91316 ⎘
Preparation of ethers; Preparation of compounds having groups, groups or groups; Preparation of ethers by dehydration of compounds containing hydroxy groups
PREPARATION OF ALPHA-NECRODYL ISOBUTYRATE FROM DIENES
#2METHOD FOR PRODUCING (POLY)ALKYLENE GLYCOL MONOALKYL ETHER
#311-HALO-1,1-DIALKOXY-7-UNDECENE COMPOUND AND PROCESSES FOR PREPARING A 11,11-DIALKOXY-4-UNDECENYLTRIARYLPHOSPHONIUM HALIDE COMPOUND, A TRIENAL COMPOUND, AND A DIENAL COMPOUND
#4METHOD AND COMPOUND USEFUL IN PREPARATION OF OREXIN-2 RECEPTOR ANTAGONIST, AND LEMBOREXANT HAVING FEW IMPURITIES
#5A BICYCLOPENTYL THIANTHRENIUM COMPOUND, PROCESS FOR PREPARING THE SAME AND THE USE THEREOF
#6SYNTHETIC METHANOL HAVING LOW DEUTERIUM CONTENT FROM NON-FOSSIL RESOURCES
#7FLUORINATED ALKOXYVINYL ETHERS AND METHODS FOR PREPARING FLUORINATED ALKOXYVINYL ETHERS
#8METHOD OF PRODUCING BIO-DERIVED BRANCHED ALKYL GLYCERYL ETHER, AND BIO-DERIVED BRANCHED ALKYL GLYCERYL ETHER PRODUCED BY SAID METHOD
#9PROCESS FOR MAKING ETHERS FROM ETHANOL
#10UNIQUE ANALOGS OF NATURAL LIGNANS USEFUL FOR TREATING TRIPLE NEGATIVE BREAST CANCER
#11MIXTURE OF STEREOISOMERS OF A SULFATED GLYCOLIPID
#12ANTIFOAM / DEFOAM FORMULATION
#13A CATALYST FOR THE CONVERSION OF CO2-RICH SYNGAS TO METHANOL AND CONVENTIONAL SYNGAS TO DIMETHYL ETHER
#14METHOD AND SYSTEM FOR PREPARING DIMETHYL ETHER
#15PROCESS AND INTERMEDIATES FOR PREPARATION OF ISOFETAMID
#16Production of Acetic Acid through Cryogenic Separation of Syngas
#17SCM-38 molecular sieve, preparation method thereof, and use thereof
#18ALKOXYLATION OF CANNABIDIOL AND OTHER CANNABINOIDS
#19VOLATILE OR SEMI-VOLATILE NATURAL ANTIOXIDANTS SOURCED FROM A COMESTIBLE BYPRODUCT
#20RESIST COMPOUND FOR PHOTOLITHOGRAPHY, METHOD FOR FORMING THE SAME, AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICES USING THE SAME
#21CO2 conversion device
#22PROCESS FOR STARTING UP A PLANT FOR REMOVING ISOBUTENE FROM A C4-HYDROCARBON MIXTURE
#23ZEOLITE CATALYST, PROCESS FOR PREPARATION AND APPLICATION THEREOF
#24METHOD TO CONTROL SYNGAS COMPOSITION FROM AN ENGINE-BASED SYNGAS GENERATOR
#25METHOD FOR CATALYTIC CONVERSION OF GLYCERIN INTO PRODUCTS OF HIGH ADDED VALUE, AND USE
#26Methods for preparing and purifying environmentally compatible detergents
#27DIMETHYL ETHER PRODUCTION VIA DRY REFORMING AND DIMETHYL ETHER SYNTHESIS IN A VESSEL
#28METHOD FOR PERFORMING MITSUNOBU REACTION BETWEEN ALCOHOLIC HYDROXYL GROUP DONOR AND ACTIVE HYDROGEN DONOR
#29Catalyst for synthesizing dimethylether or methylacetate from synthetic gas, method for preparing the same, and method for preparing dimethylether or methylacetate using the same
#30METHOD AND PLANT FOR PREPARING DIMETHYL ETHER
#31FLUORINATED ALKOXYVINYL ETHERS AND METHODS FOR PREPARING FLUORINATED ALKOXYVINYL ETHERS
#32MULTIFUNCTIONAL CATALYST FOR THE CONVERSION OF CARBON DIOXIDE
#33NOVEL GLYCOSIDE COMPOUND AND PRODUCTION METHOD THEREFOR
#34POLYHYDROXY AROMATIC INTERMEDIATE, PREPARATION THEREOF AND USE THEREOF IN POLYCONDENSATE WATER-REDUCER WITH BRANCHED SIDE CHAINS
#35INTEGRATED PRODUCTION PROCESS OF TERT-BUTYL ETHERS OF GLYCEROL OR ISOOCTENE STREAM
#36DIAMINE MONOMER COMPOUND, METHOD FOR PREPARING THE SAME, RESIN, FLEXIBLE FILM, AND ELECTRONIC DEVICE
#37Dimethyl ether production via dry reforming and dimethyl ether synthesis in a vessel
#38TRIFUNCTIONAL PROCESSES IN CATALYTIC DISTILLATION
#39TERPENOL ETHERS
#40Catalyst for synthesizing dimethylether or methylacetate from synthetic gas, method for preparing the same, and method for preparing dimethylether or methylacetate using the same
#4111-HALO-1,1-DIALKOXY-7-UNDECENE COMPOUND AND PROCESSES FOR PREPARING A 11,11-DIALKOXY-4-UNDECENYLTRIARYLPHOSPHONIUM HALIDE COMPOUND, A TRIENAL COMPOUND, AND A DIENAL COMPOUND
