Full Industrial Scale Research Articles

Scale-up of plug-flow reactors in anaerobic treatment of agro-industrial wastes

This study is aiming to evaluate the optimization potential of anaerobic digestion systems for the treatment of complex agro-industrial wastes at an industrial scale. In previous work, the performance of a 20 L pilot-scale Plug Flow Reactor (PFR) that was able to operate at Organic Loading Rates (OLRs) of up to 25 kg Chemical Oxygen Demand (COD) m−3 d−1, was demonstrated. This concept was then successfully transferred in a semi-industrial scale PFR of a volume equal to 50 m3, and the optimal operational parameters were evaluated. The construction of a full industrial scale facility followed, utilizing initially a 380 m3 PFR. Since PFR systems in practice do not behave ideally, due to short Length to Diameter ratio (L/D) and/or higher axial dispersion, the ideal PFR behavior was compared with real data of the non-ideal industrial-scale system; a performance reduction of 25–30 % was detected. However, the disadvantage of the non-ideal behavior of PFRs can be overcome by the cascaded arrangement of two such reactors (2 × 380 m3 PFRs), leading to a total volume reduction of 35 %, as depicted by experimentation on the industrial scale cascaded PFRs. The optimal design parameters for the PFRs are provided.

Economic supply chain modelling of industrial insect production in the Netherlands

Abstract Defatted larvae meal (dLM), specifically from black soldier flies, could help overcome the animal protein gap. As insect production is an emerging sector, current economic research is scarce and very diverse. Thus, the aim of this research was to develop a simulation model that enables the analysis of full industrial scale costs of producing dLM and to provide insight in the distribution of these costs in the insect supply chain. The deterministic supply chain model is built on three modules, technical, transition and economic module, which all follow a previously defined supply chain structure and allow to extract quantity and price information for intermediate or final products. The model was parameterized and checked for plausibility in multiple consultation rounds with the INSECTFEED consortium and business partners. Additionally, model behaviour was checked with scenario, sensitivity, and break-even price analyses. In the default situation 5.57 tDM raw substrate and 26.7 million neonates are required to produce 1 tDM dLM for a price of €5,116/tDM. Most costs are added in the raw substrate delivery (€1,952/tDM) and production and collection (€821/tDM) step. Important cost factors are the raw substrate (€1,939/tDM) and building and inventory (€1,459/tDM). Parameters with high relative response rate towards the price of dLM are the feed conversion rate, dry matter percentage of larvae, raw substrate price, larvae density, labour wage and growth rate. To reach break-even prices for substituting fish meal with alive grown larvae (AGL) (€1,318/tDM AGL), improving production parameters is not sufficient. Just changing prices of raw substrate to −€78/tDM or frass to €1,175/tDM would enable a profitable operation. However, these are not deemed as realistic in mass production. Although there is some insecurity in data, the model results are the most realistic representation of industrial scale production amounts and costs.

Sieving and Covering of Wood Chips Improves Storability

Minimising dry matter losses during storage of comminuted forest fuels is desirable from both an economic and a sustainability perspective. This study examined fuel quality and amount of recovered energy during the storage of forest wood chips stored at full industrial scale at three locations, and the effect of sieving and covering piles with a water-resistant, vapour-permeable fabric. Sieving wood chips before storage, that is, reducing the number of fines smaller than 8 mm, reduced the cumulative dry matter losses to <2%, while cumulative dry matter losses after storage for 4–6 months using current practices, that is, unsieved and uncovered, reached 10.6%. The combined effect of storage management led to a value loss of 11.5%, while both covering and sieving led to lower losses, with the combination of sieving and covering giving a 1.3% value increase, and thus, increased storability.

Advanced comminution modelling: Part 2 - Mills

This second part paper explores rock breakage mechanisms, the life cycle of rocks in mills and the strong influence of end walls on charge motion within mills. We present recent advances in particle-based modelling of mills for comminution focused around wear and the effect of slurry and slurry phase grinding. Three mill scenarios are considered:1.Media flow and the resulting wear evolution of the belly and end wall liners and the resulting change in mill performance for a full industrial scale dry ball mill (modelled using DEM)2.Axial slurry transport and mixing in a wet overflow industrial scale ball mill (modelled using fully coupled DEM and SPH)3.Effect of mill speed on slurry and solid charge motion and the resulting grinding of fine particles in a 1.8 m diameter wet Hardinge pilot mill (modelled using fully coupled DEM and SPH with advection-diffusion-population balance equations solved for the slurry size distribution for each SPH particle)These demonstrate the nature and level of fidelity that is now possible to include in particle-scale comminution models. They provide insights into the critical importance of curtain flows generated by the end walls of tumbling mills, on wear behaviour on liners, on the structure of slurry pools and mill discharge and on the adverse effect on grinding of increasing mill speed.

