Biomass Flow Research Articles

4E analysis and optimization of a novel hybrid biomass-solar system: Focusing on peak load management and environmental emissions

Renewable energies are available as clean sources to replace fossil fuels. Providing continuous power without compromising the environment through hybridizing solar and biomass source is one of the promising solutions. This paper seeks to address thermodynamic, economic, and environmental analysis of a multi-generation system with the aim of supplying heating, cooling, electricity, fresh-water, and hydrogen. To do this, the considered system is divided into on-peak, mid-peak, and off-peak periods and modeled based on the consumption pattern at different hours of the day and night. Due to the availability of renewable energy during peak consumption periods, biomass, solar, and hybrid biomass-solar energies are used as energy sources. This leads to a reduction in biomass consumption and carbon dioxide emissions through storing approximately 10 tons of biomass during the day. A sensitivity analysis of the factors affecting the system’s function indicated that a growth in solar radiation from 600 to 1000 W/m2, results in a 35% improvement in exergy efficiency, a 2.7% raise in the total cost rate, and a 32.4% drop in CO2 emissions of the system. Moreover, by changing the biomass flow rate from 0.5 to 1.5 kg/s, the exergy efficiency and total cost rate improved by 9.28%, 1.3%, respectively, and the CO2 emissions rate increased from 0.41 to 1.14 tons/MWh. In addition, focusing on addressing economic and environmental concerns, the optimization of the proposed hybrid system is performed in two categories of objective functions. In the second category optimization, exergy efficiency, fresh water production, total cost rate and CO2 emissions are determined as 31.75%, 74.75 kg/s, 324.60 $/h and 3.55 tons/MWh, respectively.

The role of particle size and other properties on silo discharge behaviour of chipped wood biomass

To achieve net-zero carbon emissions by 2050, the UK government emphasizes the pivotal role of sustainable bioenergy in electricity, transportation, and heating. However, challenges persist in handling biomass particulate solids in production facilities, leading to economic impacts. This study investigates the flow characteristics of stemwood chips from four tree species using a novel drum chipper. Experimental analyses include bulk density measurements, silo discharge studies, biomass flow property assessments, and wall friction measurements. Comparative analyses are performed using Jenike's procedure for building wedge-shaped silos, with a focus on predicting the critical opening size to prevent arching. Additionally, the paper delves into the creation of statistical models aimed at identifying key factors influencing the flow behaviour during silo discharge. Emphasis is placed on understanding potential discrepancies between theoretical predictions and experimental results concerning critical silo openings for arch-free discharge. The results contribute to understanding the factors influencing the flow behaviour of wood chips, informing silo design considerations. Our findings suggest limitations in applying traditional silo design methods, urging further research for more accurate predictions.

Assessing the energy trap of industrial agriculture in North America and Europe: 82 balances from 1830 to 2012

Early energy analyses of agriculture revealed that behind higher labor and land productivity of industrial farming, there was a decrease in energy returns on energy (EROI) invested, in comparison to more traditional organic agricultural systems. Studies on recent trends show that efficiency gains in production and use of inputs have again somewhat improved energy returns. However, most of these agricultural energy studies have focused only on external inputs at the crop level, concealing the important role of internal biomass flows that livestock and forestry recirculate within agroecosystems. Here, we synthesize the results of 82 farm systems in North America and Europe from 1830 to 2012 that for the first time show the changing energy profiles of agroecosystems, including livestock and forestry, with a multi-EROI approach that accounts for the energy returns on external inputs, on internal biomass reuses, and on all inputs invested. With this historical circular bioeconomic approach, we found a general trend towards much lower external returns, little or no increases in internal returns, and almost no improvement in total returns. This “energy trap” was driven by shifts towards a growing dependence of crop production on fossil-fueled external inputs, much more intensive livestock production based on feed grains, less forestry, and a structural disintegration of agroecosystem components by increasingly linear industrial farm managements. We conclude that overcoming the energy trap requires nature-based solutions to reduce current dependence on fossil-fueled external industrial inputs and increase the circularity and complexity of agroecosystems to provide healthier diets with less animal products.

