Distillation Stage Research Articles

Analysing separation and reaction stage performance in a reactive cyclic distillation process

In this paper the production of MTBE from isobutene and methanol via reactive cyclic distillation is studied with a mass and energy balance stage model. This study shows the first application of a reactive cyclic distillation stage model, where reaction equilibrium is assumed. A cyclic distillation process with a column design equivalent to a conventional column for MTBE reactive distillation has been simulated. The cyclic operated column gives high conversions of reactants, high product throughput and low energy requirements. By investigating the reactive stage behaviour it was found that the periodic operation can give an overall higher degree of separation and production of MTBE compared to the conventional column design. This is due to higher degree of separation in the cyclic operation, which favours the desired reaction. With no back-mixing of the liquid holdups the overall mass transfer and conversion in a reactive cyclic distillation process is increased compared to that of a conventional reactive separation scheme. Thereby, an improved cyclic operated column design with reduced number of stages was realised.

Different distillation stages Baijiu classification by temperature-programmed headspace-gas chromatography-ion mobility spectrometry and gas chromatography-olfactometry-mass spectrometry combined with chemometric strategies

Liquid–liquid microextraction (LLME) combined with gas chromatography–olfactometry–mass spectrometry (GC–O–MS) was used to detect the variations in volatile compounds during the distillation process (head, heart, and tail) of raw Baijiu produced by different layers of fermented grains; 47 aroma compounds were sniffed and identified. Moreover, temperature-programmed headspace gas chromatography–ion mobility spectrometry (TP-HS–GC–IMS) was applied to characterize the Baijiu distillation process for the first time. The 3D fingerprint spectrum clearly showed a variation in volatile compounds from different distillation stages, and most compounds showed a downward trend. In addition, multivariate statistical analysis, including principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), etc., confirmed ten aroma active markers related to classification, indicating that these markers had a great influence on the flavor of raw Baijiu.

Utilization of Bioetanol Fermentation Waste Pineapple and Coconut Water as Disinfectants With Bacteria Saccharomyces Cerevisiae

Research analysis of sugar content and the effect of ethanol content on bioethanol from old coconut water and pineapple peel with the help of Saccharomyces Cerevisease bacteria. The condition of the spread of the Corona Virus or COVID-19 in Indonesia, thus making bioethanol produced from fermenting pineapple peel waste and old coconut water for disinfectant products to spray around homes and public places to reduce bacteria and viruses. The production of bioethanol is carried out by pre-treating coconut water and pineapple peel, the fermentation stage with Saccharomyces cerevisiae yeast and the distillation stage. The result of the highest bioethanol content was 32% with a mass of 5 g yeast with a time of 24 hours. The highest calorific value at 72 hours was 211.95 kcal/kg. The result of the highest specific gravity at 24 hours and the mass of yeast 4 g is 0.98 g/ml. Based on the bioethanol quality requirements, the bioethanol produced is not in accordance with the bioethanol quality requirements, this is due to the absence of nutrient decomposing bacteria so that it is less than optimal in converting glucose into bioethanol.

Utilization of Bioetanol Fermentation Waste Pineapple and Coconut Water as Disinfectants With Bacteria Saccharomyces Cerevisiae

Research analysis of sugar content and the effect of ethanol content on bioethanol from old coconut water and pineapple peel with the help of Saccharomyces Cerevisease bacteria. The condition of the spread of the Corona Virus or COVID-19 in Indonesia, thus making bioethanol produced from fermenting pineapple peel waste and old coconut water for disinfectant products to spray around homes and public places to reduce bacteria and viruses. The production of bioethanol is carried out by pre-treating coconut water and pineapple peel, the fermentation stage with Saccharomyces cerevisiae yeast and the distillation stage. The result of the highest bioethanol content was 32% with a mass of 5 g yeast with a time of 24 hours. The highest calorific value at 72 hours was 211.95 kcal/kg. The result of the highest specific gravity at 24 hours and the mass of yeast 4 g is 0.98 g/ml. Based on the bioethanol quality requirements, the bioethanol produced is not in accordance with the bioethanol quality requirements, this is due to the absence of nutrient decomposing bacteria so that it is less than optimal in converting glucose into bioethanol.

