The document describes a process for preparing alcohols by hydrogenating carboxylic acids or esters at elevated temperature and pressure in the presence of catalysts containing oxides of group IV and VI elements. Specifically, the hydrogenation is carried out at 250-400°C and 5-100 bar in the presence of primary or secondary alcohols, with a molar hydrogen to alcohol ratio of at most 800.
The document describes organopolysiloxane nitriles, which are novel compounds that can be used as intermediates to produce amide and acid substituted polysiloxanes. The organopolysiloxane nitriles have the general formula R'RNCCH(CH2)xSiO, where R' is a methyl or hydrogen, N has a value of 1 to 3, and R is a monovalent hydrocarbon radical without aliphatic unsaturation. The compounds can be prepared by reacting an unsaturated nitrile with a chlorosilane or by condensing a chloromethylalkoxysilane with an ethyl cyanoacetate. Co-polymers of the silox
This document describes a British patent from 1957 for an improved device for measuring distances along lines on maps. The device uses a plurality of rotatably enclosed drums connected end-to-end in a rigid housing. One end of the housing has a map-engaging wheel geared to the adjacent drum. Adjacent drums are interconnected with lost-motion couplings so that the second drum of a pair only rotates after the first drum reaches a predetermined angle of rotation. Each drum has calibration or scale markings that register with a window or slit in the housing. The drums preferably carry decimal scale numerals that successively register with the window to directly indicate long distances.
This document describes amino derivatives of acrylic and methacrylic acids of the formula CH2=C-COO-A-NR'CN, where R is H or CH3, R' is an alkyl, cycloalkyl, aryl, or aralkyl group, and A is a C2-C4 alkylene group with at least two carbons between oxygen and nitrogen. Methods are provided for preparing these monomeric compounds and polymers or copolymers made from them. Illustrative examples show the preparation of various N-cyano-N-alkylaminoalkyl acrylates and methacrylates.
This document describes amino derivatives of acrylic and methacrylic acids, including their preparation and properties. Specifically, it provides new amino derivatives of the formula CH2=C-COO-A-NR'R"CN where R is hydrogen or methyl, R' is an alkyl, cycloalkyl, aryl or aralkyl group, and A is a C2-C4 alkylene group having at least two carbon atoms between oxygen and nitrogen. It describes methods of preparing these monomeric compounds and polymers or copolymers made from them. The methods include reacting cyanogen chloride or bromide with compounds having the formula CH2=C(R)COO-A-NHR' in the presence
The document describes GB786014 (A), a patent from 1957 regarding improvements to the polymerization of normally gaseous mono-olefins. Specifically, it summarizes the patent as relating to a process that converts normally gaseous mono-olefins like ethylene and propylene to high molecular weight solid polymers through contact with a catalyst containing an oxide of a metal from Group 5a or 6a of the periodic table, and an aluminum compound co-catalyst of the general formula AIRx, where R is hydrogen or a monovalent hydrocarbon radical. The polymerization can be carried out at temperatures between 50-230°C and pressures from atmospheric to 15,000-30,000 psi
This document describes several methods for quantitatively analyzing the components of organic compounds:
1. Carbon and hydrogen are estimated by burning the compound in oxygen and measuring the amount of water and carbon dioxide produced.
2. Nitrogen can be estimated using the Dumas or Kjeldahl methods, which involve heating the compound to produce nitrogen gas or ammonia for measurement.
3. Other elements like halogens, sulfur, phosphorus, and oxygen can be estimated through various oxidation and precipitation reactions to form compounds that can be weighed or titrated. Formulas are provided for calculating the percentage of each element from the experimental results.
Group #7 from COMSATS Institute of Information Technology presented on the chemistry of petrochemical processes related to ethylene. They discussed ethylene properties, major products including ethylene oxide and acetaldehyde. For ethylene oxide, they described its production through the controlled oxidation of ethylene over a silver catalyst. For acetaldehyde, they explained its production through both older ethanol oxidation methods and newer ethylene oxidation using a homogeneous Wacker catalyst at 130°C. They concluded that ethylene is a very important raw material for chemicals and polymers.
This document describes a proposed project to build a methane to acetic acid plant in Bangladesh. The plant would produce 300 tons per day of 99% acetic acid and 450 tons per day of 91.5% methanol using methane from a local natural gas field as the raw material. Several processes for converting methane to methanol and methanol to acetic acid are considered, including catalytic, thermal cracking, photo-catalytic, and biological methods. The document selects the ICI process for methane to methanol conversion and the Cativa process for methanol to acetic acid conversion.