The Determination of Combustion for Different Pellets Based on Ostwald Diagrams in a Domestic Stove under Experimental Conditions

The global energy scenario is becoming a vital aspect of the sustainable economic development of regions and countries. Current changes in energy production, mainly due to scarcity and geopolitical factors, have proven the need for changes in energy distribution towards a lower energy dependence. Moreover, a considerable amount of biomass waste is generated in many regions, because of agro-industrial activities, whose management could contribute to energy production. The aim of this work was to study the optimization of the combustion process in a biomass stove by using different raw materials as fuels, such as pine, poplar, and plum tree pellets. For that purpose, power, excess air, and biomass content were optimized, among other parameters, and exhaust gases were analyzed with a Testo 335 analyzer, while temperatures were recorded with temperature probes. In conclusion, high yields were found for the optimized parameters of the studied biomass products (ranging from 91.1% for poplar pellets to 92.34% for pine pellets), making these three biomass fuels suitable for combustion in the abovementioned stove. Also, increasing biomass flow by 25% in the stove contributed to a higher efficiency of the process, especially in the case of plum tree pellets.

A bi-objective robust model for minimization of costs and emissions of syngas supply chain

Producing syngas from forest-based biomass could facilitate the transitions in energy and forest sectors by replacing natural gas; reducing emissions and wastes; and generating revenues. Optimizing the economic and environmental impacts of the biomass supply chains can help realizing these benefits. In this study, a bi-objective robust optimization model is developed for tactical supply chain planning of forest biomass gasification at a pulp mill. It optimizes the monthly flow, inventory, and preprocessing of biomass while minimizing annual costs and emissions. Robust optimization with an adjustable risk of constraint violation is used to model the uncertainties in supply and cost of biomass. The average cost and emissions of the robust Pareto-optimal solutions are 68% and 41% higher than those in the deterministic solutions, respectively. Although, the cost and emissions and their trade-off in the deterministic case are more favorable, the robust solutions ensure no biomass shortage while avoiding over-conservatism.

Simulations of biomass compression-screw feeding using a compressible non-Newtonian constitutive model

There is global interest in the conversion of biomass into sustainable low-carbon-footprint fuels and chemicals as an alternative to non-renewable fossil feedstocks. Feeding biomass solids into pressurized reactors is one of the key steps in biomass conversion. Predicting mechanical failure and energy requirements for this step helps avoid upstream processing bottlenecks and enables efficient operation of a biorefinery. In this work, we developed a predictive computational model for biomass screw feeders that capture the highly viscous, non-Newtonian and compressible behavior of biomass slurries. Biomass compressible behavior is formulated by an equation of state and the non-Newtonian rheology is represented by a density-dependent viscosity model. Experimental data from two compression screw-feeder systems are presented as a validation for our model. Our model successfully predicted the location of the compressed biomass “plug”, biomass flow rate, and the required torque at different operating conditions for the experimental conditions studied in this work.

Analysis on the transpiration response of Japanese cedar (Crytomeria fortunei) and influencing factors after expansion of moso bamboo (Phyllostachys edulis)

Moso bamboo (Phyllostachys edulis) expansion into adjacent forests has been reported to alter the local water cycle. Transpiration is the most important component of the water budget. However, the changes in transpiration within Japanese cedar forests following moso bamboo expansion, as well as the primary factors driving these changes, remain unclear. In this study, we conducted an investigation in a mixed plantation of Japanese cedar and moso bamboo, a pure Japanese cedar forest, and a Japanese cedar forest after the removal of moso bamboo, from July 2017 to June 2018. We measured leaf area index (LAI), root biomass (Root), and sap flow density (Js). The annual transpiration of Japanese cedar significantly decreased from 521.48 mm in the pure Japanese cedar forest to 293.34 mm in the mixed plantation of Japanese cedar and moso bamboo. Likewise, the leaf area index decreased from 5.26 to 3.96, and the root biomass decreased from 252.78 g/m2 to 160.24 g/m2. In Japanese cedar forest, the transpiration in summer (189.47 mm) is greater than the sum of transpiration in autumn and winter (143.36 mm). The partial least squares path modeling (PLS-PM) analysis demonstrated that the decrease in root biomass was the direct cause of the reduced transpiration, while the decrease in leaf area index primarily led to the decline in root biomass. The results imply that the expansion of moso bamboo changed the above-ground canopy structure of Japanese cedar through the competition of above-ground mechanical damage, which reduced the leaf area and photosynthetic capacity of Japanese cedar, and then affected the below-ground root biomass, finally leading to the reduction of transpiration and the variation of ecohydrological process.