#42Production of acetic acid through cryogenic separation of syngas
#43PROCESS FOR GENERATING A MIXED MULTICOMPONENT VAPOR FOR PREPARATION OF MONOALKYL ETHERS OF DIPHENOLS
#44Natural gas dehydration
#45Methods of etherification
#46Intensified process of synthesis of dialkyl ethers using a step conical reactor
#47METHOD AND COMPOUND USEFUL IN PREPARATION OF OREXIN-2 RECEPTOR ANTAGONIST, AND LEMBOREXANT HAVING FEW IMPURITIES
#48Process and catalyst to convert methanol and toluene to styrene
#49Process for dehydrating methanol to dimethyl ether
#50Process for dehydrating alcohols to ethers
#51Process for dehydrating methanol to dimethyl ether
#52Methods, systems, and catalysts for the direct conversion of syngas to high-octane hydrocarbons
#53METHOD FOR PRODUCING DIVINYL ETHER COMPOUND HAVING ALKYLENE SKELETON
#54Process for making ethers via enol ethers
#55SELECTIVE DIMERIZATION AND ETHERIFICATION OF ISOBUTYLENE VIA CATALYTIC DISTILLATION
#56Process for producing a renewable isoparaffin compound, renewable isoparaffin compound and use of the renewable isopraffin compound
#57Processes for producing ethers and olefins from primary alcohols
#58Fluorinated alkoxyvinyl ethers and methods for preparing fluorinated alkoxyvinyl ethers
#59Bioderived fuels and methods of making the same
#60Method for preparing 2-tert-butyl-4-methoxyphenol and new crystal form thereof
#61CATALYSTS FOR PRODUCING ALCOHOLS AND ETHERS FROM SYNTHESIS GAS
#62Volatile or semi-volatile natural antioxidants sourced from a comestible byproduct
#63METHOD FOR PRODUCING FAT ALCOHOL ETHOXYLATES
#64DERIVATIVES OF 1,3-PROPANEDIOL
#65ESTERS AND ETHERS OF 3-METHYL-PENTANE-DIOL AND UNSATURATED DERIVATIVES THEREOF AND THEIR USE AS AROMA CHEMICAL
#661,2-dichloro-1-(2,2,2-trifluoroethoxy)ethylene, production method therefor, and uses thereof
#67Method for preparing ethers of cycloaliphatic or araliphatic diols
#68Compound of 3,3,3′,3′-tetramethyl-1,1′-spirobiindane-based phosphine ligand, and preparation method thereof
#69Process for dehydrating methanol to dimethyl ether
#70Process for dehydrating methanol to dimethyl ether product
#71Process for synthesis of a phenoxy diaminopyrimidine compound
#723,4-DIHYDROXYPHENETHYL 3-HYDROXYBUTANOATE, PREPARATION AND USE THEREOF
#73Methods for methanol-to-gasoline conversion with post-processing of heavy gasoline hydrocarbons
#74Bimetal-incorporated mesoporous silicates for alcohol dehydration and related methods
#751,2-diacylglycerol compound, preparation method therefor, and immunomodulator containing same as active ingredient
#76METHOD FOR PREPARING A CAMGAL MIXED OXIDE, A CAMGAL MIXED OXIDE OBTAINABLE THIS WAY AND THE USE THEREOF FOR OLIGOMERIZATION OF GLYCEROL
#77Methods for methanol-to-gasoline conversion with forwarding methanol processing
#78Process and system for producing dimethyl ether
#79Bioderived fuels and methods of making the same
#80Catalyst and process for preparing dimethyl ether
#81Catalyst system and process for preparing dimethyl ether
#82PROCESS AND PLANT FOR PRODUCING OLEFINS FROM OXYGENATES
#83Preparation of natural zeolite catalyst and the method of producing dimethyl ether from methyl alcohol using this catalyst
#84Process for dehydrating methanol to dimethyl ether
#85Layered catalyst loading for synthesis gas conversion
#86Process for dehydrating methanol to dimethyl ether product
#87Single-loop octane enrichment
#88Process and catalysts for the production of diesel and gasoline additives from glycerol
#89A PERSONAL CARE COMPOSITION
#90Process for etherification of mixed olefinic light naphtha and simultaneous reduction of methanol in the product
#91Ether blends via reactive distillation
#92Method of producing solution composition containing monoetherified product, solution composition, and method of producing polymerizable compound