The document describes organopolysiloxane nitriles, which are novel compounds that can be used as intermediates to produce amide and acid substituted polysiloxanes. The organopolysiloxane nitriles have the general formula R'RNCCH(CH2)xSiO, where R' is a methyl or hydrogen, N has a value of 1 to 3, and R is a monovalent hydrocarbon radical without aliphatic unsaturation. The compounds can be prepared by reacting an unsaturated nitrile with a chlorosilane or by condensing a chloromethylalkoxysilane with an ethyl cyanoacetate. Co-polymers of the silox
This document describes a British patent from 1957 for an improved device for measuring distances along lines on maps. The device uses a plurality of rotatably enclosed drums connected end-to-end in a rigid housing. One end of the housing has a map-engaging wheel geared to the adjacent drum. Adjacent drums are interconnected with lost-motion couplings so that the second drum of a pair only rotates after the first drum reaches a predetermined angle of rotation. Each drum has calibration or scale markings that register with a window or slit in the housing. The drums preferably carry decimal scale numerals that successively register with the window to directly indicate long distances.
This document describes amino derivatives of acrylic and methacrylic acids of the formula CH2=C-COO-A-NR'CN, where R is H or CH3, R' is an alkyl, cycloalkyl, aryl, or aralkyl group, and A is a C2-C4 alkylene group with at least two carbons between oxygen and nitrogen. Methods are provided for preparing these monomeric compounds and polymers or copolymers made from them. Illustrative examples show the preparation of various N-cyano-N-alkylaminoalkyl acrylates and methacrylates.
This document describes amino derivatives of acrylic and methacrylic acids, including their preparation and properties. Specifically, it provides new amino derivatives of the formula CH2=C-COO-A-NR'R"CN where R is hydrogen or methyl, R' is an alkyl, cycloalkyl, aryl or aralkyl group, and A is a C2-C4 alkylene group having at least two carbon atoms between oxygen and nitrogen. It describes methods of preparing these monomeric compounds and polymers or copolymers made from them. The methods include reacting cyanogen chloride or bromide with compounds having the formula CH2=C(R)COO-A-NHR' in the presence
The document describes GB786014 (A), a patent from 1957 regarding improvements to the polymerization of normally gaseous mono-olefins. Specifically, it summarizes the patent as relating to a process that converts normally gaseous mono-olefins like ethylene and propylene to high molecular weight solid polymers through contact with a catalyst containing an oxide of a metal from Group 5a or 6a of the periodic table, and an aluminum compound co-catalyst of the general formula AIRx, where R is hydrogen or a monovalent hydrocarbon radical. The polymerization can be carried out at temperatures between 50-230°C and pressures from atmospheric to 15,000-30,000 psi
This document describes several methods for quantitatively analyzing the components of organic compounds:
1. Carbon and hydrogen are estimated by burning the compound in oxygen and measuring the amount of water and carbon dioxide produced.
2. Nitrogen can be estimated using the Dumas or Kjeldahl methods, which involve heating the compound to produce nitrogen gas or ammonia for measurement.
3. Other elements like halogens, sulfur, phosphorus, and oxygen can be estimated through various oxidation and precipitation reactions to form compounds that can be weighed or titrated. Formulas are provided for calculating the percentage of each element from the experimental results.
Group #7 from COMSATS Institute of Information Technology presented on the chemistry of petrochemical processes related to ethylene. They discussed ethylene properties, major products including ethylene oxide and acetaldehyde. For ethylene oxide, they described its production through the controlled oxidation of ethylene over a silver catalyst. For acetaldehyde, they explained its production through both older ethanol oxidation methods and newer ethylene oxidation using a homogeneous Wacker catalyst at 130°C. They concluded that ethylene is a very important raw material for chemicals and polymers.
This document describes a proposed project to build a methane to acetic acid plant in Bangladesh. The plant would produce 300 tons per day of 99% acetic acid and 450 tons per day of 91.5% methanol using methane from a local natural gas field as the raw material. Several processes for converting methane to methanol and methanol to acetic acid are considered, including catalytic, thermal cracking, photo-catalytic, and biological methods. The document selects the ICI process for methane to methanol conversion and the Cativa process for methanol to acetic acid conversion.
The document summarizes the steps taken in a synthesis of thymol from para-cymene. The key steps involve:
1. Nitrating para-cymene to form nitrocymene, then reducing nitrocymene to form cymidine.
2. Sulfonating cymidine to form cymidine-sulfonic acid.
3. Converting cymidine-sulfonic acid to diazocymene-sulfonic acid, then to cymylhydrazine-p-sulfonic acid upon treatment with sodium bisulfite.
4. Removing the hydrazine group from cymylhydrazine-p-
1) The document describes new therapeutically active derivatives of barbituric acid having the general formula bicyclo l 1 2 3 l octenyl-( 2)-C-X C = A OC-N-H.
2) Eight examples are provided for preparing various bicyclo-octenyl barbituric acids and their derivatives through condensation reactions between functional derivatives of bicyclo-octenyl cyanoacetic or malonic acid and urea or related compounds.
3) The resulting products include 5-(bicyclo-octenyl)-5-methyl barbituric acid and salts thereof, which form colorless needles with a melting point of 266 C.
