Bench-scale Unit Research Articles

Scaling a bifunctional catalytic Fixed-Bed reactor for acetone-to-mesitylene Jet-Fuel additive production

De-fossilization of the aviation sector will require the use of renewable synthetic jet fuels and additives that comply with strict regulations. One such additive, mesitylene, can be produced using a novel sustainable process based on the fermentation of biomass waste to acetone, followed by the self-condensation of acetone to mesitylene. This study addresses the viability of gas-phase self-condensation of acetone, catalyzed by TiO2 and Al-MCM-41 acid catalysts, at a technological readiness level of TRL-4.The reactor used was a bench-scale fixed-bed reactor (28 mm diameter and 500 mm height) loaded with commercial-sized catalyst pellets (1/8″ diameter). It was equipped with a jacket for heat transfer using flowing thermal oil. The performance of commercial-scale reactors was approximated under conditions of 275 °C, 280 kPa, and a space velocity of 50–500 mol/kg·h.The catalyst pellets exhibited significant mass transfer resistances, which limited the reaction rate. This, in turn, reduced the deactivation rate caused by the adsorption of high-molecular-weight condensation products on the strongest acid sites. Additionally, the product distribution differed between pellet and powder forms of the catalysts, with higher yields of isophorone and mesitylene being observed on TiO2 and Al-MCM-41 pellets, respectively. A reaction and mass transfer model was proposed and fitted to the bench-scale data.The study also considered the combination of both catalyst pellets in the same reactor for the bench-scale unit. It was demonstrated that mesitylene yield could be improved, with the best configuration being two separate beds placed consecutively in the reactor with a catalyst ratio of 1:2 (TiO2:MCM-41).

Capabilities of Microbial Consortia from Disparate Environment Matrices in the Decomposition of Nature Organic Matter by Biofiltration

Dissolved organic matter (DOM) plays a pivotal role in drinking water treatment, influencing the performance of unit processes and final water quality (e.g. disinfection byproduct risk). Biofiltration is an effective method of reducing DOM, but currently lacks a comprehensive appreciation of the association between microbial profiles and biofiltration performance. In this study, bench-scale biofiltration units inoculated with microbial consortia from river and soil matrices were operated successively for comparing their efficacy in terms of DOM removal. The results showed that biofiltration units receiving soil microbes were significantly superior (p < 0.05) to those receiving river inoculated microbes in terms of decomposing DOM recalcitrant fractions and reducing DBP formation potential, resulting in DOC and DBP precursor removals of up to 58.4 % and 87.9 %, respectively. Characterization of the taxonomic composition revealed that differences in the microbial assembly of the two biofilter groups were subject to deterministic rather than stochastic factors. Furthermore, more complicated interspecific relationships and niche structures in soil inoculated biofilters were deciphered by co-occurrence network, providing a plausible profile on a taxonomic division of labor in DOM stepwise degradation. Accordingly, the contribution of microbial compositions was found to be of greater importance than the GAC mass and biomass attached to the media. Thus, this study has advanced the understanding of microbial-mediated DOM decomposition in biofiltration, and also provided a promising strategy for enhancing the process for water use via developing appropriate engineered consortia of bacteria.

PIV investigation on the effect of gas distributor design for fluidization of Geldart A spherical particles

This is a hydrodynamics study on gas distribution during fluidization of the industrially relevant Geldart A type particles. The impact of 10 different distributor designs comprising perforated distributors (pitch and orifice arrangement pattern varied) and nozzle distributors (nozzle size varied) were studied experimentally on a bench-scale unit. Particle flow homogeneity in air was determined by a novel Particle Image Velocimetry (PIV) analysis of the freeboard velocity field. Over 50 PIV particle phase vector field images are presented and analysed. Bed expansion, Particle attrition with and without fines, velocity profiles with and without fines and effect of fines on bed expansion were ascertained. Best distributor design for a unit such as Fluid Catalytic Cracking (FCC) regenerator and FCC riser were found to be 0.8 cm and 0.6 cm nozzle plates distributors respectively. Confirmation with previous study revealed a correlation between homogeneous distribution of particulate flow and lower number of turbulence zones.

