Derived oil production by catalytic pyrolysis of scrap tires

Scrap tires were pyrolyzed in a continuously stirred batch reactor in the presence and absence of catalysts. The maximum yield of derived oil was up to 55.65 wt%at the optimum temperature, 500 °C. The catalytic pyrolysis was performed using 1.0 wt%（on a scrap tire weight basis） of catalysts based on ZSM‐5, USY,β, SAPO‐11, and ZSM‐22. The oil products were characterized using simula‐tion distillation, elemental analysis, and gas chromatography‐mass spectrometry. The results show that using a catalyst can increase the conversion of scrap tires to gas and decrease char by‐products;the yield of derived oil remains unchanged or a little lower. The oils derived from catalytic pyrolysis had H/C ratios of 1.55–1.65 and contained approximately 70–75 wt%light oil, 0.3–0.58 wt%S and 0.78–1.0 wt%N. Catalysts with high acid strengths and appropriate pore sizes, such as ZSM‐5, USY,β, and SAPO‐11, increased the amount of single‐ring aromatics in the light‐middle‐fraction oil to 45 wt%. The derived oil can therefore be used as a petrochemical feedstock for producing high‐value‐added chemical products or fuel oil.

Secondary Cracking of Gasoline and Diesel from Heavy Oil Catalytic Pyrolysis

This paper investigated the secondary cracking of gasoline and diesel from the catalytic pyrolysis of Daqing atmospheric residue on catalyst CEP-1 in a fluidized bed reactor.The results show that the secondary cracking reactivity of gasoline and diesel is poor,and the yield of total light olefins is only about 10%(by mass).As reaction temperature increases,ethylene yield increases,butylene yield decreases,and propylene yield shows a maximum.The optimal reaction temperature is about 670℃for the production of light olefins.With the enhance- ment of catalyst-to-oil mass ratio and steam-to-oil mass ratio,the yields of light olefins increase to some extent. About 6.30%of the mass of total aromatic rings is converted by secondary cracking,indicating that aromatic hy- drocarbons are not easy to undergo ring-opening reactions under the present experimental conditions.

Establishment of Kinetic Model for Catalytic Pyrolysis of Daqing Atmospheric Residue

An 8-lump kinetic model was proposed to predict the yields of propylene, ethylene and gasoline in the catalytic pyrolysis process of Daqing atmospheric residue. The model contains 21 kinetic parameters and one for catalyst deactivation. A series of experiments were carded out in a riser reactor over catalyst named LTB-2. The ki- netic parameters were estimated by using sub-model method, and apparent activation energies were calculated according to the Arrhenius equation： The predicted yields coincided well with the experimental values. It shows that the kinetic parameters estimated by using the sub-model method were reliable.

Physicochemical Features of Phosphorus-Modified ZSM-5 Zeolite and Its Performance on Catalytic Pyrolysis to Produce Ethylene

The physicochemical features of phosphorus-modified ZSM-5 zeolites (SiO2/Al2O3 molar ratio is 25) were characterized by XRD(X-ray diffraction), BET(Brunauer, Emmett and Teller spcific surface area measurement), NH3-TPD(ammonia temperature-programmed desorption) and MASNMR(magic angle spinning nuclear magnetic resonance), and the performance on catalytic pyrolysis to produce ethylene was investigated with a light hydrocarbon fixed bed micro-reactor with n-octane as feed. The results show that the acid site density, acid intensity and hydrothermal stability of ZSM-5 zeolite were improved by phosphorus modification. When P2O5 content in ZSM-5 zeolite is higher than 2.5%, phosphorus modification can prevent ZSM-5 zeolite crystal structure transformation from orthorhombic to monoclinic. In addition, the dealumination of ZSM-5 zeolite framework was moderated by phosphorus modification under high temperature hydrothermal treatment. The results of n-octane pyrolysis on phosphorus-modified ZSM-5 zeolites show that ethylene yields of zeolites with different phosphorus content are almost the same under the same n-octane conversion. However, the modified zeolites with higher pyrolysis activity give lower yield of propene, butene and total olefin than lower pyrolysis activity under the same n-octane conversion.