This is a summary of the topic "Alcohols" in the GCE O levels subject: Chemistry. Students taking either the combined science (chemistry/physics) or pure chemistry will find this useful. These slides are prepared according to the learning outcomes required by the examinations board.
Alcohols are compounds containing a hydroxyl (-OH) group. They are named based on the carbon chain and position of the hydroxyl group. Alcohols can be produced through fermentation of sugars by yeast or through hydration of alkenes with steam. They have low boiling points, are colorless and volatile. Alcohols can undergo combustion, oxidation, and dehydration reactions. Ethanol is used as a fuel and solvent, while alcohols in general have industrial and medical uses.
Aldehydes contain a carbonyl group with at least one hydrogen attached to the carbonyl carbon. They are intermediate in properties between alcohols and alkanes, with higher boiling points than alkanes due to dipole-dipole interactions. Aldehydes are readily oxidized to carboxylic acids and reduced to primary alcohols. They react with alcohols to form hemiacetals and acetals through addition reactions. Hemiacetals contain both a hydroxyl and alkoxy group bonded to the same carbon.
1) The document describes novel pyrrolidine compounds called 3,3-dimethyl-2,5-dioxopyrrolidine-4-propionic acids and their derivatives.
2) These compounds can be prepared by reacting 4-methylpentane-1,3,4-tricarboxylic acid compounds with ammonium hydroxide and then heating the resulting ammonium salt.
3) Specific examples are provided for preparing starting materials and converting them to the target 3,3-dimethyl-2,5-dioxopyrrolidine-4-propionic acid compounds.
1) The document describes novel pyrrolidine compounds called 3,3-dimethyl-2,5-dioxopyrrolidine-4-propionic acids and their derivatives.
2) These compounds can be prepared by reacting 4-methylpentane-1,3,4-tricarboxylic acid compounds with ammonium hydroxide and then heating the resulting ammonium salt.
3) Specific examples are provided for preparing starting materials and converting them to the target 3,3-dimethyl-2,5-dioxopyrrolidine-4-propionic acid compounds.
This document provides an overview of the polymerization process used in petroleum refining to produce high octane gasoline. Polymerization involves combining light olefin gases like ethylene and propylene into higher molecular weight hydrocarbons using a phosphoric acid catalyst. It was widely used in the 1930s-40s but replaced by alkylation after WWII before making a comeback due to leaded gasoline phase outs. Polymerization occurs at 300-450°F and 200-1200 psi to polymerize olefins into gasoline blending components with octane numbers of 83-97. Safety risks include fires and runaway reactions due to cooling water loss or corrosion from phosphoric acid exposure.
Reserpine(Structure Elucidation, Extraction and Isolation)Mohammad Khalid
Reserpine(Structure Elucidation, Extraction and Isolation)
Introduction
Constitution of reserpine
Structure of Reserpic acid
Structure of Yobyrine
Synthesis of Yobyrine
Structure of Reserpine
Synthesis of Reserpine
Classification
Extraction
Isolation:
Identification test
Mode of Action
This document provides guidelines for naming aldehydes and ketones based on their structure. It explains that the name is comprised of a prefix, root, and ending. The prefix indicates any substituents and their location. The root is based on the longest carbon chain containing the carbonyl group. The ending "-al" denotes an aldehyde, while "-one" denotes a ketone. It provides examples of applying these rules to name different aldehydes and ketones based on their structure diagrams.
This document describes a process for preparing polymers or resinous oils from selected steam cracked distillate streams. Specifically, it involves:
1) Distilling the C5 fraction from a steam cracked naphtha stream and thermally treating it to dimerize cyclopentadiene, then separating the dimers.
2) Polymerizing the remaining distillate fraction using a Friedel-Crafts catalyst such as aluminum chloride or boron fluoride at temperatures from -200°F to 150°F to produce resinous oils or resins.
3) The resulting products can be used in paints, varnishes, printing inks, or further modified.
The key process variables in an alkylation unit are reaction temperature, acid strength, isobutane concentration, and olefin space velocity. Reaction temperature and acid strength affect product quality, with lower temperatures and appropriate acid strengths producing higher quality alkylate. Isobutane concentration is generally expressed as the isobutane to olefin ratio, with higher ratios increasing octane number and yield. Olefin space velocity also affects product quality, with lower velocities increasing octane number. Sulfuric acid and hydrofluoric acid are the primary catalysts used. Olefins and isobutane are the main feedstocks.
Carboxylic acids have the general formula R-COOH. They can be synthesized through oxidation of alcohols and arenes, carbonation of Grignard reagents, and hydrolysis of nitriles. As acids, they ionize in water and react with bases. They can be converted to functional derivatives like acid chlorides, esters, and amides. They undergo reactions such as reduction, alpha-halogenation, and electrophilic aromatic substitution. Spectroscopically, they show a C=O stretch around 1700 cm-1 and a COOH proton around 12 ppm.
