超声波对重质油4组分分布的影响

渣油的饱和分、芳香分、胶质和沥青质4组分的分布直接影响各工艺的产品产率与产品质量,对重质油加工具有十分重要的意义.探索超声波作用对油品4组分含量变化的影响,为进一步探索超声波对重质油4组分的化学作用提供依据.结果表明:超声波作用对重质油4组分的分布有影响,可以促进饱和分和芳香分质量分数的增加,胶质和沥青质质量分数的降低.本试验范围内,超声温度50～60℃,超声时间15 min,超声频率28 kHz,超声功率200 W,与原料油相比,重质油4组分中饱和分和芳香分质量分数增加率分别为5％和4％,胶质和沥青质质量分数分别减少了2.5％和7.5％.     

不同原油界面活性组分的分离及表征

用极性分离法将胜利油田孤东1#、孤东4#原油和大庆原油分离为饱和分、芳香分、胶质、沥青质组分(S、Ar、R、As)。孤东1#和孤东4#沥青质组分质量分数(14.43%、11.35%)明显高于大庆原油沥青质组分质量分数(0.09%),而饱和分组分质量分数(47.08%、46.54%)低于大庆原油饱和分质量分数(68.08%)。孤东1#和孤东4#原油的原油组分(S、Ar、R、As)氧的质量分数、酸值由大到小的排序为:沥青质>胶质Ⅰ>芳香分>饱和分。而大庆原油的原油组分酸值由大到小的排序为:胶质Ⅰ>沥青质>芳香分>饱和分;大庆原油的饱和分组分中氧质量分数较低,饱和分中氧质量分数在原油氧中所占比例最高(0.375%),饱和分中的氧化物对大庆原油的界面活性影响不可忽视。在3种原油所有原油组分中,孤东1#原油沥青质的酸值最大(16.45 mg KOH/g沥青质),说明孤东1#原油沥青质组分含有较多酸性基团,反应活性较强。色-质分析结果表明,孤东原油饱和分正构烷烃在C10-C37呈双正态分布,大庆原油饱和分正构烷烃主要分布在C10-C38,基本呈正态分布。     

渣油及其组分黏度的分子层次组成关联研究

渣油由于自身的黏度大和流动性差制约其加工和运输,所以渣油高黏度的来源成为探究的关键。本研究把不同渣油分离成SARA (饱和分、芳香分、胶质、沥青质)四个组分并进行黏度和分子组成的关联研究。研究结果表明:从组分含量来看,渣油黏度影响的灰色关联顺序为:沥青质>饱和分>胶质>芳香分。饱和分黏度远小于渣油的黏度,说明饱和分是渣油体系主要的稀释剂。从组分分子层次来看,发现饱和分的黏度贡献主要来源于环烷烃的贡献,环数越多对饱和分黏度影响越大。芳香分的黏度贡献主要来源于N1O1类和N1类化合物的分布。除了金属元素Ni及Fe元素,胶质黏度很大程度受O1类化合物的影响。     

石油产品中残炭测定实验的教学改革

论文针对中国石油大学化学综合实验中残炭测定项目进行教学改革。选取燃料油和渣油为原料,对石油产品进行四组分的分离,将原料分为饱和分、芳香分、胶质和正庚烷沥青质。用自动微量残炭仪测定原料及各组分的胶质、沥青质中的残炭,研究残炭在石油产品组分中的分布。结果表明:石油产品中的残炭主要来源于样品中的胶质和沥青质。自动微量残炭测定法适合测定油品组分中的残炭。     

渣油组成和结构分析及加工方案探讨

介绍国内外多种减压渣油的组成和形态分析结果,着重剖析沥青质、胶质的结构。列举了固定床渣油加氢前后三组分的特点;概括了渣油重溶剂脱沥青油杂质的残留率及加氢后数据;阐述了Ni和V的存在形态及反应转化、沥青质中氮化物种类及脱氮催化剂的现状。针对渣油加氢催化剂结焦、金属沉积、氮化物中毒问题,指出应注意的事项,渣油加工倾向于采用溶剂脱沥青-重蜡油加氢-催化裂化组合工艺。     

渣油加氢处理过程中氢分压对杂质脱除率的影响

针对渣油加氢过程中不同功能催化剂级配装填的特点,运用渣油加氢中试装置,考察了氢分压对不同活性催化剂加氢处理产物性质的影响,分析了渣油中杂质的脱除分布规律。结果表明,在渣油加氢处理过程中,氢分压恒定时,随着加氢深度的增加,渣油中硫、氮、金属和残炭等杂质含量都降低;同一反应器中,随着氢分压升高,加氢产物中杂质含量总体呈降低趋势。随氢分压升高,渣油中各杂质的总脱除率先升高后略有降低,其中氮和残炭的总脱除率变化最明显。氮主要是在R4和R5反应器中脱除,而残炭则主要是在R2、R3和R4反席器中脱除．并日．两种杂质的脱除率随氧分压的变化旱姗不同的蛮化规律。     

