in the automobile sector, the power generation industry, and marine applications.

In this research, a laminate was produced by assembling five textile layers. These layers were a coated double-sided knitted structure, a non-woven fabric, a hydrophilic membrane that was thermally assembled to a surface veil, and an open-work knitted fabric. The laminated textile's breathability, windproofness, and waterproofness were evaluated. The multi-layered fabric was windproof, and its water vapor permeability was 347.297 g·m-2·s-1 (CV= 8.902%). Its resistance to water penetration was equal to 117.68 Schmerber (CV = 7.81%). The assembled fabric's mechanical properties were also evaluated. Young’s modulus values were equal to 2 MPa (CV= 8.613%) and 1.6 MPa (CV= 8.349%) for both fabric directions. Its flexural rigidity was 5056.659 mg·cm and its surface total deformation was lower than 450 μm when measured under 20, 40, 60, and 80 mN loads. Based on the results obtained, it was concluded that the developed multi-layered fabric could be used to produce raincoats and jackets to protect the wearer from light rain and drizzle.

This work studied the one-step conversion of ethane (C2H6) to ethylene oxide (EO) in an AC parallel plate dielectric barrier discharge (DBD) system with two frosted glass plates under ambient temperature and atmospheric pressure. EO is directly produced from C2H6 in a single step without the requirement to separate and recycle ethylene. The effects of the applied voltage, input frequency, and O2/C2H6 feed molar ratio on the EO synthesis performance were examined. The results showed that a higher applied voltage and lower input frequency generated more highly energetic electrons, resulting in a higher current. More electrons collided with reactant gas molecules to initiate plasma reactions, increasing C2H6 and O2 conversions. The increased O2/C2H6 feed molar ratio enhanced C2H6 and O2 conversions. The optimum conditions were found to be an applied voltage of 7 kV, input frequency of 550 Hz, and O2/C2H6 feed molar ratio of 1:1, which demonstrated the highest EO selectivity (42.6%), EO yield (19.4%), and lowest power consumption per EO molecule produced (6.7 x 10-18 Ws/molecule).

This research investigates the steady, two-dimensional, incompressible flow of a pseudoplastic Williamson fluid subjected to a linearly stretched sheet. The study incorporates the effects of magnetic fields, chemical reactions, and thermophoresis on fluid behavior. By applying boundary layer techniques and similarity transformations, the governing equations are simplified for numerical analysis. The MATLAB bvp4c solver is employed to solve the reduced equations. The obtained results are visually represented and thoroughly discussed to comprehend the model's physical characteristics. The investigation highlights the magnetic field's influence, chemical reaction, and impact of thermophoresis particle deposition on the flow behavior of Williamson fluid over the extended sheet. Moreover, significant roles are found for chemical reactions and thermophoresis parameters in determining the fluid concentration near the boundary layer. It is observed that an increase in the chemical reactions and thermophoresis parameters results in a reduced thickness of the fluid concentration near the boundary layer. Notably, an increase in Schmidt value also diminished the thickness of the fluid concentration close to the boundary layer. The magnetohydrodynamic parameter significantly influences the fluid's velocity and temperature near the surface. It has been noted that an increase in the magnetohydrodynamic parameter decreases the fluid’s velocity and increases the temperature near the surface. The impact of skin friction coefficient and Nusselt number and the impact of mass transfer coefficient on Williamson fluid will be discussed. The findings acquired are examined in relation to existing research and the correlation is provided as a table.

Determination of sugar, nitrogen, and phosphorus consumption by kombucha culture is necessary to gain additional insight into the kombucha metabolic pathways and nutritional value of the produced beverages and to set a basis for optimizing the conditions for large-scale production. Kombucha beverage was made using effluent obtained from grape must clarification phase of white wine production. The fermentation medium was prepared by diluting the sterilized initial medium with approximately 16% of total reducing sugars to 3, 5, and 7% of total reducing sugars. The duration of the fermentation was nine days at 20, 25, and 30°C. Sugars, nitrogen, and phosphorus content were measured using DNS, Kjeldahl, and molybdenum blue methods, respectively. The highest sugar content was in the initial medium (16.34%) and the lowest was after nine days of fermentation at 30°C with 3% initial sugar content (0.17%). Residual levels of sugars, nitrogen, and phosphorus after three days were modeled using response surface methodology. The proposed mathematical models for sugars and nitrogen content showed an exceptional correlation with the experimentally obtained values. With this study insight into kombucha’s consumption of basic nutrients, nutritional value of the obtained products, and optimization of product composition was provided.

This study characterizes oak (sessile and pedunculate oak) and alternative wood (black locust, Myrobalan plum, wild cherry, and mulberry) species as important sources of volatile compounds of aged spirits. Nowadays, their fragments are used to hasten the brandies’ aging process. The ATR-FTIR spectra of analyzed wood samples are similar, only the mulberry FTIR spectrum contains unique peaks primarily due to its highest lignin content (40.93%). Using the untargeted GC-MS approach, a total of forty-one volatile compounds were identified in the wood extracts in a model spirit solution. The volatile profiles of alternative wood extracts in a model spirit solution were significantly different, both quantitatively and qualitatively, compared to those of oak. Coniferyl (23.14 μg/g—26.6 μg/g) and sinapyl (23.56 μg/g—25.82 μg/g) alcohols were the most abundant volatile compounds in investigated oak extracts. Resorcinol and coniferyl alcohol were the most abundant volatile compounds in black locust, sakuranin in wild cherry, while resorcinol and β-resorcinaldehyde in mulberry wood. To the best of our knowledge, sakuranin has not been detected in wild cherry wood until now. Besides wood chemical characteristics, the technology used during the aging process strongly influences on volatile profiles of aged brandies, thus, these compounds are potential chemical markers for discrimination between wood species as well as aging technologies.