Amine gas treating is a process that uses aqueous solutions of alkanolamines like monoethanolamine to remove hydrogen sulfide and carbon dioxide from gases. The process involves an absorber unit where the amine solution absorbs the acid gases from the sour gas stream, producing a sweetened gas. The rich amine is then regenerated in a stripper, producing a lean amine that is recycled and an acid gas stream that is usually sent to a Claus process to produce elemental sulfur. Common amines used include MEA, DEA, and MDEA.
This document summarizes four organic chemistry reactions:
1. The Meerwein-Pondorf-Verley reduction uses aluminum iso-propoxide to reduce carbonyl compounds to alcohols.
2. The Oppenauer oxidation is the reverse of the MPV reduction and uses aluminum alkoxides to oxidize secondary alcohols to ketones.
3. The Beckmann rearrangement converts oximes to N-substituted amides using acidic catalysts like phosphorus pentachloride.
4. The Michael reaction involves the 1,4-addition of enolates to α,β-unsaturated carbonyls to form 1,5-dicarbonyl products
The document discusses carboxylic acids, esters, and amides. It begins by defining key terms like carbonyl group and discusses the importance of carboxylic acids in nature. Examples of important carboxylic acids are given. The structures of carboxylic acids and their derivatives are explained. Nomenclature rules for systematically naming carboxylic acids, esters, and amides according to IUPAC are provided with examples.
The document summarizes the steps taken in a synthesis of thymol from para-cymene. The key steps involve:
1. Nitrating para-cymene to form nitrocymene, then reducing nitrocymene to form cymidine.
2. Sulfonating cymidine to form cymidine-sulfonic acid.
3. Converting cymidine-sulfonic acid to diazocymene-sulfonic acid, then to cymylhydrazine-p-sulfonic acid upon treatment with sodium bisulfite.
4. Removing the hydrazine group from cymylhydrazine-p-
1) The document describes new therapeutically active derivatives of barbituric acid having the general formula bicyclo l 1 2 3 l octenyl-( 2)-C-X C = A OC-N-H.
2) Eight examples are provided for preparing various bicyclo-octenyl barbituric acids and their derivatives through condensation reactions between functional derivatives of bicyclo-octenyl cyanoacetic or malonic acid and urea or related compounds.
3) The resulting products include 5-(bicyclo-octenyl)-5-methyl barbituric acid and salts thereof, which form colorless needles with a melting point of 266 C.
This is a summary of the topic "Alcohols" in the GCE O levels subject: Chemistry. Students taking either the combined science (chemistry/physics) or pure chemistry will find this useful. These slides are prepared according to the learning outcomes required by the examinations board.
Alcohols are compounds containing a hydroxyl (-OH) group. They are named based on the carbon chain and position of the hydroxyl group. Alcohols can be produced through fermentation of sugars by yeast or through hydration of alkenes with steam. They have low boiling points, are colorless and volatile. Alcohols can undergo combustion, oxidation, and dehydration reactions. Ethanol is used as a fuel and solvent, while alcohols in general have industrial and medical uses.
Aldehydes contain a carbonyl group with at least one hydrogen attached to the carbonyl carbon. They are intermediate in properties between alcohols and alkanes, with higher boiling points than alkanes due to dipole-dipole interactions. Aldehydes are readily oxidized to carboxylic acids and reduced to primary alcohols. They react with alcohols to form hemiacetals and acetals through addition reactions. Hemiacetals contain both a hydroxyl and alkoxy group bonded to the same carbon.
1) The document describes novel pyrrolidine compounds called 3,3-dimethyl-2,5-dioxopyrrolidine-4-propionic acids and their derivatives.
2) These compounds can be prepared by reacting 4-methylpentane-1,3,4-tricarboxylic acid compounds with ammonium hydroxide and then heating the resulting ammonium salt.
3) Specific examples are provided for preparing starting materials and converting them to the target 3,3-dimethyl-2,5-dioxopyrrolidine-4-propionic acid compounds.
1) The document describes novel pyrrolidine compounds called 3,3-dimethyl-2,5-dioxopyrrolidine-4-propionic acids and their derivatives.
2) These compounds can be prepared by reacting 4-methylpentane-1,3,4-tricarboxylic acid compounds with ammonium hydroxide and then heating the resulting ammonium salt.
3) Specific examples are provided for preparing starting materials and converting them to the target 3,3-dimethyl-2,5-dioxopyrrolidine-4-propionic acid compounds.
This document provides an overview of the polymerization process used in petroleum refining to produce high octane gasoline. Polymerization involves combining light olefin gases like ethylene and propylene into higher molecular weight hydrocarbons using a phosphoric acid catalyst. It was widely used in the 1930s-40s but replaced by alkylation after WWII before making a comeback due to leaded gasoline phase outs. Polymerization occurs at 300-450°F and 200-1200 psi to polymerize olefins into gasoline blending components with octane numbers of 83-97. Safety risks include fires and runaway reactions due to cooling water loss or corrosion from phosphoric acid exposure.
