Feed distribution in distillation: Assessing benefits and limits with column profile maps and rigorous process simulation

This contribution describes the column profile map (CPM) methodology for designing distributed feed distillation columns. For non‐sharp product distributions, a case study shows that energy savings of approximately 35% can be obtained if the feed stage(s) are designed optimally. Feed distribution allows capital cost savings, expands operating leaves, and can obtain greater separation feasibility. However, this column only has benefits in ternary and higer‐order systems and when product distributions are non‐sharp. To validate these counter‐intuitive claims, a real Benzene, p‐Xylene, Toluene system is modeled using CPMs, and the resulting design parameters are transported to Aspen Plus^®. Using a sum of squared errors objective function to quantify savings, a cost saving trend very similar to the one predicted by the CPM method is obtained. This article therefore describes a complete design methodology for distributed feed systems and provides convincing evidence of benefits of such a system. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1668–1683, 2013     

Pharmaceuticals Removal by Adsorption with Montmorillonite Nanoclay

The problem of purifying domestic and hospital wastewater from pharmaceutical compounds is becoming more and more urgent every year, because of the continuous accumulation of chemical pollutants in the environment and the limited availability of freshwater resources. Clay adsorbents have been repeatedly proposed as adsorbents for treatment purposes, but natural clays are hydrophilic and can be inefficient for catching hydrophobic pharmaceuticals. In this paper, a comparison of adsorption properties of pristine montmorillonite (MMT) and montmorillonite modified with stearyl trimethyl ammonium (hydrophobic MMT-STA) towards carbamazepine, ibuprofen, and paracetamol pharmaceuticals was performed. The efficiency of adsorption was investigated under varying solution pH, temperature, contact time, initial concentration of pharmaceuticals, and adsorbate/adsorbent mass ratio. MMT-STA was better than pristine MMT at removing all the pharmaceuticals studied. The adsorption capacity of hydrophobic montmorillonite to pharmaceuticals decreased in the following order: carbamazepine (97%) > ibuprofen (95%) > paracetamol (63–67%). Adsorption isotherms were best described by Freundlich model. Within the pharmaceutical concentration range of 10–50 µg/mL, the most optimal mass ratio of adsorbates to adsorbents was 1:300, pH 6, and a temperature of 25 °C. Thus, MMT-STA could be used as an efficient adsorbent for deconta×ating water of carbamazepine, ibuprofen, and paracetamol.     

Technoeconomic Mixed Integer Nonlinear Programming (MINLP) optimization for design of Liquid-Liquid Extraction (LLE) cascades in continuous pharmaceutical manufacturing of atropine

Continuous Pharmaceutical Manufacturing (CPM) offers operational and economic benefits over the currently dominant methods implemented by industry. The demonstrated continuous flow synthesis of atropine facilitates modeling and optimization of its upstream continuous manufacturing. This study implements MINLP optimization of a continuous Liquid-Liquid Extraction (LLE) flowsheet superstructure for total cost minimization of an upstream atropine CPM plant. The steady-state process model considers reactor design from regressed kinetic parameters including investigation of maximum allowable PFR reactor dimensions to maximize the benefits of API flow synthesis. Continuous LLE modeling considers solute partitioning between phases, UNIFAC-modeled liquid–liquid equilibria and mass transfer correlations for LLE design. Optimal LLE design configurations from the considered superstructure require fresh solvent added to the first vessel in co-current flow in addition to the countercurrent flow in the cascade. Optimization results indicate toluene as the best solvent choice, with total costs of 3.944 × 10⁶ GBP for a plant capacity of 10³ kg API year⁻¹.     

Complex integration of processes

Pinch analysis is nowadays a practical tool for designing heat exchanger networks in chemical and process industries. Rules for integrating process units have also been worked out in the last decade or two. Process units can be described as different types of energy unit operations, donors and acceptors. Yet, heat integration alone is not sufficient for process integration. The largest savings are achieved when simultaneously optimizing enthalpy and mass flows — energy and material recycling is required to save the natural resources and protect the nature. Mathematical programming is increasingly used to optimize the problems both in continuous and batch operations. Task integration is spreading out: multifunctional units lower the capital investment, thus, the total annual cost Recent development of the complex integration with examples and reasonable forecast of the future development is presented in the paper.     