Sustainable food packaging materials have significant interest in addressing environmental issues by making renewable substitutes such as bioplastics based on pectin. Orange peel has a relatively high pectin content of 42.5%, which can be synthesized into bioplastics. Pectin-based bioplastics tend to have limitations in terms of mechanical and physical strength due to the hygroscopic nature of pectin. This study aims to determine the effect of adding glycerol and sago starch on the characteristics of orange peel pectin-based bioplastics. The casting method was used in the bioplastic formulation using the variation of the pectin:starch ratio (75:25, 65:35, 55:45; and 50:50%) and glycerol composition (10, 20, 30, and 40%). Based on the results, the pectin obtained was categorized as low methoxyl pectin and ester pectin. The characterizations of bioplastics achieved the maximum value of the tensile strength of bioplastics was 4.22 MPa, obtained by adding pectin:starch (50:50%) and 10% glycerol. The maximum value of the elongation properties at the break of bioplastics is 24%, obtained by adding the composition of pectin:starch (75:25%) and 40% glycerol. The more additions of the pectin:starch and glycerol composition result in a higher water vapor evaporation rate. Hence, utilizing orange peel pectin-based bioplastics offers a sustainable solution by exploring repurposing waste to create bioplastics for food packaging, thereby contributing to environmental preservation.

The main reaction parameters examined were the amount of blast furnace slag, the hydration duration, ammonium acetate concentration, and temperature. The Response surface methodology was employed to quantify their impact on the sorbent's surface area. Using a central composite design, the surface area of the resulting sorbent corresponding to Brunauer- Emmett-Teller (BET) was investigated. The sorbents produced range in surface area from 49.89 to 155.33 m2/g. Additionally, the effectiveness and response prediction capacities of the Response Surface Methodology (RSM) and Artificial Neural Network (ANN) modeling methodologies were investigated. The models were assessed using various statistical metrics, including (MSE) mean squared error, (ARE) average relative errors, the (SSE) sum of squared errors, (HYBRID) Hybrid fractional error function, (SAE) Sum of the absolute errors, (R2)coefficient of determination, and Root means square. According to statistical evidence, the ANN approach surpassed the RSM-CCD model approach. The surface area of the sorbent was shown to be significantly influenced by interactions between variables in addition to all the individual variables examined. The sorbent was made from a material with substantial structural porosity based on SEM. The functional groups were identified using FTIR. The XRF determined the elemental composition of BFS-based sorbents.

The present study conceptualizes and simulates a methanol production process through the direct hydrogenation of captured CO2. CuO/ZnO/ZrO2 was employed as the catalyst and Aspen HYSYS was used for the process simulation. Configurational optimization of the process flowsheet was carried out using a step-by-step hierarchical approach. Many alternate flowsheets have resulted, and their capital investment, product cost, and profitability measures were calculated. The discrimination among the competing flowsheets was carried out based on net profit and percent return on investment. The retained flowsheet was further analyzed for optimizing the recycle ratio and evaluating the effect of the price of captured CO2, green H2, natural gas (fuel), and catalyst on the economic performance of the plant. The optimum value of the recycle ratio was computed to be 4.23. Additionally, it was found that the price of H2 is the most important parameter in defining the feasibility and profitability of the process. Mathematical correlations were also developed that relate the profitability and price of the above-mentioned feed materials.

Hydrothermal co-liquefaction (HTCL) is the prominent process for producing bio-products with a higher conversion rate. It is performed at high temperatures and pressure in the presence of water. Earlier, it was mostly conducted in batch reactors, but it has major limitations including operating volume, back mixing, and tedious process for high productivity. With that, the present investigation is performed on designing the screw shaft for the high-pressure HTCL process. The dimensional factors including flight length, pitch, helix angle, and depth were considered to design the optimal screw shaft. Likewise, principal stresses, shear stress, bending stress, bending moment, and total deformation were regarded as inevitable response variables to analyze the internal strength of the shaft. In this regard, the Taguchi approach provides the L9 (34) orthogonal array as an experimental design. Then, the numerical results from the transient structural analysis were analyzed with the assistance of statistical methods such as Grey Relational Grade (GRG), Grey Fuzzy Reasoning Grade, Analysis of Variance (ANOVA), and Taguchi method to find the most influential dimensions for minimizing the response variable. Consequently, the results from both GRG and Taguchi optimization were compared, and selected the most optimum parameters.

This investigation employs the salt bath nitriding to extend the service life and improve the surface characteristics of AISI 52100, commonly employed in bearing applications. A wear test was conducted using a pin-on-disc device according to the ASTM G-99 standard, and the findings show a 30% reduction in wear loss. Sliding wear experiments were conducted at 1.5 m/s with a 5 N force at room temperature on uncoated and nitrided pins which was obtained as optimum value from RSM. The three variables and five levels of central composite design (CCD) were utilized to reduce the number of trials and the model relations were examined through ANOVA. Surface hardness, friction coefficient, wear coefficient, and loss in wear are measured over pins without coating and nitride pins. Investigations were done into how 5W30 oil affected passive and drip lubrication. Nitride substrates had a hardness of 590 HV. Also, nitriding has a favorable effect on the friction coefficient, lowering it by up to 23%. The 5W30 lubricant will further decrease the friction coefficient. The lowest friction coefficient was seen with the addition of 14% drip oil lubrication. Significantly less wear loss in the pin was caused by a combination of high hardness and low friction coefficient.

