Decanter Centrifuge Research Articles

Simulation of Different Control Strategies of a Three-Phase Induction Motor Coupled to a Real Decanter Centrifuge for Olive Oil Extraction Focusing on Energy Saving

This study presents the analysis and modeling of the optimal connection between an asynchronous three-phase electrical induction motor and a horizontal centrifuge used in olive oil extraction. The simulation, carried out using the well-established Simscape Electrical by Matlab R2024a, offers the advantage of reducing the purchasing cost of the electronic drivers and electric motors to be tested. Different connection cases among the electronic motor driver, the electric motor, and the horizontal centrifuge were examined. The findings indicate that the oversizing of the electric motor is required to increase the machine efficiency and to reduce the overall specific energy consumption; however, the asymptotic behavior of the specific energy consumption, being related to the motor power, places a limit on the motor oversizing. Indeed, raising the motor power reduces the specific energy consumption; however, this effect can be unimportant if considering the higher cost involved in purchasing both the electrical motor and the electronic motor driver. The results show that an overall percentage saving of specific energy consumption of 3.1% and 4.0% can be achieved with a slight (7.5 kW) and a medium (11 kW) oversizing of the electric motor, respectively.

Food grade pilot scale strategy for non-thermal extraction and recovery of phenolic compounds from orange peels

The orange peels (OP) derived from orange juice factories consist of several polymers and molecules that could be recovered using a biorefinery approach. This study presents a pilot-scale strategy for the extraction and recovery of phenolic compounds from OP, aiming to demonstrate a sustainable, non-thermal process that operates without the use of solvents and complies with food-grade standards. The extraction process was conducted in a food-grade manner on a 1000 L scale, starting with the enzymatic hydrolysis of pectin in the biomass, followed by ultrasound-assisted extraction (UAE) at 54 W/gslurry and 20 °C. Solid/liquid separation via decanter centrifuge allowed to recover the solution containing the phenolic compounds, that was further purified via sequential cross-flow microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF). The final product was analysed by HPLC-ESI-TOF-MS, revealing an interesting phenolic profile with several potential bioactivities and a total polyphenol content (TPC) of 3.3 g/L. The food-grade analysis confirmed the potential application of the final product in food-related processes, such as food packaging or fortification. This work highlights a scalable and environmentally friendly method to convert agro-food waste into valuable bioactive compounds, aligning with green chemistry principles and zero-waste strategies.

Techno-economic comparison of flocculation combined with dissolved air flotation versus sedimentation for microalgae harvesting

Microalgae are a promising new source of biomass but the harvesting method needs to optimised to reduce the production cost. In a two-step harvesting process, the bulk water is removed via flocculation (first step) followed by complete dewatering using centrifugation (second step). Flocs can be separated from the bulk water using either gravity sedimentation or dissolved air flotation (DAF). DAF requires a more complex setup and demands more energy than sedimentation, but it is faster and generates a sludge with a higher dry matter content. This study aims to compare the performance of DAF and sedimentation in laboratory experiments and then estimates the cost for a 100-hectare farm using sedimentation versus DAF for harvesting (step-1) and using a decanter centrifuge (step-2) for dewatering. Chlorella vulgaris was the model species and poly(dimethylaminoethyl methacrylate) (pDMAEMA) was synthesised and used as the flocculant. In bench-scale testing, sedimentation and DAF achieved maximum harvesting efficiencies of 87 % and 98 %, respectively. Sedimentation was slow and generated a sludge with low solids content (1.1 %). DAF achieved a fast separation and generated a sludge with 3× higher solids content of 3.4 %. When estimating the costs of biomass harvesting at 100-hectare scale, DAF was found to have higher capital and operating expenditure than sedimentation. However, when combining harvesting with the dewatering step in a two-stage harvesting-dewatering system, the total capital and operating expenditure was projected to be 20–38 % and 10–18 % cheaper, respectively, than sedimentation. This is due to the faster separation, higher sludge solids content, and greater separation efficiencies obtained via DAF than sedimentation. Hence, DAF is recommended over sedimentation for harvesting microalgae. Importantly, this study showcases that contrary to conventional belief, flocculation–DAF is cheaper than flocculation–sedimentation for large-scale algal harvesting.