Ethyl carbamate in Chinese liquor (Baijiu): presence, analysis, formation, and control.

Ethyl carbamate (EC) is a genotoxic and carcinogenic compound that is also a by-product of fermented foods (bread, sour milk, soy cheese, etc.) and alcoholic beverages (wine, sake, distilled liquor, etc.). Studies have showed that ethyl carbamate is ingested by humans primarily through the consumption of alcoholic beverages. Many countries have thus established EC limits for alcoholic beverages. Chinese liquor (Baijiu) is a traditional and unique distilled liquor, which has a huge consumption in China due to its excellent color, flavor, and taste. Therefore, the control of EC in Chinese liquor is of great significance. This review summarized for the first time the progress in presence level, analysis method, formation mechanism, and elimination strategy of EC of Chinese liquor in recent decades. KEY POINTS: • GC-MS and HPLC are the main methods to quantify EC in Chinese liquor. • EC is formed in the fermentation, distillation, and storage stage. • EC content can be reduced from raw material, microorganism, and production process.

A novel downstream process for highly pure 1,3-propanediol from an efficient fed-batch fermentation of raw glycerol by Clostridium pasteurianum.

An efficient downstream process without prior desalination was developed for recovering 1,3‐propanediol (1,3‐PDO) with high purity and yield from broth of a highly productive fed‐batch fermentation of raw glycerol by Clostridium pasteurianum. After removal of biomass and proteins by ultrafiltration, and concentration by water evaporation, 1,3‐PDO was directly recovered from the broth by vacuum distillation with continuous addition and regeneration of glycerol as a supporting agent. Inorganic salts in the fermentation broth were crystallized but well suspended by a continuous flow of glycerol during the distillation process, which prevented salt precipitation and decline of heat transfer. On the other hand, ammonium salt of organic acids were liberated as ammonia gas and free organic acids under vacuum heating. The latter ones formed four types of 1,3‐PDO esters of acetic acid and butyric acid, which resulted in yield losses and low purity of 1,3‐PDO (< 80%). In order to improve the efficiency of final 1,3‐PDO rectification, we examined alkaline hydrolysis to eliminate the ester impurities. By the use of 20% (w/w) water and 2% (w/w) sodium hydroxide, > 99% reduction of 1,3‐PDO esters was achieved. This step conveniently provided free 1,3‐PDO and the sodium salt of organic acids from the corresponding esters, which increased the 1,3‐PDO yield by 7% and prevented a renewed formation of esters. After a single stage distillation from the hydrolyzed broth and a followed active carbon treatment, 1,3‐PDO with a purity of 99.63% and an overall recovery yield of 76% was obtained. No wastewater with high‐salt content was produced during the whole downstream process. The results demonstrated that the monitoring and complete elimination of 1,3‐PDO esters are crucial for the efficient separation of highly pure 1,3‐PDO with acceptable yield from fermentation broth of raw glycerol.

ANALISIS KADAR PROTEIN PADA TEPUNG JAGUNG, TEPUNG UBI KAYU DAN TEPUNG LABU KUNING DENGAN METODE KJEDHAL

Protein is a polymer consisting of amino acid monomers which are connected to form linear bonds called Peptide bonds. The presence of nitrogen is a special feature of protein compounds because this element is not found in simple fat and carbohydrate compounds. This study aims to determine the protein content in corn flour, cassava flour, and pumpkin flour using the Kjedhal method. Protein analysis by the Kjedhal method is basically divided into three stages, namely: the destruction stage, the distillation stage, and the titration stage. The results showed that the protein content in corn flour was 9.32%, cassava flour was 8.45%, and pumpkin flour was 0.62%. The conclusion of this study is the greatest protein content found in corn flour.