Various purification methods have been developed to improve local salt quality, with the NaCl content above 94%. Bentonite is one of the materials used as binder impurities in purification. The purpose of the study was to synthesize a modified bentonite using an alkaline solution, which includes sodium hydroxide (NaOH) and potassium hydroxide (KOH) with various concentrations (1 M, 1.5 M, 2 M, and 2.5 M) and determined levels of Na+, Ca2+ and Mg2+ metals using AAS. The bentonite and activating agent 1 M (1:10) were stirred for three hours. Then, the bentonite was dried for two hours in an oven at 110°C. The activated bentonite was dried for four hours at 170°C. The activated bentonite was characterized using XRD, FTIR, and SEM. The basal spacing d001 on the diffractogram bentonite was significantly unaffected by alkaline activation. FTIR analysis represents the stretching vibration of -OH shifts towards a lower wavenumber. Alkaline activation reduced impurities from bentonite and increased the pore surface''s porosity. NaCl levels in people's salt increased after being activated using alkaline. The increase in Na+ levels was followed by a decrease in Ca2+ and Mg2+ contents. KOH-activated bentonite had a higher NaCl level than NaOH-activated bentonite.

One of the major environmental problems caused by stainless-steel industries is the liquid effluents generated during the production processes. It contains a high concentration of metal ions such as Fe (III), Cr (III), Cr (VI), and Ni (II) in HF and HNO3 mixture, oil, and rinse wastewater. The used pickling waste stream has a pH of 0.5 and Total Dissolved Salts (TDS) of 520g/L with a density of 1.20g/CC. The present work focused on recycling pickling effluent by combining filtration, resins, and neutralization to remove metal ions efficiently and F- greater than 99.5%. To remove TDS, laboratory experiments were performed using micro and ultra-filters with a membrane area 0.2m2. Cr (VI) was removed using TulsionFSMP 6301 resin and desorption using NaNO3 and subsequent conversion into Na2Cr2O7 as a by-product. For neutralization, Ca(OH)2 and NaOH were used to precipitate metal ions, and the resulting filtrate was polished using ZrOCl2 to remove F- to 0.12 mg/L effectively. The nitrate was recovered as NaNO3. Adsorption isotherm and kinetic studies were utilized for Cr (VI) from experimental data, and a process flow diagram was developed, which can eventually be tested on a larger scale.

In this work, turbulent bed contractor (TBC) hydrodynamics have been studied in terms of bed expansion (Hd/Hst) using a particular approach to predict this important property for the design of such equipment. The study is based on 1604 sets of experimental data on the bed expansion, obtained by varying the operating variables (gas velocity, liquid spray, packing characteristics, static bed height, and free opening of the supporting grid). The prediction of the bed expansion necessitates the estimation of gas and liquid holdups. To achieve this, we employed a variety of correlations derived from existing literature, comprising six equations for gas holdup and twenty equations for liquid holdup estimation. Out of a total of 120 cases, bed expansion was estimated, and the accuracy of the model was evaluated by calculating the mean absolute error in percentage (MAPE), root mean square error (RMSE), correlation coefficient (ρXY), and explained variance (VECV). This study identified suitable correlations for gas and liquid holdups, leading to predictions with acceptable errors. Furthermore, statistical analysis was employed in a subsequent phase of the study to determine the most appropriate correlations for predicting bed expansion among those proposed by various authors.

This study discusses fluoride removal efficiency from phosphogypsum (PG) on a lab-scale experiment matrix designed by the Box-Behnken method. Temperature, solid/liquid ratio, and time were supposed to influence fluoride removal efficiency from PG by various salt solution media. Experiment matrices were designed according to salt solution types: seawater, 5% NaCl, and 10% NaCl solutions. The factor-response analysis showed a direct proportionality between fluoride removal efficiency and temperature. The optimum fluoride removal conditions based on the experimental data obtained by the multi-variable design matrix were determined by the Design Expert v.12 software. The optimum temperature, time, and solid/liquid ratio were 80 °C, 3 h, and 0,174 for seawater. The software predicted a 73,31% fluoride removal efficiency at the optimum conditions, whereas the experimental value was 74,99%. Since the actual vs. predicted data show high consistency, results might also be useful when industrial-scale fluoride removal to a predetermined level is required prior to a particular use of PG. PG has a high potential as an alternative raw material, and fluoride removal might be important in recycling applications. This study provides a novel pre-industrial scale fluoride removal inventory, especially for the fertilizer and cement industry.

The catalytic production of diphenylmethane from the reaction of benzene with benzyl alcohol was investigated using HZSM-12 and desilicated HZSM-12 that was obtained by treating ZSM-12 with 0.2M NaOH solution at 85 °C for 60 min. The untreated and alkaline treated ZSM-12 zeolites were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherms, scanning electron microscopy, inductively coupled plasma optical emission spectrometry, and temperature-programmed desorption of ammonia. The desilicated HZSM-12 showed promising catalytic performance with benzyl alcohol conversion of 100% and the selectivity to diphenylmethane of 74% and 87% in 4 h and 8 h reaction time, respectively. The reaction parameters affecting benzyl alcohol conversion and product distribution were also presented. The activities of fresh and regenerated catalysts were compared, and characterization results indicated that the occluded organic molecules decreased the number of acidic sites of the catalyst after the reaction and regeneration.