#93Integrated methanol separation and methanol-to-gasoline conversion process
#94Mn/CeOcatalyst for dimethyl ether production via oxidative dehydration of methanol
#95Modified monomer, modified polymer including the same, and methods of preparing the same
#96Aromatic compositions and methods for obtaining them
#97Compound and method for producing same
#98Efficient process for converting heavy oil to gasoline
#99PROCESSES AND APPARATUSES FOR TOLUENE METHYLATION IN AN AROMATICS COMPLEX
#100Anionic surfactants and detergents comprising them
#101METHOD FOR CONVERTING NATURAL GAS TO DIMETHYL ETHER
#102Liquid crystal compound containing a difluormethoxy bridge and application thereof
#103System and process for the production of renewable fuels and chemicals
#104SMALL SCALE PRODUCTION OF METHOXY COMPOUNDS
#105Dehydration-hydrolysis processes and catalysts therefor
#106Catalytic membrane reactor for dimethyl ether synthesis from carbon dioxide and hydrogen
#107Integrated process for making propene oxide and an alkyl tert-butyl ether
#108Conversion of methane to dimethyl ether
#109Fuel synthesis from an aqueous solution
#110Ether blends via reactive distillation
#111DERIVATIVES OF 1,3-PROPANEDIOL
#112Process for producing a multifunctional product and the device for applying said process
#113Systems and methods for producing dimethyl ether from natural gas
#114Configuration in single-loop synfuel generation
#115Polyisobutylene-based thermoplastic elastomers
#116Single-loop octane enrichment
#117Bisphenol alternative derived from renewable substituted phenolics and their industrial application
#118Method of preparation of mixed metal oxide using glucose oxidation assisted precipitation
#119Systems and methods for manufacture of dimethyl ether (DME) from natural gas and flare gas feedstock
#120Chiral ligand-based metal-organic frameworks for broad-scope asymmetric catalysis
#121Device For Evaluation Of At Least One Performance Criterion Of Heterogeneous Catalysts
#122Process for generating a mixed multicomponent vapor for preparation of monoalkyl ethers of diphenols
#123Utilization and recycling of emitted carbon dioxide
#124Low viscosity low volatility lubricating oil base stocks and processes for preparing same
#125Method and reaction equipment for preparing dimethyl ether and olefin from methanol
#126ZERO EMISSION POWER PLANT WITH CO2 WASTE UTILIZATION
#127Process for the co-production of acetic acid and dimethyl ether
#128Synthesis of honokiol
#129Process for the co-production of acetic acid and dimethyl ether
#130Process for the production of dimethyl ether from gaseous mixtures of carbon monoxide, hydrogen and methyl acetate
#131Ethanol production via dimethylether recycle
#132Branched chain-containing aromatic compound
#133Preparation of polyglycerols
#134Hydrogen-assisted adsorption of sulphur compounds from olefin mixtures
#135Process and Installation for the Production of Dialkyl Ether
#136Fracking with COfor shale gas reforming to methanol
#137Process for the acid-catalysed dehydration of ethanol
#138Method and system for obtaining dimethyl ether from syngas
#139METHOD FOR PRODUCING DIMETHYL ETHER AND DEVICE SUITABLE THEREFOR
#140Low Pressure Dimethyl Ether Synthesis Catalyst
#141Processes for converting biomass-derived feedstocks to chemicals and liquid fuels
#142Actinic ray-sensitive or radiation-sensitive resin composition, actinic ray-sensitive or radiation-sensitive film, mask blank provided with actinic ray-sensitive or radiation-sensitive film, photomask, pattern forming method, method for manufacturing electronic device, electronic device, compound, and method for producing compound
#143Process for preparing chloroacetaldehyde acetals