沥青质加氢过程中的结构组成变化

综述了原油沥青质在加氢处理中结构组成变化的研究现状。现有的研究主要针对沥青质加氢过程中H/C原子比随加氢条件变化如何变化,S,N,V,Ni脱除状况,以及加氢处理中沥青质相对分子质量及分子结构的变化,沥青质晶体结构参数的变化。结果表明:加氢处理后沥青质C,H质量分数降低,H/C原子比且随加氢条件变化苛刻而降低。沥青质的S较易脱除,由于N,V,Ni位于沥青质芳环系中,所以难以脱除,且随着反应条件的苛刻,其质量分数增加。反应中沥青质烷基侧链变短、侧链数变少,芳环数减少,芳核缩合度增加,芳香度增加,沥青质平均相对分子质量降低,总环数增加。加氢转化后沥青质芳香层层数M减少,芳香层层间距dm和芳香层堆积高度Lc降低。通过这几方面的研究结果分析,对解决加氢处理中沥青质引起的催化剂生焦及轻质油收率低等不利影响具有重要的理论指导意义。     

中低温煤焦油中金属Fe分布及其赋存形态

煤焦油中的金属是有害元素,分析其含量与分布,以及金属赋存状态,对综合利用煤焦油意义重大,本论文首先将煤焦油分成四个组分,分别是饱和分,芳香分,胶质、沥青质和甲苯不溶物,分析各族组分中Fe含量;其次研究分析不同类型Fe含量分布。研究结果表明:煤焦油中胶质、沥青质和甲苯不溶物组分中金属Fe含量较高,计算结果表明Fe元素主要存在于胶质与沥青质中,各占34.3%和59.1%。煤焦油中Fe元素90.6%存在于油相中,赋存状态为石油酸Fe、卟啉Fe和非卟啉Fe。     

反应时间对加氢沥青质结构变化的影响

在高压反应釜中对煤焦油进行催化加氢反应,利用XPS和元素分析对不同加氢反应时间下提取的煤焦油沥青质进行表征,系统分析加氢油品四组分变化、沥青质转化率、化学组成和杂原子赋存形态的变化。结果表明,随着反应时间的延长,加氢油品中饱和分和芳香分收率增大,胶质和沥青质收率减小。加氢后沥青质转化率逐渐增大,分子量先减小后增大,沥青质中氧原子主要以羰基氧和碳氧单键形式存在,氮原子主要以吡咯氮、吡啶氮和质子化吡啶形式存在。     

反应温度对煤焦油沥青质组成与结构的影响

以中低温煤焦油为原料,在高压釜反应器内进行加氢实验,研究反应温度对加氢油品中沥青质组成与结构的影响。结果表明:在实验研究加氢工艺条件下,沥青质转化率随反应温度的升高而增加;与原料沥青质相比,在350—410℃不同温度下加氢后的沥青质中硫、氮、氧杂原子含量均降低,但脱除规律不一致,杂原子硫和氧含量随温度的升高而降低,但氮原子含量随温度的升高呈先增加后降低的趋势,说明各杂原子脱除规律与其赋存形态有关;另外,不同反应温度下沥青质平均分子结构参数相差很大,反应温度越高,沥青质缩合度越大。加氢反应压力为7 MPa时,反应温度不宜高于380℃。     

渣油在加氢处理中的硫分布和硫类型变化

采用硫分布和硫类型(GC-SCD)分析技术对渣油在加氢处理过程中硫含量及硫化物进行定量研究,结果表明:硫的总脱除率为86.98%,在上流式和固定床两个阶段的脱除率分别为51.11%和35.87%.渣油随馏分变重,硫含量增加.在<400 ℃渣油馏分中硫化物的类型为苯并噻吩类和二苯并噻吩类,结构复杂的硫化物在上流式反应阶段...     