Bioethanol Purification from Fermentation of Suweg Starch Using Two Stage Distillation Method

This study aims to employ two-stage distillation in the purification of fermented ethanol. Furthermore, 200g/L Suweg starch was fermented by Simultaneous Saccharification and Fermentation (SSF) method using StargenTM 002 and Saccharomyces cerevisiae at a concentration of 1.5% (w/w) and 1.10% (w/w), respectively. Therefore, 99.52 g/L or 13.82% bioethanol was produced and further purified through a distillation method. Subsequently, the first stage was performed in a column without filling material, while the second was in a column with glass ball-shaped material (marbles). This two phase exposure was conducted to expand the contact between the bioethanol-water vapor mixture and the suffing material. In addition, the temperature was set at 78ºC, while the duration was varied at 45, 60, 75, and 90 minutes. Therefore, the samples were analyzed using high-performance liquid chromatography (HPLC) and the maximum yield of 94.6% was produced at 75 minutes.

Промышленные технологии переработки отработанных масел

A brief review of the state of collection, disposal and processing of used oils shows the availability of their resource in the country and the main trends in the organization of qualified collection, disposal and processing according to the lubricating oil version. The relevant technologies are given for individual stages and in general for enterprises, the choice of which depends on the quality and characteristics of raw materials. The advantage of the technological scheme, including coagulation purification at the stage of raw material preparation and vacuum distillation with the selection of distillate fractions and the residue, followed by additional purification of the residue, is shown. The use of this technology makes it possible to increase the yield and quality of the target product, which is practically impossible for the raw materials currently available in the Russian Federation using other technologies.

Greedy Layer Pruning: Decreasing Inference Time of Transformer Models

Fine-tuning transformer models after unsupervised pre-training reaches a very high performance on many different NLP tasks. Unfortunately, transformers suffer from long inference times which greatly increases costs in production and is a limiting factor for the deployment into embedded devices. One possible solution is to use knowledge distillation, which solves this problem by transferring information from large teacher models to smaller student models, but as it needs an additional expensive pre-training phase, this solution is computationally expensive and can be financially prohibitive for smaller academic research groups. Another solution is to use layer-wise pruning methods, which reach high compression rates for transformer models and avoids the computational load of the pre-training distillation stage. The price to pay is that the performance of layer-wise pruning algorithms is not on par with state-of-the-art knowledge distillation methods. In this paper, greedy layer pruning (GLP) is introduced to (1) outperform current state-of-the-art for layer-wise pruning (2) close the performance gap when compared to knowledge distillation, while (3) using only a modest budget. More precisely, with the methodology presented it is possible to prune and evaluate competitive models on the whole GLUE benchmark with a budget of just $\$300$. Our source code is available on this https URL.

Reactive Distillation for the Production of Cyclohexanol

Cyclohexanol is an organic chemical intermediate product widely used in chemical&lt;br /&gt; industry and commonly produced by cyclohexene hydration. Because of the low mutual&lt;br /&gt; solubility of cyclohexene and water, the reaction is limited by chemical equilibrium,&lt;br /&gt; which has the disadvantage of low conversion of cyclohexene. In this paper, the hydration reaction of cyclohexene catalysed by A-36 cation exchange resin catalyst was analysed by Aspen Plus V8.6 simulation software in the presence of isophorone as cosolvent.&lt;br /&gt; The process model of synthesising cyclohexanol by catalytic distillation was verified by&lt;br /&gt; process experiments. The simulation experiments were carried out using the process&lt;br /&gt; model, and suitable operating conditions of the catalytic distillation column were obtained. These are: ketene feed ratio 1.5, alkene/water ratio 0.5, distillation stage trays 5,&lt;br /&gt; reaction stage trays 12, stripping stage trays 6, cyclohexene feed at the 18th tray, water&lt;br /&gt; and isophorone feed at the 5th tray, reflux ratio 3, feed ratio (D/F) 0.25. Under these&lt;br /&gt; operating conditions, the conversion of cyclohexene can reach 40.63 %.

