络合铁法液相氧化还原脱硫技术中络合剂的优化研究

络合铁法液相氧化还原脱硫技术具有清洁、高效、运行成本低等优点,符合海上天然气开采的要求,但是为了提高脱硫效率,降低设备规模,需要开发新型的高浓度络合铁体系脱硫催化剂。本文通过对不同的络合铁催化剂络合铁离子效果和脱硫效果的比较,并对络合剂进行优化,得到了最优的络合剂配方,其配制方法为EDTA∶柠檬酸=1∶3,C₍(E D TA))=0.2 m o l/L,先加入0.5 8 m o l/L的F e³⁺,再加入0.2 m o l/L的F e²⁺,用Na OH、Na HCO₃、Na₂C O₃调节溶液的p H至7,该体系脱硫效率为96.43%,饱和硫容为5.76 g/L。     

氧化-还原法制备石墨烯

石墨烯是2004年发现的二维新型碳材料,具有独特的物理性质和广阔的研究前景。作为石墨烯研究的基础,石墨烯的制备一直备受关注,研究进展迅速。简要分析制备石墨烯的四种主要方法(机械剥离、晶体外延生长、氧化还原、化学气相沉积)的原理和特点。重点从还原剂的选择、还原特点及还原效果评述氧化还原法制备石墨烯的研究进展,并对未来氧化-还原法制备石墨烯可能的发展方向进行展望。     

铁法氧化还原脱硫溶液再生实验室内研究

在室内研究络合铁吸收溶剂配方溶液进行吸收低浓度硫化氢实验的基础上,进行了常压空气氧化再生的实验研究。通过一系列单因素实验,考察了溶液初始pH值、液气比和温度在一定时间范围内对再生率的影响,并且在最佳再生实验条件下确定了合适的再生时间,最后对3个不同配方在最佳工艺条件下进行了对比实验,得到再生率较高的脱硫再生溶液。     

螯合铁脱硫工艺在天然气行业的应用

液相氧化还原法螯合铁脱硫工艺在中国天然气脱硫应用已经20a,就20a来螯合铁脱硫工业在中国天然气行业的应用情况做详细的介绍,并就应用范围、问题情况等进行总结.     

天然气中MDEA法脱硫技术的研究

论文介绍了天然气能源的重要性。针对MDEA法脱硫技术介绍了其国内外研究现状,论述了MDEA法脱硫技术的工艺原理及工作流程,对天然气MDEA法脱硫技术进行了展望。     

加氢柴油超深度氧化脱硫研究

采用KMnO4/HCl体系氧化大庆炼化公司加氢柴油,考察了反应温度、氧化时间、HCl溶液的pH值、氧化剂用量等对氧化脱硫效果的影响,最佳反应条件下柴油的脱硫率可达92.3%。在氧化过程中,采用红外光照射可使反应时间由30 min缩短到20 min,直接水洗氧化产物即可使柴油的脱硫率达到90%以上。与未使用红外光照射的氧化-萃取过程相比,省去了萃取剂及其回收费用,简化了操作流程,降低了超低硫柴油的生产成本。     

络合铁-多酚类液相脱硫催化剂氧化-还原行为研究

通过化学实验，研究了络合铁-多酚类液相脱硫催化剂的脱硫-再生反应行为和热力学趋势，结果表明，脱硫反应和再生反应都属于氧化-原反应，反应进程中电势-pH的变化规律反映了氧化-还原反应的反应速度和反应程度；催化剂溶液较适宜酸碱度为8．25≤pH≤8．50。     

煤氯化铜氧化脱硫的研究

在间歇式压力釜内,以氯化铜为脱硫剂,系统考察了时间、温度、添加剂等反应条件对脱硫的影响,并对加氨的作用机理、氯化铜溶液的循环使用进行了初步的探讨。试验结果证明:氯化铜溶液既能脱除无机硫,也能脱除有机硫。在最佳条件下脱硫率达91％,氯化铜的回收率达83.5％。比较有效的添加剂为氨水和氯化铁。由于氨的弱碱性、溶胀性及与铜离子的络合性,加氨有效地提高了脱硫效率。因此氯化铜有可能成为更具实际意义的工业性的脱硫剂。     