This study examines the operating pressure effect on the manufacture of biodiesel from Palm Kernel Fatty Acid Distillate (PKFAD) by using para-Toluene Sulfonic Acid (PTSA) catalyst. The operating pressures studied are the vacuum pressures of 70 kPa, 80 kPa, 90 kPa, and 100 kPa, which varied with PTSA concentrations of 5%, 10%, 15%, 20%, and 25%, and the molar ratios of methanol and PKFAD are 5:1, 6:1, 7:1, 8:1, 9:1, and 10:1. Biodiesel production from PKFAD was carried out with reaction duration of 120 minutes and reaction temperature at 50 0C. The amounts of fatty acids converted to biodiesel were calculated based on the initial and acid numbers after the esterification reaction. The results show that a vacuum pressure of 70 kPa to 100 kPa provides a conversion above 96% for all catalyst concentrations and all methanol and PKFAD molar ratios. The highest conversion of PKFAD to biodiesel of 98.6% is obtained at an operating pressure of 80 kPa, a catalyst concentration of 25%, and the molar ratio of methanol and PKFAD is 10:1. The biodiesel characteristics obtained in this study have met the standards of the American Society for Testing Materials.

The present numerical study aims to present the effect of a titled oscillating thin plate with different inclination angles on the Al2O3-water nanofluid flow and heat transfer performance. The subsequent work establishes methods for forming fluid-structure interactions by the impact of Al2O3-water nanofluid at 0.1-1.0 vol. % volume fraction upon the thin plate using COMSOL Multiphysics 5.4. The turbulent model is solved using the (k-ε) model, and the flow assembly around the thin plate obstacle has been confirmed at the Reynolds number of Re=4×104. It exemplifies how Nanofluid flow interaction can distort structures. The turbulent, two-dimensional, stationary, and incompressible flow around an oscillating thin plate with inclined angles with upstream and downstream mounted inside a horizontal channel was studied. The numerical study includes an investigation of the effect of five inclination angles of the thin plate (30, 60, 90, 120, and 150°) on the pressure, velocity, and temperature contours of the Al2O3-water nanofluid. Also, the study presented the drag profile and left a force on the thin plate caused by the fluid flow. The results showed that a titled oscillating thin plate inside the flow direction increases pressure drop, von Mises deformation stress, x-displacement and drag force fields, and the Nusselt number. Where the pressure increased from 2.61×103 to 6.21×103 pa, the von Mises stress increased from 4.43×106 to 1.78×107 N/m, and the X-displacement increased from 1.6 to 5.5 mm when increasing the plate angle from 30 to 90°.

Cumene is a precursor for producing many organic chemicals and is thinner in paints and lacquers. Its production process involves one of the large-scale manufacturing processes with complex kinetics. Different classical control strategies have been implemented and compared in this process for the cumene reactor. As a system with large degrees of freedom, a novel approach for extracting the state space model from the COMSOL Multiphysics implementation of the system is adopted here. Internal Modern Control (IMC) based PI and PID controllers are derived for the system. The system is reduced to the FOPDT and SOPDT model structure to derive the controller setting using Skogestad half rules. The integral time is modified for excellent set point tracking and faster disturbance rejection. From the analysis, it can be stated that the PI controller suits more for this specific process. The particle swarm optimization (PSO) algorithm, an evolutionary computation technique, is also used to tune the PI settings. The PI controllers with IMC, Zeigler Nichols, and PSO tuning are compared, and it can be concluded that the PSO PI controller settles at 45 s without any oscillations and settles down faster for the disturbance of magnitude 0.5 applied at t = 800 s. However, it is computationally intensive compared to other controller strategies.

This study aims to determine whether drying is a suitable preservation method for gilaburu fruit and the changes in the bioactive components of gilaburu fruit (Viburnum opulus L.) at the end of the drying process. In this study, gilaburu fruits were dried in a cabinet dryer at different temperatures (50°C, 60°C, and 70°C). The analyses of trans-resveratrol, water-soluble vitamins, organic acids, and phenolic compounds were made using the HPLC method, while total phenolic contents and antioxidant activity were spectrophotometric. As a result of drying of gilaburu fruit at 50°C, 6 °C, and 70°C, the highest component loss was observed at 70°C. Losses of 73.64% and 84.08%, respectively, were detected in the total phenolic substance and antioxidant capacity content of gilaburu fruit after drying at 70°C. While the trans-resveratrol content was 1.26±0.05 (g/100 g dry weight (DW)) in fresh fruit, it reduced to 0.31±0.03, 0.30±0.01 and 0.21±0.01 after drying at 50°C, 60°C and 7 °C, respectively. In terms of vitamins, the highest loss was seen in niacin. The contents of ascorbic acid, pyridoxine, niacin and thiamine contents of fresh gilaburu fruit decreased after drying at 50°C, 60°C and 70°C. In addition, drying kinetics of water-soluble vitamins, total phenolic contents, antioxidant activity, and trans-resveratrol were modeled. The Page model best described the drying behavior of fruits at 70°C, and the parabolic model at both 50°C and 60°C. Thermal degradation of water-soluble vitamins, total phenolic contents, antioxidant activity, and trans-resveratrol were fitted in the first-order kinetic model.

The machining of extremely hard material in conventional machining requires high energy. Therefore stress-free, burr-free, and high-accuracy machining technique like Electro Chemical Micro Machining (ECMM) with extra features is recommended. To improve efficiency, various electrolytes such as Magnet Associated Electrolytes (MGAE), Metal Particle Mixed Electrolytes (MPME), and Carbon Pellets Mixed Electrolytes (CPME) are employed. The micro-holes were drilled over the work material MONEL 400 alloy. The parameters for the studies are electrolyte type, concentration (g/l), machining voltage (V), and duty cycle (%). The responses of ECMM are estimated through material removal rate (MRR) in μm/sec and overcut in μm. The results are optimized using Multi-objective optimization based on ratio analysis (MOORA) and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR). Both techniques produce the same optimal parameter, 18th experiment CPME, 50% duty cycle, 11 V machining voltage, and 28 g/l electrolyte concentration. It is the best optimal parameter solution for machining. According to the ANOVA table of both, the type of electrolyte plays a 62.6% and 60.37% contribution, respectively, to machining performance. Furthermore, the scanning electron microscope (SEM) image analysis perused on the micro holes to extend the effect of different electrolytes on machining surfaces.

