665.753 There are two causes of Russia's lagging behind Western Europe and the USA in stiffening the quality requirements for automotive gasolines. Environmental pollution by exhaust gases only occurs in our country in large cities, since the volume of automotive gasolines consumed per unit of territory is 15-20 times less than in the USA and 4-5 times less than in Europe [1][2][3]. The second cause is the large number of automobiles with engines that satisfy Euro-2 requirements [4].Unleaded automotive gasolines are produced at almost all domestic oil refineries (OR). GOST R 51105-97 and GOST R 51866-2002 which replaced GOST 2084 required a major change in the production technology for their basic components. Fundamentally improving the quality of gasolines is only possible by reducing the total sulfur content -to less than 50(10) ppm, restricting the benzene content -to less than 5-1 vol. %, the total aromatic hydrocarbon content -to less than 35 vol. %, and the olefin content to less than 14 vol. %, and using high-octane additives in them -alcohols or ethers, detergents, and multifunctional additives.The basic components of commercial gasolines are the naphtha cuts from catalytic reforming and cracking. High concentrations of benzene and aromatics or olefins are characteristic of these components.The high benzene content in reforming naphtha cuts is due to aromatization of cyclohexane, methylcyclopentane, and n-hexane, and also to disproportionation and dealkylation of C 7 and higher hydrocarbons.The benzene content in the products of transformation is 4.5-5.5 wt. % in reforming of the 85-180°C cut and 1.4 wt. % in reforming of the 105-180°C cut.Removal of cuts that contain the hydrocarbons listed above from the reforming feedstock significantly reduces the supplies of high-octane components of gasoline when the refinery has no isomerization and alkylation processes. In addition, the higher end point in distillation of reforming feedstock negatively affects the vaporizability of commercial gasolines made from naphtha cuts from this process and requires addition of important amounts of light, low-octane, straight-run, IBP-62(85)°C cuts. 0009-3092/06/4204-0235
The results of a pilot run of the LF-35/21-1000 reforming unit with continuous regeneration of the catalyst at LUKOIL -Nizhegorodnefteorgsintez Co. are reported. It was found that all of the blocks and units operate in accordance with the project requirements. Dependences that correlate the quality of reforming naphtha with its yield and the yield of hydrogen-containing gas and power consumption with the output of the unit were obtained.Catalytic reforming naphtha occupies a leading position (52.8 vol. %) in Russia's gasoline stock (more than 30 million tons/year) [1]. This is due to catalytic reforming units with periodic catalyst regeneration, the base for production of high-octane components of unleaded automotive gasolines, as well as catalytic cracking naphthas, in all large oil refineries [2,3]. The proportion of catalytic reforming and cracking naphthas is decreasing significantly in high-quality gasolines due to stiffening of the requirements for the content of benzene (less than 1 vol. %), aromatics (less than 35 vol. %), and olefins (less than 5 vol. %) [4].The universal introduction of catalytic reforming in oil refinery (OR) manufacturing schemes is also due to the fact that hydrogen-containing gas (HCG) is the second target product of this process. The concentration of hydrogen in HCG is 75-93% as a function of modification of the process. Production of environmentally clean jet and diesel fuels is directly correlated with the presence of industrial hydrogen in the refineries, i.e., catalytic reforming units [5].The basic trends in improving catalytic reforming are:the efficiency of the catalysts; 363 • • • • • revamping and retooling the units with a stationary bed of catalyst with a step with continuous regeneration of the catalyst; • • • • • introducing units with continuous regeneration of the catalyst; • • • • • improving process and heat-and mass-exchange equipment [6]. In 2004, LUKOIL -Nizhegorodnefteorgsintez Co. completed construction of the LF-35/21-1000 unit based on Platforming CCR UOP technology at a pressure of 0.35 MPa under a medium-term program for re-equipping and developing production.After completion of construction and starting the unit up, studies were conducted to determine the optimum composition of the feedstock and target product, power consumption and real consumption of material and technical resources, to establish the correspondence of the real operating parameters with the rated parameters, to optimize operation of control systems, and to determine the cycle between repairs based on the results of operating compressor equipment in the different operating conditions of the unit.The studies of the feedstock hydrotreating block were conducted for 138 days, the reforming block was investigated for 132 days, and the catalyst regeneration block was studied for 95 days. The feedstock load varied from 67 to 120 tons/h, and the catalyst circulation rate varied from 400 to 715 kg/h. The unit operated in six regimes.The basic indexes of operation of the hydrotreating block are rep...
