Laboratory-scale System Research Articles

Theoretical and Experimental Analysis of Osmotically Assisted Reverse Osmosis for Minimum Liquid Discharge.

Osmotically assisted reverse osmosis (OARO) is an innovative process that shows promising potential in the treatment of brine produced by conventional reverse osmosis (RO) systems. This study presents a theoretical and experimental analysis of the OARO process, focusing on its application to achieve minimum liquid discharge (MLD). This theoretical analysis includes the development of a mathematical model to describe the transport phenomena occurring during OARO. By considering mass balance equations coupled with transport equations, the theoretical model allows for the simulation of a full-scale system consisting of a single-stage RO and a four-stage OARO. Experimental investigations are also conducted to validate the theoretical model and to evaluate the performance of the OARO process. A laboratory-scale OARO system is designed and operated using a synthetic RO brine. Various operating conditions, including applied pressure, feed concentration, and draw concentration, are varied to investigate their effects on process performance. The experimental results demonstrate the feasibility of OARO as an MLD solution and also validate the predictions of the theoretical model, confirming its reliability for process optimization and design. The results of the theoretical analysis show that OARO has the potential to significantly improve water recovery compared to conventional RO. Based on the simulation, the optimal operating conditions are explored, leading to a significant reduction (up to 89%) in the volume of brine discharge.

Sulfidation of CoCuOx Supported on Nickel Foam to Form a Heterostructure and Oxygen Vacancies for a High-Performance Anion-Exchange Membrane Water Electrolyzer.

Anion-exchange membrane water electrolyzer (AEMWE) is attracting attention for hydrogen production owing to its ability to employ nonprecious metal catalysts and high energy conversion efficiency. Spinel-structured transition metal oxides exhibit excellent potential in oxygen evolution reaction (OERs). Nevertheless, the research on highly active and durable spinel-structured electrodes for the anodic OER of AEMWE is deficient. Herein, a self-supported S-CoCu oxide/nickel foam (S-CoCuOx/NF) anode was synthesized through a two-step method (electrodeposition and sulfidation). The formation of abundant oxygen vacancies and heterostructure collaboratively enhances the electron and mass transfer, resulting in an overpotential of 313 mV at 100 mA cm-2 for OER. For the lab-scale AEMWE system with the S-CoCuOx/NF anode, a current density of 1 A cm-2 was obtained at 1.87 V (cell voltage) with high durability for 110 h (1 A cm-2) at 60 °C. The results will provide insights into developing the spinel structure-derived anode for high-performance AEMWE.

Performance analysis of dual-evaporator ejector refrigeration system in different configurations: Experimental investigation

This study aimed to assess the effectiveness of an ejector refrigeration cycle, using a laboratory-scale experimental system operating in different configurations. The investigated configurations consisted of a conventional vapour compression refrigeration (CVCR) system and a dual evaporator ejector system (DEES) operated in two modes: DEES with a single thermal expansion valve (DEESA) and DEES with dual thermal expansion valves (DEESB). The findings revealed that the utilization of the ejector enhanced the refrigerant's mass flow rate. Additionally, the DEESA configuration achieved higher cooling capacities compared to the CVCR. Moreover, the DEESA configuration achieved up to 21% higher coefficient of performance (COP) values. On the other hand, when the system was operated in the DEESB configuration, it yielded lower evaporation temperatures and higher superheating degrees in comparison to DEESA. Based on the evaluations, it can be concluded that the ejector operates more efficiently in systems with dual evaporators, thereby making positive contributions to overall system performance.

Solar Disinfection Using Zero Valent Iron for Inactivation of Escherichia coli and Total Coliforms in Water Using a Raceway Reactor

Contamination from microorganisms is one of the gravest types of water pollution. In 2022, there were 842,000 new cases of gastrointestinal diseases worldwide. The aim of this study was to size, construct, and evaluate a Raceway reactor (28 L total capacity) as a laboratory-scale solar disinfection system for the inactivation of Escherichia coli and total coliforms in water, using Zero Valent Iron (ZVI). For this purpose, a sample of E. coli contaminated potable water was treated with steel wool as a source of ZVI and solar irradiation. Using a 23 factorial design with four central points and a total of 12 trials, the following was investigated: the effect of the Fe0 dose (0.6–1.8 g L−1); it should be noted that both the natural and drinking waters of the study area have iron concentrations of less than 0.1 mg L−1. Depth tests of the treated water in the reactor were carried out at different levels (5, 7 and 9 cm) and with a duration of four to six hours. Therefore, it is concluded that the reactor/ZVI is effective for the disinfection of E. coli and total coliforms at concentrations >2419.6 MPN/100 mL, reaching 99.96% disinfection for both cases; it is also a cost-effective treatment due to its inexpensive inputs.