Hydrochar fractionation and composition in batch and continuous hydrothermal liquefaction

Understanding differences in hydrochar characteristics in batch and continuous hydrothermal liquefaction (HTL) is crucial in determining suitable valorisation routes for this byproduct, given its high nutrient load and carbon sequestration potential.This study thoroughly characterised hydrochar from batch and continuous HTL at 300, 325 and 350 °C, elucidating their main differences and shedding light on the operational parameters causing them. For this purpose, a bench-scale continuous HTL unit with in-line solids separation was commissioned. It was possible to differentiate primary and secondary char and infer their formation mechanism.The results showed that batch hydrochar yields were higher (24–26%) than continuous (primary and secondary) char yields (15–19%). In both reactions, higher temperatures led to chars with lower carbon and nitrogen contents. The ash content of batch hydrochars was lower than that of continuous primary chars, revealing that the in-line char separator effectively removed inorganic impurities at reaction conditions and produced a cleaner biocrude. The nutrient distribution in the HTL products showed batch biocrudes were more contaminated by Na, K and Fe, while in the continuous biocrudes, only Fe was detected. Moreover, less carbon migrated to the solids from continuous HTL, indicating that removing inorganics may reduce secondary char formation.Batch hydrochars showed a higher presence of oxygenated and nitrogenated compounds, while the continuous primary chars had a higher share of alkanes and alkenes.These differences may imply that batch reactions may not serve as indicators, in terms of hydrochar characteristics, for HTL upscaling to industrial plants.

Feedback control strategy of Fischer–Tropsch process in a micro-GtL plant

Gas-to-liquid technology monetizes flared natural gas to produce green fuel while reducing carbon emissions. In the first step, oxygen reforms methane to CO and H2 followed by Fischer–Tropsch synthesis (FTS), which is highly exothermic and requires a tight temperature control to avoid thermal runaway. Bench-scale units are insufficient to generate basic data to design dynamic control systems for pilot-plants, particularly for intensified processes, because of uncertainties related to heat losses and the spatial and temporal reaction rates. Here, we propose a simulation-based feedback controller design strategy to initially estimate the parameters of a proportional Integral (PI) controller. We applied a power law model to design the controller in Aspen V12 and tested its robustness with a fractional lumped model as an alternative. An Excel ‘solver module’ estimated heat exchange parameters considering the fluidized bed hydrodynamics at steady state. Then, through dynamic simulation, we identified the parameters of a ‘first-order plus dead time’ model via a step response of the reactor temperature to design the PI temperature controller. The controller parameters were characterized by the internal model control (IMC) approach, which is robust to upstream disturbances, kinetic model mismatch, and heat exchange uncertainties.

Synthesis of high-performance biocompatible polymeric membranes incorporated with zirconium-based MOF for an enhanced brackish water RO desalination

A nanosized zirconium 1,4- dicarboxybenzene metal-organic framework (UiO-66-MOF) was synthesized and impregnated into cellulose acetate (CA) polymeric matrix to enhance the membrane characteristics for brackish water desalination. Phase inversion was used for the fabrication of CA/UiO-66 hybrid membranes (CAU-X), where X is the concentration of immobilized UiO-66 nanoparticles (UiO-66-NPs) into CA polymeric matrix. Morphological structure and functional groups were investigated through different characterization techniques to prove the successful synthesis of the prepared UiO-66-NPs, the blank CA membrane, and hybrid CAU-X membranes. For more CAU-X characteristics, porosity, contact angle, and tensile strength were measured. The obtained data demonstrated that the impregnation of zirconium-based-NPs had a positive influence on the blank CA membrane properties. Additionally, the performance of the fabricated membranes was investigated in reverse osmosis (RO) bench-scale unit. The performance results for the pristine CAU-0 membrane showed a high salt rejection (SR) of 99.8% and a permeate water flux (PWF) of 1.14 L/m2.h. In comparison to pristine CA membrane, CAU-X hybrid membranes have a slightly lower SR and a higher PWF. It was found that the hybrid CAU-0.02 membrane had almost a doubled PWF of 2.8 L/m2.h with only 2% sacrificed SR of 97.6% compared with CAU-0 membrane. Moreover, a much better PWF of 3.4 L/m2h and a sufficient SR of approximetly 92% were obtained by CAU-0.05 membrane. Thus, CAU-0.05 was selected to further test its performance under different operating parameters. Results revealed that the optimum parameters were recorded for a sodium chloride feed stock of 5000 ppm operating at 25 °C temperature and pressure up to 15 bar.Graphical