Continuous granulation in the pharmaceutical industry

Traditionally the manufacturing of pharmaceutical dosage forms has been a batch-wise process and continuous processes have limited applications in a pharmaceutical manufacturing plant. However, several factors (reduction of cost, improved process efficiency, optimal use of equipment, flexibility in production capacity) are stimulating the pharmaceutical industry to investigate the opportunities offered by continuous processes. This paper discusses some of the techniques which could be implemented in a continuous granulation process of pharmaceuticals.     

Evaluation of thermal and energy consumption behavior of novel foamed copper slag based geopolymer masonry blocks

The building sector is focused on adopting passive design strategies to reduce the energy needs of the building envelope. Currently there has been lack of research related to the understanding of thermal and energy efficiency performance of foamed geopolymer based material. In this regard, this research provides a solution of thermally efficient wall material developed from copper industry by-product (copper slag). All the performance criteria (i.e. physical, mechanical and thermal) of the developed foamed copper slag geopolymer (FCSG) blocks as a building block was found to be in compliance with the performance of standard commercial product (i.e., autoclave aerated block). Further, the numerical analysis of the developed FCSG material is performed and the conjugate heat transfer through three different solid-wall zones to the fluid domain is perceived. The incompressible conjugate heat transfer solver is developed in the open-source computational fluid dynamics (CFD) tool OpenFOAM to perform the present numerical analysis. It is noted that the temperature in the fluid zone for the FCSG layer attained less than 300 (K) however, for the red clay bricks it reaches 302 (K). Hence, the thermal efficiency of the FCSG incorporated insulation layer reduces the heat transmission from outdoor to indoor, consequently improving the comfortable environment of occupants. Further, the developed blocks were subjected to simulation study using eQuest tool to understand the influence of its thermal characteristics on energy demands. The study found that the yearly energy savings was found to be 7.5% in comparison to commercially available clay bricks. Also, the cost savings can reach up to 8.94% during the peak summer month and 7.4% annually. Thus, the developed blocks emphasize waste utilization, providing better indoor thermal for occupant and energy efficiency benefits for end-users. Thus, achieving overall sustainability as a building envelope component.     

Optimization of environmental impact reduction and economic feasibility of solvent waste recovery using a new software tool

The environmental impact reduction and operating costs savings associated with the purification and recovery of solvent waste in the manufacture of active pharmaceutical ingredients (API's) were investigated. A software toolbox has been developed that combines Aspen Plus^® process simulation with SimaPro^® and Ecosolvent life cycle assessment (LCA) databases. A LCA approach was used in order to consider the environmental impact beyond pharmaceutical production plant boundaries. The feasibility of a relatively small flexible equipment-skid capable of recovering multiple solvent waste streams was evaluated. Distillation and pervaporation were considered to separate binary waste solvent mixtures. Optimum distillation reflux ratio and feed stage were determined to maximize the environmental impact reductions and operating cost savings. The optimum reflux ratio was significantly higher than 1.2 times the minimum reflux ratio suggested by traditional heuristics. The emissions and cost reductions obtained were as much as 49% and 56% higher, respectively, as compared to using the conventional optimum reflux ratio. A comprehensive cash flow analysis showed that the recovery of low volume solvent waste streams is economically feasible, despite traditional thinking. Three case studies from Pfizer are presented to show how our software tool can aid in green engineering decision making.     

工业固废活化钾长石-CO2矿化提钾的生命周期碳排放与成本评价

利用工业固废活化非水溶性钾长石矿,矿化固定二氧化碳（CO₂）并提钾工艺,是同时处理工业固废、开发钾资源、减排CO₂等一举多得的CCUS路线。采用生命周期评价（LCA）方法,以生产含1 t K₂O的钾肥为功能单元,以传统的高炉冶炼钾长石制可溶性钾肥并联产白水泥工艺作为参照,对比评价了两种钾长石-工业固废体系矿化CO₂联产钾肥工艺过程的碳减排潜力和经济性。对工艺从原料开采、运输到产品生产的生命周期的温室气体排放量（简称“碳排放”）和成本进行了全流程的核算,研究了更全面的产品碳排放和成本分配方法。结果表明,无论是碳排放还是经济性,钾长石-工业固废体系矿化CO₂联产钾肥工艺均较传统工艺有很大提高,碳减排潜力分别可达81.16%和20.48%左右,成本可节约34.75%和45.11%左右。     

制药工程工艺设计课程教学改革探索与实践

制药工程工艺设计是高等学校制药工程专业的核心课程,在总结该课程教学过程中所存在的一些问题基础上,对课程教学进行了改革探索,通过优化教学内容、推行案例教学、运用启发式教学、应用现代化教学手段、改进考核方法等措施,提高了课程的教学成效。     

Semicontinuous granulation—the process of choice for the production of pharmaceutical granules?