Rechargeable Biomass Battery for Electricity Storage/generation and Concurrent Valuable Chemicals Production

AbstractThe development of a rechargeable battery that can produce valuable chemicals in both electricity storage and generation processes holds great promise for increasing the electron economy and economic value. However, this battery has yet to be explored. Herein, we report a biomass flow battery that generates electricity while producing furoic acid, and store electricity while yielding furfuryl alcohol. The battery is composed of a rhodium‐copper (Rh1Cu) single‐atom alloy as anode, a cobalt‐doped nickel hydroxide (Co0.2Ni0.8(OH)2) as cathode, and furfural‐containing anolyte. In a full battery evaluation, this battery displays an open circuit voltage (OCV) of 1.29 V and a peak power density up to 107 mW cm−2, surpassing most catalysis‐battery hybrid systems. As a proof‐of‐concept, we demonstrate that this battery produces 1 kg furoic acid with 0.78 kWh electricity output, and yields 0.62 kg furfuryl alcohol when 1 kWh electricity is stored. This work may shed light on the design of rechargeable batteries with value‐added functionality such as chemicals production.

Rechargeable Biomass Battery for Electricity Storage/generation and Concurrent Valuable Chemicals Production.

The development of a rechargeable battery that can produce valuable chemicals in both electricity storage and generation processes holds great promise for increasing the electron economy and economic value. However, this battery has yet to be explored. Herein, we report a biomass flow battery that generates electricity while producing furoic acid, and store electricity while yielding furfuryl alcohol. The battery is composed of a rhodium-copper (Rh1 Cu) single-atom alloy as anode, a cobalt-doped nickel hydroxide (Co0.2 Ni0.8 (OH)2 ) as cathode, and furfural-containing anolyte. In a full battery evaluation, this battery displays an open circuit voltage (OCV) of 1.29 V and a peak power density up to 107 mW cm-2 , surpassing most catalysis-battery hybrid systems. As a proof-of-concept, we demonstrate that this battery produces 1 kg furoic acid with 0.78 kWh electricity output, and yields 0.62 kg furfuryl alcohol when 1 kWh electricity is stored. This work may shed light on the design of rechargeable batteries with value-added functionality such as chemicals production.

Experimental and theoretical study of heat and mass transfer in a continuous, vertical and coaxial pyrolysis reactor for high porosity biochar production

The development of a high porosity biochar production facility to meet an industrial need requires a detailed knowledge of the thermochemical phenomena of pyrolysis. The main challenge of this work is the production of biochar with a high porosity in large quantities, and producing a residual gas that can be used for drying biomass. Two complementary tools have been here developed and operated: a patented prototype and a designing numerical model. The model was developed in parallel with tests on the prototype and a characterisation phase of the various materials involved in the pyrolysis process in order to increase the correspondence between numerical model and experimental results. The model is used to predict, depending on the geometry chosen, the temperature in the pyrolysis zone, the heating rate and residence time corresponding to the applied biomass flow rate, as well as the biochar and gas mass yields.This study demonstrated the ability of the experimental plant to produce a high porosity biochar with a specific surface of 200m2.g-1 in the best case and a constant carbon content around 90% on dry basis due to the separation of the partial oxidation and pyrolysis zones. Following a material characterisation phase and a customisation of the parameters of the Arrhenius formalism adapted to pine bark, the numerical model shows a strong correspondence in terms of temperatures, biochar yield and thermochemical kinetics with the experimental observations from the prototype.

An integrated sustainable system fueled by Co-Combustion of legume straw biomass and synthesis gas of SOFC: Optimization study using Signal-To-Noise ratio analysis

A novel tri-generation system of power, heating, and freshwater is developed in this study. The system integrates of a supercritical CO2 Brayton cycle, a solid oxide fuel cell, and a desalination system of humidification-dehumidification type. The system is fueled by a combustion of the synthesis gases of the solid oxide fuel cell helping by a legume straw biomass flow. The heat is recovered from the combusted gases and triggers the supercritical CO2 Brayton cycle and the desalination system. The key variables of the solid oxide fuel cell are evaluated and their influences on the voltages are examined in details. They are optimized using Taguchi approach and signal-to-noise ratio analysis to achieve the maximum solid oxide fuel cell power. Current density of 9375 A/m2, utilization factor of 0.7, temperature of 900 K, steam to carbon ratio of 2, anode recycling coefficient and cathode recycling coefficient of 0 are recognized to be the optimal conditions. The fuel cell power is 625.3 kW in this optimal state. The system provides 674.6 kW of net power, 157.3 g/h of mass flow rate of freshwater and 13812 kg/h of mass flow rate of hot water in its optimum condition.