Immune globulin subcutaneous, human 20% solution (Xembify®), a new high concentration immunoglobulin product for subcutaneous administration

Immune globulin subcutaneous, human 20% solution (IGSC-C 20%, Xembify®)—a new 20% immunoglobulin (IgG) liquid product for subcutaneous (SC) administration—has been developed by Grifols. The IGSC-C 20% formulation is based on knowledge acquired from the formulation of Immune Globulin Injection (Human),10% Caprylate/Chromatography Purified (IGIV-C 10%, Gamunex®-C). The protein concentration was increased from 10% to 20% to provide a smaller volume for SC administration. The IGSC-C 20% manufacturing process employs the same caprylate/chromatography purification steps as IGIV-C 10%, with the addition of an ultrafiltration step so that the product can be formulated at a higher protein concentration. IGSC-C 20% has been produced at full industrial scale to support clinical studies and licensure. These batches were characterized using a comprehensive panel of analytical testing. The new IGSC-C 20% product maintains the same composition, neutralizing activity, purity, and quality characteristics found in IGIV-C 10%.

A parametric study of the drying process of polypropylene particles in a pilot-scale fluidized bed dryer using Computational Fluid Dynamics

Fluidized Bed Dryer (FBD) is one of the efficient methods for drying moist particulate products. At the same time, the design and optimization of a full industrial scale FDB requires extensive studies. Using a pilot-scale dryer can be deemed as an efficient tool to obtain essential information on the drying phenomenon. Although these kinds of experimental analyses can provide valuable insight, there are still some operational limitations, including high-pressure or high-temperature conditions, which make the use of a computational procedure highly desirable. In this study, Computational Fluid Dynamics (CFD) approach has been employed to investigate a dryer. The results of numerical simulations were verified using the experimental data obtained from a pilot-scale dryer. The present investigation aims to study the effects of different operating conditions. It was observed that the impacts of gas inlet temperature were negligible, as the dryer was equipped with a thermal jacket, while the gas injection velocity had significant effects on the dryer’s performance. Moreover, the efficiencies of the conical and horizontal gas distributors were compared and it was concluded that the conical configuration results in better performance. The numerical and experimental investigation from this study can facilitate the design and scale-up of an industrial dryer plant.

Microbubble intensification of bioprocessing.

Microbubbles have been involved in industrial processing since the 1970s with the introduction of dissolved air flotation into common practice. The turn of the century saw microbubbles become regularly used in medical imaging. But in bioprocessing, only this decade has seen rapid advances in R&D, with some bioprocesses, particularly in wastewater treatment, adopted at full industrial scale, and others at pilot scale, such as anaerobic digestion and fermentation, which is full industrial scale for many biomanufacturing and pharmaceutical processes. This article reviews the methods of microbubble generation only briefly, as it turns out only one generation method, fluidic oscillation through microporous diffusers, has the requisite features for introduction into full scale fermentation processes. Subsequently, six fundamental physicochemical hydrodynamics mechanisms that have been exploited by microbubble innovations in bioprocessing are presented and analyzed, particularly for the roles they play in bioprocessing applications. Some examples are drawn with applications to microalgal and yeast processing, as well as usage in wastewater treatment processes. Because the smallest microbubbles can increase rates in some of these six fundamental processes by several orders of magnitude over conventional processing methods, with the optimal contacting patterns, the promise for wider exploitation in bioprocessing is substantial.