Tablets represent the majority of dosage forms sold worldwide. High-quality granules are a prerequisite for a robust manufacturing of millions and millions of tablets needed. Thus, the preparation of pharmaceutical granules is an important standard operation procedure in the pharmaceutical industry. Due to the pressure on the costs of medication, there is a constant search for new concepts to reduce the manufacturing costs and the time to market keeping simultaneously constant or even improving the quality of the product. With respect to this trend, the following questions and problems will be treated in detail. (1) Is it possible to replace in the pharmaceutical industry the batch-type manufacturing process for granules by a quasi-continuous or continuous process being successfully introduced in the food industry? (2) Can scale-up problems be avoided by introducing a quasi-continuous process? (3) Using a continuous process, is it possible to keep or even to improve the high quality of the granules? (4) Is it possible to increase the productivity? (5) What will be the cost savings using a quasi-continuous process compared to the classical batch-type procedure? (6) Is it possible to shorten the development time, i.e. the time to market for a new product using a continuous or quasi-continuous manufacturing process for pharmaceutical granules? (7) What type of organizational business model is needed to achieve the desired results? Experiences with a new quasi-continuous equipment, the Glatt Multicell^R, will be presented as a case study.     

Recent Development in Improving Energy Efficiency of Glass Furnaces

The energy required for continuous glass melting usually accounts for about 30 -75% of the total energy consumptions supplied to the glass industry, and the energy cost contributes to about 10 25% of total glass manufacturing cost depending upon the type of glass and manufacturing efficiency. Typically, energy efficiency of glass furnaces offers major opportunities for manufacturing cost reduction. Significant rising of energy cost, environmental requirements for clean air and pressure for reducing global warming and carbon dioxide emissions, as well as the cost of capitals are main drivers for the technology developments. In this paper, energy efficiency of glass furnaces is discussed. Technology developments in selective batching, oxy -fuel firing with preheating batch and cullet, non - conventional advanced melting systems, such as segmented glass melting and submerged combustion melting, as well as using math modeling to optimize fuel distribution for energy savings are presented.     

Cost optimization of a combined power and water desalination plant with exergetic,environment and reliability consideration

The present study deals with the multi-objective optimization for designing a combined gas turbine and multi stage flash desalination plant. In optimization approach, the exergetic, economic and environmental aspects have been considered, simultaneously. In order to achieve the optimal design, Multi-objective genetic algorithm (MOGA) is applied as a suitable optimization technique. The thermoenvironomic objective function is obtained by integrating the environmental impacts and thermoeconomic objective. By applying the optimization approach, this objective function is minimized, whereas system exergy efficiency is maximized. Moreover, equipment reliability using the state-space and the continuous Markov method is incorporated in optimization results to improve the products' cost values. The optimization results show that the cost of products and environmental cost impact are reduced by 13.4% and 53.4%, respectively, whereas a 14.8% increase happens in total exergy efficiency. Therefore, improvement in all objectives has been achieved using the optimization process, although the power and water productions have not changed much. Additionally, the sensitivity analysis shows the relationship between the fuel cost, pollution damage cost and the objective functions.     

连续法合成邻(对)硝基苯甲醚

邻(对)硝基苯甲醚是十分重要的化工原料,用于制备多种染料、医药和食品添加剂。生产邻(对)硝基苯甲醚的传统方法都是间歇法操作,周期长、能耗高、效率低。吉林石化公司研究院开发成功了连续法合成邻(对)硝基苯甲醚的工艺技术,用静态混合器代替传统的搅拌釜作为反应器,缩短了反应时间,降低了硝基苯酚钠的含量,提高了硝基苯甲醚的选择性,使装置生产能力大幅提高,生产成本下降,同时减少了操作强度,改善了操作环境。     

Characterization and optimization of an oscillatory baffled reactor (OBR) for ozone-water mass transfer