Finite element modeling of biomass hopper flow

Hoppers are widely used biomass handling devices that channel bulk biomass from storage to subsequent handling equipment. Jenike’s longstanding approach, based on the Mohr-Coulomb model, has been successfully used to design hoppers handling cohesionless granular materials such as grains and other agricultural produces. However, designing a hopper to ensure reliable biomass flow is found to be challenging due to cohesion, irregular particle shape, and bulk material elastoplasticity. This study aims to address the biomass handling engineering challenge with alternative constitutive material models concerning the flow behavior of bulk solids. Finite element modeling is an approach that allows for implementation of different material models, whose underlying constitutive theories assist in investigating the origin and manifestation of bulk mechanical behavior of granular materials. This study focuses on the incipient gravity hopper flow of two types of biomass feedstocks, i.e., ground corn stover and Douglas fir wood. Three widely used constitutive material models, i.e., Mohr-Coulomb model, modified Cam-Clay model, and Drucker-Prager/Cap model, are implemented. Using the flow pattern represented by the volume of biomass exhibiting more than 7% of axial strain (Kamath and Puri, 1999), the finite element model predicts that the bulk corn stover particulate material forms an arch, which represents a hampered transition from the static state to the dynamic flow-state out of the hopper, whereas bulk Douglas fir wood particulate material develops a reliable mass flow pattern. A laboratory scale hopper was used to experimentally determine the biomass flow conditions, which were subsequently compared with the predicted onset of flow by a finite element model (FEM). The developed FEM was found to correctly predict the initiation of mass flow for the milled Douglas fir wood, whereas corn stover was predicted to establish a strong core flow suggesting an unreliable handling characteristic. This observation aligns with the reported poor handling of milled corn stover.

Optimization of a near-zero-emission energy system for the production of desalinated water and cooling using waste energy of fuel cells

In the present study, a biomass-based multi-purpose energy system that can generate power, desalinated water, hydrogen, and ammonia is presented. The gasification cycle, gas turbine, Rankine cycle, PEM electrolyzer, ammonia production cycle using the Haber-Bosch process, and MSF water desalination cycle are the primary subsystems of this power plant. On the suggested system, a thorough thermodynamic and thermoeconomic evaluation has been conducted. For the analysis, the system is first modeled and investigated from an energy point of view, after which it is similarly studied from an exergy point of view before the system is subjected to economic analysis (exergoeconomic analysis). The system is evaluated and modeled using artificial intelligence to aid in the system optimization process after energy, exergy, and economic modeling and analysis. The resulting model is then optimized using a genetic algorithm to maximize system efficiency and reduce system expenses. EES software does the first analysis. After that, it sends the data to MATLAB program for optimization and to see how operational factors affect thermodynamic performance and overall cost rate. To find the best solution with the maximum energy efficiency and lowest total cost, multi-objective optimization is used. In order to shorten computation time and speed up optimization, the artificial neural network acts as a middleman in the process. In order to identify the energy system's optimal point, the link between the objective function and the choice factors has been examined. The results show that increasing the flow of biomass enhances efficiency, output, and cost while raising the temperature of the gas turbine's input decreases cost while simultaneously boosting efficiency. Additionally, according to the system's optimization results, the power plant's cost and energy efficiency are 37% and 0.3950$/s, respectively, at the ideal point. The cycle's output is estimated at 18900 kW at this stage.

SPH modeling of biomass granular flow: Theoretical implementation and experimental validation

The commercialization of biomass-derived energy is impeded by flowability challenges arising from the feeding and handling of granular biomass materials in full-scale biorefineries. To overcome these obstacles, a robust and accurate model to simulate the flow of granular biomass is indispensable. However, conventional mesh-based numerical codes are limited by inherent mesh distortion in simulating large deformation that commonly occurs in granular biomass handling. In this study, we propose a graphics processing unit (GPU)-accelerated meshless Smoothed Particle Hydrodynamics (SPH) code to model the flow of granular biomass materials. A modified void ratio-based mass conversation, a hybrid particle-to-particle/surface frictional boundary treatment, and a hypoplastic constitutive model are implemented. Four numerical examples, an elastic block sliding on inclined planes, sand column collapse, Angle of Repose, and axial compression tests for pine chips, were simulated using the developed SPH code. The results demonstrate good agreement between numerical predictions and analytical and experimental data for all four examples, validating the SPH code and increasing confidence that it can be applied to simulate more complex granular biomass handling processes, such as hopper feeding or auger conveyance.