Research on Ethylene and Propylene Formation during Catalytic Pyrolysis of Methylcyclohexane

The influence of operating parameters and type of zeolite catalysts on formation of ethylene and propylene during catalytic pyrolysis of methylcyclohexane (MCH) was studied in a laboratory fixed fluidized bed reactor. The results indicated that higher reaction temperature and lower WHSV tended to produce more ethylene and propylene, among which the reaction temperature was an important factor influencing the ethylene formation. Compared with the FAU and BEA type zeolites, the MFI structured zeolite catalyst, thanks to more acid sites and smaller pore diameter of the catalyst, was conducive to the formation of ethylene and propylene. The protonation occurred on different C—C bonds and C—H bonds in the carbon chain of MCH led to different product slates, and the protonation on C—C bonds located at naphthenic ring was favorable to the formation of ethylene and propylene.

Catalyst for Increasing Ethylene and Propylene Production and Its Industrial Application in a Catalytic Pyrolysis Unit

Light olefins,particularly ethylene and propylene,are the most important building blocks for the petrochemical industry,and demand for their production has been increasing.The catalytic pyrolysis process(CPP)and the corresponding catalyst,developed by SINOPEC Research Institute of Petroleum Processing Co.,Ltd.,are designed to maximize the light olefin yield from catalytic cracking of heavy feedstocks.However,owing to the continuing degradation of feedstocks,the original catalyst can no longer maintain its activity.Herein,we describe the rational design of the new catalyst,Epylene,from a new metal-modified hierarchical ZSM-5 zeolite and matrix.Epylene was tested in the CPP unit of Shaanxi Yanchang Coal Yulin Energy and Chemical Company.A test run and base run were conducted to demonstrate the better performance of Epylene compared with the original catalyst.The properties of the feedstocks and the operating conditions in both runs were similar.The light olefin yield was increased from 33.95%to 36.50%and the coke yield was only 9.58%in the test run,which was lower than that in the base run.

Correlation Models for Light Olefin Yields from Catalytic Pyrolysis of Petroleum Residue

Correlation models for light olefin yields from residue catalytic pyrolysis are studied. Experiments are carried out in a confined fluidized bed reactor for Daqing (China) atmospheric residue catalytic pyrolysis over LCM-5 pyrolyzing catalyst. The influences of reaction temperature, residence time and the weight ratios of catalyst-to-oil and steam-to-oil on light olefin yields are researched. Correlation models for light olefin yields are established, and the model parameters obtained, with the least square method. Results for error analysis and the F-statistical test show that the correlation models have high calculation precision.

Studies on Catalytic Pyrolysis of Daqing Atmospheric Residue

Catalytic pyrolysis of Daqing atmospheric residue on catalyst CEP-1 was investigated in a confined ffuidized bed reactor. The results show that reaction temperature, the mass ratios of catalyst to oil and steam to oil have significant effects on product distribution and yields of light olefins. The yields of light olefins show the maxima with the increase of reaction temperature, the mass ratios of catalyst to oil and steam to oil, respectively. The optimized operating conditions were determined in the laboratory, and under that condition the yields of ethylene, propylene and total light olefins by mass were 15.9%, 20.7% and 44.3% respectively. The analysis of pyrolysis gas and pyrolysis liquid indicates that CEP-1 has good capacity of converting heavy oils into light olefins, and there is a large amount of aromatics in pyrolysis liquid.

Catalytic Pyrolysis of Soybean Oil with CaO/Bio-Char Based Catalyst to Produce High Quality Biofuel

In this paper,CaO/bio-char was synthesized by directly co-pyrolysis of Ca(OH)_(2) and rice straw,and used as catalyst to catalytic pyrolysis of soybean oil to produce high quality biofuel.In this co-pyrolysis process,CaO particles has been successfully embedded on the bio-char surface.During the catalytic pyrolysis process,CaO/biochar showed a good catalytic performance on the deoxygenation of soybean oil.Pyrolysis temperature affected the pyrolysis reactions and pyrolytic products distributions dramatically,higher pyrolysis temperature lead to seriously cracking reactions,lower bio-oil yield and higher gases yield,and lower pyrolysis temperature lead to higher bio-oil yield with higher oxygenated compounds content and lower hydrocarbons contents,the suitable pyrolysis temperature was around 650℃.Under the optimal conditions(650℃ with WHSV at 6.4 h^(−1) and carrier gas flow rate at 100 ml/min),the selectivity(%)of hydrocarbons in the bio-oil was more than 90%.CaO/bio-char catalyst still shows good catalytic deoxygenation activity after 4 cycles.1 g of CaO/bio-char catalyst can catalyze pyrolysis of 32 g of soybean oil to produce high-quality liquid fuel.Bio-char based catalyst has been proved to be a promising catalyst for catalytic conversion of triglyceride-based lipids into high quality liquid biofuel.

