膜接触器法高压吸收CO2过程及数学模拟研究

天然气是一种环保、清洁的化石能源，在目前世界能源结构中占据的比例仅次于石油和煤。天然气中含有的一定量酸性气体需要脱除，传统吸收法存在设备体积庞大、投资较高、有效传质面积小、难以控制气液流速、气相压力损失较大等缺点。膜接触器克服了传统吸收塔的这些工艺缺陷，近年来得到人们广泛关注。目前膜接触器中常用的材料是聚偏氟乙烯（PVDF）和聚丙烯（PP）等，但这些材料的化学稳定性较差，容易被吸收液润湿；目前，天然气开采的出口压力通常较高，而膜接触器相关研究还仅限于低压过程，实际应用性较差，需要进行高压吸收的探索。 采用具有优异化学稳定性的聚四氟乙烯（PTFE）材料制备膜接触器，研究了高压下天然气中CO2脱除过程。系统地考察了操作压力、吸收剂种类、吸收剂浓度、吸收剂流量以及气体流量等对CO2脱除率和传质通量的影响。实验发现，高压下物理吸收过程中，1.0-5.0MPa下吸收效率均高于常压，实验条件下的PTFE中空纤维膜传质性能不及PVDF膜，PTFE膜孔结构仍需优化；高压化学吸收时，压力越高，N-甲基二乙醇胺（MDEA）的吸收性能越好。由于MEA溶液的临界穿透压比MDEA低，MEA溶液比MDEA更容易造成膜润湿，因此高压下乙醇胺（MEA）高压吸收性能与MDEA相反，吸收性能随压力升高而趋近物理吸收。增加吸收剂中醇胺浓度、降低气体流速和增加吸收剂流量可以在一定程度上提高CO2脱除率，达到CO2出口要求。可见PTFE膜不仅可以在低压膜吸收过程中正常应用，而且在高压膜吸收过程也能提供良好的性能。 建立了二维传质数学方程，对膜接触器高压吸收CO2传质过程进行数学模拟，并结合COMSOL 软件和边界条件进行数学求解。模型预测分析，膜润湿程度越高，传质越差。实验结果对非润湿和部分润湿模型进行验证，相比非润湿模型，部分润湿模型能更好地与实验结果相吻合。以水和0.1mol/LMDEA为吸收剂进行计算，部分润湿模型分析，常压下PTFE膜未润湿，而压力越高膜润湿率越大。5.0MPa下，物理吸收和化学吸收过程中膜的润湿率分别为9%和5.2%

一种吸收液再生的方法及其专用装置

本发明公开了一种吸收液再生的方法及其专用装置，其包括以下过程：含酸性气体的吸收液送入膜接触器的管程或壳程进行解吸再生，膜接触器壳程或管程采用氮气吹扫。吹扫后的氮气含酸性气体，进入采用酸性气体分离膜的膜分离装置进行酸性气体分离，分离出的氮气再通入膜接触器壳程或管程用于膜接触器中酸性气体的吹扫，使氮气得以循环利用。此外，采用氧氮分离膜的膜分离装置分离出压缩气体中氮气，以补充操作过程中损失的氮气。本发明通过使用膜接触器法再生吸收液，提高了传质面积，降低了吸收液再生温度，并通过吹扫氮气的循环利用，有效降低了吸收液的再生能耗。本发明设备简单，易于操作

Aripiprazole versus other atypical antipsychotics for schizophrenia

BACKGROUND: In most western industrialised countries, second generation (atypical) antipsychotics are recommended as first line drug treatments for people with schizophrenia. In this review we specifically examine how the efficacy and tolerability of one such agent - aripiprazole - differs from that of other comparable second generation antipsychotics. OBJECTIVES: To evaluate the effects of aripiprazole compared with other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychoses. SEARCH METHODS: We searched the Cochrane Schizophrenia Group Trials Register (November 2011), inspected references of all identified studies for further trials, and contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information. SELECTION CRITERIA: We included all randomised clinical trials (RCTs) comparing aripiprazole (oral) with oral and parenteral forms of amisulpride, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine for people with schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. Where possible, we calculated illustrative comparative risks for primary outcomes. For continuous data, we calculated mean differences (MD), again based on a random-effects model. We assessed risk of bias for each included study. MAIN RESULTS: We included 12 trials involving 6389 patients. Aripiprazole was compared to olanzapine, risperidone and ziprasidone. All trials were sponsored by an interested drug manufacturer. The overall number of participants leaving studies early was 30% to 40%, limiting validity (no differences between groups).When compared with olanzapine no differences were apparent for global state (no clinically important change: n = 703, 1 RCT, RR short-term 1.00 95% CI 0.81 to 1.22; n = 317, 1 RCT, RR medium-term 1.08 95% CI 0.95 to 1.22) but mental state tended to favour olanzapine (n = 1360, 3 RCTs, MD total Positive and Negative Syndrome Scale (PANSS) 4.68 95% CI 2.21 to 7.16). There was no significant difference in extrapyramidal symptoms (n = 529, 2 RCTs, RR 0.99 95% CI 0.62 to 1.59) but fewer in the aripiprazole group had increased cholesterol levels (n = 223, 1 RCT, RR 0.32 95% CI 0.19 to 0.54) or weight gain of 7% or more of total body weight (n = 1095, 3 RCTs, RR 0.39 95% CI 0.28 to 0.54).When compared with risperidone, aripiprazole showed no advantage in terms of global state (n = 384, 2 RCTs, RR no important improvement 1.14 95% CI 0.81 to 1.60) or mental state (n = 372, 2 RCTs, MD total PANSS 1.50 95% CI -2.96 to 5.96).One study compared aripiprazole with ziprasidone (n = 247) and both the groups reported similar change in the global state (n = 247, 1 RCT, MD average change in Clinical Global Impression-Severity (CGI-S) score -0.03 95% CI -0.28 to 0.22) and mental state (n = 247, 1 RCT, MD change PANSS -3.00 95% CI -7.29 to 1.29).When compared with any one of several new generation antipsychotic drugs the aripiprazole group showed improvement in global state in energy (n = 523, 1 RCT, RR 0.69 95% CI 0.56 to 0.84), mood (n = 523, 1 RCT, RR 0.77 95% CI 0.65 to 0.92), negative symptoms (n = 523, 1 RCT, RR 0.82 95% CI 0.68 to 0.99), somnolence (n = 523, 1 RCT, RR 0.80 95% CI 0.69 to 0.93) and weight gain (n = 523, 1 RCT, RR 0.84 95% CI 0.76 to 0.94). Significantly more people given aripiprazole reported symptoms of nausea (n = 2881, 3 RCTs, RR 3.13 95% CI 2.12 to 4.61) but weight gain (7% or more of total body weight) was less common in people allocated aripiprazole (n = 330, 1 RCT, RR 0.35 95% CI 0.19 to 0.64). Aripiprazole may have value in aggression but data are limited. This will be the focus of another review. AUTHORS' CONCLUSIONS: Information on all comparisons are of limited quality, are incomplete and problematic to apply clinically. Aripiprazole is an antipsychotic drug with a variant but not absent adverse effect profile. Long-term data are sparse and there is considerable scope for another update of this review as new data emerges from the many Chinese studies as well as from ongoing larger, independent pragmatic trials