Zeolite Apgiia for Adsorption Based Carbon Dioxide Capture

Adsorption of synthetic flue gas on a commercial zeolite 13X (APGIIA) with targeted Si/Al ratio has been studied aiming to design an adsorption process for CO₂ capture from post-combustion power plants. Adsorption equilibrium of pure gases (CO₂ and N₂) has been measured in a wide range of temperatures: 303, 333, 363, 393, 423, 473 K. Adsorption equilibrium was fitted with the multisite Langmuir model. The adsorption capacity of the zeolite pellets for CO₂ is 4.54 mol/kg and 0.26 mol/kg for N₂ at 303 K and 100 kPa. The dynamic behavior of the pellets in a fixed bed was also studied by measuring breakthrough curves. Adsorption and desorption was analyzed in order to understand the regeneration of the adsorbent.

Based on equilibrium and kinetic data, two different adsorption technologies were simulated: Vacuum Pressure Swing Adsorption (VPSA) and Temperature Swing Adsorption (TSA). A CO₂ recovery of 63.0% with 72.1% purity was obtained using a five-step PSA cycle included rinse step. In a 5-step TSA process, however, a CO₂ purity of 78.7% and recovery of 76.6% can be achieved under a heating temperature of 423 K.     

Investigation of premature aging of zeolites used in the drying of gas streams

Abstract

The presence of humidity in gas streams is usually associated to several problems in the performance of industrial unit operations. Therefore, gas drying is one of the most important primary stages in the process that is commonly carried out by adsorption, using hydrophilic porous materials. These materials are typically regenerated by temperature swings (TSA), which in the presence of contaminants in the gas stream, may lead to adsorbent degradation and reduced lifespan of the drying process. The objective of this study is to investigate the hydrothermal stability of a zeolitic material used in the process of natural gas drying, by means of an aging test developed to simulate the operating conditions of a typical TSA. The textural characteristics, elemental analysis, and H₂O/CO₂ adsorption capacity are determined along the heating/cooling cycles. The presence of hydrocarbons, represented by n-heptane, is the most significant factor that contributed to the aging of the adsorbent within the temperature and pressure ranges under study.     

Lysines Acetylome and Methylome Profiling of H3 and H4 Histones in Trichostatin A—Treated Stem Cells

Trichostatin A ([R-(E,E)]-7-[4-(dimethylamino) phenyl]-N-hydroxy- 4,6-dimethyl- 7-oxo-2,4-heptadienamide, TSA) affects chromatin state through its potent histone deacetylase inhibitory activity. Interfering with the removal of acetyl groups from lysine residues in histones is one of many epigenetic regulatory processes that control gene expression. Histone deacetylase inhibition drives cells toward the differentiation stage, favoring the activation of specific genes. In this paper, we investigated the effects of TSA on H3 and H4 lysine acetylome and methylome profiling in mice embryonic stem cells (ES14), treated with trichostatin A (TSA) by using a new, untargeted approach, consisting of trypsin-limited proteolysis experiments coupled with MALDI-MS and LC-MS/MS analyses. The method was firstly set up on standard chicken core histones to probe the optimized conditions in terms of enzyme:substrate (E:S) ratio and time of proteolysis and, then, applied to investigate the global variations of the acetylation and methylation state of lysine residues of H3 and H4 histone in the embryonic stem cells (ES14) stimulated by TSA and addressed to differentiation. The proposed strategy was found in its simplicity to be extremely effective in achieving the identification and relative quantification of some of the most significant epigenetic modifications, such as acetylation and lysine methylation. Therefore, we believe that it can be used with equal success in wider studies concerning the characterization of all epigenetic modifications.     

荒煤气/焦炉气压缩机深度除焦方法对比

结合国内工厂实际调研情况,针对荒煤气/焦炉气中焦油在离心压缩机设备中沉积堵塞的问题,对比分析了包括二次电捕焦油、段间喷水(油)、吸附脱除、段间油洗等深度除焦方法,结果表明,当TSA、油洗塔单独应用在深度除焦过程中时,都能取得较好的效果。当上游预处理后的焦油含量未达到预期指标或波动较大时,TSA+油洗塔、段间喷水(油)+油洗塔组合使用,可以确保达到更好的除焦效果。     

