Effects of coal rank and reaction conditions upon coprocessing coal with waste tyre

It is well known that the amount of waste tyre increases every year, and a numerous amount of waste tyre is landfilled or dumped all over the world, which causes environmental problems, such as destruction of natural places and the risk of fires. Coprocessing waste tyre and coal is considered as one of the effective processing methods of both materials. Upon coprocessing lower rank coal (Wyoming, C; 68%) with waste tyre, the synergistic effects to upgrading, such as the increase of oil yield and the decrease of residue yield, were appeared. However, the synergistic effects were not observed on coprocessing two kinds of higher rank coals with waste tyre. The reactions of coal with benzophenone were carried out to discuss the hydrogen donatability of coal. Conversion of benzophenone to diphenylmethane on the reaction with Wyoming coal was higher than those of higher rank coals. Accordingly, it was considered that the synergistic effects to upgrading upon coprocessing Wyoming coal with waste tyre were obtained owing to the enhancement of stabilization of radicals from tyre and Wyoming coal through the hydrogen donation from both tyre and Wyoming coal. The effects of reaction temperature and the amount of solvent upon coprocessing Wyoming coal with waste tyre were also discussed in this study.     

The upgrading of petroleum residuum and coal in catalytic coprocessing

The combined catalytic reactions using different types of petroleum residuum and coal were performed at 425°C and 60 minutes in the presence of hydrogen to upgrade both materials to high quality synthetic fuels. In order to improve this coprocessing technology, the effect of the chemical and physical properties of both materials on the coprocessing product yields was investigated through a parametric study. In all reaction combinations, substantial increase in maltene production and high coal conversions of over 84% were observed regardless of petroleum residuum type and coal rank. The petroleum residuum properties of specific gravity and conradson carbon residue had effects on asphaltene production and coal conversion. The results of quantitative analysis for the amount of coal upgraded during coprocessing lead to conclude thata large amount of coal converted to maltene fraction due to high catalytic activity and reactive hydrogen donor richness of coprocessing system. However, most of the heavier fractions were formed primarily from coal regardless of the type of residuum used.     

废旧轮胎催化裂解研究进展

废旧轮胎因产量高、难降解、污染环境,被称为最难处理的“黑色垃圾”之一。催化裂解是一种处理废旧轮胎的重要手段,可以实现其高效转化与资源化利用,同时得到高附加值的化学产品,如单环芳烃、低碳烯烃与柠檬烯等。本文基于轮胎的物理结构与化学组成、催化裂解过程与裂解产物特征、反应器类型与特征、催化剂类型与作用原理、工艺条件等问题综述了废旧轮胎的催化裂解产物分布规律。通过对比反应器、催化剂与工艺条件对产物分布的影响,进一步分析了当前实现废旧轮胎催化裂解工业化的问题,并基于当前废旧轮胎催化裂解的研究现状,提出应集中设计适应于大规模处理的反应器与配套工艺,同时开发高稳定性与对特定产物高选择性的催化剂,从而实现对废旧轮胎以低能耗、高转化、高价值为特点的资源化利用。     

Catalytic coprocessing of coal and petroleum residues with waste plastics to produce transportation fuels

Coprocessing reactions with waste plastics, petroleum residues and coal were performed to determine the individual and blended behavior of these materials using lower pressure and cheaper catalysts. The plastic used in this study was polypropylene. The thermodegradative behavior of polypropylene (PP) and PP/petroleum residues/coal blends were investigated in the presence of solid hydrocracking (HC) catalysts. A comparison among various catalysts has been performed on the basis of observed temperatures. The higher temperatures of initial weight loss of PP shifted to lower values by the addition of petroleum residues and coal. The catalysts were also tested in a fixed-bed micro reactor for the pyrolysis of polypropylene, petroleum residues and coal, alone and blended together in nitrogen and hydrogen atmosphere. High yields of liquid fuels in the boiling range 100-480 °C and gases were obtained along with a small amount of heavy oils and insoluble material such as gums and coke. The results obtained on the coprocessing of polypropylene with coal and petroleum residues are very encouraging as this method appears to be quite feasible to convert plastic materials into liquefied coal products and to upgrade the petroleum residues and waste plastics.     