Layer formation on quartz bed particles during fast pyrolysis of grass

Commercial fast pyrolysis technologies use bed materials, normally natural sand mainly consisting of quartz, acting as circulating heat carrier materials. Nowadays, the commercial conversion of biomass into fast pyrolysis bio-oil (FPBO) is still using ash-lean woody residues as a feedstock since the application of more abundant and possibly cheaper ash-rich agricultural biomass is currently at a significantly lower technology readiness level (TRL). To promote FPBO production from ash-rich biomass, the ash-related issues during the operation process need to be further studied. In the present investigation, the characteristics and formation process of layers formed on quartz bed particles, collected from a bench-scale fast pyrolysis unit based on the rotating cone technology, were studied. Two grass residues, representative of typical Si-K-rich agricultural biomass fuels, were used as feedstocks. Quartz bed particles at different sampling times from startup with fresh bed particles were collected. Scanning Electron Microscopy/Energy-Dispersive Spectroscopy (SEM/EDS) was employed to characterize the layer properties. Bed particle layers exhibited an uneven and discontinuous distribution on the quartz surface. This distribution over bed particles, as well as layer thickness, increased with the operational time. The dominating elements contained in layers were Si, K, Ca, and Cl (excluding O), which resembled that of individual bed ash particles found in the bed samples. In addition, the interpretation of the results was supported by thermodynamic equilibrium calculations. The findings suggest that the process of layer formation was governed by the direct adhesion of non-melted bed ash particles during the fast pyrolysis of grass.

The effect of recycle stream on slurry-phase hydrocracking of vacuum residue: An experimental and modeling approach

The effect of the recycle stream on slurry-phase hydrocracking (HCK) of vacuum residue was examined using a continuous bench-scale unit with the aim of attaining process optimization. This was achieved through a model-based approach that links experimental investigations, kinetic modeling, and model-based optimization. The experiments were conducted at various reaction temperatures, liquid hourly space velocity of fresh feed (LHSVFF) and recycle ratios at a pressure of 160 bar, with the fresh feed containing 1000 wt. ppm of molybdenum. The HCK kinetic model was modified to incorporate the recycling effects and accurately predict the experimental data. The adapted model confirmed that the unconverted residue in recycle operating mode (ROM) became more refractory. By implementing the modified kinetic model in a dynamic Simulink model, the prediction accuracy of RES conversions and product yields can be improved by up to 25.1 wt.% in the case of the lowest conversion. A sensitivity analysis using the dynamic model showed that the temperature exerted a greater impact on the RES conversion and recycle ratio in ROM. An operational stability index was also proposed to prevent operation failure in ROM. Finally, an optimal operating condition from the parametric study was found to meet several process goals simultaneously.