Fertilizer coatings are considered mandatory to protect the physical quality of fertilizer granules. They continue to be developed due to compliance with novel fertilizer types and, most importantly, future environmental and animal-plant health regulations. As known, bio-based contents are sustainable and eco-friendly compared to petroleum-based materials. However, many types of coatings are commonly composed of unsustainable, costly, and can be ecologically toxic, such as paraffin or mineral oil. This article presents a comparative research study to provide eco-friendly anticaking coatings composed of lignosulfonate-modified biopolymer and vegetable waxes instead of conventional coatings. This research mainly aims to find alternative ingredients instead of a petroleum-derivatives in conventional coatings. According to the results, an anticaking coating containing lignosulfonate-modified biopolymer improved the granule structure of calcium ammonium nitrate fertilizer. It showed the best anticaking performance compared to other coating types. Vegetable-based coatings, on the other hand, gave results in appropriate intervals, especially at low concentrations, and showed a valuable way to develop better versions in future studies. As a result, it is seen that biopolymers can replace paraffin-based products.

This study investigated the influence of different regimes of immersion batch frying of peanuts on its specific energy consumption. The investigation was conducted via simulation, where energy consumption was calculated using various heat power/peanut mass ratios. As the result of the applied optimization procedure within the examined domain and calculation data, it was estimated that a regime with 24 kW of heating power and 28.6 kg of peanuts gave the minimum specific energy consumption. Besides that, the resulting surface could serve as a basis for designing and operating the frying equipment in more favorable regimes in terms of energy efficiency.

The data acquisition from the freeze-drying process is important for obtaining freeze-dried samples with the desired final moisture content under various operating conditions. The current study extensively presents a simple and low-cost methodology for implementing a data acquisition system in a laboratory-scale freeze dryer. The results showed that higher drying temperatures (40°C) increased the errors involved in measuring the mass of material; nevertheless, the application of correction blank curves statistically significantly reduced those errors. In general, the system developed provided precise and accurate measurements of the temporal changes in the sample mass and temperature, and chamber pressure variations, allowing monitoring of the production process of freeze-dried samples with low final moisture contents.

Fructooligosaccharides (FOS) are fructose oligomers beneficial to human health and nutrition for prebiotic sugars. Their production occurs by a transfructosylation reaction in sucrose molecules catalyzed by fructosyltransferase enzymes (FTase, E.C.2.4.1.9) adhered to microbial cells. The purpose of this work was to study the preparation, enzymatic activity, and stability of glutaraldehyde-crosslinked Aspergillus oryzae IPT-301 cells used as a biocatalyst for the transfructosylation reaction of sucrose in a packed bed reactor (PBR), aiming at FOS production. The highest transfructosylation activity (AT) was presented by the biocatalyst prepared by cross-linking at 200 rpm and 45 min. The highest AT in the PBR was obtained at 50 °C, with flow rates from 3 mL min-1 to 5 mL min-1 and sucrose concentrations of 473 g L-1 and 500 g L-1. The enzymatic kinetics was described using the Michaelis-Menten model. Finally, the biocatalyst showed constant AT of approximately 75 U g-1 and 300 U g-1 for 12 h of reaction in the PBR operating in continuous and discontinuous flow, respectively. These results demonstrate a high potential of glutaraldehyde-crosslinked A. oryzae IPT-301 cells as heterogeneous biocatalysts for the continuous production of FOS in PBR reactors.

In the present paper, a gamma alumina (γ-Al2O3) loaded zinc oxide (ZnO) nano-catalyst (ZnO/γ-Al2O3) has been synthesized and used to accelerate the removal of sulfur compounds from light gas oil by oxidative desulfurization (ODS) process. The synthesized nano-catalysts have been characterized by atomic force microscopy (AFM) and Brunauer-Emmett-Teller (BET). The ODS process has been conducted in a batch reactor at various reaction temperatures and batch times varying between 30 to 90 °C and 20 to 80 min, respectively. DBT removal was highest (93.781%) while using synthesized nano-catalyst (9% ZnO/γ-Al2O3) at 90°C and 80 min reaction time. Based on the obtained experimental data, a new mathematical modeling technique was performed for the ODS operation under mild experimental conditions to evaluate the most appropriate kinetic variables for the newly synthesized nano-catalysts. Simulation results indicate a good match with experimental observations with less than 5% absolute average error for all runs. The optimization procedure of the process condition displays that > 98% DBT could be eliminated within 200 min, at 87 °C, in the existence of synthesized nano-catalyst (9% ZnO/γ-Al2O3).