Performance evaluation of a lab-scale subsurface flow-constructed wetland system for textile industry wastewater treatment.

This study compares biochar (BCW) systems' pollutant removal effectiveness to conventional subsurface flow (CCW) in constructed wetland systems to treat textile wastewater. The two systems were identical in construction, but the biochar was 0.1 m thick over gravel and sand (maximum flow rate of 0.021 m3 h-1) as the primary medium over CCW (flow rate of 0.02 m3 h-1). The results revealed that the BCW approach was more efficient than the CCW system (pebble over sand and gravels) in removing and lowering heavy metals below thresh hold limits such as Cr, Cd, Cu, Pb, Ni, and Zn. The alkaline nature of textile water achieves neutrality in both CCW and BCW. However, BCW is more efficient due to a larger active surface area and the ability to filter out more metal and organic ions. TDS reduction efficiency in BCW was 53.07%, compared to 40.04% in CCW. Heavy metal removal was 100% in BCW at 3 to 12 h, whereas it takes 6 to 24 h in CCW (82% for Cr to 93% for Cu). The quick removal of Na from textile wastewater by BCW was reversed and achieved equilibrium in 24 h in contrast to the CCW system (> 24 h). The findings obtained at the lab scale level demonstrated that the BCW system was more effective in reducing TDS, neutralizing the alkalinity of textile wastewater, and removing heavy metals. This study strongly supports the potential application of biochar-constructed wetlands for textile wastewater treatment.

Battery-Based Energy Storage System from Solar Panels Utilization for Worship House Applications in Carang Wulung Village

Due to the topography and hilly terrain in the area, there is still a hamlet in Carang Wulungvillage that does not have a low-voltage electricity network from PLN, namely Gondang Hamlet. As a result of this limitation, there is a place of worship (musala) in Gondang Hamlet that has not been adequately taken care of and is considered unfit when viewed from the availability of electricity. The community in this predominantly Muslim hamlet experiences lighting problems during congregational prayers at night until dawn. The lack of a power source for speakers also prevents the use of speakers to mark the prayer times. Based on this background, a battery-based energy storage system from solar panels was developed for this community service activity. The stages of community service activities carried out include surveying the needs for the installation of solar panel and battery installation systems, assembling several system components, testing the laboratory-scale system, installing the system that has been assembled and tested, and conducting socialization and training for residents on the use, operation, and maintenance of the solar panel system. The residents are happy that this community service activity has been carried out because they can worship comfortably at any time without relying on PLN as a source of electricity

Constructed wetlands with recycled concrete for wastewater treatment in cold climate: Performance and life cycle assessment

This study investigated the technical, environmental, and economic feasibility of using recycled construction material (concrete) as substrate in constructed wetlands for cold climate decentralized domestic wastewater treatment. The wastewater treatment efficiency was examined, and life cycle assessment (LCA) and cost benefit analysis were performed. The technical feasibility was assessed in lab-scale two-stage wetland systems with recycled concrete or lava stone as substrates, which were operated at 22 °C and 5 °C with local wild plants and vegetables. The wetlands removed ∼85 % and ∼51 % of organics and ∼67 % and ∼34 % TN at 22 °C and 5 °C, respectively; no significant difference was found between concrete and lava stone. The heavy metal contents in the cultivated vegetables met WHO standards for human consumption, showing the feasibility of nutrient recovery from the treated wastewater. A comparative LCA of septic tank standalone, septic tank + constructed wetland (with recycled concrete), and gravity-driven ceramic membrane (GDCM) system was performed. This aims to illustrate the benefits of intensifying the existing treatment process (i.e., septic tank) with the constructed wetland, with an alternative membrane-based treatment technique as benchmark. The LCA results revealed that using waste materials as the substrate in constructed wetlands could reduce the environmental impact of wetlands. Installation of the wetland as posttreatment of the septic tank (1) could reduce ∼50 % of eutrophication potential without increasing global warming impact compared to the septic tank alone; (2) had ∼90 % higher global warming impact and ∼40 % lower eutrophication impact compared to GDCM. Economic analysis revealed that the total cost of septic tank + constructed wetland (0.143 €/m3) was comparable to the septic tank alone (merely 3.5 % difference), and 49 % lower than that of GDCM (with recycled membranes). Therefore, the septic tank + constructed wetland scenario could be favorable for sensitive areas with eutrophication potential regarding its technical, economical, and environmental feasibility.