Electric field forward osmosis (EFFO) fouling mitigation in algae harvesting

Efficient microalgae harvesting is crucial for sustainable biofuel production. Forward osmosis (FO) membranes offer a cost-effective solution for algae separation but are prone to membrane fouling. To address this, a bench-scale FO membrane unit was created, utilizing an aquaporin thin film composite FO membrane. The unit was combined with an electric field in both continuous and pulsing modes, employing stainless steel (SS) meshes to mitigate fouling during Chlorella vulgaris dewatering. Generally, applying higher electric potentials in continuous mode demonstrated improved water flux and flux recovery. The electric field forward osmosis (EFFO) configuration achieved significantly higher fluxes at applied potentials of −0.1, −0.4, and −1.0 V compared to the control. An electric potential as high as −10 V effectively removed fouling by inducing H2 gas formation on the SS cathode. Additionally, the application of high electric potential led to increased settling velocity, possibly due to electrocoagulation and the release of metals. Conversely, carbon fiber electrodes had no impact on algal cell morphology. Both higher salinity levels and increased potential enhanced lipid contents in algal biomass. Overall, EFFO technology in algae harvesting offers improved efficiency by reducing membrane fouling and increasing water flux, enabling cost-effective and sustainable biofuel production from microalgae.

Multi-scale experimental investigation on the fluidization of Geldart B 13X zeolite particles: A comprehensive dataset for CFD validation

The fluidization of zeolite 13X in a bubbling fluidized bed was experimentally investigated. The objective is to analyze the fluidization behavior of particles in a lab-scale system with a total of 1.5 million particles, enabling accurate characterization of uncertainties. Validation datasets were generated for the fluidization process in a bench-scale rectangular unit. A comprehensive characterization of the particle properties, including size, density, coefficient of friction, coefficient of restitution, and minimum fluidization velocity, is presented using advanced diagnostic tools. Corresponding fluidized bed measurements, such as pressure drop and bed expansion, are reported under three test settings with different flow rates. The tested particles have a Sauter mean diameter of 1,345 μm and a density of 2,054 kg/m3. It is classified in Geldart group B for its vigorous bubbling and good mixing behavior. With increasing the superficial inlet velocity from 0.347 to 0.740 m/s corresponding to 1.41–3.01 Umf, where Umf = 0.2458 m/s is the minimum fluidization velocity, the particles tend to transit from bubbling flow to slug/plug flow regimes. Using high-speed imaging, bubble sizes and velocities in the pseudo-two-dimensional (2D) fluidized bed could be obtained directly. The data acquisition rate is 1200 fps, far above the quantities of interest (QoI) dominant frequency (typically below 10 Hz). The QoI obtained from this study were statistics of interface height, differential pressure, and particle velocities using particle image velocimetry. The results confirm consistency given the use of randomization and repeat in the run order as well as multiple batches of bed material. This experimental dataset can serve as a benchmark for validating numerical models and as a blind study for the multiphase flow modeling community.

Role of grinding method on granular activated carbon characteristics.

A coconut shell (AC1230CX) and a bituminous coal based (F400) granular activated carbon (GAC) were ground with mortar and pestle (MP), a blender, and a bench-scale ball milling unit (BMU). Blender was the most time-efficient for particle size reduction. Four size fractions ranging from 20 × 40 to 200 × 325 were characterized along with the bulk GACs. Compared to bulk GACs, F400 blender and BMU 20 × 40 fractions decreased in specific surface area (SSA, -23% and -31%, respectively) while smaller variations (-14% to 5%) occurred randomly for AC1230CX ground fractions. For F400, the blender and BMU size fraction dependencies were attributed to the combination of (i) radial trends in the F400 particle properties and (ii) importance of shear (outer layer removal) versus shock (particle fracturing) size reduction mechanisms. Compared to bulk GACs, surface oxygen content (At%-O1s) increased up to 34% for the F400 blender and BMU 20 × 40 fractions, whereas all AC1230CX ground fractions, except for the blender 100 × 200 and BMU 60 × 100 and 100 × 200 fractions, showed 25-29% consistent increases. The At%-O1s gain was attributed to (i) radial trends in F400 properties and (ii) oxidization during grinding, both of which supported the shear mechanism of mechanical grinding. Relatively small to insignificant changes in point of zero charge (pHPZC) and crystalline structure showed similar trends with the changes in SSA and At%-O1s. The study findings provide guidance for informed selection of grinding methods based on GAC type and target particle sizes to improve the representativeness of adsorption studies conducted with ground GAC, such as rapid small-scale column tests. When GACs have radial trends in their properties and when the target size fraction only includes larger particle sizes, manual grinding is recommended.