Enhancing decanter centrifuge process design with data‐driven material parameters in multi‐compartment modeling

AbstractPredicting the separation performance of decanter centrifuges is challenging due to dynamic events within the apparatus. Current methods for designing decanter centrifuges rely on simplified models, often leading to inaccuracies. Consequently, manufacturers must perform time‐intensive pilot scale experiments to derive their own correction factors. Growing computing power sparks interest in alternative modeling strategies. Grey box models (GBM) combine mechanistic white box models (WBM) and data‐driven black box models (BBM), with the optimal structure (parallel or serial) varying by application. For modeling decanter centrifuges, we propose a serial GBM that comprises an artificial neural network that outputs unknown material parameters into a first‐principle multi‐compartment model. Comparing this approach to alternative data‐driven modeling strategies (pure BBM, parallel GBM), we conclude that the serial GBM excels in terms of extrapolation, prediction ability, and transparency while also enabling a better comprehension of the separation process.

Resolved Simulation for the Prediction of Classification in Decanter Centrifuges

Solid–liquid separation plays a decisive role in various industrial applications particularly in the treatment and purification of suspensions. Solid bowl centrifuges, such as the decanter centrifuge, are commonly employed in these processes as they operate continuously and enable high throughputs with short processing times. However, predicting the separation performance of solid bowl centrifuges proves to be challenging due to dynamic phenomena within the apparatus, such as particle settling, sediment build-up, consolidation and sediment transport. In practice, design considerations and the dimensioning of the apparatus rely on analytical models and the manufacturer’s expertise. Computational Fluid Dynamics (CFD) offers a way to deepen our understanding of these devices by allowing detailed examination of flow phenomena and their influence on the separation processes. This study utilizes the open-source software OpenFOAM to simulate multiphase flow in a laboratory-scale decanter centrifuge, solving individual transport equations for each particle size class. The basis is the characterization of the material through targeted laboratory experiments to derive material functions that describe the hindered settling and the sediment consolidation. Furthermore, experiments on a laboratory decanter served as validation. The results demonstrate the solver’s capability to replicate clarification and classification within the apparatus. Furthermore, the solver supports the definition of geometries tailored to specific separation tasks. This research demonstrates the potential of CFD for a better understanding of complex centrifuge processes and for optimizing their design to improve performance.

Comparison of Struvite as a P Source with Chemical Fertilizers and Evaluation of Additional Contribution to Growth and Mineral Nutrition of Lettuce Grown on Acidic and Calcareous Soils

This study investigated the effects of two different struvites (Struvite1 (STR1) and Struvite2 (STR2)) with different P amounts on the P nutrition of lettuce grown in acid and calcareous soils and fertilizer efficiency against di-ammonium phosphate (DAP), monoammonium phosphate (MAP), triple superphosphate (TSP), and 20–20-20 (NPK fertilizer). Two distinct forms of STR1 and STR2 obtained from the biogas liquid digestate (LD, liquid fraction of a centrifuge decanter) at different molar ratios (NH4+/Mg2+/PO43−), STR1 (1.0/1.3/1.0), and STR2 (1.0/1.3/1.3) were used. The results showed that struvites were the most effective treatments for plant growth. STR1 and STR2 treatments increased the plant fresh weights by 2.7-fold in acidic soil and 2.1-fold in alkaline soil. As for the plant dry weights, STR1 and STR2 treatments increased the plant dry weights by 2.4–2.2-fold and 2.3–2.2-fold in acid and alkaline soils, respectively. Struvites were more effective on the total plant weights than other fertilizers. Struvite-applied plants yielded higher P concentrations, uptakes, and recovery than MAP, DAP, TSP, and 20–20-20 fertilizers for both soils. Due to its constituent Mg, STR1 and STR2 were found to be the most effective materials for the Mg nutrition of the plants. It was also determined that they contributed to the N and K nutrition of the plants more than most other fertilizers. In conclusion, it was seen that struvites are not only a good source of P but also a fertilizer material with a high agronomic value. Therefore, they can be evaluated as an alternative fertilizer source.

Fractionation of edible fats—Separation of fat‐covered particles by decanter centrifuge

AbstractThis work investigates the feasibility of using a decanter centrifuge to separate solid particles coated with a high melting fat from a liquid oil. The process involves feeding cold silica particles into a melt, upon which the hardstock fat crystallizes, and the particles are subsequently separated using a decanter centrifuge. Being the first attempt for such a design, only the separation step is studied, and a model system is used. It comprised canola oil (CO), fully hydrogenated rapeseed oil a priori crystallized on silica gel particles. Different particle sizes and accelerations of gravity were studied. To measure the success of this separation process, the data from light microscopy, and differential scanning calorimetry of the feed, oleins, and stearins were used. The findings show that the separation of the fatty particles used in this work, and liquid oil in decanter centrifuges is feasible while future research should focus on the crystallization part of the process. The model developed to describe the oil‐holding capacity of the cake focuses on the capillary liquid entrapped in the spaces between the particles and sufficiently represents the experimental findings which show that separation efficiencies increase with increasing centrifugal acceleration.Practical Applications: This work introduces an alternative fat fractionation process by separating a model system of CO, FHRO, and solid entrainers through a decanter centrifuge. The results can be potentially used for the development of a fully continuous dry fractionation process, which can achieve in one step higher SE than the conventional ones and can be tripalmitate‐selective.