Ozone-water mass transfer was investigated using an oscillatory baffled reactor (OBR) operated as a semi-batch and as a co-current up flow continuous reactor. The effects of input ozone concentration, input gas and water flow rates, and oscillation conditions on gas hold up, volumetric mass transfer coefficient and mass transfer efficiency were determined. The same reactor was operated as a baffled column (without oscillation) and as a bubble column to assess the effect of the reactor arrangement on the mass transfer. The results show that the OBR was 5 and 3 times more efficient for ozone-water mass transfer than the baffled and bubble columns, respectively. The enhancement obtained with OBR over the baffled column reactor was found to decrease with gas flow rate due to changes in bubble flow pattern from homogenous to heterogeneous. Under continuous flow conditions, the performance of the baffled reactor and the OBR were found to be twice efficient for ozone-water mass transfer than when operating under semi-batch conditions. The mass transfer effeciency (MTE) was found to increase from 57% using the baffled reactor to 92% with OBR under continuous flow at water and gas superficial velocities of 0.3 and 3.4 cm s⁻¹, respectively.     

Impact of ammonia fiber expansion (AFEX) pretreatment on energy consumption during drying,grinding, and pelletization of corn stover

Pretreatment and densification of biomass can increase the viability of bioenergy production by providing a feedstock that is readily hydrolyzed and able to be transported over greater distances. Ammonia fiber expansion (AFEX?) is one such method targeted for use at distributed depots to create a value-added and densified feedstock for bioenergy use. However, the pretreatment process results in a high-moisture material that must be dried, further size reduced, and pelletized, all of which are energy-intensive processes. This work quantifies the energy consumption required to dry, grind, and densify AFEX-pretreated corn stover compared to non-pretreated stover and explores the potential of reduced drying as a means to conserve energy. The purpose of this work is to understand whether material property changes resulting from AFEX pretreatment influence the material performance in downstream formatting operations. Material properties, heat balance equations, and a rotary drum dryer model were used to model a commercial-scale rotary drum dryer for AFEX-pretreated corn stover, showing the potential to reduce dryer energy consumption by up to 36% compared to non-pretreated corn stover. Laboratory-measured grinding and pelleting energies were both very sensitive to material moisture content. Overall, the total energy required for drying, grinding, and pelleting amounts to a savings of up to 23 kWh/dry Mg for the AFEX-pretreated material when dried to a low moisture content, equating to up to 0.61 $/Mg savings for gas and electricity. Grinding and pelleting of high-moisture AFEX-pretreated stover was shown to be more costlier than the savings collected through reduced drying. Although the energy and cost savings shown here are modest, the results help to highlight operational challenges and opportunities for continued improvement.     

煤制乙二醇关键单元技术与低碳集成工艺的研究进展

我国乙二醇对外依存度居高不下,而富煤少油的资源特性使得我国煤制乙二醇技术具有较好的成本与原料优势,发展迅速。本文综述了国内外煤制乙二醇技术的技术现状和发展趋势,重点介绍了煤气化、草酸二甲酯合成和乙二醇合成与精制等关键单元技术的技术特征、工艺流程和技术进展,并分析了相关单元对整个煤制乙二醇系统技术经济性能的影响。针对现有煤制乙二醇技术存在能耗高、质能效率低和CO₂排放大的问题,着重讨论了集成CO₂高效利用的煤与富氢资源联供制乙二醇集成工艺的进展,包括耦合焦炉气、页岩气和绿氢等资源的新工艺等。以焦炉气为例,集成不同重整技术的新工艺使得传统工艺的碳效率和?效率分别提升了23.35%~39.17%和4.25%~10.12%,生产成本降低了8.73%~19.88%,内部收益率提高了3.6%~9.6%。因此,集成富氢资源与CO₂高效利用的煤制乙二醇创新工艺是该行业向高效-经济-清洁可持续发展的重要方向。     

Ultrathin microcrystalline hydrogenated Si/Ge alloyed tandem solar cells towards full solar spectrum conversion