Optimization and Evaluation for the Capacitive Deionization Process of Wastewater Reuse in Combined Cycle Power Plants

Combined cycle power plants (CCPPs) use large amounts of water withdrawn from nearby rivers and generate wastewater containing ions and pollutants. Despite the need for wastewater reclamation, few technologies can successfully convert the wastewater into make-up water for CCPPs. Therefore, this study aimed to apply capacitive deionization (CDI) for wastewater reclamation in CCPPs. Using a bench-scale experimental unit, which included ion exchange membranes and carbon electrodes, response surface methodology (RSM) was used to optimize the operating conditions of the CDI process to increase the total dissolved solids (TDS) removal and product water ratio. The optimal conditions were found to be a voltage of 1.5 V, a flow rate of 15 mL/min, and an adsorption/desorption ratio of 1:0.8. The changes in CDI performance with time were also studied, and the foulants on the membranes, spacers, and electrodes were examined to understand the fouling mechanism. The TDS removal decreased from 93.65% to 55.70% after 10 days of operation due to the deposition of scale and organic matter. After chemical cleaning, the TDS removal rate recovered to 93.02%, which is close to the initial condition.

A low-cost in-situ bioremediation process for perchlorate contaminated aqueous phase.

Perchlorate is a known endocrine-disrupting micropollutant. The efficiency of a low-cost in-situ bio-remediation process for perchlorate-contaminated aqueous phase was evaluated in a bench-scale unit in this study. The two-stage process unit comprises an anaerobic leach bed unit (5.3L) for generating leachate and an anaerobic filter bed unit (10L) inoculated with an isolated perchlorate reducing Serratia marcescens (GenBank Accession No. JQ807993). Organic leachate produced from anaerobic digestion of vegetable waste served as a sole substrate for the perchlorate reduction, and needle-felt natural fibre was used as a filter bed medium. The filter bed unit removed 98.5% of perchlorate at 10mg/L initial concentration (volumetric loading, 39mg/L/day) at an optimal soluble COD concentration of 40mg/L in the leachate and a hydraulic retention time of 6.15h. Controlled leachate delivery results in an effluent COD <20mg/L, reducing the risk of residual organic contamination in the treated water. Considering the many advantages, this approach would be more feasible for treating perchlorate-contaminated aquifers, streams, and surface canals.

Evaluation of a hydrodynamic cavitation-type bubble generator in a prototype bench-scale flotation unit for poultry processing wastewater treatment

ABSTRACT Dissolved Air Flotation (DAF) systems are designed to remove oil and grease (O&G) and total suspended solids (TSS) in wastewater treatment. These systems require saturation tanks, water pumps, and high-pressure compressors to control the pressure, hydraulic retention time, and airflow parameters. DAF process efficiency depends on complex operational controls associated with these components, and the most critical aspect of an effectively operating DAF unit is a generated bubble size. This work presents the design and operational test of a flotation unit prototype that replaces the saturation tank and high-pressure compressors present in DAF with the CARMIN microbubble injector, the evaluation of the proposed system's TSS and O&G removal efficiency was carried out considering different initial configurations of the injector to change the generated microbubble size, four synthetic wastewater solutions, and poly aluminum chloride as a flocculant to establish the potential of this system for the poultry processing wastewater treatment. Mean microbubble size results were obtained from 47.41 µm to 116.17 µm. The average removal efficiency of TSS exceeded 65% under a high concentration of suspended particles (1,560 mg/l) and 80% under a lower TSS concentration (795 mg/l). Meanwhile, 70% and 90% of O&G were removed from high (400 mg/l) and low (100 mg/l) initial O&G concentrations, respectively. These removal levels are similar to those reported in the literature for DAF for poultry processing wastewater, albeit with a simple configuration and better controllability and scalability.