Effects of plasma treatment of digestates on pH, nitrification and nitrogen turnover during storage and after soil application

Acidification through plasma treatment technology presents a potential solution to mitigate nitrogen losses throughout the manure management chain, offering a dual benefit of atmospheric nitrogen incorporation into manures while inducing acidification. This study evaluated the use and effectiveness of plasma treatment technology as a one-time acidification strategy for digested slurry during long-term storage, its effects on slurry nitrogen (N) availability and subsequent release in the soil. A digestate from a full-scale anaerobic digester was separated using a decanter centrifuge, and the resultant liquid fraction (LF) was plasma treated to achieve three different initial pH levels (4.27, 5.03 and 5.42). After that, a storage experiment was set up for 180 days to monitor the evolution in pH and changes in NH4+, NO3- and NO2-. Concurrently, a soil incubation experiment was conducted to study the N turnover for 80 days after incorporating the organic materials (Liquid fraction, plasma-treated liquid fractions, digestate and raw slurry). Plasma treatment significantly increased total N and the proportion of inorganic N in the slurries by fixing atmospheric N as NO3- and NO2- and reduced the slurry pH depending on the treatment duration. After six months of storage, pH increased by 0.91 pH units in the plasma-treated liquid fraction with the highest initial pH (LFpH-5.42). Plasma treatment significantly increased net inorganic N release in soil by 5–14 % compared to a non-treated liquid fraction. Unexpected prolonged inhibition of NH4+ nitrification in soil for over 80 days after applying plasma-treated slurries was observed. In conclusion, plasma treatment emerges as a promising alternative to acid- and bio-acidification strategies, offering prolonged low slurry pH stabilisation, improved fertiliser value and delayed NH4+-N nitrification in soil.

Resolved Simulation of the Clarification and Dewatering in Decanter Centrifuges

Solid–liquid separation is a fundamental operation in process engineering and thus an important part of many process chains in the preparation of slurries in the chemical industry and other parts of the industrial environment. For the separation of micron-sized particles which, due to their size, do not settle or settle very slowly in the earth’s gravity field, centrifuges are often used. The preferred choice are often decanter centrifuges because they work continuously and stabilize the process against product fluctuations due to their adjustment possibilities. The design of the apparatus is complex: The main components of the apparatus are the cylindrical-conical bowl, which rotates at a high speed, and a screw located inside the bowl, which rotates in the same direction at a low differential speed to transport the separated solids out of the apparatus. Geometrical properties of the apparatus, as well as the adjustable operating parameters, such as rotational speed or differential speed, have a significant influence on the separation. In practice, analytical models and the experience of the manufacturers form the basis for the design. Characteristics of the disperse phase, interactions with the liquid, as well as the influence of the flow on the separation, are not taken into account. As a consequence, the transfer to industrial scale always requires a large number of pilot-scale experiments, which are time-consuming and expensive. Due to the increasing computational power, computational fluid dynamics (CFD) provides one possibility to minimize the experimental effort in centrifuge design. In this work, the open-source software OpenFOAM is used to simulate the multi-phase flow in a laboratory decanter centrifuge. For validation, experiments were carried out on a laboratory scale and the main operating parameters, such as speed, differential speed, and volume flow rate, were varied. The simulation results show a good agreement with the experimental data. Furthermore, the numerical investigations show the influence of the flow on the separation of the particles. To evaluate the transportability of a material, the transport efficiency was introduced as a dimensionless parameter. In addition, the simulation allows the consideration of the individual velocity components, making it possible to generate an impression of the complex three-dimensional flow in the apparatus for the first time.