#144Method for producing a latent heat storage material and dialkyl ether as a latent heat storage material
#145Surfactant composition comprising ether compound and catalytic process for manufacturing thereof
#146Method for Producing N-Butane Derivatives
#147METHOD FOR PRODUCING HYDROCARBON PRODUCTS
#148Configuration in single-loop synfuel generation
#149Catalyst and manufacturing method thereof and method for manufacturing hydrogenated bisphenol A or derivatives thereof using the same
#150Systems and methods for manufacture of dimethyl ether (DME) from natural gas and flare gas feedstock
#151ALKYL POLY GLYCOL-ETHERS AND THEIR SYNTHESIS
#152Process and plant for preparation of one or more reaction products
#153Process for the preparation of 3-aryl-2-hydroxy propanoic acid compounds
#154CATALYSTS AND METHODS FOR ALCOHOL DEHYDRATION
#155Process and plant for producing olefins from oxygenates
#156Low dielectric constant polymer containing dinaphthyl and hexafluorocyclobutyl ether unit, preparation method and use
#157Process for the production of acetic acid and dimethyl ether
#158Ether blends via reactive distillation
#159One-pot process for the production of biodiesel and glycerol ether mixtures useful as biofuels
#160Production of acrylic acid and ethanol from carbonaceous materials
#161ENHANCED OIL RECOVERY FROM A CRUDE HYDROCARBON RESERVOIR
#162Integrated process for the preparation of compounds useful as fuel components
#163Dehydration-hydrolysis processes and catalysts therefor
#164Catalysts and methods for alcohol dehydration
#165Method for the Production of Hyperbranched Polyglycerol
#166Catalyst and process for the production of acetic acid and dimethyl ether
#167Integrated process for making acetic acid
#168Process for the preparation of phosphorous containing mesoporous alumina catalyst for selective dehydration of methanol to dimethyl ether
#169PROCESS FOR THE PREPARATION OF HYDROCARBONS
#170Catalysts and methods for alcohol dehydration
#171Process for dehydration of ethanol to ethylene at low energy consumption
#172Method for producing polyoxymethylene dimethyl ethers
#173Process for dehydration of ethanol into ethylene using pretreatment of the feedstock
#174Process for producing renewable jet fuel compositions
#175Process for preparing linear butenes from methanol
#176Process for production of DME from crude methanol
#177Method and system for producing liquid fuel and generating power
#178Method for producing dimethyl ether and device suitable therefor
#179Process for the preparation of dimethyl ether
#180Novel Polyisobutylene-Based Thermoplastic Elastomers
#181Preparation of hydroxy-benzylbenzene derivatives
#182Method for producing alkoxy-hydroxybenzaldehyde that is substantially free of alkyl-alkoxy-hydroxybenzaldehyde
#183Method for coproducing isobutene and MTBE from tert-butanol mixture in a catalytic distillation column
#184Process for producing renewable jet fuel compositions
#185CATALYSTS AND METHODS FOR ALCOHOL DEHYDRATION
#186Catalysts and methods for alcohol dehydration
#187Method for starting up a DME synthesis reactor
#188Methods and apparatuses for processing hydrocarbons
#189FLUID-SPARGED HELICAL CHANNEL REACTOR AND ASSOCIATED METHODS
#190Cyclic compound containing functional group or containing no functional group, and method for producing same
#191Preparation of an ether compound
#192CATALYTICALLY ACTIVE BODY FOR THE SYNTHESIS OF DIMETHYL ETHER FROM SYNTHESIS GAS
#193Catalysts and methods for alcohol dehydration
#194Cooled reactor for the production of dimethyl ether from methanol
#195System and method for producing gasoline
#196Process for the production of 1,3-butadiene
#197Phosphine ligands for catalytic reactions
#198DIMETHYL ETHER (DME) PRODUCTION PROCESS