Application of response surface methodology (rsm) for optimisation of cod removal from tofu wastewater in an adsorption process using silica adsorbent

The entry of pH, turbidity, COD, and TSS pollutants from tofu wastewater decreases discharge water quality and may affect the discharge water treatment process. This study aims to find variations in the mass and size of silica and the optimum adsorption time on the removal efficiency of pH, turbidity, COD, and TSS from tofu wastewater using silica adsorbent with applying surface response methodology. Chemical treatment was carried out to meet turbidity, COD, and TSS parameters. The research method used a laboratory-scale batch system with adsorbent size, mass, and adsorption time variations. From the research conducted, it obtained that the best removal for the pH test was the 100 mesh silica variation in the treatment of 3.295 gr with an adsorption time of 37 minutes; the pH value after removal was 4.87, for the turbidity test was 80 mesh silica variation in the treatment of 10 gr with an adsorption time of 15 minutes and the turbidity value after removal was 114 NTU, for the COD test, the best removal was obtained from a variation of 8.74937 gr of 104,342 mesh size silica at 39.0248 minutes of contact time with a COD value after removal of 851.33 mg/l, then for the TSS test was the 80 mesh silica variation in the treatment of 10 gr with an adsorption time of 59 minutes and the TSS value after removal was 65 mg/l.

Comments: Join Us at ATCE in San Antonio

We’re looking forward to attending the SPE Annual Technical Conference and Exhibition (ATCE) next month in San Antonio, Texas, at the Henry B. Gonzales Convention Center. It kicks off with the opening general session, “Expanding the Opportunities to Sustainably Fuel the World,” on Monday, 16 October. The offerings in a roster of 45 technical sessions begin Monday afternoon and continue through Wednesday. More than 15 pre-conference training courses are available, 1-day courses on 15 and 19 October and 2-day courses on 14 and 15 October. All will take place at the convention center meeting rooms and tickets must be purchased separately. Discounted pricing for advance registration is available until 14 September. Participants receive 0.8 Continuing Education Units (CEUs) for 1-day courses and 1.6 CEUs for 2-day courses. Special sessions are scheduled daily. Among the topics on Monday is the 11th SPE Comparative Solution Project (CSP). The call for participation was announced in March at the 2023 SPE Reservoir Simulation Conference. The goal is to provide a common platform and reference case for numerical simulation of geological carbon storage (GCS), specifically development of simulations of realistic complexity. This session will provide an overview of a recently completed forecasting and validation study conducted on a laboratory-scale proxy GCS system. The annual PetroBowl championship competition on 16 October pitches SPE student chapter teams against each other in a series of quick-fire rounds, answering technical and nontechnical industry-related questions. The contest has grown in size and popularity since its debut in 2002, and in 2015 expanded globally with the introduction of six regional qualifier contests. Regional qualifier competitions now take place in the Africa, Asia Pacific, Europe, South America and Caribbean, Middle East, and North America SPE regions, and the top 32 teams are invited to the PetroBowl championship. The Annual Awards Banquet on 17 October will recognize our members who were selected as the 2023 SPE International Awards recipients. The President’s Luncheon and Annual Meeting of Members on 18 October will feature 2023 SPE President Medhat Kamal’s “state of the Society” presentation and conclude with President Kamal passing the gavel to 2024 SPE President Terry Palisch. In this issue, JPT introduces President Palisch’s inaugural podcast episode and transcript in which he discusses the theme he has selected for his presidency, “Creating Our Energy Future.” He highlights the challenges facing our industry and SPE members, his outlook for our industry, and what his goals will be during his presidency. He will be recording podcast episodes which you can find with transcripts in the monthly digital editions of JPT and on the JPT website. Also on 17 October, the Startup Village Energy Startup Competition and the Competition Awards Ceremony will occur in person. The competition will begin in the morning, and a reception and award ceremony will take place in the afternoon. Be sure to visit the Exhibition Hall to learn about the latest technologies from a wide variety of companies. And swing by the SPE Pavilion, booth 630, where you can learn more about SPE with staff available to answer your questions. Southwest Research Institute facilities (SwRI) is offering attendees a tour of its facilities on 19 October. SwRI is an independent, nonprofit research company headquartered in San Antonio with world-renowned test facilities and expertise that have been used by the oil and gas industry for more than 75 years. Tour registration is required. On the lighter side, when you’re ready for some downtime, San Antonio offers many attractions and restaurants. Before you go, take a look at the variety of pre-ATCE content available to watch on SPE Energy Stream. For example, Lorenzo Simonelli, chairman and CEO of Baker Hughes, shares industry insights in an interview. Sushma Bhan, SPE Data Science and Engineering Analytics Technical Section chair, moderates a panel discussion about generative AI and its value for the energy industry. Nayeem Chowdhury, head of CCUS at Project Canary, discusses the enabling of startups and innovative entrepreneurs in oil and gas with a panel of experts. Enjoy the show and your time in San Antonio!