The Bioconversion of Municipal Solid Waste in the Biodrying Reactor

The bioconversion process of municipal solid waste was assessed on the basis of the results obtained from the biodrying reactor working at a full industrial scale. The bio- reactor is a part of mechanical-biological installation following mechanical stage. The bio-reactor was equipped with measuring devices allowing the analysis of the parameters like: temperature both inside the waste and also air above the waste and also the humidity of waste during the 14 days of the biodrying process. The kinetics of bioconversion was assessed basing on measured the loss of ignition (LOI) parameter detected during the biodrying process. The LOI value of the samples varied from 17.03% d.m. to 30.34% d.m. depending on the location inside the reactor. The estimated kinetic rate constant kT of the bioconversion of biomass in the industrial reactor was kT = 0.3141.In analyzed case study the calorific value of product leaving the full-scale bio-reactor is too low to use this product as an alternative fuel. As was stated, the reason of this is too low a share of the carbon-rich fraction in the feedstock.

Environmental sustainability assessment of renewables‐based propylene glycol at full industrial scale production

AbstractBACKGROUNDGlycerol, a by‐product from oleochemical or biodiesel production, can be used to produce renewables‐based propylene glycol (PG). The environmental sustainability of PG was evaluated using life‐cycle assessment. The effect of shifting from petrochemical to renewables‐based PG was assessed by using data from an industrial scale renewables‐based PG production plant. A contribution analysis was performed to identify the hotspots in the production process. The effects of implementing a sustainable sourcing strategy and producing steam/electricity by combined heat and power (CHP) were assessed.RESULTSA switch from petrochemical to renewables‐based PG results in a reduction of the climate change impact between 40% and 60% kg CO2 eq. A shift of burden is found to agriculture‐related indicators. For the biodiesel and oleochemical production route, respectively, 73% and 59% of the impact on climate change is related to feedstock production. By implementing two improvements, the emitted CO2 eq. for biodiesel PG could be reduced by 38%.CONCLUSIONSSwitching from petrochemical to renewables‐based PG has a clear environmental benefit for slowing climate change. However, the shift of burden towards agriculture‐related indicators shows the need to ensure sustainable agricultural practices. Combining both on‐site improvements and a more sustainable supply chain effectively decreases the environmental impact. © 2019 Society of Chemical Industry

Major accident hazard in biodiesel production processes

The number of biodiesel production plants is rapidly growing around the world, and the related “green” technologies are developing to full industrial scale within a brief time. The exploitation of these relatively new technologies with a low operational experience is however leading to an increase in the number of accidents in this industrial sector. To better address and characterise the problem of the high accident rate in the “green” technologies in biodiesel production, an in-depth statistical analysis of past accidents has been performed. The set of records analysed (93 events, from 2003 to 2017) has been selected to depict the most relevant factors affecting the accident rate, e.g. the age of the plant and its status at the time of the accident or unit and substances involved. Correlations between characteristics of the unwanted events, such as scenario and causes, have been evidenced. The analysis of the frequency and severity of past accidents allowed an estimate of the risk figure with respect to major accident hazard for biodiesel industry, unveiling the misconception for which green technologies as biodiesel production are often perceived as safer.

Removal and immobilization of heavy metals in contaminated soils by chlorination and thermal treatment on an industrial-scale

Heavy metals contaminated soils are a potential exposure hazard to the public. This study demonstrated the application of chlorination and thermal treatment for remediation of heavy metals-contaminated soils on a full-industrial scale. Five soil samples were treated at a soil remediation factory equipped with an internally-heated rotary kiln (length: 17 m; diameter: 4 m; rotating speed: 0.60 rpm). The target soil temperature was set at about 950 °C. During treatment, calcium chloride was added to facilitate chlorination. The chlorination and thermal treatments effectively removed Pb and Cd and led to the slight removal of Cu and Zn but was not effective for Cr and Ni. Chlorination and thermal treatment also significantly reduced the bioaccessibility of heavy metals in soils, particularly Pb and Cd. The results of sequential extraction revealed that thermal treatment generally decreased the carbonate (C2), Fe/Mn oxide (F3) and organic matter (O4) fractions but tended to increase the residual (R5) fractions of heavy metals, indicating that the chlorination and thermal treatment also favored the immobilization of heavy metals. Overall, the results of this study suggest that remediation of heavy metals-contaminated soils by chlorination and thermal treatment is technologically feasible and that there is great potential for practical application of this method.