Reserpine(Structure Elucidation, Extraction and Isolation)Mohammad Khalid
Reserpine(Structure Elucidation, Extraction and Isolation)
Introduction
Constitution of reserpine
Structure of Reserpic acid
Structure of Yobyrine
Synthesis of Yobyrine
Structure of Reserpine
Synthesis of Reserpine
Classification
Extraction
Isolation:
Identification test
Mode of Action
This document provides guidelines for naming aldehydes and ketones based on their structure. It explains that the name is comprised of a prefix, root, and ending. The prefix indicates any substituents and their location. The root is based on the longest carbon chain containing the carbonyl group. The ending "-al" denotes an aldehyde, while "-one" denotes a ketone. It provides examples of applying these rules to name different aldehydes and ketones based on their structure diagrams.
This document describes a process for preparing polymers or resinous oils from selected steam cracked distillate streams. Specifically, it involves:
1) Distilling the C5 fraction from a steam cracked naphtha stream and thermally treating it to dimerize cyclopentadiene, then separating the dimers.
2) Polymerizing the remaining distillate fraction using a Friedel-Crafts catalyst such as aluminum chloride or boron fluoride at temperatures from -200°F to 150°F to produce resinous oils or resins.
3) The resulting products can be used in paints, varnishes, printing inks, or further modified.
The key process variables in an alkylation unit are reaction temperature, acid strength, isobutane concentration, and olefin space velocity. Reaction temperature and acid strength affect product quality, with lower temperatures and appropriate acid strengths producing higher quality alkylate. Isobutane concentration is generally expressed as the isobutane to olefin ratio, with higher ratios increasing octane number and yield. Olefin space velocity also affects product quality, with lower velocities increasing octane number. Sulfuric acid and hydrofluoric acid are the primary catalysts used. Olefins and isobutane are the main feedstocks.
Carboxylic acids have the general formula R-COOH. They can be synthesized through oxidation of alcohols and arenes, carbonation of Grignard reagents, and hydrolysis of nitriles. As acids, they ionize in water and react with bases. They can be converted to functional derivatives like acid chlorides, esters, and amides. They undergo reactions such as reduction, alpha-halogenation, and electrophilic aromatic substitution. Spectroscopically, they show a C=O stretch around 1700 cm-1 and a COOH proton around 12 ppm.
Amine gas treating is a process that uses aqueous solutions of alkanolamines like monoethanolamine to remove hydrogen sulfide and carbon dioxide from gases. The process involves an absorber unit where the amine solution absorbs the acid gases from the sour gas stream, producing a sweetened gas. The rich amine is then regenerated in a stripper, producing a lean amine that is recycled and an acid gas stream that is usually sent to a Claus process to produce elemental sulfur. Common amines used include MEA, DEA, and MDEA.
This document summarizes four organic chemistry reactions:
1. The Meerwein-Pondorf-Verley reduction uses aluminum iso-propoxide to reduce carbonyl compounds to alcohols.
2. The Oppenauer oxidation is the reverse of the MPV reduction and uses aluminum alkoxides to oxidize secondary alcohols to ketones.
3. The Beckmann rearrangement converts oximes to N-substituted amides using acidic catalysts like phosphorus pentachloride.
4. The Michael reaction involves the 1,4-addition of enolates to α,β-unsaturated carbonyls to form 1,5-dicarbonyl products
The document discusses carboxylic acids, esters, and amides. It begins by defining key terms like carbonyl group and discusses the importance of carboxylic acids in nature. Examples of important carboxylic acids are given. The structures of carboxylic acids and their derivatives are explained. Nomenclature rules for systematically naming carboxylic acids, esters, and amides according to IUPAC are provided with examples.
El documento enumera cuatro posiciones clave en la industria hotelera: recepcionista o front desk, botones o bell boy, jefe de recepción y ama de llaves.
Facilities Management at BYU-Idaho has low visibility and customers lack knowledge about the organization, leading to confusing customer relations. Feedback from informed customers who understand where to go, who to talk to, and what problems Facilities Management addresses has been extremely positive. The BYU-Idaho Learning Model aims to build testimonies of the gospel, provide a quality and diverse education, prepare students for lifelong learning and employment, and maintain a wholesome environment.
The document discusses why studying management is important, noting that management skills are valuable for both career and personal success. It also outlines several new challenges facing managers today, such as globalization, technology, diversity, and knowledge management, and explains the roles and responsibilities of managers in organizations.
This document discusses smart phone apps for agriculture. It begins by listing the major operating systems - iOS, Android, Windows, and Blackberry. When choosing a system, iOS is easy to use but limited to Apple devices, Android has a wide variety of devices and prices, Windows is new to apps, and Blackberry is trying to make a comeback. It then covers specifications like screen size, memory, connectivity and battery life. Accessories like cases and screen protectors are discussed. Applications available include email, calendars, and some manufacturer-specific apps. The document demos basic uses and asks how attendees use smart devices. It finishes with an overview of using cloud storage and sharing files across devices.