Reaction characteristics of maximizing light olefins and decreasing methane in C_(5) hydrocarbons catalytic pyrolysis

When converting C_(5) hydrocarbons to light olefins by catalytic pyrolysis,the generation of low value-added methane will affect the atomic utilization efficiency of C_(5) hydrocarbons.To improve the atomic utilization efficiency,different generation pathways of light olefins and methane in the catalytic pyrolysis of C_(5) hydrocarbons were analyzed,and the effects of reaction conditions and zeolite types were inves-tigated.Results showed that light olefins were mainly formed by breaking the C_(2)-C_(3) bond in the middle position,while methane was formed by breaking the C_(1)-C_(2) bond at the end.Meanwhile,it was discovered that the hydrogen transfer reaction could be reduced by about 90%by selecting MTT zeolite with 1D topology and FER zeolite with 2D topology under high weight hourly space velocity(WHSV)and high temperature operations,thus leading to the improvement of the light olefins selectivity for the catalytic pyrolysis of n-pentane and 1-pentene to 55.12% and 74.60%,respectively.Moreover,the fraction ratio of terminal C_(1)-C_(2) bond cleavage was reduced,which would reduce the selectivity of methane to 6.63%and 1.83%.Therefore,zeolite with low hydrogen transfer activity and catalytic pyrolysis process with high WHsV will be conducive to maximize light olefins and to decrease methane.

The role and potential of attapulgite in catalytic pyrolysis of refinery waste activated sludge

Pyrolysis is a promising technology for the treatment of refinery waste activated sludge(rWAS).In this study,attapulgite as a natural clay was used to enhance the pyrolysis of rWAS.The yields,characteristics of pyrolytic products,pyrolytic kinetics and mechanisms were investigated.The attapulgite improved the conversion of rWAS into non-condensable gases and pyrolytic liquids.The bio-oil quality improved and the biochar yield reduced.The average activation energy of Stage Ⅰ(230-400℃)and Stage Ⅱ(400-500℃)decreased by 36.5%and 49.7%,respectively,compared to rWAS alone.Al_(2)O_(3)and Fe_(2)O_(3)in attapulgite enhanced the dealkylation reaction and cracking of C-C bonds.The content of the gasoline(<C_(13))fraction of bio-oil doubled relative to rWAS alone.Attapulgite promoted the deoxygenation,dehydroxylation and dehydrogenation reactions of O-containing compounds,and the content of CO and CO_(2) in non-condensable gases increased.Addition of attapulgite(rWAS:attapulgite ratio of 1:1)decreased the O mobility from 14.6%to 12.8%relative to rWAS alone.Also,the content of saturates in bio-oil increased from 38.5 wt%to 47.2 wt%and the lower heating value(LHV)increased from 6.8 kcal/kg to 8.4 kcal/kg.The heavy metals originally in rWAS were fixed into the pyrolytic residue and the environmental risks are low.This study demonstrates the role and potential of attapulgite in catalytic pyrolysis of rWAS with an added advantage of increased cost-effectiveness.

Catalytic Pyrolysis of Biodiesel Surrogate over HZSM-5 Zeolite Catalyst

To obtain insight into the catalytic reaction mechanism of biodiesels over ZSM-5 zeolites,the pyrolysis and catalytic pyrolysis of methyl butanoate,a biodiesel surrogate,with H-type ZSM-5(HZSM-5)were performed in a flow rereac tor under atmospheric pressure.The pyrolysis products were identified and quantified using gas chroma to graphy-mass spec trome try(GC-MS).Kine tic modelling and experimental results revealed that H-atom abstraction in the gas phase was the primary pathway for methyl butanoate decomposition during pyrolysis,but dissociating to ketene and methanol over HZSM-5 was the primary pathway for methyl butanoate consumption during catalytic pyrolysis.The initial decomposition temperature of methyl butanoate was reduced by approximately 300 K over HZSM-5 compared to that for the uncatalyzed reaction.In addition,the apparent activation energies of methyl butanoate under catalytic pyrolysis and homogeneous pyrolysis conditions were obtained using the Arrhenius equation.The significantly reduced apparent activation energy confirmed the catalytic performance of HZSM-5 for methyl but anoa te pyrolysis.The act iva tion t empera ture may also affec t some catalytic proper ties of HZSM-5.Overall,this study can be used to guide subsequent catalytic combustion for practical biodiesel fuels.