Enhancing biogas plant production using pig manure and corn silage by adding wheat straw processed with liquid hot water and steam explosion

BackgroundPig manure utilization and valorization is an important topic with tightening regulations focused on ecological and safety issues. By itself pig manure is a poor substrate for biogas production because of its excessive nitrogen content relative to available organic carbon. Such substrate is alkaline, and methanogenesis can be suppressed, and so additional substrates with high organic carbon must be added. The most promising is straw, which is available from adjacent biogas plant cultures. However, the abundant lignocellulosic biomass of wheat straw undergoes slow decomposition, and only a fraction of the chemical energy can be converted into biogas; thus economical methods for pretreatment increasing bioavailability are sought.ResultsA method was investigated to increase the methane yield in a full-scale plant for co-fermenting pig manure with corn silage, which was the default substrate in the original source reactors. Increased lignocellulosic bioavailability of wheat straw was achieved by combining liquid hot water (LHW) and steam explosion (SE). According to FT-IR analysis, the treatment resulted in hemicellulose hydrolysis, partial cellulose depolymerization, and lignin bond destruction. Low-mass polysaccharides (0.6 × 103 g mol−1) had significantly higher concentration in the leachate of LHW-SE wheat straw than raw wheat straw. The methanogenic potential was evaluated using inoculum from two different biogas plants to study the influence of microorganism consortia. The yield was 24–34% higher after the pretreatment process. In a full-scale biogas plant, the optimal conditions were ~ 165 °C, ~ 2.33 MPa, and 10 min in LHW and ~ 65 °C and ~ 0.1 MPa for SE. The processes did not generate detectable inhibitors according to GC–MS analysis, such as furfural and 5-hydroxymethylfurfural.ConclusionsThe LHW-SE combined pretreatment process increases the bioavailability of carbohydrates from wheat straw. The LHW-SE treated wheat straw gave similar biogas yields to corn silage, thus enables at least partial replacement of corn silage and is good for diversification of substrates. Surprisingly, microorganisms consortia from other biogas plant fed with other substrates may have higher efficiency in utilization of tested substrate. Thus, methanogenic consortia may be considered in the process of optimization at industrial scale. The efficiency was calculated, and the LHW-SE may be profitable at full industrial scale and further optimization is proposed.

Pilot plant for electron beam treatment of flue gases from heavy fuel oil fired boiler

The pilot scale electron beam flue gas treatment (EBFGT) plant was constructed at Saudi Aramco's Refinery in Jiddah, Saudi Arabia. The plant was designed to treat 2000Nm3/h of flue gas emitted from a heavy fuel oil fired boiler. A unique mobile electron accelerator unit (600keV, 20kW) made by EB TECH Co., Ltd., Korea was used as a beam source. The pilot plant operation proved the high potential of the technology for simultaneous control of sulfur dioxide (SO2) and nitrogen oxides (NOx) emissions. The obtained removal efficiencies reached 98.5% for SO2 and 83.1% for NOx. Two types of byproduct collection devices – cartridge bag filter and electrostatic precipitator – were tested. The obtained byproduct was a high quality fertilizer that can be used directly or as a substrate for NPK blends manufacturing. The soluble part of the byproduct was almost pure ammonium sulfate (98% to 99%) with some amount of ammonium nitrate. The content of heavy metals in the byproduct was very low and lower than the allowed standards by two orders of magnitude. The results of the research are the basis for the design of a full industrial scale EBFGT plant for treatment of flue gas from heavy fuel oil combustion.

Computational prediction of performance for a full scale Isamill: Part 1 – Media motion and energy utilisation in a dry mill

The Isamill is a horizontal stirred media mill used for fine and ultrafine grinding. Discrete Element Method (DEM) simulation has been used in this paper to study the behaviour of the media and the collisional environment in a full industrial scale Isamill. The DEM modelling has been able to provide a general understanding of the force balances that control the mill performance and the quantitative variation of key performance measures such as power draw and peak collision energy with changes in mill operating parameters and media properties. The key factor controlling the behaviour of the media and mill performance is the force balance on the media adjacent to the rotating discs of the impellor. Gravity and any applied axial pressure gradient play a critical role by providing a restoring force that presses the media bed against the discs which enables energy transfer from the discs to the adjacent media. Three important aspects of the media flow are identified with the holes in the discs playing a critical role in media transport and generating high speeds media jets in the upper half of the mill.