Effects of organic nitrogen compounds on hydrotreating and hydrocracking reactions

A major issue encountered in hydrotreating and hydrocracking reactions, as in many others fixed bed catalytic processes, is the decrease of catalytic activity with time on stream. The organic nitrogen compounds act as temporary poisons in hydroprocessing catalysts besides being coke precursors. The inhibiting effects of nitrogen compounds present in crude oil have been studied on SRGO hydrotreating reactions and VGO hydrocracking reactions. The results show that selective removal of nitrogen by adsorption using silica and alumina in varying proportions, would not only increase the HDS catalyst activity by more than 60%, but would also reduce hydrogen consumption. This step of nitrogen removal can be installed additionally in the upstream of an existing SRGO HDS reactor to achieve higher desulphurization or can be designed with the grass roots units.

The inhibition effects of nitrogen on VGO hydrocracking have been studied at different temperatures and the reaction has been found to be highly non-linear in nature and the conversion rapidly drops and the slope becomes less steep as the nitrogen level increases. At higher reaction temperature, the drop in activity or conversion with feed nitrogen is less than that in lower temperatures due to the higher rate of desorption of nitrogen compounds at elevated temperatures. The drop in conversion with nitrogen compounds present in VGO indicates the presence of organo nitrogen compounds having higher basicity compared to the nitrogen compounds by pyridine doping. The hysteresis exists in adsorption/desorption of nitrogen compounds and it indicates that desorption is a very slow process. With the increase of nitrogen compounds in the feed, the conversion drops rapidly and it takes long time to reach an equilibrium value. Similarly, with the step increase in reactor temperature, nitrogen desorption takes place at a slow rate and the conversion level comes to an equilibrium value after 8 days.

The observed effects of nitrogen inhibition on SRGO hydrotreating and VGO hydrocracking conversion are explained reasonably well by kinetic models.     

Release characteristics of nitrogen and phosphorus in Aerobic and intermittent Aerobic Sludge Digestion

Batch digestion experiments of biological sludge by continuous aeration and intermittent aeration were performed to find the release characteristics of nitrogen and phosphorus in this study. Nitrogen content of the sludge increases for the endogenous respiration period, but the content gradually decreases to the same content of raw sludge. Nitrogen removal efficiency was up to 42.7% for 34 days by the intermittent aerobic digestion of which aeration ratio was 0.25 and the removal efficiency was dependent on aeration ratio. Phosphorus does not release until the phosphorus content reaches a limit content. So, phosphorus content of sludge increases gradually to this limit. After the phosphorus content of the sludge reaches this limit, phosphorus will be released proportional to VSS reduction rate.     

温度对推流式微氧污泥床脱氮效能的影响

研究了温度变化对推流式微氧污泥床(PMSB)运行过程中同步脱氮除碳处理低碳氮比污水效能的影响。结果表明,反应器在33℃运行,NH4+-N和TN去除率分别稳定在90%和80%以上,COD去除率达到91.5%。温度的阶段性下降(33~15℃)导致功能菌群活性受到抑制,污泥氮负荷(NRR)由75.5 mg/(g·d)降至15℃时51.3 mg/(g·d)。15~33℃污泥活化能为14.8 k J/mol,胞外聚合物(EPS)含量随着温度的降低显著升高。温度回升至30℃时脱氮效能迅速恢复,表明反应器对温度变化的适应性较强。     

Fuel characteristics of wheat-based Dried Distillers Grains and Solubles (DDGS) for thermal conversion in power plants

For many years, the sole use of Dried Distillers Grains and Solubles (DDGS) has been as a feed for livestock, due to its high protein and fiber content. Recently there has been interest in DDGS as a power station fuel. In this study, DDGS produced from wheat has been studied for its fuel properties. Pyrolysis studies were conducted via Thermogravimetric Analysis (TGA) and pyrolysis gas chromatography-mass spectrometry (py GC-MS): the former was used to calculate the apparent first order kinetics while the latter helped to characterise pyrolysis products such as methoxyphenols and long chain fatty acids and esters. Fast heating rate chars were made, and nitrogen and sulphur partitioning between volatiles and chars are reported. In addition the chars were studied for their combustion behavior via Simultaneous Thermogravimetric Analysis with Mass Spectrometry detection (STA-MS) to study the conversion of char nitrogen and sulphur to different nitrogen and sulphur-containing species. In addition DDGS was combusted in a 50 kW fluid bed furnace, and the nitrogen species also monitored. DDGS is predicted to have a high alkali index that predicts high fouling tendency due to the high potassium and sodium contents in the ash. The phosphorus content in DDGS ash is also very high. Pyrolysis studies showed some oil evaporation/decomposition occurring at lower temperatures compared to decomposition of the lignocellulosic material. Nitrogen and sulphur partitioning showed that approximately 91% N and 94% S were given off as volatiles. The char was enriched with nitrogen but depleted in sulphur. Char combustion took place in two distinct stages indicating the presence of two types of chars, which yield selective evolution of S and N species during their combustion. Fluid bed combustion studies showed release of both HCN and ammonia during initial stages, when the bed is heating and the fuel undergoes devolatilisation. Steady-state combustion gave NO and N₂O emissions of 290 and 30 ppm respectively, with HCN and NH₃ emissions dropping to below 1 ppm. Agglomeration of the bed was avoided by keeping the combustion temperature below 900 °C     