Thermal and catalytic conversion of waste polyolefines

Waste samples of polyethylene and polystyrene were cracked thermally or in the presence of catalyst and hydrogen in closed autoclaves. The obtained products were submitted to analysis, unsaturated hydrocarbons in gasoline and diesel fuel range boiling were hydrogenated over platinum catalyst. It was stated that the optimum thermal cracking temperature of waste polyolefines is 410–430°C, in the case of catalytic process lower temperature, ca. 390°C, can be used, with reaction time ca. 1.5 an hour. More than 90% yield of gas and liquid fractions with b.p.<360°C was attained. The dependencies between process parameters, feed composition and product yield as well as composition of the obtained fuel fractions were found. On the basis of the obtained results hypothetical continuous process of waste plastics processing for engine fuel production was presented.     

Effects of solvent composition on coprocessing coal with petroleum residua

The effect of solvent composition on coprocessing of coal and petroleum solvents is examined under a variety of reaction conditions. The effects of solvent modification procedures on enhancing methylene chloride/methanol (MeCl/MeOH) soluble coal conversion and pentane soluble oil production are studied. Solvent modification procedures performed prior to coprocessing reactions include pentane deasphalting, catalytic hydrotreatment, H-donor addition, and blending of coal-derived liquids with petroleum solvents. Oil production and coal conversion were variously affected by the different solvent modifications. Prior hydrotreatment of petroleum solvents generally enhanced coal conversion, as did H-donor addition. The presence of a hydrotreating catalyst exerted a leveling effect on the effects of solvent modification. Blending of coal liquids and petroleum solvents resulted in complex and not readily predictable interaction. Solvents yielding the highest MeCl/MeOH soluble coal conversion were not generally the optimal solvents for pentane soluble oil production.     

Catalytic coprocessing of LDPE with coal and petroleum resid using different catalysts

Catalytic coprocessing of low density polyethylene (LDPE) with coal and heavy petroleum resid was investigated using four different catalysts that included both hydrotreating and hydrocracking catalysts. Reaction systems that were evaluated included LDPE alone; LDPE with coal; and LDPE, coal, and resid. The catalysts used were NiMo/Al₂O₃, a hydrotreating catalyst with some hydrocracking activity, and the hydrocracking catalysts Zeolyst 753, NiMo/zeolite, and HZSM-5. These catalysts were reacted individually or in combinations of 10 wt.% of each hydrocracking catalyst in NiMo/Al₂O₃. The catalytic reactions were performed at two temperatures, 400 and 430°C, using 1 wt.% of each catalyst or a combination of catalysts on a total feed basis. The effects of the different catalysts on the reaction products were measured in terms of solvent fractionation and total boiling point distribution. Reactions at the higher reaction temperature of 430°C resulted in substantially higher conversion and production of lighter products than the reactions at 400°C. The LDPE reaction system was sensitive to the catalyst type, and yielded increased conversion and lighter products when Zeolyst 753 and NiMo/zeolite were used. By contrast, the conversion and product slate obtained from the LDPE and coal systems were low and showed no effect due to the different types of catalyst. Introduction of resid to the LDPE/coal system increased the reactivity of the system and allowed the catalysts to have a larger effect. The hydrocracking catalysts were the most active in producing more conversion and hexane soluble material. Comparison of the effect of increasing the reaction time up to 5 h with 1 wt.% catalyst loading to the effect of increasing the catalyst loading from 1 wt.% to 10 wt.% for a reaction time of 1 h showed that increased reaction time was much more effective than catalyst loading in converting the solid LDPE to liquid reaction products.     

Copyrolysis of scrap tires with waste lubricant oil

Two different types of scrap tires, passenger car tire (PCT) and truck tire (TT) with waste lubricant oil (WLO) were copyrolyzed in a fixed bed reactor at the temperatures of 550, 650 and 800 °C under nitrogen atmosphere. Copyrolysis products were investigated comparatively. The gaseous products were analyzed by GC–TCD. The physical and chemical properties of copyrolysis oils were characterized by means of ASTM methods, GC–FID, GC–MS, and ¹H NMR. In addition, boiling point distributions of hydrocarbons in copyrolysis oils were determined by using simulated distillation curves in comparison with commercial diesel. An increase in the temperature had no effect on the product distributions of copyrolysis and the composition of copyrolysis oils. However, the types of scrap tires strongly effected the product distributions and compositions of copyrolysis oils. Copyrolysis of PCT/WLO produced less amount of liquid and more amount of solid residue than that of copyrolysis of TT/WLO. However, the naphtha and aromatic content in oils from copyrolysis of PCT/WLO was found more than that of TT/WLO. The amount of aromatic content in copyrolysis oils found to be less than that of scrap tire derived oils. By comparing the copyrolysis oils with commercial diesel, copyrolysis oils contained lighter fraction than that of commercial diesel whereas the specific gravities and viscosities of copyrolysis oils were higher than that of commercial diesel.     