超重力湿式氧化法脱除焦炉煤气中硫化氢

以H2S、CO2和空气模拟焦炉煤气,以超重机为脱硫设备,采用湿式氧化法脱除焦炉煤气中的H2S,研究了超重力因子、液气比、气液接触时间、原料气中H2S含量等工艺参数对脱硫率的影响规律,结果表明：脱硫效率随着超重力因子、液气比、气液接触时间和原料气中H2S浓度的增大而增大。确定了适宜的工艺参数,在气液接触时间为0.15 s的条件下,获得了98%以上的脱硫效率,CO2的脱除率稳定在1.0%左右,超重力法脱硫技术实现了高效、快速脱硫。在生产现场建成了处理气量为10000 m3/h的工程化超重力湿式氧化法脱硫装置,运行结果显示：超重力湿式氧化法脱除焦炉煤气中H2S技术具有脱硫效率高、气液接触时间短、操作弹性大、设备体积小等优点,H2S脱除率可稳定在90%以上,应用前景广阔。     

超重力-双碱法脱除模拟烟气中二氧化硫的研究

以碳酸钠为吸收剂,氢氧化钙为再生剂,探讨了超重力环境下脱除模拟烟气中SO2的效果。考察了吸收剂温度、pH、钠离子浓度、烟气中SO2浓度、超重力机转速及液气比对SO2脱除率的影响。结果表明,在超重力环境下气液仅通过50 mm的旋转床层,脱硫率可达90.62%。     

Catalyst modification and process design considerations for the oxidation of low concentrations of hydrogen sulfide in natural gas

Low concentrations of hydrogen sulfide (H₂S) in natural gas can be selectively oxidized over an activated carbon catalyst to elemental sulfur, water and a small fraction of sulfur dioxide (SO₂). Efforts to improve catalyst performance and product sulfur quality have been made by a) modification of the catalyst composition b) removal of the heavy hydrocarbons from the feed and c) choice of reaction conditions. The use of a guard bed to absorb heavy hydrocarbons and operation at elevated pressures show positive results. A preliminary flow diagram incorporating these findings has been prepared for a small commercial unit capable of processing sour natural gas containing 1.0% H₂S.     

超重力旋转填料床中天然气水合物含气量研究

研究了在旋转填料床中制备天然气水合物,主要考察了超重力因子β、液气比等因素对含气量的影响。实验结果表明,当在压力5 MPa、温度277.15 K状态下:含气量随着超重力因子β增大而增大,β大于120后对含气量的影响不明显;天然气水合物含气量随液气比的增大呈现出先增大后减小的趋势,其最佳液气比为10 L/m3。结合晶体化学方法探讨了超重力方式合成天然气水合物的机理。与传统方式相比,加快了溶解、成核及生长过程,最终含气量显著提高。     

铁基脱硫剂超重力法脱除硫化氢

用N₂和H₂S的混合气模拟含硫天然气, 以铁基脱硫剂为脱硫液, 采用超重力旋转填充床(RPB)进行脱除H₂S的集约化实验研究, 考察了原料气H₂S质量浓度、含硫原料气流量、脱硫液流量、温度及RPB转子转速对H₂S脱除率的影响。实验结果表明, 铁基脱硫剂超重力法脱除H₂S的较佳工艺条件为原料气H₂S含量14g/m³, 原料气流量0.45m³/h, 脱硫液流量13.5L/h, 脱硫液温度40℃, RPB转子转速1000r/min。在此条件下, H₂S脱除率稳定在99.98%以上, 脱硫后净化气H₂S含量小于2mg/m³。另外, 舍弃再生用RPB, 采用直接向脱硫富液储槽鼓空气的方法, 脱硫剂氧化再生良好, 脱硫效果保持不变, 且可长时间稳定运行。因此, 铁基脱硫剂超重力法脱硫工艺简单、效率高、设备体积小, 可实现海洋油气平台天然气或石油伴生气脱硫的集约化, 工业化应用前景广阔。     