Flocculating fine cuttings particles suspended within partially hydrolysed polyacrylamide (PHPA) solutions used as drilling fluids in mineral exploration

Aqueous solutions of high molecular weight partially hydrolysed polyacrylamide (PHPA) are used in mineral exploration drilling to increase fluid viscosity and thereby help maintain the suspension of fine cuttings being brought to the surface. However, clarifying such suspensions prior to drilling fluid recycling can be problematic, leading to recirculating particle loads that can impact on drilling performance. Total particle encapsulation by adsorbed polymer is assumed to stabilize suspensions, thereby preventing subsequent flocculation. Batch testing with aggregation monitored in real-time by focused beam reflectance measurement (FBRM) confirmed anionic flocculants were ineffective, but significant aggregation was achieved with a nonionic product. Field trials dosing a nonionic flocculant in advance of a decanter centrifuge required higher dosages, but still consistently reduced centrate solids by ∼ 50 %. This indicates cuttings particle surfaces may in fact be accessible for flocculant absorption and particle bridging, but the charged tails of adsorbed PHPA prevent any such access by similar anionic flocculants.

Direct recycling of carbon black and graphite from an aqueous anode slurry of lithium-ion batteries by centrifugal fractionation

Centrifugation is a promising method for direct recycling of lithium-ion battery materials from an aqueous slurry. The present work investigates the continuous fractionation of an aqueous anode slurry into the active material graphite and the conductive carbon black in a decanter centrifuge. To evaluate the separation success, two analytical methods utilizing the different particle sizes and sedimentation velocities of the materials were developed and tested. Both methods can detect graphite separation efficiencies up to 90 % based on centrate samples. The detectability of carbon black in sediment samples is more sensitive for the sedimentation analysis, which can measure carbon black separation efficiencies down to 1 %, in contrast to the particle size analysis, allowing the detection of separation efficiencies down to 10 %. Both methods provide similar results in terms of assessing the separation process in the lab-scale decanter centrifuge. At a centrifugal acceleration of 352 g and a volume flow of 66 l/h, more than 90 % graphite can be separated with a low carbon black deposition between 10 % and 20 %. Thus, a high recovery of graphite and carbon black from an aqueous anode slurry by using a decanter centrifuge is basically possible.

Fractionation of proteins from alfalfa juice at demonstration scale: Effects of temperature and centrifugation strategies on removal of green protein and recovery of the soluble white protein fraction

Given the growing global demand for protein, alfalfa (Medicago sativa) has emerged as a promising alternative protein source for both animal feed and human nutrition due to its high protein content and nutritional value. This study investigated the fractionation of proteins in freshly pressed alfalfa juice into green and white fractions, with focus on optimizing the recovery of the white protein fraction, which holds significant potential for various food applications. Two sets of demonstration-scale experiments were conducted to evaluate the impact of temperature and centrifugation techniques on the fractionation process. The goal was to achieve the optimal coagulation and removal of the green fraction while concurrently enhancing the yield of the white protein fraction. The first set of experiments explored heat treatment at four different temperatures (50 °C, 55 °C, 60 °C, and 65 °C), followed by decanter centrifugation. Optimal coagulation of the green fraction with higher white protein fraction yield was observed at 55 °C. In the second set of experiments, a constant temperature was maintained (55 °C) while testing three different separation scenarios. A two-stage centrifugation approach employing decanter and disc-stack high-speed centrifuges proved most effective, removing most of the coagulated green fraction and preserving over 80% of the white fraction in the residual juice after heat treatment. Complete removal of the green fraction was not achieved, and an additional microfiltration step was introduced to clarify the residual juice. Microfiltration retained up to 50 % of the white protein, resulting in a significant reduction in the overall recovery yield. The results indicate that achieving high recovery yields of soluble white protein remains a challenge and requires further optimization of the fractionation process.

Characterization of the Effect of a Novel Production Technique for 'Not from Concentrate' Pear and Apple Juices on the Composition of Phenolic Compounds.

The consumption of 'not-from-concentrate' (NFC) fruit juices can be a convenient and enjoyable way to incorporate the nutritional benefits and flavors of fruits into one's diet. This study will focus on the effect of production of juices from apple and pear fruits, by using centrifugal decanter and tangential filtration, on the profile of polyphenols as a valuable source of bioactive compounds. Likewise, by-products from the juice industry were characterized in order to understand the high-value-added potential based on their composition of polyphenols. Briefly, apple and apple juice showed great contents of chlorogenic acid (0.990 ± 0.021 mg/g of DW), the dihydrochalcone phloridzin (1.041 ± 0.062 mg/g of DW), procyanidins (0.733 ± 0.121 mg/g of DW) and quercetin derivatives (1.501 ± 0.192 mg/g of DW). Likewise, the most abundant compounds in pear and pear juices were chlorogenic acid (0.917 ± 0.021 mg/g of DW), caffeoylquinic acid (0.180 ± 0.029 mg/g of DW), procyanidins (0.255 ± 0.016 mg/g of DW) and quercetin derivatives (0.181 ± 0.004 mg/g of DW). Both temperature and tangential speed affect the amount of phenolic compounds in fruit juices, highlighting the need to control the technological process to obtain a more nutritious/healthier beverage. Overall, NFC juices arise as a better option when compared with concentrated juices. Furthermore, the higher yield of phenolic compounds found in fruit pomace clearly open new ways for upcycling this fruit by-product as a high-value-added ingredient.