Numerical simulations of the flow surrounding particle agglomerates were carried out using computational fluid dynamics to assess the ability of five RANS turbulence models to estimate the drag coefficient in particle agglomerates. Simulations were carried out in steady conditions for Reynolds numbers between 1 and 1500. Streamlines showed that symmetrical agglomerates present a velocity profile similar to the single sphere profile. Results showed that both Spalart-Allmaras and SST k-ω turbulence models could represent the flow profile in the regions near and far from the walls of the agglomerates and the wake region in the rear of the agglomerates. The RNG k-ε model showed poor quality in predicting the velocity profile and the drag coefficient. The drag coefficient obtained by simulations presented a trend better represented by the Tran-Cong model, also showing that deviations from the predictions decreased as the packing density of the agglomerate increased. The use of steady RANS simulations showed to be a feasible and efficient method to predict, with low computational cost, the drag coefficient in particle agglomerates. For the transition and turbulent flows, results presented good agreement, with deviations between -15% and 13%, while for lower Reynolds numbers, deviations varied between -25% and 5%.

By integrated management system (IMS) based on integrated main indicators (IMI), the quality of health, safety and environmental management specifically for chemical industries was well increased. This study aimed to evaluate and compare integrated and efficient indicators in two chemical industries in Iran by health, safety, and environment (HSE) management system (MS). The integrated indicators were divided into HSE domains in the form of a questionnaire by proposed method and the weight of each of them was calculated from 101 features in the field. A list of criteria, sub-criteria, and integrated indicators was first prepared for assessing the performance of the HSE-MS system, and Delphi was finalised with the help of experts, and then the results were weighed by ANP and DEMATEL methods for two companies. Finally, 101 integrated and efficient indicators were extracted for performance evaluation to demonstrate the application of the DEMATEL, ANP method to select effective indicators in measuring HSE-MS performance in two chemical industries. In this study, the mean scores per weight of HSE indicators for chemical industries A and B increased from 2.38 to 2.79 and 1.84 to 2.056 in the beginning of 2017 up to the end of 2018. The mean score of HSE indicators for companies A and B were archived (2.65 and 2.93) and (1.95 and 2.16), respectively, in the spring/winter of 2017 and 2018. So, HSE-MS and IMS help chemical industries to improve HSE and management systems to achieve high-quality industry in different options, especially in human sources. Although in this study all trends of HSE indicator had a moderate phase with positive rate from spring 2017 up to winter 2018 for two companies A and B but company B moved slowly as compared to company A. [ABSTRACT FROM AUTHOR]

Freeze storage and pasteurization of human milk are common treatments in milk banks. However, thermal treatment changes milk quality for preterm infants’ nutrition. Therefore, this paper aimed to examine preterm human milk's nutritional profile and antioxidant potential after storage, pasteurization, and after supplementation with a fortifier. The effects of storage processes were estimated on the mature preterm milk of 30 breastfeeding women. Total proteins, lipids, and lactose were determined after thermal processing and supplementing mature preterm milk with a fortifier. The ferric-reducing antioxidant potential method and lipid peroxidation inhibition assay determined the antioxidant capacity. Protein concentration decreased after frozen storage and pasteurization (p

The study of drying kinetics and characteristics of agricultural products is essential for drying time estimation, designing dryers, and optimizing the drying process. Moisture diffusivity under different drying conditions is crucial to process and equipment design. The drying kinetics of paddy using a cabinet tray dryer was modeled using an Artificial Neural Network (ANN) technique. For predicting moisture ratio and drying rate, the Levenberg- Marquardt (LM) training algorithm with TANSIGMOID and TANSIGMOID hidden layer activation function provided superior results. A comparative evaluation of the predicting abilities of ANN and 12 different mathematical drying models was also carried out. The Midilli model was adequate for fitting the experimental data with an R2 comparable to that of the ANN. However, the RMSE observed for ANN (0.0360) was significantly lower than that of the Midilli model (0.1673 to 0.712). Effective moisture diffusivity increased with an increase in temperature from 15.05 10-9 m2/s to 28.5 10-9 m2/s. The activation energy for drying paddy grains varied between 6.8 kJ/mol to 7.3 kJ/mol, which showed a moderate energy requirement for moisture diffusion.

This study proposes the use of mass balance and the method of McCabe-Thiele in the absorption column for the removal of drying air humidity with ethylene glycol and energy balances in heat exchangers for the determination of the optimum operating conditions of a factory to produce recycled polyester fibers from polyethylene terephthalate (PET) flakes. The evaluation of these machines involved the combination of variables such as temperature, flow rate, specific heat, and operational efficiency to guarantee the correct adjustment of the physicochemical properties of the fluids and materials of the process. The efficiency of the absorption column was determined at 25%, and a diagram correlating ethylene glycol humidity, the dew point of the drying air, and the efficiency of humidity removal from the PET flake dryer were constructed to define what is the most appropriate configuration for operation. By the graph curves, it was found that the humidity of ethylene glycol for absorption should be inferior to 1% (w/w) to guarantee a dew point < -27°C at 175°C of the drying air introduced in the dryer, which would finally promote a removal with efficiency superior to 91% of the PET flake humidity for values < 0.005% (w/w).

This work illustrates the prediction of frost action mechanisms on ceramic compacts and their biocorrosion resistance to fungus action. The ceramic compacts were produced from two raw materials: coal fly ash (40 wt.%) and clay material (60 wt.%). The ceramics models were made in laboratory conditions by pressing (P = 45 MPa), drying (105°C, 3h), and sintering (1100°C, 1 h; heating rates 3°C/min and 10°C/min.). The mechanisms responsible for the deterioration of the designed ceramic compacts were defined based on the values of the total porosity, pore size distribution, pore critical radius, and the Maage factor, as well as on the values of water permeability. The biocorrosion process was investigated using Aspergillus niger fungus as a model microorganism. The different degrees of fungus colonization on the designed compacts were comparatively analyzed based on the Scanning Electron Microscopy investigation results. The gained results are encouraging as they show that the utilization of fly ash (40 wt.%) in ceramic composites is possible without significant deterioration of their durability (frost action and microbiological corrosion resistance) compared with the ones whose production was based only on clay material.