Feasibility study on the removal of toluene from the air stream by activated carbon/zeolite imidazolate framework composite material

In the present study, a porous composite material (activated carbon (AC)@ zeolitic imidazolate framework-8 (ZIF-8)) was synthesized by in situ method to remove toluene from the gas phase. The adsorption capacity, initial removal efficiency, breakthrough time, pressure drop, desorption and regeneration of this adsorbent were compared with those of ZIF-8 and AC to determine the most suitable adsorbent. The adsorption performance of the adsorbents for toluene was also evaluated in a laboratory scale system based on BS EN ISO 10121–1:2014 and previous studies. The toluene adsorption capacities of AC, ZIF-8 and AC@ZIF-8 were 1278.7, 2828.91 and 4538.09 mg/g, respectively, at 30.5 °C, 10 mg adsorbent mass, flow rate of 300 mL/min and relative humidity of 33%. In addition, the initial removal efficiencies of AC @ZIF-8, ZIF-8 and AC were 99.51%, 88.67% and 86.01%, respectively. The 50% breakthrough time of the composite was 16045 s, which was 3.5 times that of AC and 1.6 times that of ZIF-8. Moreover, the composite retained a 99.93% capacity after six reuse cycles. The in situ synthesis of AC @ZIF-8 composite was an efficient method and the adsorbent was successfully synthesized. This composite material exhibited high adsorption capacity for the removal of toluene from the air stream. In addition, the adsorbent proved to be cost-effective, maintaining a 99.93% capacity after several reuse cycles (99.93%). Considering the high cost of MOF synthesis and the drawbacks of AC, such as low selectivity, the synthesized AC @ZIF-8 composite can be used for air purification and adsorption processes.

(Invited) Emergent Absorbers, Interfaces, and Integration Methods for Chalcopyrite-Based Photoelectrochemical Water Splitting Devices