Study on the structure of energy‐saving bend pipes in a decanter centrifuge

AbstractDecanter centrifuges are widely used in solid–liquid separation, and saving their energy consumption is very important. In this paper, a bend pipe installed at the end of the decanter centrifuge was designed to save energy, and the effect of different structural parameters of the energy‐saving bend pipes on the outlet velocity and the reaction torque was investigated. The results revealed that the outlet velocity and the reaction torque were reduced with the increase in the number of pipes, outlet area, and pipe length. Increasing the radial position had little effect on the outlet velocity, but increased the reaction torque. Decreasing the outlet area and increasing the radial position both weaken the separation performance of the decanter centrifuge. The best separation performance and reaction torque effect were achieved in a suitable structure. Furthermore, the turbulent intensity was reduced from 143% to 135% in the new machine installed with bend pipes. The energy‐saving efficiency dropped with the increase of the rotational speed and the value was 13.1% under 2500 rpm. The separation performance of the new machine was similar to that of the original machine, and the dewatering speed was increased with the increase of the axial position.

Analysis of Manure Separation Technology Efficiency into Fractions Followed by Liquid Fraction Rectification

Introduction. There is not enough data on the used intensive technologies of processing pig manure into organic fertilizer to accurately calculate the content of nutrients in the final products and, accordingly, their doses of application. Aim of the Article. To determine the efficiency of pig manure processing technology, which includes liquid fraction rectification, by the quantitative and qualitative characteristics of manure and final products, and to trace the redistributing total nitrogen between the final products on the example of a pilot pig breeding complex production. Materials and Methods. For the study, there was chosen a typical pig-breeding complex, where the pig manure processing included slurry acidification, flocculation, separation into fractions in a decanter centrifuge, rectification of liquid fraction, passive composting of solid fraction, and long-term storing of liquid fraction. The technology allows producing three types of end products: solid organic fertilizer, concentrated liquid (ammonia water), and fertilizer solution. Quantity and quality of pig manure and the end products were calculated by the known methods. Experimental studies were performed to compare the results. Samples were analyzed in the analytical laboratory of Institute for Engineering and Environmental Problems in Agricultural Production in 2022. Three replications were carried out for each sample. The experimental data were statistically analysed in MS Excel. Results. Quantitative and qualitative characteristics of pig manure, its solid and liquid fractions, and end products were calculated. The difference between the calculated and actual values does not exceed 10.2% that indicates the reliability of calculations. Discussion and Conclusion. The introduction of a new technology at the pig-breeding complex has reduced atmospheric emissions by 10% due to the nitrogen conservation, has reduced operating costs for transporting organic fertilizer by 47% due to the concentration of nutrients in a smaller volume and has improved soil fertility through fertilizer irrigation.

Optimising mechanical separation of anaerobic digestate for total solids and nutrient removal

Mechanical separation of anaerobic digestate has been identified as a method to reduce pollution risk to waterways by partitioning phosphorus in the solid fraction and reducing its application to land. Separators have adjustable parameters which affect separation efficiency, and hence the degree of phosphorous partitioning, but information on how these parameters affect separation performance is limited in the literature. Two well known technologies were investigated, decanter centrifuge and screw press, to determine the most efficient method of separation. Counterweight load and the use of an oscillator were adjusted for the screw press, while bowl speed, auger differential speed, feed rate and polymer addition were modified for the decanter centrifuge. Separation efficiency was determined for total solids, phosphorus, nitrogen, potassium, and carbon, and the total solids content of resulting fractions was measured. The decanter centrifuge had higher separation efficiency for phosphorus in all cases, ranging from 51% to 71.5%, while the screw press had a phosphorus separation efficiency ranging from 8.5% to 10.9% for digestate of ∼5% solids (slurry/grass silage mix). Separation by decanter centrifuge partitioned up to 56% of nitrogen in the solid fraction leaving a reduced nitrogen content in the liquid fraction available for land spreading; this nitrogen would most likely need to be replaced by chemical fertiliser which would add to the cost of the system. The decanter centrifuge is better suited to cases where phosphorus recovery is the most important factor, while the screw press could be advantageous in cases where cost is a limiting factor.