On-Line Photoionization Mass Spectrometric Study on Behavior of Ammonia Poisoning on H-Form Ultra Stable Y Zeolite for Catalytic Pyrolysis of Polypropylene

In this work, pyrolysis photoionization time-of-flight mass spectrometry （Py-PI-TOFMS） was applied to study the behavior of ammonia poisoning on H-form ultra stable Y （HUSY） zeolite for the catalytic pyrolysis of polypropylene （PP）. Firstly, ammonia poisoning on HUSY was performed to obtain the suitable catalysts with different strength and amounts of acid sites. Secondly, online photoionization mass spectra for the pyrolysis products of PP and HUSY with various acid strength were recorded at different pyrolysis temperatures. Finally, the formation curves of various pyrolysates of PP/HUSY with the increase of temperature were determined. Our results indicate that the formation temperatures, yields and selectivity of the pyrolysis products of PP demonstrate obvious relationship with the acid strength of HUSY.

Study on Technology for Quenching Catalytic Pyrolysis Gas

This article describes the application of technology for quenching catalytic pyrolysis gas at the Daqing commercial CPP test unit and the Shenyang commercial CPP production unit.On the basis of results for application of the Shenyang CPP unit this paper puts forward an improved process flow scheme for quenching the pyrolysis gas and made calculations using the process flowsheet software.Case Ⅰ of the process flow scheme,which is designed for full circulation of slurry,intends to use the pyrolysis light oil and fresh feed oil as the quenching media with the product slurry oil and fresh feedstock being discharged from the quench cooler bottom and routed directly to the reactor so that the fresh feed oil can be preheated prior to pyrolysis.Case Ⅱ of the process flow scheme intends to adopt recycle oil as the quenching medium with the product slurry and recycle oil being discharged from the quench cooler bottom to the fractionator,which then delivers the slurry from the bottom.These two cases for improving the process flow diagram can all effectively control the density and viscosity of the quenching medium to secure the smooth operation of quench cooler.

Techno-Economic Evaluation of Thermal and Catalytic Pyrolysis Plants for the Conversion of Heterogeneous Waste Plastics to Liquid Fuels in Nigeria

Techno-economic potentials of thermal and catalytic pyrolysis plants for the conversion of waste plastics to liquid fuels have been widely studied, but it is not obvious which of the two plants is more profitable, as the existing studies used different assumptions and cost bases in their analyses, thereby making it difficult to compare the economic potentials of the two plants. In this study, industrial-scale thermal and catalytic waste plastics pyrolysis plants were designed and economically analyzed using ASPEN PLUS. Amorphous silica-alumina was considered the optimum catalyst, with 3:1 feed to catalyst ratio. Based on 20,000 tons/year of feed and 20% interest rate, the catalytic plant, having a net present value (NPV) of &#83582208 million, was found to be economically less attractive than the thermal plant, having the NPV of &#83582426.4 million. On the contrary, sensitivity analyses of the two plants at a feed rate of 50,000 tons/year gave rise to a slightly higher NPV for the catalytic plant (&#83589861 million) than the thermal plant having NPV of &#83589838 million, thereby making the former more economically attractive for processing large amounts of waste plastics into liquid fuels. Consequently, as the catalytic plant showed a better scale economy and would produce higher quality liquid fuels than the thermal plant, it is recommended for commercialization in Nigeria.

Effects of Light Olefins Formation during Catalytic Pyrolysis of n-Heptane

The influence of zeolite structure and process parameters (including reaction temperature and catalyst/oil ratio) on rules for formation of ethylene and propylene in the course of catalytic pyrolysis of n-heptane was studied in a small- scale fixed fluid catalytic cracking unit. Test results have revealed that compared to the USY zeolite and Beta zeolite, the catalytic pyrolysis of n-heptane in the presence of the ZRP zeolite catalyst can result in higher yield and selectivity of ethyl- ene and propylene, while a higher reaction temperature and a higher catalyst/oil ratio can promote the formation of ethylene and propylene during catalytic pyrolysis of n-heptane. The ethylene formation reaction is more sensitive to the changes in reaction temperature, whereas the changes in catalyst/oil ratio are more influential to the propylene formation reaction. This paper has made a preliminary exploration into the different reaction pathways for formation of ethylene and propylene on zeolites with different structures.