“Biomass from somewhere?” Governing the spatial mismatch of Viennese biomass consumption and its impact on biodiversity

Vienna’s biomass demand is large and nearly all biomass consumed in the city is produced in the regional and global hinterland. This raises the question, how the socioecological conditions at specific places somewhere in the world are impacted by urban consumption and how negative impacts can be addressed and mitigated by urban actors. Here we focus on the city’s biodiversity footprint and argue that the spatial mismatch between the social-ecological impacts of biomass production and consumption and its impact on biodiversity on the one hand, and the governance instruments available at a city level mentioned by the interviewed experts on the other hand, must be considered when looking for bottom-up governance strategies of urban actors. We combine food regime theory, the analysis of biomass flows and a multiscalar governance approach to analyze “biomass from somewhere” in three important sectors of biomass use in Vienna – food, energy and construction timber. We find that consumption in Vienna requires 3.1 Mio. t of primary biomass per year (2010–2013), of which 59 % are for food, 28 % for material (only 1.3 % for construction) and 13 % for energy; roughly half of this biomass was sourced from Austria, the rest from other countries, mainly in Europe. While governance instruments at the city level are quite effective with respect to urban ecosystems and conservation within the city, they are insufficient to tackle biodiversity loss in the global hinterland. Important leverage points at the city scale are public procurement and the promotion of consumption patterns with lower land and primary biomass demand. An important prerequisite is unambiguous information and labelling concerning the biodiversity impacts of biomass products which is complicated by the fact that indirect land use effects need to be considered. Currently, none of the governance measures investigated includes extensive biodiversity criteria. We conclude that to effectively address the spatial mismatch, a different mode of production – regulated at higher scales and including mandatory measures – and a different mode of consumption as well as a reduction of consumption and production is required.

Design and economic analysis of a pre-treatment process of coffee husks biomass for an integrated bioenergy plant

The beneficiation of coffee produces a large amount of bio-waste, indicating that new policies need to be put into place to address the residues efficiently. Recent studies have shown that coffee husk, particularly, has significant potential for generating electricity but requires a pre-treatment step for efficient thermochemical conversion. Since information about the viability of a pre-treatment process is urgent and necessary and remains insufficient, this study aims to design and perform the economic analysis of a pre-treatment plant of coffee husks, which includes drying, comminution, and densification stages. Drying kinetics experiments were conducted at the laboratory scale to estimate the drying time for the dryer design. A methodology was proposed to encompass equipment design, use of utilities, investment, and total plant costs toward a definition of the optimal operating condition. The economic decision criteria were the net present value (NPV), the payback time (P), and the internal rate of return (IRR). The influence of the drying conditions was analyzed through the leveled cost of production per mass of the briquette (LCM). The results show that the bed height and air inlet temperature were the drying variables with the greatest influence on the design and economics of the plant. The lowest LCM values were obtained for higher values of air temperature, bed height, and biomass flow rate. Economic decision criteria indicated that the project is viable, with an NPV in the range of 28 to 98 million dollars, 166%–574% IRR, and a payback period of 7 months and 7 days.

Numerical simulation of multiphase flow and co-gasification of biomass and coal for a new test reactor

Numerical simulation of multiphase flow and co-gasification of biomass and coal for a new test reactor

Does invasion by armored catfish shift trophic ecology of native fishes? Evidence from stable isotope analysis.

Popular as aquarium fish, armored catfishes from South America (Pterygoplichthys spp.) have been introduced and become invasive in tropical and subtropical regions worldwide. These ecosystem engineers can deplete basal resources (e.g., periphyton and detritus), with potential negative effects for native fauna. We studied the trophic ecology of fishes in the Usumacinta River Basin, Guatemala, where Pterygoplichthys is now widespread and locally abundant. We analyzed stable isotopes (δ13 C, δ15 N) in fish tissues and basal resources to assess the potential impact of Pterygoplichthys on the trophic ecology of six co-occurring native fishes that feed at a similar trophic level (Astyanax aeneus, Dorosoma petenense, Thorichthys pasionis, Oscura heterospila, Poecilia mexicana, and Gambusia sexradiata). The study was conducted during the dry season in the La Pasion (LPR; high invasion) and San Pedro (SPR; low invasion) rivers. We compared isotopic spaces occupied by native fish and Pterygoplichthys, estimated isotopic overlap, and evaluated the trophic displacement of native species. We also evaluated the relationships of environmental factors, including the relative biomass of the invasive catfish, with δ13 C and δ15 N signatures. Except for P. mexicana, native species had lower isotopic overlap with the catfish in LPR. Native fish isotopic spaces were compressed and shifted toward higher trophic positions in LPR relative to SPR. Benthic food resources were important for Pterygoplichthys in both rivers, and water-column resources had greater relative importance (RI) for native species in LPR. Native fish δ13 C was significantly associated with Pterygoplichthys biomass, conductivity, and water flow velocity; and water depth and sedimentation had a significant association with native fish δ15 N. Findings provide evidence that invasive Pterygoplichthys, along with environmental factors, impact the trophic ecology of native fish in the Usumacinta Basin. Additional field research conducted over longer time periods and mesocosm experiments that account for fish assemblage and environmental variation could elucidate Pterygoplichthys impacts via food resource depletion or habitat alteration.