Photoelectrochemical (PEC) water splitting has the potential to become an efficient method for renewable hydrogen production. However, the efficiency, projected cost, and durability of lab-scale systems are not yet at the level required to make this technology economically feasible. Amongst all materials studied to date, the chalcopyrite class is arguably one of the most promising classes for PEC water splitting, as it has already demonstrated low-cost and high photoconversion capabilities as a photovoltaic material. In the context of PEC, our group demonstrated that co-evaporated 1.65 eV bandgap (EG) CuGaSe2 is capable of evolving hydrogen with Faradaic efficiency greater than 85% and generate photocurrent densities over 15 mA.cm-2, as measured in a 3-electrode configuration in 0.5M H2SO4 under simulated AM1.5G illumination. Unfortunately, CuGaSe2’s narrow EG limits its integration as top absorber into a dual junction stacked PEC device (also known as hybrid photoelectrode, HPE). In the present communication, we report on our latest efforts to synthesize wide-EG (1.8-2.0 eV) chalcopyrites, compatible with the HPE integration scheme, and capable of generating saturated photocurrent densities greater than 10 mA/cm2. We present specifically results on EG tunable Cu(In,Ga)(S,Se)2, Cu(In,Ga)S2, CuGa(S,Se)2 and CuGa3Se5. We also discuss some of the strategies developed to improve their surface energetics for the hydrogen evolution reaction, including the use of bandgap tunable MgZnO n-type buffer layers. Finally, we introduce the concept of semi-monolithic tandems, a new integration scheme where wide- and narrow-bandgap chalcopyrites are first integrated on separate substrates and then exfoliated, and finally bonded to create fully functional tandem device.

Benchmarking and Simulation of Solid-Oxide Steam Electrolysis for Propellant Production in a Vacuum Chamber-Simulated Lunar Environment

NASA and other space agencies have prioritized the development of in-situ resource utilization (ISRU) technology for producing critical materials such as propellants in space. Electrolysis to split water found in lunar, asteroid, and Martian environments provides a pathway for liquid H2 and O2 production, but the challenges of deploying such technology in extraterrestrial environments put an extreme emphasis on minimizing specific energy (measured in kWhelec/kgH2) and system specific mass (system kg/(kgH2/h)). High-temperature, solid oxide electrolysis cell (SOEC) systems have the potential to achieve lower specific energy than conventional liquid-phase alkaline and polymer electrolyte membrane (PEM) electrolysis systems, but this requires efficient thermal integration and minimization of balance of plant loads in order to take advantage of the lower electrolysis voltages for steam (vs. liquid H2O). The high operating temperatures of SOECs, however, require significant system mass for steam generators, heat exchangers for recuperation, and insulation of the electrolysis stack, particularly for space applications where ambient temperatures may be extremely low.This NASA-sponsored collaboration between OxEon Energy and Colorado School of Mines explored the feasibility of a lunar-based SOEC system, which was modeled and demonstrated at the lab-scale by operating a breadboard system, consisting of a SOEC stack and associated balance of plant BOP) in a cryogenic vacuum chamber in order to simulate a lunar environment. The combined »2.5-kWelec SOEC stack and BOP achieved a specific energy < 50 kWhelec/kgH2 at an H2 production rate of > 0.075 kgH2/h operating in the cryo-vacuum chamber.This study has benchmarked system-level models of the lab-scale SOEC stack based on doped-zirconia electrolytes fabricated at OxEon and designed to operate near thermoneutral voltage (1.28 V/cell) at 800°C. The stack BOP includes a steam generator, an oil-free scroll compressor, cathode and anode exhaust recuperators, and a H2 dryer, which uses cold incoming liquid water feeds to cool the cathode exhaust and condense most of the excess H2O in the H2 product stream out. Operation of this demonstration system provides a basis for designing scaled-up lunar fuel production systems of 40 kgH2/h. The success of the lab-scale tests in terms of thermal integration and the benchmarked models suggest a pathway to such a full-scale SOEC system that can achieve < 46 kWhelec/kgH2 with much lower specific mass.Both the modeling and the lab-scale demonstration tests revealed that system specific energy was most sensitive to stack steam utilization, and that achieving < 50 kWhelec/kgH2 required stack steam utilization > 75%. In addition, effective thermal integration that limited the electrical heating primarily to steam generation is critical to minimizing the SOEC-system BOP loads. The stack was shown to run reliably at steam utilizations > 90% with a single pass feed. Efforts will be presented on how to simulate such high utilization at larger scales for full lunar deployment. Additional testing of the lab-scale system in larger cryo-vacuum chambers at NASA during 2023 will allow for further confirmation of thermal management strategies to ensure reliable SOEC operation for lunar production of H2/O2 propellants.