Renewable p-Xylene Production by Co-catalytic Pyrolysis of Cellulose and Methanol

This work developed a one-step process for renewable p-xylene production by co-catalytic fast pyrolysis (co-CFP) of cellulose and methanol over the different metal oxides modified ZSM5 catalysts. It has been proven that La2O3-modified ZSM5(80) catalyst was an effective one for the production of biobased p-xylene. The selectivity and yield of p-xylene strongly depended on the acidity of the catalysts, reaction temperature, and methanol content. The highest p-xylene yield of 14.5 C-mol% with a p-xylene/xylenes ratio of 86.8% was obtained by the co-CFP of cellulose with 33wt% methanol over 20%La2O3-ZSM5(80) catalyst. The deactivation of the catalysts during the catalytic pyrolysis process was investigated in detail.The reaction pathway for the formation of p-xylene from cellulose was proposed based on the analysis of products and the characterization of catalysts.

Production of aryl oxygen-containing compounds by catalytic pyrolysis of bagasse lignin over LaTi0.2Fe0.8O3 prepared by different methods

To realize the resource and high-value utilization,a new approach,named bagasse lignin(BL) used to produce aryl oxygen-containing compounds by catalytic pyrolysis over perovskite,was proposed,LaTi0.2Fe0.8O3(LTF) samples prepared by the sol-gel method(SG) and the solid-state reaction method(SS)were characterized.The catalytic action on BL pyrolysis was performed by the test of TG-DTG and the evaluation of the fixed bed micro-reactor,the components and contents of the products were determined.The results show that LTF samples have cubic perovskite phase,LTF prepared by SG(LTF-SG) is porous with larger specific surface area than LTF prepared by SS(LTF-SS).During the pyrolysis of BL,the addition of LTF lowers the pyrolysis temperature and the activation energy,the contents of CO2 and CO in gaseous products reduce by 4.6%-8.0% and 30.7%-34.3%,respectively,the total content of aryl oxygencontaining compounds(including phenolics,guaiacols,syringols and phenylates) in liquid products increases from 62 wt% to more than 72 wt%,and LTF-SG shows better catalytic performance.LTF samples have nice phase and catalytic stabilities for BL pyrolysis after five successive redox cycles.

Catalytic pyrolysis of Pubescens to phenols over Ni/C catalyst

The pyrolysis of Pubescens over Ni/C catalyst was studied at 350°C in H2 flow.The presence of Ni/C catalyst efficiently improved the degradation of raw materials,and produced bio-oil with high content of phenols but low contents of acetic acid,furfural and water.In the reaction,Ni/C catalyst plays the role of catalytic decomposition and catalytic hydrogenation.The existence of the carbon carrier favors the formation of active Ni in small sizes with more defects,which results in high catalytic activity of Ni in biomass decomposition and selective production of phenols.

Preparation of bio-oil by catalytic pyrolysis of corn stalks using red mud

Red mud is a solid waste residue with alkaline nature(pH>12)-originating from the Bayer process in the production of alumina,which was probed in catalytic pyrolysis to determine its feasibility as a solid catalyst for bio-oil formulation.The red mud was characterized using X-ray fluorescence,XRD(X-ray diffraction),TG-DTG(thermogravimetry-derivative thermogravimetry),BET(surface area and pore size analyzer)measuring and testing techniques.Experiments of non-catalytic and catalytic pyrolysis of 40-60 mesh size corn stalk powder were channelled for bio-oil production in a fixed bed reactor.It was ascertained that adding different proportions of red mud had minute influence on bio-oil production rate and product distribution.The study signaled that liquid yield from the catalytic pyrolysis was lower than that from non-catalytic pyrolysis.Through a series of bio-oil characterization,it was encountered that the most obviously change in the bio-oil from catalytic pyrolysis was significant acidity reduction(pH>4).Meanwhile,the content of ketones and phenols was enhanced.Hence,the co-processing of agricultural waste and by-products alumina industry may offer an economical and environmentally friendly way of catalytic pyrolysis with abbreviating the red mud environmental effects.