Contribution of the mix renewable energy potentials in delivering parts of the electric energy needs in the west region of Cameroon

The constant supply of energy remains a great challenge in many developing countries and Cameroon is no exception. It is necessary to explore other renewable energy sources that have environmental and energy potential. However, there is limited and sparse literature on the potential of renewable energy sources in Cameroon and its western part in particular. This limits investment and policy design that can lead to the exploitation of renewable energy sources. There is thus a need for more research on renewable energy development to better inform energy policies. This paper investigates the potential and extent to which available renewable energy sources can contribute to the electric power sector in the western part of Cameroon is on estimating the potential of hydroelectric, solar and biomass energy resources. A cross-sectional method, observations and literature review were used to determine the water flow and electrical energy potential of different biomass. The results show that the electrical potential of hydroelectricity is 11.68 GWh/year, for solar represents 44.12 GWh/year, and the energy of biomass 8586.42 GWh/year, 135.53 GWh/year and 13.05 GWh/year for agricultural, animal and forestry residues; they have a rate of access to electricity of 6.64%, 25.08%, 4881.46%, 77.05%, and 7.42% respectively. This potential can satisfy needs of 18 526 464 households. According to results obtained and in order to provide a sustainable solution by improving access to electricity, living standards and socio-economic conditions of populations; two hybrid cogeneration thermal-solar power plants can be installed at the limits of the decentralized areas of Bamboutos-Mifi-Menoua and Koung Khi, which are nearby areas with high population density. Hydroelectric plants can be installed to electrify villages that are far from the national network.

Life-cycle traits in the demosponge Hymeniacidon perlevis in a land-based fish farm.

The demosponge Hymeniacidon perlevis is characterized by wide geographic distribution and great adaptability to numerous and highly variable climatic and hydrological conditions. Indeed, the species can colonize many different environments, including several unusual ones, such as concrete drainage conduits of a marine land-based fish farm plant. This research aimed to enhance existing knowledge on the reproductive cycle and growth performance of H. perlevis while also evaluating the impact of a controlled supply of trophic resources, wastewater flow and constant water temperature on these biological traits. Specimens included in this one-year study inhabited drainage conduits of a land-based fish farm. The approach included measurements of sponge biomass and occurrence and abundance of reproductive elements across different seasons and environmental parameters, such as fish biomass, trophic resources, and wastewater flow. Sponge growth and reproductive elements, including oocytes, spermatic cysts, and embryos, were measured monthly in sponges positioned in the drainage conduit, thus with different trophic resources but with constant water temperature. Finally, we used generalized additive models to describe variables that contribute the most to the growth of sponges. Growth performance showed marked variations during the study period. The highest increase in sponge volume was observed from August/September to January/March. The volume of sponges was principally determined by the reduction of reared fish biomass and the increase of pellet amount and wastewater flow. Sponge specimens exhibited an active state during the entire study, as proven by the occurrence of recruits. However, sexual elements were only sporadically observed, thus not permitting the recognition of a true sexual cycle. The results of the present study confirmed that H. perlevis exhibits high flexibility and adaptability to the differential, and somewhat extreme, environmental conditions. Indeed, this species can live, grow and reproduce in the drainage conduits of the fish farm, where the species face constant darkness, water temperature and continuous nutritional supply. In such conditions, H. perlevis display an active state during the entire year, while avoiding stages of decline and long dormancy usually observed in wild populations. It seems plausible that stable environmental conditions induce an almost continuous sexual phase, probably under the control of endogenous factors. No asexual elements were detected, although it was impossible to exclude the contribution of asexual reproduction in the origin of the newly settled sponges, which were repeatedly detected throughout the study. The growth performance seemed linked to the fish farm conditions, thus providing useful indications on the best maintenance conditions for H. perlevis in land-based integrated multitrophic systems, where the species could be used for wastewater treatment.