Corporate class mutual funds provide tax benefits compared to traditional mutual funds. Investments within a corporate class structure are treated as a single entity for tax purposes, allowing investors to rebalance portfolios without immediate tax consequences. Distributions from corporate class funds are more tax-efficient, consisting primarily of capital gains and Canadian dividends taxed at a lower rate than regular income. This tax treatment leaves more money growing in the investor's account compared to traditional mutual funds. Corporate class is suitable for individual investors with non-registered funds who seek tax-efficient rebalancing and cash flow in retirement.
The ideological problematic of (big) data and Social InformaticsMichael Marcinkowski
The document discusses the ideological issues surrounding big data and social informatics. It notes that to understand the social impacts of technology, one needs a theory of how systems can influence individuals and groups. It also states that the topics of social informatics can be conceptual constructs rather than just empirical facts. The document examines the movements of computerization and dataization, and describes social informatics as both empirical and critical in its approach to big data. It briefly discusses the concepts of empiricism, ambient literature, and peak empiricism in relation to data.
El documento presenta una serie de modelos y teorías sobre el comportamiento del consumidor y la toma de decisiones. Describe conceptos como la motivación, la percepción, el aprendizaje y la memoria del consumidor. También analiza factores que influyen en la decisión de compra como las características personales, sociales y culturales del consumidor. Finalmente, resume diferentes modelos y teorías sobre el proceso de decisión del consumidor.
The document discusses the goals of a human rights blog, including publishing posts three times a week to increase awareness, promote events, and encourage activism. It provides statistics on current visitor numbers and analyzes traffic. Suggestions for improving the blog include guest posting, additional pages, upgrading to a new version of WordPress for better social sharing and SEO plugins, and expanding use of social media. The document concludes by asking for any other comments or concerns.
The United Nations has acknowledged that it previously overestimated the number of hungry people worldwide. A new study shows about 870 million people are undernourished, which the UN calls "unacceptable". While the UN once said over 1 billion people suffered from hunger, it now believes progress against hunger has been better than thought, though nearly 870 million people still lack adequate food, over 12% of the global population. The situation is particularly dire in Africa, where more people are becoming hungry.
The document analyzes a Toyota Camry television commercial from 2012. It uses celebrities, humor, and attractive models to appeal to consumers. Specifically, it features Kelly Clarkson to increase credibility and each model is given screen time to provide testimonials. The ad aims to show that the Toyota Camry meets high expectations for quality and features the newest Entune technology for streaming media, navigation, and connectivity. The target audience is ages 18 and older who want updated features in a new car model.
O documento discute os conceitos de transparência, resiliência e segurança em sistemas distribuídos. São descritos tipos de transparência como localização, migração e replicação que ocultam aspectos da distribuição dos recursos dos usuários. Também são abordados conceitos como disponibilidade, tolerância a falhas e medidas para proteger a segurança dos dados e recursos.
This document describes an e-Education project for Gaza that aims to provide teacher training for learning difficulties via teleconference due to the blockade of Gaza. The project will use a teleconference system facilitated by the UNRWA to allow direct training of teachers on learning difficulties without physical travel. It has official partners including Hitotsubashi University for infrastructure, ReadyFor for crowd-funding, and the University of Jordan for human resources. The project aims to be non-profit and financially sustainable through donations and future DVD sales. It has already won a DEC award and seeks short-term funding and expertise from the DEC community to save children in Gaza through this distance learning solution.
This document discusses smart phone apps for agriculture. It begins by listing the major operating systems - iOS, Android, Windows, and Blackberry. When choosing a system, iOS is easy to use but limited to Apple devices, Android has a wide variety of devices and prices, Windows is new to apps, and Blackberry is trying to make a comeback. It discusses specifications like screen size, memory, connectivity and battery life. Accessories like cases and screen protectors are also covered. The document demonstrates basic app uses and how the cloud can be used to access files across devices. It concludes by asking for questions and sharing.
Lecture 4 (H2SO4), it is manufacturing and descriptionnewarqadir51
This document discusses the production of sulfuric acid through the contact process. It begins by describing the properties of sulfuric acid and how it is sold. It then discusses how earlier plants were simpler but modern plants recover energy through cogeneration. The contact process is described, including the exothermic reaction of SO2 to SO3, how temperature and equilibrium affect conversion, and the multi-pass converter design. Catalyst materials and converter design are also covered. Finally, it briefly discusses how SO3 is absorbed into sulfuric acid in the absorption tower to form oleum.
Lecture 4 (H2SO4), it is manufacturing and descriptionnewarqadir51
This document discusses the production of sulfuric acid through the contact process. It begins by describing the properties of sulfuric acid and how it is sold. It then discusses how earlier plants were simpler but modern plants recover energy through cogeneration. The contact process is described, including the exothermic reaction of SO2 to SO3, how temperature and equilibrium affect conversion, and the multi-pass converter design. Catalyst materials and converter design are also covered. Finally, it briefly discusses how SO3 is absorbed into sulfuric acid in the absorption tower to form oleum.