Development of yeast and microalgae consortium biofilm growth system for biofuel production

BackgroundThe current study aimed to develop a laboratory-scale biofilm photobioreactor system for biofuel production. Scope & ApproachDuring the investigation, Jute was discovered to be the best, cheap, hairy, open-pored supporting material for biofilm formation. Microalgae & yeast consortium was used in this study for biofilm formation. ConclusionThe study identified microalgae and yeast consortium as a promising choice and ideal partners for biofilm formation with the highest biomass yield (47.63 ± 0.93 g/m2), biomass productivity (4.39 ± 0.29 to 7.77 ± 0.05 g/m2/day) and lipid content (36%) over 28 days cultivation period, resulting in a more sustainable and environmentally benign fuel that could become a reality in the near future.

High-rate upflow anaerobic sludge blanket bioreactor for the treatment of olive mill effluents: Laboratory and pilot scale systems investigation

Olive mill effluents are amongst the most prominent waste streams produced in Mediterranean countries, with their uncontrolled disposal in soil, without any prior treatment, having significant environmental and social effects. Anaerobic digestion has been extensively studied for the treatment of various waste streams, from industrial waste to agricultural and livestock residues. Some of the major advantages of anaerobic digestion relate to energy and soil fertilizer production. The scope of this work was the experimental optimization of the organic loading rate of anaerobic UASB digesters processing olive mill wastewater effluents. The optimization procedure was performed in a laboratory and a pilot scale set-up. The results showed that the maximum organic loading rate that could be applied to such a system was 5–6 gCOD/LR/d, without the need for any pretreatment. Moreover, it was exhibited that the large period of inoculum acclimatization to the olive mill effluents improved the phenols degradation inside the reactor, which reached 59%.

Fate of micropollutants in a lab-scale urban wastewater system: Impact of iron-rich drinking water treatment sludge

Iron rich drinking water treatment sludge (Fe-DWTS) could be a potential alternative for Fe salts in controlling sulfide in the sewer network. This study investigated the impact of in-sewer dosed Fe-DWTS on the fate of 26 different intrinsic organic micropollutants in wastewater by using a lab-scale integrated system consisting of sewer reactors and a sequential batch reactor (SBR) to simulate urban wastewater collection and treatment. The batch results revealed that seven among these 26 compounds had higher removal in the Fe-DWTS dosed sewer reactor compared to the control sewer reactor. In contrast, the removal of 7 out of the 26 investigated compounds were reduced, along with the biofilm methanogenic activity due to the long-term Fe-DWTS dosing. Cycle experiments in the SBR showed that the removal of acesulfame was enhanced and the formation of carbamazepine, desvenlafaxine, tramadol and hydrochlorothiazide were reduced, compared to their behaviour in the control SBR. However, the long-term experiments showed no adverse or beneficial effect of in-sewer dosed Fe-DWTS on the removal of most micropollutants in the SBR. Codeine, trimethoprim and gabapentin were exceptions with slightly higher concentrations in the experimental SBR effluent, possibly due to change in microbial composition.

Membrane-assisted reactive crystallisation for the recovery of dissolved phosphorus in vivianite form from liquid effluents

Novel membrane crystallisation processes resolve the mixing challenge on conventional crystallisers, by providing fixed interfacial area over which supersaturation is controlled for nucleation. Moreover, the membrane surface is thought to reduce interfacial energy and encourage micromixing. In this regard, a novel membraneassisted reactive crystallisation (MARC) process was used in this work for the dissolved phosphorous recovery in form of vivianite crystals from a phosphate-rich solution by means of the dosing of iron (II). To characterise the role of the boundary layer in controlling nucleation, a batch lab-scale system was used for the crystallization tests, and different hydraulic conditions (Reynolds ranging from 105 to 395) and polymeric membranes were tested. The crystallisation process was influenced by the hydraulic conditions, in which a low liquid velocity led to a lower induction time and vivianite supersaturation, and therefore, higher nucleation rates. Membrane properties were characterised to establish their role in the modification of the critical free energy requirement for nucleation, and for the promotion of micromixing, as possible factors that can be used to modify nucleation kinetics. As result, the bulk induction time tended to decrease with the increase in membrane hydrophobicity, roughness, pore size and porosity. Spherical vivianite nanoparticles were always synthesised with a mean size around 35 nm and a narrow distribution independently of the hydraulic conditions and membrane used. Finally, the crystallisation kinetic conformed to a diffusion-dependent nucleation mechanism, in which higher residence times for mixing increased the ion collision probability for nucleation. Importantly, this study demonstrated that MARC is an attractive prospect for nutrient recovery from wastewaters where crystal nucleation can be easily controlled by setting the operational conditions and membrane properties, eliciting considerable process intensification over existing conventional crystalliser.