#199System and method for producing gasoline or dimethyl ether
#200Catalysts and methods for alcohol dehydration
#201Efficiency, flexibility, and product value of a direct alkanes to oxygenates process
#202Catalysts For Forming Diethyl Ether
#203Processes for converting biomass-derived feedstocks to chemicals and liquid fuels
#204Process for the production of pure methylal
#205Synthesis of drop-in liquid fuels and chemicals from methanol, ethanol or syngas using mixed catalysts
#206Fluorinated aromatic bis(acyl)-containing compounds and polyesters prepared therefrom
#207Alkoxylation of crude bisphenol A
#208Family of aryl, heteroaryl, O-aryl and O-heteroaryl carbasugars
#209Fuels and fuel additives production from glycerol conversion using a monohydric alcohol and heterogeneous catalysis
#210Efficient, self sufficient production of methanol from a methane source via oxidative bi-reforming
#211Dual-bed catalytic distillation tower and method for preparing dimethyl ether using the same
#212Recycling carbon dioxide via capture and temporary storage to produce renewable fuels and derived products
#213Methods for making polyglycerol
#214Catalyst and method for the direct synthesis of dimethyl ether from synthesis gas
#215LOW PRESSURE DIMETHYL ETHER SYNTHESIS CATALYST
#216Catalytically active body for the synthesis of dimethyl ether from synthesis gas
#217Catalytic alkylation of alcohols to liquid ethers and organic compounds to alkylated products
#218Process for the production of dimethyl ether
#219METHODS FOR PRODUCING LIGHT OLEFINS
#220Fluorine-containing vinyl ether compound and method for producing the same
#221Production of alcohols having three carbon atoms from carbonaceous materials
#222Production of alcohols having at least four carbon atoms from carbonaceous materials
#223PTP1B inhibitors, synthesis thereof and application thereof in preparation of medicaments for treating type 2 diabetes mellitus
#224Process for producing phosphorus modified zeolite catalysts
#225METHOD OF BIOBASED CHEMICAL PRODUCTION FROM CRUDE BIOGLYCERIN OF RECYCLED OIL, GREASE, AND FAT ORIGIN
#226Synthesis of DME using a fluid pluralized bed reactor
#227Process for the preparation of dimethyl ether
#228Processes for preparing polytrimethylene ether glycol
#229Conversion of carbon containing feedstock
#230PROCESS TO PREPARE AN ETHANOL-DERIVATE
#231Method for making dimethyl ether by reactive-distillation
#232MANUFACTURE OF DIMETHYL ETHER FROM CRUDE METHANOL
#233Process for making polyglycerol ethers of fatty alcohols
#234PROCESS FOR THE PREPARATION OF AN ALLYL ALKYL ETHER BY CATALYTIC ALLYLATION
#235Condensation of alcohols for biofuel production
#236Process for producing acetic acid and dimethyl ether using a zeolite catalyst
#237Process for the preparation of polyalkylene ether glycol
#238Process for preparing dimethyl ether and process for preparing a mixture of dimethyl ether and methanol
#239Fluid-sparged helical channel reactor and associated methods
#240Dual-bed catalytic distillation tower and method for preparing dimethyl ether using the same
#241Single loop multistage fuel production
#242Conversion of carbon dioxide to methanol using bi-reforming of methane or natural gas
#243Process to prepare olefins from aliphatic alcohols
#244Method and system for producing methanol and dimethyl ether
#245Production of biodiesel fuels which are low in glycerin and sulfur
#246Fluorinated aromatic bis(acyl)-containing compounds and polyesters prepared therefrom
#247Branched chain-containing aromatic compound
#248CATALYTIC REACTIONS USING IONIC LIQUIDS
#249Phosphine ligands for catalytic reactions
#250Hydro(chloro)fluoroolefins and Method for Preparation Thereof
#251Method and device for producing dimethyl ether from methanol