Copyrolysis of scrap tires with waste lubricant oil

Two different types of scrap tires, passenger car tire (PCT) and truck tire (TT) with waste lubricant oil (WLO) were copyrolyzed in a fixed bed reactor at the temperatures of 550, 650 and 800 °C under nitrogen atmosphere. Copyrolysis products were investigated comparatively. The gaseous products were analyzed by GC–TCD. The physical and chemical properties of copyrolysis oils were characterized by means of ASTM methods, GC–FID, GC–MS, and ¹H NMR. In addition, boiling point distributions of hydrocarbons in copyrolysis oils were determined by using simulated distillation curves in comparison with commercial diesel. An increase in the temperature had no effect on the product distributions of copyrolysis and the composition of copyrolysis oils. However, the types of scrap tires strongly effected the product distributions and compositions of copyrolysis oils. Copyrolysis of PCT/WLO produced less amount of liquid and more amount of solid residue than that of copyrolysis of TT/WLO. However, the naphtha and aromatic content in oils from copyrolysis of PCT/WLO was found more than that of TT/WLO. The amount of aromatic content in copyrolysis oils found to be less than that of scrap tire derived oils. By comparing the copyrolysis oils with commercial diesel, copyrolysis oils contained lighter fraction than that of commercial diesel whereas the specific gravities and viscosities of copyrolysis oils were higher than that of commercial diesel.     

催化裂化油浆的性质及其与煤共液化的研究进展

介绍了催化裂化（FCC）油浆的化学特点及其传统应用,综述了催化裂化油浆与煤共液化的高附加值研究现状。这不仅为改善煤液化循环溶剂的性能提供了新思路,也为FCC油浆探索了一条高效洁净利用的新途径。总结前人研究成果,取得成绩及面临问题的基础上,指出了今后研发的焦点——煤油共处理,拓宽催化裂化油浆的应用途径,对于中国的煤直接液化事业具有重要的指导意义。     

Fuel production from waste vehicle tires by catalytic pyrolysis and its application in a diesel engine

An alternative fuel production was performed by pyrolysis of waste vehicle tires under nitrogen (N₂) environment and with calcium hydroxide (Ca(OH)₂) as catalyst. The sulfur content of liquids obtained were reduced by using Ca(OH)₂. The liquid fuel of waste vehicle tires(TF) was then used in a diesel engine to blend with petroleum diesel fuel by 5%(TF5), 10%(TF10), 15%(TF15), 25%(TF25), 35%(TF35), 50%(TF50), and 75%(TF75) wt. and pure (TF100). Performance characteristics such as engine power, engine torque, brake specific fuel consumption (bsfc) and exhaust temperature and emission parameters such as oxides of nitrogen (NOx), carbon monoxides (CO), total unburned hydrocarbon (HC), sulfur dioxides (SO₂) and smoke opacity of the engine operation with TF and blend fuels of TF-diesel were experimentally investigated and compared with those of petroleum diesel fuel. It was concluded that the blends of pyrolysis oil of waste tires TF5, TF10, TF25 and TF35 can efficiently be used in diesel engines without any engine modifications. However, the blends of TF50, TF75 and TF100 resulted considerably to high CO, HC, SO₂ and smoke emissions.     

Carbon sorbents from waste crumb tires

The applicability of wastes from the chemical utilization of automobile tires as a raw material for the manufacture of carbon sorbents was studied. The thermogravimetric analysis of the thermal degradation of this raw material was performed; the proximate and ultimate analyses were carried out, and a process for the manufacture of crushed and granulated sorbents was developed. The formation of the structural and adsorptive properties of carbon sorbents based on waste crumb tires was studied. It was found that the sorbents were characterized by low and high sorption capacities for substances from aqueous solutions and saturated vapors, respectively. This phenomenon can be explained by the pore structure peculiarities of sorbents from waste crumb tires, which contained supermesopores that turned into capillaries; they are responsible for an entirely different mechanism of absorption: the capillary condensation of vapors.     

Utilizing waste tires with steel cord in coke production

The utilization of waste tires in coking, without extraction of the steel cord, is evaluated in the laboratory. The results show that using discarded tires with steel cord improves the yield and quality of the coke produced and also the yield of valuable byproducts: benzene and coal tar.     