Closed-loop dynamic real-time optimization (CL-DRTO) of a bioethanol distillation process using an advanced multilayer control architecture

The ethanol production has become an important part of the worldwide economy driven by its use as renewable energy and environmentally clean fuel. To obtain a high-level quality product, a large quantity of energy is used in the distillation stage. This work proposes to optimize the bioethanol production process applying a closed-loop dynamic real-time optimization (CL-DRTO) framework associated with advanced control strategies in the ethanol distillation facilities to improve production and minimize energy losses. A high-fidelity computational platform is developed using a software-in-the-loop (SIL) technique to demonstrate the feasible application in real cases. OLE (Object Linking and Embedding) Automation integrates Matlab and Aspen Hysys software to simulate practical scenarios currently applied in the industry. The optimization and control algorithms are developed in Matlab and the ethanol distillation process is modeled in the Aspen Hysys. Different advanced control strategies, such as IHMPC (Infinite Horizon Model Predictive Control), MIMO FSP (Filtered Smith-Predictor) and DTCGPC (Dead-Time Compensator Generalized Predictive Controller), are used to overcome the process dynamic issues, for instance, strong nonlinearity, dead-times, long time constants and coupled loops, on ethanol distillation process. A CL-DRTO layer is developed in the proposed control structure to consider economic and production aspects, guiding the process to optimal operating points. Performance indices and computational effort are used to evaluate the control behavior for disturbance rejection and reference tracking scenarios. Furthermore, economic performance is analyzed to ensure the advantages of the proposal. Results show that the proposed computational platform is able to reproduce industrial scenarios with high-fidelity. In addition, preliminary results demonstrate that advanced control structure can improve the production and profitability of the bioethanol distillery and present a powerful alternative to replace classical controllers currently used in this type of industry.

Cleaner and sustainable processes for extracting phenolic compounds from bio-waste

The frequent environment-unfriendly treatments of agro-industrial bio-wastes cause severe pollution through air pollution and through residual effluents and hazardous solid waste. These bio-wastes can contain phenolic compounds, forms of phenolic acids and flavonoids in plants. They are however the most abundant class of many phytochemicals and have been given great interest due to their health advantage and high economic value. An interesting upgrading of these bio-wastes may consist in obtaining a concentrated extract of phenolic compounds using no-toxic solvents, hence protecting the environment and human health.In this work, different alternatives of the extraction process were evaluated using an exergetic analysis. The energy and water consumptions, CO2 emissions, exergetic yield, wasted and destroyed exergy were calculated. It was found that several alternatives for recycle streams were convenient (streams with higher chemical exergy were not discharged into the environment).The energy and water consumption for the best alternative (ethanol-water ratio 1/1 including recycle stream, named E-W 1/1 Rec) were 567 MJ/h and 105 kg/h, respectively and the CO2 emission was 105 kg/h.The calculated exergy destruction indicated that the evaporation and distillation stages may be optimized towards a more sustainable operation. It is not advisable to dry the bio-waste if it will be immediately processed once generated.

Heat and mass transfer resulting in eruptive jetting from stems and leaves during distillation stage of forest fire

