IC反应器处理MTO废水的中试研究

中试研究了内循环(IC)反应器处理甲醇制烯烃(MTO)废水的启动和运行过程,同时考察了颗粒污泥的性状及沼气产量的变化情况。试验过程运行稳定,系统抗冲击性强。以絮状污泥为接种污泥,经过131 d的启动和运行,IC反应器的COD去除负荷可达10 kg/(m^3·d)以上,COD去除率可达90%以上。IC反应器中的成熟颗粒污泥形状规则、密实、粒径大、沉降速率快。IC反应器的沼气产量符合理论预期。

OEB反应器处理MTO废水的中试研究

中试研究了好氧膨胀床(OEB)反应器处理甲醇制烯烃(MTO)废水的稳定运行过程,考察了COD去除效果、填料层膨胀情况、反应器压降、反应器排泥及其它运行情况。试验过程运行稳定,膨胀填料层负荷在0.5~1.4 kg COD/m^3/d,COD去除率一直稳定在80%以上,DO比耗基本在1~3,而且废水浊度也可以得到明显去除。确认了自主开发的OEB反应器是稳定和有效的,值得进一步优化并推广使用。

An effective route to improve the catalytic performance of SAPO-34 in the methanol-to-olefin reaction

An effective route to improve the catalytic performance of SAPO-34 in the methanol-to-olefin reaction by simple oxalic acid treatment was investigated. The samples were characterized by XRD, SEM, N2 adsorption-desorption, XRF, TG, 29Si MAS NMR and NH3-TPD techniques. The results indicated that the external surface acidity of SAPO-34 was finely tuned by oxalic acid treatment, and the selectivity to C2H4 on SAPO-34 and the catalyst lifetime in the methanol-to-olefin reaction were greatly improved.

厌氧滤池(AF)在MTO废水处理中的应用

甲醇制烯烃(MTO)是重点发展的煤化工新技术,同时煤化工又是污染严重的行业,经济有效的消减污染物排放量是实施煤化工项目的先决条件。MTO装置排放的高浓度废水中COD浓度很高,采用厌氧滤池去除MTO废水中COD,并将其转化为甲烷,是实现COD减排和资源回收的有效途径,可为MTO装置的废水达标排放和经济运行提供技术支撑。

一体式低氧生化技术和新型BAF技术在MTO废水处理中的应用

MTO废水具有石油类和COD值较高、含部分难生物降解和有毒物质、水质受生产装置影响波动较大的特点。本文通过某MTO废水处理及回用项目实例介绍,分析了一体式低氧生化处理技术和高分子惰性有机滤料BAF技术在MTO废水生化及深度处理中的适用性和优势,并介绍了该技术的主要工艺参数。

厌氧技术在MTO高浓度废水处理中的应用

从中天合创S-MTO装置合成气急冷塔排放出的一股废水,COD浓度高达1 500～2 000 mg/L。采用厌氧技术处理该股废水,在负荷为2～3 kg COD/m^3·d的条件下,可以保证出水COD基本稳定在150 mg/L以下,COD去除率达到90%以上。与好氧技术相比,厌氧技术负荷高,占地小,抗冲击,污泥量少,具有良好的经济效益和社会效益。

甲醇制烯烃高浓废水深度处理回用实例

山东恒通化工股份有限公司MTO装置生产过程中排出的工艺废水、汽提废水中主要含有甲醇、二甲醚、醛酮类等有机物,同时含有反应过程中副产的重质烃类物质,为使这两股废水达到回用标准,采用“厌氧+好氧”的混合生化处理技术进行处理,处理后污水能够达到中水回用装置进水指标要求,再通过“砂滤+超滤+反渗透”的中水回用装置进行深度处理,处理后的绝大多数污水可以作为循环水系统补水,少量浓盐水经生化处理后可达标排放。

Effect of SiO_(2)/Al_(2)O_(3)ratio on the conversion of methanol to olefins over molecular sieve catalysts

A series of SAPO-34 molecular sieves with different SiO_(2)/Al_(2)O_(3)ratios have been synthesized for the methanol-to-olefin(MTO)reaction.Their physico-chemical properties are characterized by various techniques such as X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),Fourier transform infrared spectroscopy(FT-IR)and N2 adsorption-desorption.The results are compared with those of the commercial HZSM-5,which show that the crystallinity and particle diameter of SAPO-34 as well as HZSM-5 increase with SiO_(2)/Al_(2)O_(3)ratio.The variation of BET surface area of SAPO-34 is different from that of HZSM-5 and the sample with SiO_(2)/Al_(2)O_(3)ratio of 0.4 exhibits the highest BET surface area.FT-IR spectra indicate that HZSM-5 has both Brǿnsted and Lewis acid sites and Brǿnsted acid sites are stronger,whereas SAPO-34 samples are dominated only by Lewis acid sites.When the SiO_(2)/Al_(2)O_(3)ratio increases,propylene and butylenes become the predominant product of the MTO reaction over HZSM-5.In contrast,the main products of this reaction catalyzed by SAPO-34 are ethylene and propylene.According to the product distribution,the reaction mechanism over HZSM-5 catalysts is proposed.

Insight into the Dual Cycle Mechanism of Methanol-to-OIefins Reaction over SAPO-34 Molecular Sieve by Isotopic Tracer Studies

Methanol-to-olefins(MTO)reaction is one of the important non-petroleum routes to produce light olefinsover acidic molecular sieves.In this study,the complete reaction course of MTO on SAPO-34 molecular sieve with retained organics evolution from induction period to deactivation period was investigated systematically at different weight hourly space velocities(WHSV)of methanol.By the aid of 12C/3C-methanol isotopic switch experiment,the dual cycle mechanism involving aromatics-based cycle and alkenes-based cycle was evaluated during the whole reac-tion process.The detailed reaction route varied with the evolution of the retained organics in the catalyst at different reaction stages.The aromatics-based cycle and alkenes-based cycle alternately dominate the reaction process.In the efficient reaction period,aromatics-based cvcle is the main reaction mechanism,while in the induction and deactiva-tion periods.the contribution of alkenes-based cvcle mechanism will become more important.