Scaling of dust explosion violence from laboratory scale to full industrial scale – A challenging case history from the past

The standardized KSt parameter still seems to be widely used as a universal criterion for ranking explosion violence to be expected from various dusts in given industrial situations. However, this may not be a generally valid approach. In the case of dust explosion venting, the maximum pressure Pmax generated in a given vented industrial enclosure is not only influenced by inherent dust parameters (dust chemistry including moisture, and sizes and shapes of individual dust particles). Process-related parameters (degree of dust dispersion, cloud turbulence, and dust concentration) also play key roles. This view seems to be confirmed by some results from a series of large scale vented dust explosion experiments in a 500 m3 silo conducted in Norway by CMI, (now GexCon AS) during 1980–1982. Therefore, these results have been brought forward again in the present paper. The original purpose of the 500 m3 silo experiments was to obtain correlations between Pmax in the vented silo and the vent area in the silo top surface, for two different dusts, viz. a wheat grain dust collected in a Norwegian grain import silo facility, and a soya meal used for production of fish farming food. Both dusts were tested in the standard 20-L-sphere in two independent laboratories, and also in the Hartmann bomb in two independent laboratories. Pmax and (dP/dt)max were significantly lower for the soya meal than for the wheat grain dust in all laboratory tests. Because the available amount of wheat grain dust was much larger than the quite limited amount of available soya meal, a complete series of 16 vented silo experiments was first performed with the wheat grain dust, starting with the largest vent area and ending with the smallest one. Then, to avoid unnecessary laborious changes of vent areas, the first experiment with soya dust was performed with the smallest area. The dust cloud in the silo was produced in exactly the same way as with the wheat grain dust. However, contrary to expectations based on the laboratory-scale tests, the soya meal exploded more violently in the large silo than the wheat grain dust, and the silo was blown apart in the very first experiment with this material. The probable reason is that the two dusts responded differently to the dust cloud formation process in the silo on the one hand and in the laboratory-scale apparatuses on the other. This re-confirms that a differentiated philosophy for design of dust explosion vents is indeed needed. Appropriate attention must be paid to the influence of the actual dust cloud generation process on the required vent area. The location and type of the ignition source also play important roles. It may seem that tailored design has to become the future solution for tackling this complex reality, not least for large storage silos. It is the view of the present author that the ongoing development of CFD-based computer codes offers the most promising line of attack. This also applies to design of systems for dust explosion isolation and suppression.

A novel in-line NIR spectroscopy application for the monitoring of tablet film coating in an industrial scale process

Film coating of tablets is a multivariate pharmaceutical unit operation. In this study an innovative in-line Fourier-Transform Near-Infrared Spectroscopy (FT-NIRS) application is described which enables real-time monitoring of a full industrial scale pan coating process of heart-shaped tablets. The tablets were coated with a thin hydroxypropyl methylcellulose (HPMC) film of up to approx. 28μm on the tablet face as determined by SEM, corresponding to a weight gain of 2.26%. For a better understanding of the aqueous coating process the NIR probe was positioned inside the rotating tablet bed. Five full scale experimental runs have been performed to evaluate the impact of process variables such as pan rotation, exhaust air temperature, spray rate and pan load and elaborate robust and selective quantitative calibration models for the real-time determination of both coating growth and tablet moisture content. Principal Component (PC) score plots allowed each coating step, namely preheating, spraying and drying to be distinguished and the dominating factors and their spectral effects to be identified (e.g. temperature, moisture, coating growth, change of tablet bed density, and core/coat interactions). The distinct separation of HPMC coating growth and tablet moisture in different PCs enabled a real-time in-line monitoring of both attributes. A PLS calibration model based on Karl Fischer reference values allowed the tablet moisture trajectory to be determined throughout the entire coating process. A 1-latent variable iPLS weight gain calibration model with calibration samples from process stages dominated by the coating growth (i.e. ≥30% of the theoretically applied amount of coating) was sufficiently selective and accurate to predict the progress of the thin HPMC coating layer. At-line NIR Chemical Imaging (NIR-CI) in combination with PLS Discriminant Analysis (PLSDA) verified the HPMC coating growth and physical changes at the core/coat interface during the initial stages of the coating process. In addition, inter- and intra-tablet coating variability throughout the process could be assessed. These results clearly demonstrate that in-line NIRS and at-line NIR-CI can be applied as complimentary PAT tools to monitor a challenging pan coating process.