The use of coal liquefaction catalysts for coal/oil coprocessing and heavy oil upgrading

The catalytic hydrogenation of heavy oil and mixed coal-heavy oil (coprocessing) systems has been the focus of a recent study at the Federal Energy Technology Center (FETC). The intent of this effort was to extend the use of coal liquefaction technologies to heavy oil upgrading and coprocessing systems. Specifically, new dispersed molybdenum-based catalysts developed at FETC and a novel silica-doped hydrous titanium oxide (HTO : Si)-supported NiMo catalyst developed at Sandia National Laboratories (SNL) were tested in these systems. The results indicate the potential of coal liquefaction catalysts for use in coprocessing and heavy oil upgrading. High conversions of coal–oil mixtures were observed with dispersed catalyst loadings as low as 100 ppm Mo. Similar results were observed in heavy oil systems. Also, the novel NiMo/HTO : Si catalyst was at least as effective as commercially-available supported catalysts (e.g. Amocat 1C) for conversion of high boiling point material to distillable products and aromatics removal.     

煤油共炼残渣掺配水煤浆气化评价研究

将延长石油集团煤油共炼残渣与煤掺配制备水煤浆进行高温气化处理。结果表明,在分散剂的作用下,残渣的掺配量可达到水煤浆总重的5%,水煤浆成浆性良好,气化性能优良,对气化工艺、设备及后续工艺无不良影响,能够实现对残渣的资源化利用及无害化处理。     

煤油共炼残渣掺配水煤浆气化评价研究

将延长石油集团煤油共炼残渣与煤掺配制备水煤浆进行高温气化处理。结果表明,在分散剂的作用下,残渣的掺配量可达到水煤浆总重的5%,水煤浆成浆性良好,气化性能优良,对气化工艺、设备及后续工艺无不良影响,能够实现对残渣的资源化利用及无害化处理。     

等离子条件下废轮胎与生物质的共热解

The gaseous products of co-pyrolysis of waste tires and biomass under DC arc plasma condition were investigated. The results showed that the volumetric concentration of acetylene in carbon-containing gases obtained when waste tires, biomass and coal were separately pyrolyzed was 14.6%, 13.7% and 10.6% respectively when the parameters experimental run were 150 A of electric current, 310 V of voltage, 2.0 m^3 · h^-1 of flux of argon, 0.65 m^3 · h^-1 of flux of main hydrogen, 0.4 m^3 ·h^-1 of flux of auxiliary hydrogen and 5.0 × 10^-4 kg · s^-1 of feed rate. Under the same condition, the volumetric concentration of acetylene in carbon-containing gases produced from the mixtures of biomass and waste tires when the mass ratio of biomass and waste tire was 1/2 increased obviously, nearly 2--3 times that of tires or biomass pyrolyzed separately. The concentration of acetylene was closely related to the volatile matter and the amount of oxygen. In addition, the possible mechanism of the pyrolysis occurred under plasma condition was proposed.     

Catalytic upgrading of liquid hydrocarbons derived from coprocessing of heavy oil and coal

Coprocessing of heavy oil and coal under elevated temperature, hydrogen pressure and low space velocity resulted in a product slurry from which the fraction distilling below 430° C was catalytically upgraded over a commercial NiMo/Al₂O₃ catalyst in a flow reactor. At 400° C, 13.3 MPa (H₂) and LHSV of 1.0 h^?1 over 90% of sulfur and nitrogen could be removed, aromaticity reduced to 16% from 26% and the API gravity increased to 36.9 from 23.8. Hydrogen consumption under these conditions was considerably lower than that obtained for upgrading the oil sands coker gas oil. Activation energies for hydrodesulfurization and hydrodenitrogenation reactions were determined to be 59.5 and 120.4 kJ/mol, respectively.     

废旧轮胎综合利用再添“巨无霸”

不久前,梧州循环经济产业园举行广西锐途再生物资有限公司年处理30万吨废旧轮胎项目试产暨中国—乌克兰纳米炭黑研发技术中心成立仪式。据介绍,该项目总投资约6亿元,规划用地200亩,采用国际先进的废旧轮胎连续式低温热裂解技术,将废旧轮胎裂解为燃料油、炭黑、改性沥青、钢丝及可燃气,实现技术研发—废旧轮胎回收—废旧轮胎裂解—成品—深度加工—销售—衍生品研发—产品定制的闭环产业链。