An inference method of team situation awareness based on mutual awareness

Team situation awareness (TSA) is a critical contributing factor in establishing collaborative relations among team members involved in cooperative activity. Currently, however, there is still a lack of a clearly understandable and commonly agreeable model of TSA. To resolve misunderstanding or conflict among team members or between a team and machines, our research aim is to find out the underlying mechanism of TSA that reflects team cognitive process in a way consistent with team cooperative activity, and to focus on how to achieve mutual understanding, and how to effectively incorporate human teams into a socio-technological system. In this paper, we argue that earlier models of TSA, where TSA was discussed as the intersection of situation awareness (SA) owned by individual team members, are inadequate for study of a sophisticated team reciprocal process. We suggest that it is necessary for the definition of TSA to integrate the notion of individual SA (ISA) into cooperative team activity. In particular, understanding of mutual awareness is an essential element in cooperative activity. We propose a new notion of TSA, which is reducible to mutual beliefs as well as ISA at three levels. Further, we develop an operational TSA inference method and discuss human competence and system-related factors that are required to build TSA. We then try to demonstrate how TSA is actively constructed via inferencing practices. We also develop criteria to assess appropriateness of TSA from two aspects: soundness and completeness of mutual beliefs. Comparison of evaluation results indicates that the notion of TSA proposed in this work is more suitable to depict team cooperative activity than conventional ones.     

Thermoelastic Phase Analysis (TPA): a new method for fatigue behaviour analysis of steels

In literature, there are already well‐established thermal methods which allow for the estimation of fatigue limit, in particular for metallic materials such as austenitic steels. These methods are based on heat source generation analysis or on surface temperature evaluation of material subjected to different types of cyclic loading. General application of methodology found limitation in those cases in which temperature changes on material related to fatigue damage were very low and, furthermore, thermal methods require high‐performance equipment and a difficult setup. This is the case, for instance, with brittle materials (such as martensitic steels), welded joints and aluminium alloys. In this work, a new thermal method named Thermoelastic Phase Analysis is used to evaluate the fatigue limit of martensitic steels. This thermal method is based on an empirical approach. The main idea is that phase of thermoelastic response of the material subjected to fatigue loading is influenced by the presence of a heat source due to dissipative phenomena related to damage. Monitoring of the phase parameter provides a more stable setup and an independent means of identifying the fatigue limit of material. The method has also proven to be potentially one order of magnitude faster than traditional thermal methods.     

焦炉煤气制氢预处理工艺的改进

针对某公司引进的一套焦炉煤气制氢装置在投产后存在的诸多问题,进行了认真研究和分析。通过在原有装置中对预处理工序等进行的一系列工艺技术改造,不仅降低了蒸汽消耗,提高了吸附剂的使用寿命,而且使装置连续运转时数突破了16 000 h。     

Analysis of purge gas temperature in cyclic TSA process

This study analyzes the effect of an operating parameter on the dynamic behavior by performing dynamic simulations of cyclic thermal swing adsorption (TSA) system, in fixed beds packed with activated carbon as an adsorbent. This TSA process purifies and regenerates the ternary mixtures consisted of benzene, toluene and p-xylene. A mathematical model, considering the dynamic variation and spatial distribution of properties within the bed, has been formulated and described by a set of partial differential algebraic equations. The models are based on non-equilibrium, non-isothermal and non-adiabatic conditions. The breakthrough curves of our simulation model are compared with those of Yun's experiments (1999). The cyclic steady-state (CSS) cycles are obtained for the various cases by cyclic simulation. The influences of the purge gas temperature on breakthrough curves, CSS convergence time, cyclic operating step time, purge gas consumed, regeneration energy requirement and adsorption ability at CSS are also discussed.     

机动目标断裂航迹粘连

针对目标跟踪系统中由于目标机动产生的断裂航迹,提出了量测缺失下的航迹粘连算法和有量测情况下的航迹粘连算法.首先,对新起始的航迹进行平滑处理.然后,利用转弯模型对断裂航迹进行外推,针对无量测情况,采用UT对转弯角速率进行估计;针对有量测情况,采用期望极大化的策略对目标状态及转弯角速率进行迭代优化.通过蒙特卡洛仿真验证了该方法能有效提高航迹连续性,减少虚假航迹数,降低目标状态估计误差.     

The analysis of thermoelastic isopachic data from crack tip stress fields

A computer program—FACTUS (fracture analysis of crack tips using SPATE)—has been developed for the efficient analysis of thermoelastic data obtained from around a crack tip. The program is based on earlier work for the determination of stress intensity factors (SIFs), and also includes a novel solution procedure for the derivation of the non-singular stress term σ _{0 x} . The program has been used in the analysis of a series of large plate specimens with central or edge slots/cracks. The derived SIFs are compared with independent values. Issues, e.g. crack closure and the extent and effect of the plastic zone, are discussed.