Evaluation of an ultrafiltration membrane for the removal of fish viruses and bacteria in aquaculture water

Ultrafiltration (UF) membranes are used to successfully remove waterborne virus and bacteria from wastewater and drinking water. However, UF membrane application in aquaculture water treatment is limited. In this study we evaluate the performance of a capillary polyethersulfone UF membrane to remove two benchmark waterborne fish pathogens: i) the infectious pancreatic necrosis virus - IPNV, which is an unenveloped icosahedral virus, and ii) the bacterium Aeromonas salmonicida, which is a Gram-negative, facultative anaerobic bacilli. Moreover, the UF membrane bench-scale unit was tested at two temperatures according to salmonid aquaculture: low (4 - 7°C) and high (16 - 19°C). Sterilised natural seawater was spiked with laboratory cultured pathogens, the water was filtrated, and the membrane permeate collected. Both pathogen solution and permeate were evaluated using a cell culture method to estimate the colony-forming units (CFU/ml) for bacteria presence, a median tissue culture infectious dose (TCID50/ml) assay for virus presence, and real-time quantitative polymerase chain reaction (RT-qPCR) for both bacteria and virus presence. The membrane permeate was negative for both virus and bacteria for all analysis and for both low and high temperatures. The results from this bench-scale study are encouraging for the application of UF membrane technology in aquaculture water treatment to prevent virus and bacteria outbreaks. Further studies should validate this UF membrane technology results in commercial aquaculture conditions.

Design and construction of a continuous pilot flotation facility: A case study for water-based oil sand extraction

In this work, the design and construction of a continuous and pilot-scale flotation facility are demonstrated. The performance of the new facility was evaluated from series of pilot flotation tests, carried out using oil sands slurry to extract bitumen—an extra-heavy form of petroleum. Results indicated that bitumen recoveries of the new pilot plant for an identical ore and water chemistry were largely dependent on air injection method, slurry conditioning time, flotation residence time, and slurry temperature. Importantly, when compared with those of bitumen extraction tests using a bench-scale Batch Extraction Unit (BEU) operated at the most optimal conditions, it was suggested that the new pilot plant produced flotation recoveries of bitumen and froth qualities at a level as good as, or even higher than, the level accomplished using the BEU at an identical ore, water chemistry and operating temperature. This continuous, pilot flotation plant could potentially serve as a pre-commercial production system that verifies a new processing aid, or as an alternative extraction technology for oil sand, coal, and mineral processing.

High-Temperature Pyrolysis for Elimination of Per- and Polyfluoroalkyl Substances (PFAS) from Biosolids

Biosolids generated as byproducts of wastewater treatment processes are widely used as fertilizer supplements to improve soil condition and ultimately agricultural products yields and quality. However, biosolids may contain toxic compounds, i.e., per- and polyfluoroalkyl substances (PFAS), which can end up in soils, groundwater, and surface water, causing adverse environmental and health effects. The purpose of this study was to investigate the application of High-Temperature Pyrolysis (HTP) treatment for biosolids management, and its efficacy in eliminating PFAS from the solid fraction. Biosolid samples were pyrolyzed at two different temperatures, 500 and 700 °C, in a continuous bench-scale pyrolysis unit. The major finding is that the treatment process at higher pyrolysis temperatures can remarkably reduce or eliminate the level of PFAS (by ~97–100 wt%) in the resulting biochar samples.

