延迟焦化装置回炼含水污油的技术探讨

介绍了一种依托延迟焦化装置的吹汽放空系统,其利用焦炭塔放空油气的废热回炼含水污油。该技术在焦化装置焦炭塔大吹汽和给水冷焦时,将含水污油注入焦炭塔的吹汽放空管道,含水污油被来自焦炭塔的高温油气加热,再经吹汽放空系统分离出不凝气、轻污油、含硫污水和重污油,使含水污油得到回炼。该技术不影响焦化装置的正常运行及产品质量,不受污油性质的限制,不仅可处理炼油厂难以处理的含水污油,而且降低了焦化装置的冷却负荷和能耗,有利于炼厂的节能减排和提高炼厂的经济效益。

炼厂回炼重污油技术的可行性研究

目前炼厂在装置正常开停工以及紧急工况下会产生大量含水重污油(含硫高且组分复杂),通常采用脱水后并入焦化装置原料线。但因脱水后其成分与渣油差异性较大,易引起加热炉炉管结焦,不利于装置的平稳生产。结合国内对放空塔系统的技术和运行特点,结合本公司生产运营特点,通过流程改造优化放空塔底重沸器为稳定热源,污油回炼量控制<10 t/h,且回炼前采样分析,油中水含量<20%,有效降低含水重污油处理成本。

超声强化炼厂含水污油破乳脱水工业化应用

炼厂含水污油的治理一直是困扰着企业的环保与经济效益的重要课题,通过对其进行快速、高效的脱水,可以达到降低能耗、减轻环境压力、降低安全风险的目的。采用含水率为60%~70%的炼油企业,进行了一次年产250000t的大型工业试验,考察了超声对污油中的水滴颗粒大小和污油粘度、界面张力的影响,超声输出电压、污油流量等因素对污油的脱水作用。研究发现,超声波对污水进行处理后,污水中的含水量有较大的提高,其平均粒径增加155.36%~184.15%,污油的粘度下降20%~22%,油水界面张下降6.32%~12.89%;在150/225 V的双频超声波下,在40 t/h的污油流量下,污油的含水量下降到2.13%。

新型组合工艺在石油炼制废水处理场污油渣处置中的应用

针对污油渣成分复杂,脱稳回炼困难,对污水处理场冲击频繁等问题,采用污油渣预处理、泥水分离处置和油气回收等组合工艺对污油渣进行治理。运行结果表明成品污油含水<3%,污水含油<300 mg/L,污泥含水<10%,具有较大的经济效益和社会效益。

Separation of Oil from Wastewater by Column Flotation

A new type of device,a dissolved-air flotation column,was developed for separation of oily wastewater. The unique design idea of the dissolved-air flotation column is the combined use of dissolved-air flotation and column flotation. The dissolved air release occurred within the column separation system. As a potential application the column was investigated for its performance in separating emulsified oil droplets in oily wastewater. A high separation efficiency was obtained in a series of tests. The aeration performance of the bubble generator used in the dissolved-air flotation column was also studied in particular.

Chemical and Sensory Properties of Olive Oil as Influenced by Different Sources of Irrigation Water

This research was conducted throughout the years 2008-2010 to study the influence of irrigation water quality on oil quality of ＂Nabali Muhassan＂ olive trees. Reclaimed municipal wastewater and fresh water were used twice a week using drip irrigation system. Rainfed olive trees of the same farm were taken as control. No significant differences were observed between rainfed, fresh water and reclaimed wastewater treatments in terms of acidity, peroxide values and UV absorbance of the extracted olive oil. Heavy metals and microbiological pathogens were not detected in all tested olive oil samples. Oleic acid was significantly higher in olive oil obtained from rainfed trees than irrigated trees. Linoleic acid content was significantly higher in reclaimed wastewater irrigated trees than the rainfed trees. Total polyphenol contents were significantly higher in oil obtained from rainfed olive trees than oil obtained from the irrigated olive trees. Results of organoleptic analysis showed no significant differences in the fruity attribute within treatments, while the bitter and pungent attributes were higher in olive oil obtained from rainfed trees as compared to that obtained from irrigated trees. No negative attributes were observed in oil obtained from the irrigated or rainfed trees and they were all classified as extra virgin grade.

Determation method for water content of diesel contaminated soil

With the increasing researches on geotechnical properties of the diesel contaminated soil( DCS),the water content measured is indispensable part during the early period. In this study,the relative error of water content measurement using the traditional method is as high as 20. 78%,which is no longer suitable for contaminated soil. Through a series of tests to measure the loss coefficient of diesel in the drying time,the authors finally proposed a modified calculation formula for test samples. The results show that the maximum relative error calculated by using the modified formula is 0. 96%,far lower than that of traditional formula,which can provide accurate data for further study of diesel contaminated soil.

Membrane fouling behavior and microbial community succession in a submerged membrane bioreactor treating harbor oily wastewater

A membrane bioreactor （MBR） was established for treating harbor oily wastewater. It showed good removal performance for chemical oxygen demand （COD）, oil content, suspended solids （SS）, and other pollutants. However, serious membrane fouling occurred. It was recognized that the extracellular polymeric substances （EPS） accumulated on the membrane surface, especially the proteins, were of great importance for the transmembrane pressure （TMP） increment and membrane fouling. The MBR was optimized via improving aeration rate and reducing the ratio of Ar/Ad （At and Ad are the cross-sectional areas of the riser and the downcomer of the MBR）. The increasing rate of TMP was slowed, indicating that the optimization strategy could effectively mitigate membrane fouling. Microbial community evolution was monitored and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE）, cloning, and sequencing of 16S ribosomal ribonucleic acid （rRNA） fragments. Results revealed that low community shift occurred during the whole operational period. Geobacter sp. and Rhodocyclales sp., which have also been identified by other studies in a petroleum refinery wastewater MBR or an infiltration basin receiving highway runoff, dominated in the MBR system throughout. Comamonas sp. was thought to accommodate the lower aeration rate in this study, while Rhodocyclales sp. preferred the higher aeration rate. In addition, during the operational time under high organic loading rate, a few species were present in abundance, and may have been responsible for the good removal performance at this time.

Biotreatment of oily wastewater by rhamnolipids in aerated active sludge system

Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra- ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote the biodegradation of pe- troleum hydrocarbons by dispersing oil into aqueous environment. In the present study, we applied rhamnolipid-containing cell-free culture broth to enhance the biodegradation of crude oil and lubricating oil in a conventional aerobically-activated sludge system. At 20 ℃, rhamnolipids （11.2 mg/L） increased the removal efficiency of crude oil from 17.7% （in the absence of rham- nolipids） to 63%. At 25 ~C, the removal efficiency of crude oil was over 80% with the presence of rhamnolipids compared with 22.3% in the absence of rhamnolipids. Similarly, rhamnolipid treatment （22.5 mg/L） for 24 h at 20℃ significantly increased the removal rate of lubricating oil to 92% compared with 24% in the absence of rhamnolipids. The enhanced removal of hydrocarbons was mainly attributed to the improved solubility and the reduced interfacial tension by rhamnolipids. We conclude that a direct application of the crude rhamnolipid solution from cell culture is effective and economic in removing oily contaminants from wastewater.