Study on the separation performance of a decanter centrifuge used for dewatering coal water slurry

The decanter centrifuge is widely used in the dewatering process of coal water slurry. In order to improve the separation performance of the decanter centrifuge, the influence of pitches, spiral blade inclination angles and rotational speeds on the separation performance was obtained by the combination of simulation and theoretical analysis. The results indicate that the higher pitch would lead to the decrease of the sediment stack height in front of the spiral blade and the residence time of the particles. With the increase of the pitch, the axial thrust and the slag solid content rate are increased first and then decreased. The best pitch is 258 mm. Using a backward tilting spiral blade can improve the distribution of sediment and enhance the radial extrusion of the spiral blade to sediment. Increasing the rotational speed can increase the tangential velocity and settling velocity of the material. When the rotational speed is less than 3000 rpm, increasing the rotational speed can improve the separation performance effectively. This paper provides references for optimizing the structure and improving the separation performance of the decanter centrifuge in the dewatering process of coal water slurry.

Continuous recovery of phosphoric acid and Rare-Earths containing particles from phosphoric acid sludge using a decanter centrifuge

Recovery of rare earth elements (REEs) from various industrial and natural streams currently draws significant attention in efforts to meet the demands of the manufacturing industry. Among many industrial byproducts and waste streams, phosphoric acid sludge could be one of the most economically feasible resources for the recovery of REEs because solid particles in the sludge contain relatively concentrated REEs, up to 3,000 ppm, while the liquid component of the sludge is valuable phosphoric acid (P2O5) that can be recovered and returned to the main product. Due to high viscosity and large solids content (e.g., 30–40 %), however, this byproduct stream requires multistep separation and purification processes. In this study, a single-step process involving a continuous-flow decanter centrifuge (CFDC) was employed to investigate its feasibility for continuous solid/liquid separation from real phosphoric acid sludge. High centrifugal forces generated from up to 1500 G gravity acceleration separate solid particles from the sludge, generating a liquid-rich stream and a solids-rich stream at the exit of the CFDC. A single pass of phosphoric-acid sludge through the CFDC yielded 95 % liquid recovery and 90 % recovery of REEs-containing solids from 20 to 34 wt% solids-containing sludge. A reduced order model developed for the CFDC operation showed good agreement with experimental data, and preliminary technoeconomic analysis revealed potential process feasibility.

Cross‐Batch Contamination in a Continuous Horizontal Decanter Centrifuge during Virgin Olive Oil Production

AbstractCross‐batch contamination in a decanter centrifuge during virgin olive oil production cannot be avoided using current technology. The extent of this contamination is investigated using industrial‐scale tests, by measuring the volatile profile and color on three consecutive oil batches, collected at the decanter outlet at different extraction times. The extent of contamination varied, pointing out qualitative consequences, as defective molecules are found. The latter are often active at low concentrations, and the measured cross‐batch contamination can lead both to the downgrading of large batches of virgin olive oils and to the adulteration of monovarietal and certified productions. An innovative method, based on the direct determination of the color (L and a* coordinates) of oil at the outlet of the decanter is able to identify the same compositional change point indicated by gas chromatography, and could be successfully used to mitigate the effects of cross‐batch contamination.Practical applications: An in‐line colorimetric system can be implemented at the decanter outlet to detect the point of change between different olive batches. Otherwise, the virgin olive oil exiting from the decanter at the beginning of one batch can be collected separately in order to avoid the contamination due to the previous batch.

Model‐based Scale Up of Solid Bowl Centrifuges Using Experimentally Determined Material Functions

AbstractThe scale up of solid bowl centrifuges is a major challenge as the process and material behavior are complex and difficult to describe. A common approach to forecast the process behavior is to use analytical models and transfer the experience gained from the lab to the industrial scale. In this context, time‐consuming and cost‐intensive pilot scale experiments are necessary. This paper presents a methodology to improve the scale up process and make it more sustainable by using a numerical model that allows the real‐time tracking of the process and a more reliable scale up process. For this approach, the material behavior is derived from laboratory experiments whereby the scalability is given. Here, the determination of material functions allows an accurate representation of the material behavior for solid bowl centrifuges of different scales. The focus of this paper is the detailed explanation of material related functions for the scale up of decanter centrifuges.