A dynamically similar lab-scale district heating network via dimensional analysis

Strict user demands and large variability in external disturbances, along with limited richness in the data collected on the daily operating conditions of district heating networks makes the design and testing of novel energy-reducing control algorithms for district heating networks challenging. This paper presents the development of a dynamically similar lab-scale district heating network that can be used as a test bench for such control algorithms. This test bench is developed using the Buckingham π theorem to the match the lab-scale components to the full-scale. By retaining the relative thermodynamics and fluid dynamics of a full-scale network in the lab-scale system, the experimental setup allows for repeatability of the experiments being performed and flexibility in the testing conditions. Moreover, the down-scaling of the experiment is leveraged to accelerate testing, allowing for the recreation of operating periods of weeks and months in hours and days. A PID controller is implemented on the lab-scale test bench to validate its response against literature data. Results show 63% efficiency during heating operations compared to 70% efficiency for a similar full-scale system, with comparable pressure losses across the system.

A practical solution to the saturation problem in feedforward control for measurable disturbances

This paper treats the problem of control signal saturation caused by feedforward control from measurable load disturbances. An efficient feedforward compensator will often give significant peaks in the control signal at fast changes in the load disturbance. These peaks may cause the control signal to reach a saturation limit. In the paper, it is shown that the anti-windup function may cause unnecessarily sluggish responses in these cases. To overcome this problem, it is suggested to reduce the gain of the feedforward compensator during periods of control signal saturation. A method to calculate this gain reduction is presented, and several simulation examples show that this idea will result in a great performance improvement in cases of saturation problems. The proposed algorithm is also tested on a lab-scale temperature control system to demonstrate the noticeable practical capabilities.

Teaching embedded control system design of electromechanical devices using a lab-scale smart farming system

This article presents the design and monitoring of a lab-scale smart farming system through the integration of control and app designs that can be used for teaching embedded control application to electromechanical systems. A combination of sensors and actuators is used to develop an Arduino-based embedded feedback control system that could be implemented in a smart farming environment. Specifically, we look at controlling electromechanical devices to actuate the fan and water pump to provide the optimal temperature and moisture, respectively, to enhance plant growth in a smart farming setting. The effectiveness of the feedback control is tested by conducting a plant growth experiment. Using garden cress ( Lepidium sativum) as a case study, the plant grown in the controlled temperature and moisture settings shows substantially healthier growth compared to the one grown in the non-controlled environment. In addition, an app is designed and developed to transform the Arduino data stream from the sensors into valuable insights that could help the users to monitor and improve the overall crop health. The developed system in this paper enables students to learn integral skills from interdisciplinary engineering fields (e.g. systems, control, mechanical and computer) to solve an agricultural problem.

Probing pipe flow impact corrosion monitoring effectiveness under corrosion monitor coupons conditions

To reduce the corrosion failure frequency of oil and gas pipelines, corrosion monitoring coupons are often used to evaluate the internal corrosion status of pipelines. However, the local flow field varies after the installation of the coupons, so the monitoring corrosion rate is different from that of the pipe wall. To evaluate the effectiveness of corrosion coupons monitoring, a lab-scale flow loop system was used to carry out flow corrosion experiments to obtain the local corrosion rates of corrosion monitoring coupons and pipe wall, respectively. Combined with the characterization of corrosion products and multiphase flow, a mechanism model of corrosion monitoring effectiveness was established. It was clear that the deviation of corrosion monitoring rate was related to the flow rate, shear force and turbulent kinetic energy. The accumulation of corrosion media and the detachment of corrosion product films resulted in variation in the morphology and the monitoring effectiveness.