#252Polyglycerol esters and their use
#253Process of producing polyglycerol from crude glycerol
#254INTERFACES THAT ELIMINATE NON-SPECIFIC ADSORPTION, AND INTRODUCE SPECIFIC INTERACTIONS
#255Method for preparing a mixture of biofuels
#256METHOD AND DEVICE FOR PRODUCING ENERGY, DME (DIMETHYL ETHER) AND BIO-SILICA USING CO2-NEUTRAL BIOGENIC REACTIVE AND INERT INGREDIENTS
#257MONOETHERIFIED DIOLS OF DIAMONDOIDS
#258Process of producing polyglycerol from crude glycerol
#259PROCESS TO PREPARE AN OLEFIN-CONTAINING PRODUCT OR A GASOLINE PRODUCT
#260Method of Fabricating Cu-Zn-Al Catalyst for Producing Methanol and Dimethyl Ether
#261Process for making diethyl ether from acetic acid
#262Production and composition of glycerol based polyols
#263MITIGATING OR ELIMINATING THE CARBON FOOTPRINT OF HUMAN ACTIVITIES
#264Polytrimethylene ether glycol or copolymers thereof having improved color and processes for their preparation
#265Process for producing dimethyl ether from methanol
#266Method for Producing a Latent Heat Storage Material and Dialkyl Ether as a Latent Heat Storage Material
#267Conversion of carbon dioxide to methanol using bi-reforming of methane or natural gas
#268Process for the production of dimethyl ether
#269Process for the Preparation of Primary Alkyl Glycerol Ethers Useful as Biofuel Additive from Glycerol
#270Process for the conversion of alcohol (s) into alcohol (s) with increased carbon-chain
#271Medium oil used for a synthesis reaction, process for preparing dimethyl ether and process for preparing a mixture of dimethyl ether and methanol
#272Alcohol Dehydration
#273Rendering natural gas as an environmentally carbon dioxide neutral fuel and a regenerative carbon source
#274Rendering petroleum oil as an environmentally carbon dioxide neutral source material for fuels, derived products and as a regenerative carbon source
#275Rendering coal as an environmentally carbon dioxide neutral fuel and a regenerative carbon source
#276Method for producing polyoxyalkylene derivative and polyoxyalkylene derivative
#277Process for making a composition comprising at least two different dialkyl ethers
#278Process for preparing dimethyl ether
#279Functionalized ionic liquids, and methods of use thereof
#280PROCESS FOR MAKING DIBUTYL ETHERS FROM ISOBUTANOL
#281PROCESSES FOR MAKING DIBUTYL ETHERS FROM 2-BUTANOL
#282PROCESS FOR MAKING DIALKYL ETHERS FROM ALCOHOLS
#283PROCESSES FOR MAKING DIALKYL ETHERS FROM ALCOHOLS
#284PROCESSES FOR MAKING DIALKYL ETHERS FROM ALCOHOLS
#285PROCESSES FOR MAKING DIBUTYL ETHERS FROM ISOBUTANOL
#286Process for the production of acrylic and methacrylic esters of poly(trimethylene ether) glycol
#287Selective oxidative conversion of methane to methanol, dimethyl ether and derived products
#288Functionalized Ionic Liquids, and Methods of Use Thereof
#289Condensation reactions for polyols
#290Alkoxylations of High Melting Point Substrates in Ketone Solvents
#291Fluidized catalytic process for production of dimethyl ether from methanol
#292Catalytic conversion of liquid alcohols to liquid ethers and oxygenated gasoline
#293ENERGY-EFFECTIVE PROCESS FOR CO-PRODUCING ETHYLENE AND DIMETHYL ETHER
#294Producing methanol and its products exclusively from geothermal sources and their energy
#295CONVERSION OF GLYCEROL TO NAPHTHA-RANGE OXYGENATES
#296Dehydration of methanol to dimethyl ether using catalysts based on a zeolite supported on silicon carbide
#297Catalytic system and process for direct synthesis of dimethyl ether from synthesis gas
#298Efficient and selective chemical recycling of carbon dioxide to methanol, dimethyl ether and derived products
#299MITIGATING OR ELIMINATING THE CARBON FOOTPRINT OF HUMAN ACTIVITIES
#300Methods of converting methanol feedstock to olefins