PFOS : perfluoro-octanesulfonic acid
PFOA : perfluoro-octanoic acid
HFPO-DA : hexafluoropropylene oxide dimer acid
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The “Handbook for Chemical Engineers and Entrepreneurs” is part of Chemiprobe project that aims to visualize the chemical value chain and turn chemical engineers into «chempreneurs» pursuing clear opportunities in commodities and fine chemicals.
https://www.chemiprobe.com
1) The document describes improvements to packaging containers that provide reinforcement and strength.
2) The containers have a non-metallic shell and bottom each with a corrosion-resistant thin inner lining that is partly inside and partly outside the container.
3) The shell has an outer reinforcing metal covering that is folded together with the outer parts of the linings to seal the container while keeping the bottom and shell unfolded.
Removal of Coke during Steam Reforming of Ethanol over La-CoOx Catalystinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
The document summarizes several methods for manufacturing styrene monomer including dehydrogenation of ethylbenzene and oxidation of ethylbenzene to ethylbenzene hydroperoxide. It focuses on describing the oxidation and dehydrogenation processes, which are the two commercially important routes. For the oxidation process, it provides the chemical reactions and process details. For the dehydrogenation process, it discusses design considerations like operating pressure, temperature and catalyst selection and their impact on conversion and selectivity. It also covers styrene purification, safety measures and flowsheet of a typical styrene plant.
1) A 0.5 wt% Au/TiO2 catalyst is effective for the selective decomposition of formic acid to CO2 and water under SCR-relevant conditions using oxygen and water as oxidants.
2) In situ DRIFTS and kinetic studies show the reaction occurs via an oxidative dehydrogenation mechanism involving water-assisted activation of oxygen on the Au/TiO2 surface.
3) A kinetic model based on a hydroperoxy-mediated C-H bond cleavage rate-determining step agrees well with experimental results.
The alkylation process combines light iso-paraffins like isobutane with C3-C4 olefins in the presence of a strong acid catalyst like sulfuric or hydrofluoric acid. This produces a high-octane gasoline blending component called alkylate. Alkylation takes place at low temperatures and pressures and produces no aromatics or olefins. Key factors that affect the process include olefin type, isobutane concentration, acid strength, temperature, and space velocity. The goal is to maximize high-octane alkylate production while minimizing undesirable side products and acid consumption.
This document describes a flux composition for soldering metals like aluminum. It comprises a zinc chloride complex salt of a pyrazoline hydrohalide and a nitrogen salt component containing a hydrazine hydrohalide and/or ammonium halide. The flux composition has the advantages of being water-soluble and non-flammable, preventing metal hydrolysis at high temperatures. It provides an even coating of zinc on aluminum surfaces and improved solder joint strength. The document discusses methods of preparing the complex salts and flux compositions and provides examples of their use in soldering aluminum.
This document describes a flux composition for soldering metals like aluminum that comprises a zinc chloride complex salt of a pyrazoline hydrohalide and a nitrogen salt component like hydrazine hydrohalide or ammonium halide. The flux composition can be used in an inexpensive, non-flammable aqueous solution without the hydrolysis or oxide formation issues of other fluxes. The zinc chloride complex salts are new products that can be prepared by reacting zinc chloride with a pyrazoline hydrohalide compound obtained from an aldehyde or ketone.
This document describes a flux composition for soldering metals like aluminum that comprises a zinc chloride complex salt of a pyrazoline hydrohalide and a nitrogen salt component. The flux composition has advantages for production line soldering as it can be used in an inexpensive, non-flammable aqueous solution without hydrolysis or oxide formation issues seen in other fluxes. The document provides details on preparing the complex salt and flux, and examples demonstrating its effectiveness in soldering aluminum.
pdf on modern chemical manufacture (1).pdfgovinda pathak
1. Ammonia is produced by heating nitrogen and hydrogen gases at high pressures of 200-900 atm and temperatures of 380-450°C in the presence of an iron catalyst.
2. Sulfuric acid is produced via the contact process, which involves catalytically oxidizing sulfur dioxide to sulfur trioxide and absorbing it in concentrated sulfuric acid.
3. Sodium hydroxide is produced through the electrolysis of sodium chloride solution using a diaphragm cell, where chlorine gas forms at the anode and hydrogen gas forms at the cathode.