湍球塔钠碱法烟气脱硫特性研究

以SO_2和空气混合模拟工业烟道气,在矩形湍球塔中进行烟气脱硫实验研究,考察了多种操作参数对脱硫率的影响。实验结果表明,增加碱液浓度、喷淋量和颗粒静床高度可以提高湍球塔脱硫效率；湍球塔脱硫效率随烟气进口温度升高而下降。     

旋转填料床净化磷肥尾气中的氨气

针对当前磷肥生产工艺尾气中氨气的处理现状,采用旋转填料床代替传统塔设备,以酸性废水为吸收液,对脱除磷肥尾气中的氨气进行了中试研究.结果表明:在进气量500m3/h、气液比1000m3/m3、超重力因子90的条件下,吸收效率达到90%以上.经连续运转,系统运行稳定,处理后磷肥尾气中的氨气达到了国家排放标准.     

The effects of pressure and temperature on the catalytic oxidation of hydrogen sulfide in natural gas and regeneration of the catalyst to recover the sulfur produced

The influence of pressure up to 5600 kPa and temperature up to 175 °C on the oxidation of low concentrations of H₂S in natural gas was studied in a fixed bed reactor over an activated carbon catalyst. Operation of this system at 5600 kPa provides higher catalyst activity (virtually 100% H₂S conversion) over a longer period of time and with lower selectivity to SO₂ than when operated at atmospheric pressure. The desorption of sulfur from a loaded catalyst occurs first from the macropores (> 100 nm) of the catalyst which contain a substantial portion of the sulfur load and then from the micropores (< 100 nm). This study also indicated that the sulfur recovery process is both rapid and effective at 327°C.     

Synthesis gas production from natural gas in a fixed bed reactor with reversed flow

The feasibility of producing synthesis gas by partial oxidation of natural gas on a Ni-catalyst in a fixed bed reactor with reversed flow was investigated by means of simulation. A one dimensional reactor model of the non-steady state heterogeneous type, accounting for internal diffusional limitations, was applied. A double temperature peak is observed just after flow reversal, influencing the selectivities at the exit through enhanced steam reforming reactions. The second peak gradually decreases in importance with time during the semi-cycle. The influence of several operating conditions on the reactor performance was studied. Most of the coke deposited in a semi-cycle can be removed after flow reversal. This observation opens new perspectives for the reversed flow operation.     

Polyurethane-based poly (ionic liquid)s for CO2 removal from natural gas

Carbon dioxide separation from CH₄ is important to the environment and natural gas processing. Poly (ionic liquid)s (PILs) based on polyurethane structures are considered as potential materials for CO₂ capture. Thus, a series of anionic PILs based on polyurethane were synthesized. The effects of polyol chemical structure and counter-cations (imidazolium, phosphonium, ammonium, and pyridinium) in CO₂ sorption capacity and CO₂/CH₄ separation performance were evaluated. The synthesized PILs were characterized by NMR, DSC, TGA, dinamical mechanical thermo analysis (DMTA), SEM, and AFM. CO₂ sorption, reusability, and CO₂/CH₄ selectivity were assessed by the pressure-decay technique. The counter-cation and polyol chemical structure play an important role in CO₂ sorption and CO₂/CH₄ selectivity. PILs exhibited competitive thermal mechanical properties. Results showed that PILPC-TBP was the best poly (ionic liquid) for CO₂/CH₄ separation. Moreover, poly (liquid ionic) base polyol (polycarbonate) with phosphonium (PILPC-TBP) demonstrated higher CO₂ sorption capacity (21.4 mgCO₂/g at 303.15 K and 0.08 MPa) as compared to other reported poly (ionic liquids). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47536.