Honey is a product of high nutritional value, used as a raw material for obtaining mead. However, adding fruit juices, including chokeberry juice, can improve mead quality. This paper aims to assess the effects that adding different quantities of chokeberry juice, with the variation of 3 amounts of inoculated yeast, has on the fermentation and physicochemical, antioxidant, and antimicrobial properties of mead. The parameters analyzed are the dry matter content, pH value, and content of volatile acids, ethanol and methanol, total phenols and flavonoids, FRAP, DPPH, and ABTS tests, and antimicrobial properties. The results obtained in this paper show that adding chokeberry juice improves the antioxidant properties of the final product and positively affects the course of mead fermentation, i.e., it has led to an increase in the maximum concentration of ethanol. Regarding the chemical composition of mead, there is no significant difference, except in the obtained ethanol content, which is the highest in samples with 10% of added chokeberry juice. Furthermore, the control sample showed the best antimicrobial activity, while the sample with 5% added chokeberry juice showed the weakest effect. Finally, the strongest effect was seen in the sample with 20% of added chokeberry juice.

The present work aims to retrofit an existing Egyptian oilfield plant to improve desalter performance and reduce the power of crude oil shipping pumps. In this work, waste heat in disposed water that represents a value is used in heating brackish water injected over desalter and in heating crude oil before shipping. ASPEN HYSYS version 11 simulation software was used. The retrofit of the considered oilfield plant is based on the implementation of two new heat exchangers to recover waste heat in the disposed water. The results showed that using waste heat to heat the brackish water in the desalter from 30°C to 71.11°C will increase the operating temperature of the desalter and thus increase the sedimentation and separation rate. On the other hand, using waste heat in heating the crude oil before shipping from 37.78°C to 71.11°C reduces the oil viscosity from 1.536 cSt to 0.9735 cSt. Reducing the viscosity of the crude oil will reduce the pressure drop of the shipping pumps, and therefore the power required to pump the oil will be reduced. The presented retrofit design can be used as a guide in upgrading existing plants and plants under the design phase.

Variable speed drives are the most promising technique for reducing electric motors' energy consumption. This paper discusses energy savings by installing variable speed drives to control rotating equipment motors such as pumps, compressors, blowers, and fans in oil processing facilities. In addition to energy savings, variable speed drives will improve overall equipment efficiency, increase reliability, and reduce greenhouse gas (GHG) emissions. An energy audit was performed on a case study to investigate energy consumption for all electric motors. Technical and operational constraints for installing and operating variable speed drives were discussed. Installation requires adjustments in operation schedules and parameters to allow reducing energy consumption. The case study has illustrated how to calculate energy savings for pipelines, air coolers, air blowers for furnaces, pumps with variable flow rates, and reciprocating compressing systems. Variable speed drives were technically and economically accepted in air blowers, fans, and pumps. Energy consumption and GHG emission were reduced by 67%. The payback period for the whole project was less than one year. Meanwhile, it was not valid for reciprocating compressors as the payback period was 6.2 years.

The challenging task in our ecosystem is to reduce acidic gas emissions to some extent. Many gases are emitted from the industries like H2S, CO, CO2, SO2, NO, and NO2 as exhaust gases. Among these gases, CO2, NO2, and SO2 are acidic, which results in adverse effects on humans, animals, and plants. The increase in the emission of CO2 gases from both anthropogenic and industrial sources resulted in CO2 mitigation studies. CO2 absorption studies were carried out using iron oxide nanofluid with the novel structured packed absorption column. Iron oxide nanoparticles were synthesized and characterized using XRD, SEM, and TEM analysis. Ammonia is used as an absorbent along with iron oxide nanofluid of three different concentrations (0.0001 w/v%, 0.001 w/v%, and 0.0015 w/v%). It was found that the iron oxide nanofluid of 0.0015 w/v% showed an improved % CO2 removal efficiency. This enhanced % CO2 removal efficiency was due to the increased interfacial area of the ameliorated contact between the liquid and gas phases. In addition, the magnetic field was introduced along with the packed column, which increased CO2 removal efficiency by 1.5%.

This study presents the modeling of thin layer drying of micropropagated Ocimum basilicum L., some quality characteristics of the dried product, and energy consumption analysis for the dryer used. The experimental drying data obtained from a previous article were used in the statistical analyses. Modeling studies were statistically carried out using the experimental data at a 1 m/s airflow rate and a temperature of 30 °C—50 °C. The statistical analysis showed that the Verma equation was the best-fit model with the lowest chi-square (χ2) and AIC values at all temperatures studied. From statistical analyses using derived drying models, it was found that the D9 equation having a χ2 value of 0.0146 and an AIC value of -528.0, was the best model fitting to experimental data. The total phenolic content, flavonoid, and antioxidant capacity of dried basil samples were measured as (2.538 ± 0.029) mg GAE/g, (2.017 ± 0.088) mg quercetin/g, and (2.263 ± 0.001) mmol TEAC/100 g d.w., respectively. From FTIR spectra, dried basil samples had typical functional groups. SEM images showed that a collapse in the surface of the leaves occurred. But, this collapse is not affecting the functional groups on the surface of the leaves. From energy consumption analyses, the optimum drying temperature was found to be 40°C. The SMER, MER, and SEC values calculated from energy consumption analysis at 40°C were 0.0043 kg/kWh, 0.0007 kg/h, and 234.81 kWh/kg, respectively.