Unraveling the carbene chemistry of oxymethylene ethers: Experimental investigation and kinetic modeling of the high-temperature pyrolysis of OME-2

Oxymethylene ethers (OMEs) form an interesting family of synthetic compounds to replace fossil fuels. This alternative liquid energy carrier can contribute to a circular carbon economy when produced via carbon capture and utilization technology using renewable electricity. Despite the potential to reduce greenhouse gas and particulate matter emissions and their ideal ignition characteristics, little is known about the thermal decomposition behavior of OMEs. In this work, new insights are obtained in the pyrolysis chemistry of oxymethylene ether-2 (OME-2) and the role of carbenes by performing experiments at high temperatures (> 850 K) in a tubular quartz reactor. The used continuous bench-scale pyrolysis unit has a dedicated on-line analysis section including comprehensive two-dimensional gas chromatography (GC × GC) coupled with flame ionization detection (FID) and mass spectroscopy (MS) to identify and quantify the full product spectrum over the complete temperature range. The reactor temperature was varied between 850 and 1150 K at a fixed pressure of 0.15 MPa and residence times of 400 to 850 ms. The major products are dimethoxymethane, formaldehyde, methyl formate, methane, CO2, CO and H2. Minor intermediate compounds comprise dimethyl ether, formic anhydride, formic acid, methoxymethyl formate and methoxymethanol. The yields of compounds with carbon-carbon bonds are low since no such bonds originally occur in OME-2. Precursors of aromatic compounds and soot particles are absent in the reactor effluent. The experimental results are simulated with a new first principles-based kinetic model for pyrolysis and combustion of OME-2. This model can predict the experimental trends of major products on average within the experimental uncertainty margin of ± 10% relative for major product species. A reaction pathway and sensitivity analysis are presented to highlight the importance of the carbenes for initiation of the radical chemistry under pyrolysis conditions.

The CREC Fluidized Riser Simulator a Unique Tool for Catalytic Process Development

The CREC Riser Simulator is a mini-fluidized bench scale unit invented and implemented in 1992, at the CREC (Chemical Reactor Engineering Centre), University of Western Ontario The CREC Riser Simulator can be operated at short reaction times, in the 3 s to 20 s range. The present review describes and evaluates the original basic concept of the 1992-CREC Riser Simulator Unit, and the improved design of the 2019-CREC Riser Simulator. Both the initial and the enhanced units are specially engineered to allow the rigorous assessment of both catalyst performance and catalytic reaction kinetics. Kinetic parameters of relatively simple and accurate mathematical models can be calculated using experimental data from the CREC Riser Simulator. Since its inception in 1992, the CREC Riser Simulator has been licensed to and manufactured for a significant number of universities and companies around the world. Several examples of scenarios where the CREC Riser Simulator can be employed to develop fluidized bed catalytic and heterogeneous reactor simulations are reported in this review. Among others, they include (a) hydrocarbon catalytic cracking, (b) the catalytic conversion of tar derived biomass chemical species, (c) steam and dry catalytic methane reforming, (d) the catalytic oxydehydrogenation of light paraffins, (e) the catalytic desulfurization of gasoline, and (f) biomass derived syngas combustion via chemical looping. In this review, special emphasis is given to the application of the CREC Riser Simulator to TIPB (tri-iso-propyl-benzene) catalytic cracking and the light paraffins catalytic oxydehydrogenation (PODH).

Dual-Media Granular Filtration System for Slaughterhouse Wastewater Treatment: A Case Study in Bangladesh

In developing countries, including Bangladesh, deliberate disposal of the untreated slaughterhouse wastewater causes environmental pollution and poses threat to public health. In this study, slaughterhouse wastewater was analyzed for the Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD5), and faecal coliforms (E. coli) were found ranging between 1,840–3,300 mg/L, 62–619 mg/L and est.&gt;3,400– 6,00,000 CFU/100 ml, respectively. A bench-scale treatment unit, adopting activated sludge process, was developed in the laboratory and the average treatment efficiency for BOD5 and TSS were found 67% and 39%, respectively. However, the efficiency for microbial removal performance was inconclusive. An additional duel-media granular filtration unit was developed to improve the effluent quality and the treatment efficiencies for BOD5, TSS and E. coli were improved to 90% to 100%. The study highlighted the level of pollution caused by the slaughterhouse wastewater disposal to the surrounding water bodies and how the decentralized treatment approach can improve water quality. Journal of Engineering Science 13(1), 2022, 41-50