Forest fires are common large-scale environmental disasters with annual death toll and damages on the scale of tens of billions of dollars. They leave scars visible from space. In the context of climate change, forest fire severity is predicted to increase. Not only forest fires release significant amounts of carbon dioxide and ash to the atmosphere, but the diminishing forest area facilitates the greenhouse effect and climate change. However, the internal mechanisms of forest fires are not fully understood, which complicates their prediction, prevention and quenching. We explore a novel mechanism responsible for fuel and water vapor supply into flame in the form of volatiles-water vapor jets erupting from plants engulfed in fire. This mechanism is significantly accelerated in comparison with the ordinary-implied evaporation/sublimation and diffusion characteristic of the diffusion flames. The eruptive jets accelerate fuel supply into the flame zone and plant drying before burning, which facilitates forest fire. They also ballast the flame zone with water vapor, i.e. provide a counter-acting flame-quenching path. Epipremnum aureum stems and oak (Quercus calliprinos) leaves are used in the experiments to study volatiles and water vapor eruption from biomass burning at the distillation stage of forest fire. The eruptive jets are observed in the experiments with horizontal stems and leaves subjected to the engulfing flame, and the results are explained and predicted theoretically. As a model system, a horizontal syringe needle filled with liquids and subjected to the surrounding flame is used as a stem substitute to separate the effect of water vapor from that of combustible volatiles modeled by ethanol. The velocity and temperature of the jets erupting from the horizontal stems or needles subjected to flame are measured and predicted, with the velocity being on the scale of 10 m/s. The theory is in good agreement with the experimental data.

Environmental assessment of food and beverage under a NEXUS Water-Energy-Climate approach: Application to the spirit drinks

The energy-water nexus is a concept widely established but rarely applied to product and, in particular, to food and beverage products, which have a great influence on greenhouse gases emissions. The proposed method considers the main nexus aspects in addition to other relevant aspects such as climate change, which is deeply linked with energy and water systems, and assessing process as well as product. In this framework, this study develops an integrated index (IWECN) that combines life cycle assessment (LCA) and linear programming (LP) to assess energetic, water and climate systems, enabling the identification of those products with minors energetic and water intensity and climate change effects and helping to the decision-making process and to the development of eco-innovation measures. In this case, the product assessed was one bottle (70 cl) of gin and two main hotspots were identified: the production of the glass bottle and the energy requirements of the distillation stage. Based on that, several eco-innovation strategies were proposed: the use of photovoltaic solar energy as energy source and the substitution of the glass bottle by a plastic one and by a tetra brick. The nexus results indicated that the use of solar photovoltaic energy and plastic as bottle material was the best alternative decreasing 58% the IWECN value of the production of one bottle of gin. The sensitivity analysis presented a strong preference for photovoltaic solar energy in comparison with electric power and for the reduction of the glass bottle weight or its substitution by a plastic bottle. The use of the IWECN index is extendable to any product with the aim of facilitating the decision-making process in the development of more sustainable products to introduce them in new green markets.

Sustainable freshwater production using passive membrane distillation and waste heat recovery from portable generator sets

More than two billion people live in areas affected by water stress. In some coastal regions, freshwater supply has been progressively improved by large-scale desalination systems, which are nowadays mostly driven by non-renewable energy sources. Here we discuss, and experimentally investigate, the use of small-scale desalination devices for freshwater production powered by waste heat from electric power generators. The water purification technology relies on a passive, multi-stage and thermally-driven membrane distillation device, recently proposed by some of the authors of this work. The distiller is powered by low-grade (temperature lower than 80 °C) waste heat, recovered from the coolant circuit of small diesel engines for electricity production. Field experiments show that, for the tested engine, up to 1.12 kWm-2 can be recovered in standard operating conditions, which yield a nearly 2.61 Lm-2h-1 freshwater production from seawater. A lumped parameter model, validated by experiments, shows that this productivity could be eventually enhanced by tuning the number of distillation stages. Utilization with exhaust gases, and thus higher feeding working temperatures, is also discussed. The proposed solution may provide a sustainable, simple, inexpensive and efficient means for freshwater production from recovered waste heat, which would otherwise be wasted to the ambient. Therefore it could be particularly effective, for instance, for field hospitals in remote or impoverished areas, especially in emergency situations.