Thin film solar cells have been proved the next generation photovoltaic devices due to their low cost, less material consumption and easy mass production. Among them, micro-crystalline Si and Ge based thin film solar cells have advantages of high efficiency and ultrathin absorber layers. Yet individual junction devices are limited in photoelectric conversion efficiency because of the restricted solar spectrum range for its specific absorber. In this work, we designed and simulated a multi-junction solar cell with its four sub-cells selectively absorbing the full solar spectrum including the ultraviolet, green, red as well as near infrared range, respectively. By tuning the Ge content, the record efficiency of 24.80% has been realized with the typical quadruple junction structure of a-Si:H/a-Si_0.9Ge_0.1:H/µc-Si:H/µc-Si_0.5Ge_0.5:H. To further reduce the material cost, thickness dependent device performances have been conducted. It can be found that the design of total thickness of 4 mm is the optimal device design in balancing the thickness and the PCE. While the design of ultrathin quadruple junction device with total thickness of 2 mm is the optimized device design regarding cost and long-term stability with a little bit more reduction in PCE. These results indicated that our solar cells combine the advantages of low cost and high stability. Our work may provide a general guidance rule of utilizing the full solar spectrum for developing high efficiency and ultrathin multi-junction solar cells.     

抗生素生产废水生化前预处理技术进展

抗生素生产废水是一种成分复杂、生物毒性高、色度高、含难生物降解有机物质的有机废水.现行的处理工艺大部分是采用生化处理,而抗生素生产废水可生化性较差,并有抑制好氧微生物生长的有毒有害物质,若不采取行之有效的生化前预处理工艺,往往难以达到设计效果.经过广泛研究,现已形成了大量可行的预处理技术,并已广泛应用到生产实践中,在抗生素生产废水治理中发挥了重要的作用.作者对现行各种抗生素生产废水预处理工艺进行了介绍,并提出了抗生素生产废水处理技术的发展方向.     

Synthesis of immobilized poly(vinyl alcohol)/cyclodextrin eco‐adsorbent and its application for the removal of ibuprofen from pharmaceutical sewage

In this project, immobilized poly(vinyl alcohol)/cyclodextrin eco‐adsorbent was synthesized and its application for the removal of ibuprofen from pharmaceutical sewage was investigated. Our eco‐adsorbent was prepared via solution blending of (2‐hydroxypropyl)‐β‐cyclodextrin (HPBCD) and poly(vinyl alcohol) (PVA), followed by glutaraldehyde treatment. The obtained eco‐adsorbent is in the form of transparent film and is very easy to handle. Its FTIR and thermal analysis results show that it is well crosslinked, preventing it from dissolving in sewage. Its adsorption rate is well described by the pseudo‐second‐order kinetic model. Its maximum ibuprofen uptake is 2.56 mg/g and is higher than those of mesoporous silica, volcanic soil, and zeolite. More than 90% of adsorbed IB molecules are desorbed after soaking the consumed adsorbent in 5% ethanol‐water solution for an hour. This implies that our eco‐adsorbent can be rapidly regenerated via simple soaking procedure, significantly reducing its operational cost during practical application. As a result, it would be a potential adsorbent for the treatment of pharmaceutical sewage. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44861.     

Preparation and Characterization of Micronized Artemisinin via a Rapid Expansion of Supercritical Solutions (RESS) Method

The particle sizes of pharmaceutical substances are important for their bioavailability. Bioavailability can be improved by reducing the particle size of the drug. In this study, artemisinin was micronized by the rapid expansion of supercritical solutions (RESS). The particle size of the unprocessed white needle-like artemisinin particles was 30 to 1200 μm. The optimum micronization conditions are determined as follows: extraction temperature of 62 °C, extraction pressure of 25 MPa, precipitation temperature 45 °C and nozzle diameter of 1000 μm. Under the optimum conditions, micronized artemisinin with a (mean particle size) MPS of 550 nm is obtained. By analysis of variance (ANOVA), extraction temperature and pressure have significant effects on the MPS of the micronized artemisinin. The particle size of micronized artemisinin decreased with increasing extraction temperature and pressure. Moreover, the SEM, LC-MS, FTIR, DSC and XRD allowed the comparison between the crystalline initial state and the micronization particles obtained after the RESS process. The results showed that RESS process has not induced degradation of artemisinin and that processed artemisinin particles have lower crystallinity and melting point. The bulk density of artemisinin was determined before and after RESS process and the obtained results showed that it passes from an initial density of 0.554 to 0.128 g·cm(-3) after the processing. The decrease in bulk density of the micronized powder can increase the liquidity of drug particles when they are applied for medicinal preparations. These results suggest micronized powder of artemisinin can be of great potential in drug delivery systems.