The spray pyrolysis method has the disadvantage of nozzle plugging, and the conventional heating model causes a large temperature gradient, which leads to unevenly heated reactants. This study used cerium chloride heptahydrate and Venturi reactor as raw material and core equipment. The technology of microwave heating was combined to prepare single-phase sphere-like cerium oxide. The mean size of the particles was near 80nm. The product was characterized via XRD, SEM, and EDS technologies. The purity, morphology, and energy consumption were compared with the conventional spray pyrolysis. Fluent software coupled with HFSS was employed to simulate the effects of different process conditions on products’ purity and temperature field in the reactor. There was good correspondence between experimental and simulated results. The results showed that as gas velocity Vg increased, the tendency of the temperature field distribution did not change. The lowest mass fraction of chlorine element reached 0.13% when the gas inlet velocity reached 1.7 m/s. When the material inlet velocity was 0.05 m/s, the mass fraction of the chlorine element was below 0.1%, which indicated that the reactants had a complete reaction. It has been calculated that the heating cost, energy consumption, and CO2 emission decreased sharply compared with the spray pyrolysis method.

Several transition metals (Fe, Cu, Ni, Cr, and Co) were inserted into the Ti-SBA-15 using two-step synthesis methods. XRD, SEM-EDX, N2 adsorption-desorption isotherms, XRF, and UV-DRS analysis were used for characterizations. The results confirmed preserving an ordered mesoporous structure, well-dispersed Ti-metal and enhanced light absorption compared with Ti-SBA-15. The photocatalytic performances were evaluated in the degradation of methylene blue under UV light. The results show that the Co-Ti-SBA-15 exhibited the highest photocatalytic activity among the prepared photocatalysts for the degradation of methylene blue. The significant activity increase might be attributed to the increased reactant adsorption by the mesoporous structure of SBA-15, the good distribution of TiO2 in the pores of SBA-15, and the increased electron transfer mobility due to metal doping. In addition to efficiency, Co-Ti-SBA-15 is a suitable catalyst for dye degradation, exhibiting good stability in methylene blue degradation over five photocatalytic runs without any deviation of the structure.

Nowadays, various industrial and urban activities result in discharging enormous quantities of various pollutants and their accumulation in the environment. Considering that heavy metals in wastewater are a serious threat to the environment and human health and that conventional methods for their removal are not highly efficient, the current study mainly focuses on estimating cyanobacterial capability to accumulate different heavy metals from water and comparing bioaccumulation and biosorption processes. Cyanobacteria Nostoc sp. was used, and five heavy metals were selected for this experiment (Cd2+, Cu2+, Pb2+, Ni2+, Zn2+). Examined concentrations of HMs were 20 mg/dm3, 80 mg/dm3, and 200 mg/dm3 for the bioaccumulation study, while 20 mg/dm3 and 80 mg/dm3 of each HMs were used for biosorption experiments. Living cells of Nostoc sp. have the highest affinity for Pb2+ (98.15%) and Cu2+ (95.14%) removal from the solution by bioaccumulation. During the biosorption process, dried biomass of Nostoc sp., besides Pb2+ (92.27%) and Cu2+ (96.00%), shows a high affinity for Cd2+ (91.00%) removal. Living cyanobacterial cells of Nostoc sp. could accumulate 82% of Zn, while dried biomass adsorbs 87% of Zn2+. Although the highest bioaccumulation of Ni2+ was only 38% while using the biosorption process, it was significantly higher (63.80%). These results could provide a preliminary study for further investigation in the direction of the development of immobilized biosorbents which could be used for industrial effluent treatment.

This work evaluated the process for heptaldehyde, undecylenic acid, and methyl undecenoate production from castor oil, methyl ester of castor oil, and ricinoleic acid. Experiments were performed in a continuous pilot-plant scale pyrolysis reactor. Those are very important green chemical products that the thermal cracking of castor oil might produce. Transesterification of castor oil produces methyl ricinoleate, and its thermal cracking generates methyl undecenoate and heptaldehyde. The pyrolysis temperatures tested were 530°C, 545°C, 560°C, and 575°C, with residence time from 17 s to 32 s and mass flow at 400 g/h of the mixture of materials with 25% distilled water. It was observed that the temperature influenced the bio-oil yield in different degree for each material. The bio-oil was characterized by iodine index, acid number, and mass, and the contents of its compounds were obtained by GC-FID chromatography. The best result for the undecylenic acid mass yield of the desired compounds occurred at 530°C, achieving 17.8% from ricinoleic acid and 16.5% from castor oil. For the heptaldehyde, the highest production was also obtained at 530°C, with a value of 20.7% from methyl ester and 15.2% from ricinoleic acid.

The potential of biogas production using fish waste (FW) and its effect on greenhouse gas (GHG) reduction and on energy production were evaluated on this research. FW was co-digested with anaerobic sewage sludge (SS). The FW was collected in the city of Bragança, northern Brazil, in which the fish industry is the main activity with a FW production of approximately 9,000 kg•day-1. The experimental part included five SS/FW ratios, and in two experiments hydrogen was added. The experiments were carried out for 30 days and the effect on the cumulative biogas and methane yields were analyzed. The GHG reduction was estimated using the amount of FW not discarded in the Bragança open dump; and the electricity generation was calculated using the methane yield. Besides, two kinetic models were performed. The results presented a GHG reduction of 1,619 tons of CO2e and an electricity production of 372 to 956 MWh•year-1. The analysis of variance indicated that the methane production was highly dependent on the SS/FW ratios which ranged from 76 to 138 mL•gvs-1. Finally, this research showed the benefit of using FW to generate biogas and electricity while reducing GHG emissions in a city where there is no energy project.