ACETONE RECOVERY USING BATCH DISTILLATION

This study focuses on determining the feasibility of obtaining maximum mole percentage of acetone (99 mole%) in the distillate stream from a 3 mole% acetone waste stream using batch distillation. The device which is used in this work has eight trays that will act as the stages of the batch distillation. The effects of varying reflux ratio and heat load (power) on acetone concentration were studied. Moreover, the operating conditions for the bath distillation column such as flooding and weeping with the extreme limits of operation were considered. The temperatures were also be recorded at each tray. The McCabe-Thiele method was used to determine the theoretical number of trays and compared with actual trays (column efficiency). For a chemical analysis of acetone/water compositions a refractometer was used for a chemical analysis, known acetone/water concentrations were analysed and used to construct a calibration curve. The results obtained showed that, the acetone concentration increases with increasing reflux ratio until a highest concentration was reached. Then, the concentration gradually decreases with increasing reflux ratio. However, the distillate stream with 99 mole % acetone was achieved at a reflux ratio of R=3 and at both powers 0.5 kw and 0.7 kw. Finally, the highest overall column efficiency reached by this work was about 75%.

Content and bioavailability of trace elements and nutrients in grape pomace.

The possible agricultural use of grape pomace could be limited by the content and mobility of metals. This is influenced by many factors. In this study, the abundance and availability of heavy metals and essential nutrients were evaluated comprehensively in different grape pomace residues from winemaking of five white and red grape varieties, before and after the distillation process. The total metal content found in grape pomace skins and seeds confirmed that there was greater metal accumulation in skins than in the corresponding seeds, with the exception of Ca and Mg. The enrichment of all metals (except K) during the distillation stage was confirmed by means of a significant correlation (R=0.996, P < 0.001) between the metal content obtained in distilled and undistilled samples. Regarding availability, multivariate statistical analysis showed different behavior among elements, but a great similarity for metal mobility in both distilled and undistilled grape pomace samples and in both skins and seeds, except for Mn, Zn and Mg. The results obtained in this study suggest the potential application of these grape residues as organic fertilizers for agricultural soils, without limitations resulting from heavy metal contamination. © 2019 Society of Chemical Industry.

Theoretical research on heat transfer law during underground coal gasification channel extension process

In order to study the heat transfer issue of underground coal gasification (UCG) channel, an extension model of cylindrical channel was established to study the temperature distribution law of UCG channel during the entire gasification process (dry and distillation stage, reduction stage and oxidation stage) based on the Fourier heat transfer theory and the Laplace transform method. Considering the radial extension of gasification boundary, this issue is a thermal conduction of moving boundary condition, and the unsteady thermal conduction mathematical equation under the moving coordinate system was established, and assumes that the gasification channel boundary satisfies the first kind of boundary condition in the entire gasification process, and the boundary temperature changes in a piecewise linear manner. The secondary Laplace transform and inversion method was used to solve the temperature equations of all stages, and the analytical solutions, which contains the initial temperature distribution function w1η+u2τ orw2η+u3τ, were also obtained. The values and their changing laws of temperature propagation range (t ≥ 30 °C, or Δt ≥ 10 °C) and the high-temperature distribution range (t ≥ 300 °C) were also given, and they are affected by the boundary temperature conditions and the radial extension rate of gasification channel.

The evaporation behaviour of ThF4 mixed of FLiNaK melt during low-pressure distillation

Low-pressure distillation of FLiNaK melt containing 50 wt % ThF4 was carried out at 910 °C and <10 Pa using thermogravimetric equipment. The weight loss curve indicated clearly two stages: a rapid distillation stage in the initial period following a very long slow stage. The analysis results showed the rapid distillation originated from the evaporation of FLiNaK, while the slow process was attributed to the evaporation of ThF4 and FLiNaK complexes. Because of the co-evaporation of ThF4 and FLiNaK, it seems not feasible to separate ThF4 from mixture salt. Hence, FLiNaK and ThF4 may be recovered simultaneously by distillation.