循环流化床厌氧氨氧化反应器脱氮性能研究

对循环流化床上部附加无纺布作填料的固定床复合式厌氧氨氧化反应器的性能进行了研究,通过控制废水的循环量来调节反应器底部微生物颗粒的流化状态,并对反应器内对富集的厌氧氨氧化菌除氮性能进行了研究。结果表明,反应器稳定运行270 d,总氮去除率及亚硝氮去除率分别维持在80%及90%以上;最大氮负荷达到15.2 kg/m3.d-1,相应的最大氮去除速率达9.9 kg/m3.d-1。通过批实验,得到反应器稳定运行期厌氧氨氧化菌比活性为0.3 kg/k.gd-1。出水悬浮物(SS)浓度检测、微生物颗粒粒径分布测试、微生物颗粒的扫描电镜(SEM)观测结果均表明,循环流化床厌氧氨氧化反应器具有较高的生物滞留能力,形成的微生物颗粒具有较佳性能。采用荧光原位测定(FISH)分析结果显示,厌氧氨氧化菌在反应器微生物群落中含量超过70%。     

Process Control of an Alternating Aerobic‐Anoxic Sequencing Batch Reactor for Nitrogen Removal via Nitrite

Nitrogen removal via nitrite is a novel technology and is becoming popular for engineering applications since it results in a saving of the aeration energy required for nitritation and external carbon sources for denitritation. An alternating aerobic‐anoxic (AAA) operational pattern was applied in a sequencing batch reactor (SBR) process to improve the nitrogen removal efficiency and achieve partial nitrification via nitrite from industrial wastewater with influent alkalinity deficiencies. The results showed that the online monitoring of the pH‐time variations during nitrification could indicate if the alkalinity was sufficient and when the ammonia nitrogen was completely oxidized. Under conditions of deficient influent alkalinity, the AAA process reduced the external alkalinity and the carbon sources addition and improved the effluent quality with ammonia nitrogen concentration below the detection limits. Half of the alkalinity previously consumed during aerobic nitrification could be recovered during the subsequent anoxic denitrification period. If the cycles of alternating aerobic/anoxic were repeated more than twice, the first nitrification cycle was stopped when the pH decreased by 0.4–0.5. The middle nitrification was terminated when the pH decreased by 0.8–1.0, and the final nitrification duration was controlled by the dissolved oxygen (DO) breakpoint and ammonia valley on the pH profile. Each anoxic time‐scale for denitrification was determined by the nitrate knee on the oxidation‐reduction potential (ORP) profile and the nitrate apex on the pH profiles. In comparison to the conventional SBR process, the AAA process with a real‐time control strategy resulted in an improved nitrogen removal efficiency of greater than 97 % under conditions of deficient influent alkalinity. Moreover, nitrogen removal via nitrite was achieved with a nitrite accumulation rate above 95 %.     

尾油循环的煤焦油加氢实验研究

利用小型固定床加氢实验装置,将煤焦油和其加氢后的尾油混合,在温度(360~420)℃、压力(13~15)MPa、氢油体积比(1 500~1 700)∶1和液体体积空速0.25 h-1条件下进行加氢处理,所得产品切割得到的汽油馏分、柴油馏分和尾油馏分,分别占产物质量的16.12%、78.83%和5.05%,且产品中硫、氮含量很低,汽油中硫含量16.7μg·g~(-1),氮含量36μg·g~(-1),柴油中硫含量102.6μg·g~(-1),氮含量97μg·g~(-1),可用作清洁燃料。结果表明,尾油循环在煤焦油加氢过程中对煤焦油具有稀释作用,不仅减轻了设备负荷,同时也可以提高汽油和柴油收率。因此,以煤焦油加氢尾油循环加氢是一种高效、绿色环保制备燃料油的方法。     

精制油氮含量对加氢裂化及其产品影响的考察

考察了高压一段串联加氢裂化工艺不同类型加氢裂化催化剂的耐氮性能、高氮条件下的催化剂活性稳定性、经历高氮运转后催化剂反应性能的恢复情况和相同裂化深度时精制油氮含量对产品分布和产品性质的影响,以及中压条件下精制油氮含量对加氢裂化转化率的影响。