Чернівецький науково-дослідний експертно-криміналістичний центр Міністерства внутрішніх справ України ВПЛИВ СПОСОБУ ГАЛЬМУВАННЯ НА ГАЛЬМІВНУ ДИНАМІКУ АВТОМОБІЛЯ Анотація. Одним із режимів руху автомобілів в місті є сповільнення, яке з поміж інших режимів руху становить близько 35%. Сповільнення може відбуватися різними способами. В роботі розглядається службове сповільнення автомобіля робочою гальмівною системою та двигуном разом з гальмами. Аналітично встановлено, що значення сповільнення автомобіля, коли водій привів у дію робочу гальмівну систему, що рухається на прямій передачі в режимі примусового холостого ходу, відрізняється від того, яке отримане при тих же умовах, коли гальмування відбувається лише гальмами. У роботі авторами розраховані порівняльні значення шляху, часу, сповільнення при використанні гальм та двигуна разом з гальмами. Ключові слова: сповільнення, способи гальмування, автомобіль, гальмування двигуном, гальмівна динаміка.
This article presents the results of experimental and computational studies of the performance of a car with a gasoline engine with spark ignition when retrofitted with a system of liquefied petroleum gas (LPG). To analyze the impact of the use of LPG instead of gasoline, the mathematical model of the car’s movement according to the modes of the European driving cycle has been refined. It was established that when using LPG for a car in the driving cycle, fuel consumption in energy units decreases by 10.38%. Gas consumption, determined in mass units, is lower than gasoline consumption. In load modes, this difference is about 8% and in idle mode, it reaches 16–18%. The adequacy of the mathematical model is confirmed by experimental studies of the car on modern equipment with the measurement of fuel efficiency and environmental performance in motion, according to the specified cycle. The deviation of the calculated fuel consumption from the results of experimental studies does not exceed 0.86%. The values of environmental indicators obtained by calculations on the mathematical model differ from the experimental ones by an average of 15%. The conducted studies showed the expediency of using LPG by retrofitting a car with a gasoline engine with an LPG power supply system and the possibility of using mathematical modeling to assess the feasibility of such retrofitting.
Чернівецький Науково-дослідний експертно-криміналістичний центр МВС України ВИКОРИСТАННЯ ДОДАТКОВИХ ЕЛЕМЕНТІВ У ПІДВІСЦІ АВТОМОБІЛЯ, ЩО ЗБІЛЬШУЮТЬ ДОРОЖНІЙ ПРОСВІТ Анотація. В умовах експлуатації автомобілів при здійсненні автотехнічних досліджень частішають випадки виявлення конструкційних змін в ходовій частині, що збільшує дорожній просвіт використанням додаткових елементів в передній та задній підвісці. В роботі розглядається використання додаткових елементів в підвісці автомобіля, які не відповідають вимогам заводу виробника, які впливають на стійкість, органи керування, а також на елементи зовнішніх світлових приладів. У роботі авторами представлено дослідження, а саме як впливає зміна дорожнього просвіту на центр ваги автомобіля, значення якого використовується при автотехнічних дослідженнях. У роботі представлено залежності експериментального визначення центра ваги автомобіля, в якому встановлено додаткові елементи у підвісках автомобіля. Ключові слова: стійкість , центр ваги, автомобіль, ходова частина, дорожній просвіт.
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