Membrane filtration and sonication for industrial wastewater reuse

This paper presents an experimental study aimed at estimating the efficiency of the innovative process of ultrafiltration (UF) combined with sonication (Son.) for the refinement of treated effluent to be reused in wet textile processes. Such a novel approach, which has not yet been employed on a full industrial scale, has been experienced at pilot scale on the secondary effluent of the Baciacavallo wastewater treatment plant (WWTP), which treats part of the effluent from one of the largest textile industry districts in Italy. The combined treatment efficiency was assessed both on ozonated and non-ozonated Baciacavallo secondary effluent. The membrane filtration process was optimized in terms of running time, backwash, chemical addition and cleaning procedures. The sonication treatment was optimized on laboratory-scale with synthetic solutions (demineralized water added with dyestuffs) in terms of hydroxyl radicals formation rate, frequency, acoustic power, hydrogen peroxide addition, contact time and pH. The optimal conditions have been applied on the pilot-scale sonicator which was used in combination with the UF treatment. According to the experimental results, the best configuration within the Baciacavallo WWTP was the sonication of non-ozonated wastewater followed by the UF. The combined treatment guaranteed the compliance with the target values for wastewater reuse in wet textile industries. This study is part of the Research Project PURIFAST (Purification of industrial and mixed wastewater by combined membrane filtration and sonochemical technologies) LIFE + ENV/IT/000439.

Separation performance of double deck banana screens – Part 2: Quantitative predictions

Banana screens are often used for high capacity separation of iron ore, coal and aggregates into different size fractions. They consist of one or more curved decks that are fitted with screen panels with arrays of square or rectangular holes. The screen structure is vibrated while a dense stream of particles flows over it and is separated according to size. The material discharging from the top of the deck is the oversize and may become a coarse product or be crushed and recycled to the screen feed. The material falling through the deck can be further separated by additional decks below. Each lower deck returns a product stream and the material passing out through the bottom deck is the undersize. In this paper, Discrete Element Method (DEM) is used to explore the separation performance of a full industrial scale double deck banana screen for a peak acceleration of 5 g. The separation efficiency of each deck is analysed and the individual contributions of each screen panel are assessed using outputs from the model. Residence time distributions for particles on each deck provide insight into both the transport characteristics along the deck and the separation performance through each deck. The top and bottom decks have very different flow behaviour with very different bed structure and motion. The stresses applied by the flowing particles to the screen cloths and the impact and abrasive wear on the screen surfaces are evaluated. Finally, the energy absorbed by particles provides insight into the extent of particle degradation produced by transiting the screen.

Separation performance of double deck banana screens – Part 1: Flow and separation for different accelerations

Banana screens are often used for high capacity separation of iron ore, coal and aggregates into different size fractions. They consist of one or more curved decks that are fitted with screen panels with arrays of square or rectangular holes. The screen structure is vibrated at high frequency to generate peak accelerations of around 4–6 g which separates particles flowing over each screen according to their size. Screens are often used to close comminution circuits and return specific size fractions of rock to different destinations such as pebble mills, crushers and back into the mills. All multi-deck screens are difficult to sample for intermediate products which makes measurement and optimization very difficult. Banana screens are even more difficult because the screen cut size varies with the varying slope of the decks. In this paper, the discrete element method (DEM) is used to simulate a full industrial scale double deck banana screen for a range of accelerations. The nature of the particle flow through this complex machine is explored for a range of peak accelerations. Critical aspects of the flow are linked to the separation performance.

The influence of bearing geometry on the residual stress state in cold drawn wire, analysed by the FEM

Finite element simulations have been performed in order to study the influence of bearing geometry on the residual stress-state in cold drawn wires. Experiments in full industrial scale have been performed in order to verify the FEM results. The residual stresses were measured with X-ray diffraction in both the axial and tangential direction. The material used was a high carbon steel for roller bearings, 100Cr6. It was found that the geometry of the bearing has a large influence of the residual stress-state. When the bearing is somewhat tapered, a gap in the beginning of the bearing is formed. This “double contact” reduces the axial and tangential residual stress to minimum or even to a compressive state. A cylindrical bearing gave no contact in the bearing at all due to elastic deformation. This resulted in a large axial and tangential residual stress. It was shown that even a small divergence from the desired bearing geometry due to the grinding of the die could affect the residual stress immensely.