This document describes polyvinyl oxo-alkanals, which are produced by reacting polyvinyl alcohols with oxo-aldehydes derived from olefins. Oxo-aldehydes are highly branched aldehydes produced via an "oxo process" involving reaction of olefins with carbon monoxide and hydrogen in the presence of a cobalt catalyst. The resulting polyvinyl oxo-alkanals have superior physical properties like low brittle point and good tensile strength compared to products made with lower aldehydes. Experimental data shows that using an oxo-octaldehyde produces polyvinyl alkanal with better low-temperature properties than one made with a mixture of
The document discusses hydrogen production via steam reforming of natural gas. Steam reforming involves four steps: reforming, shift conversion, gas purification, and methanation. It produces hydrogen at high efficiency and is the lowest cost production method currently available. However, it also produces carbon dioxide as a byproduct. Newer steam reforming plants use pressure swing absorption to produce 99.99% pure hydrogen. While steam reforming is an efficient process, it contributes to carbon dioxide emissions, so methods to capture and store the CO2 are being investigated.
Prediction of Hydrogen Production from Imperata cylindrica Using Stoichiometr...Bemgba Nyakuma
This document summarizes a study that used stoichiometric and thermodynamic modeling to predict hydrogen production from the biomass Imperata cylindrica. The study found that steam reforming of bio-oils derived from I. cylindrica pyrolysis can produce hydrogen. Optimization analysis identified the optimal conditions as 1 atm pressure, 450-750°C temperature range, and a steam-to-feed ratio of 10, under which hydrogen yield varied between 0.6-0.7 by mass fraction. The effects of temperature, pressure, and steam-to-feed ratio on product composition were also examined.
This document provides an overview of 10 common chemical oxidation reactions that can convert alcohols to aldehydes and ketones. It describes the reagents, reaction mechanisms, advantages/disadvantages, and examples for each reaction, including Jones oxidation, PCC oxidation, Swern oxidation, Dess-Martin periodinane oxidation, MnO2 oxidation, Babler oxidation, Corey-Kim oxidation, Parikh-Doering oxidation, Fetizon oxidation, and Oppenauer oxidation.
This document summarizes research on hydrogen production from methanol decomposition over platinum and ceria-promoted platinum catalysts. Key findings include:
1) Increasing the platinum loading from 2% to 9% on alumina supports decreased the temperature for full methanol conversion from 405°C to 390°C.
2) Promoting platinum catalysts (5% and 9% loadings) with 10% ceria further decreased the full conversion temperature to 345°C and 315°C, respectively, with hydrogen selectivities over 99%.
3) The best performing catalyst was 9% Pt - 10% CeO2/Al2O3, achieving full conversion at 315°C with 99
This document describes a process for producing solid chloro-paraffins. It involves subjecting a mixture of high molecular weight paraffin hydrocarbons containing more than 20 carbon atoms with comparatively low molecular weight paraffin hydrocarbons containing 5-20 carbon atoms to chlorination. The low molecular weight hydrocarbons serve as solvents, allowing chlorination at higher temperatures to produce chloro-paraffins with relatively high melting points in a simple manner. Examples are provided chlorinating various paraffin mixtures to produce chloro-paraffins with melting points up to 108°C.
1. In a process for preparing alcohols by gas phase hydrogenation of carboxylic acids or esters thereof at elevated
temperature and elevated pressure in the presence of catalysts consisting of or comprising, as hydrogenating
components, oxides of main group VI and/or subgroup IV, the hydrogenation is carried out
a) at from 250° C. to 400° C. and from 5 bar to 100 bar in the presence of
b) primary or secondary alcohols, the molar hydrogen/alcohol ratio being at most 800.
IMAGES(1)
CLAIMS(10)
We claim:
1. In a process of preparing alcohols by gas phase hydrogenation of carboxylic acids or esters thereof at elevated
temperature and elevated pressure in the presence of a catalyst comprising, as hydrogenating components, oxides
of main group IV and/or subgroup IV, the improvement comprising hydrogenating said carboxylic acids or esters
a) at from 250° C. to 400° C. and from 5 bar to 100 bar in the presence of
b) primary and secondary alcohols which have been added to the reaction mixture, the molar hydrogen/added
alcohol ratio being at most 800.
2. A process as claimed in claim 1, wherein the molar hydrogen/added alcohol ratio is from 10 to 300.
3. A process as claimed in claim 1, wherein added aliphatic primary and/or secondary alcohols having 1 to 7 carbon
atoms are used.
4. A process as claimed in claim 1, wherein the alcohol added is methanol.
5. A process as claimed in claim 1, wherein from 0.5 to 10 mol of alcohol are added per mole of starting acid or
ester.
6. A process as claimed in claim 1 wherein the hydrogenation temperature is in the range from 300° C. to 350° C.
7. A process as claimed in claim 1, wherein the hydrogenation pressure is in the range from 25 to 50 bar.
8. A process as claimed in claim 1, wherein monoclinic, cubic and/or tetragonal zirconium dioxide is used.
9. A process as claimed in claim 8, wherein the zirconium dioxide used comprises from 50 to 100% of monoclinic
zirconium dioxide.
10. A process as claimed in claim 1, wherein the oxide catalyst comprises one or more lanthanide elements or one
or more elements selected from the group consisting of chromium, manganese, zinc, indium, tin, lead, vanadium
and iron.
DESCRIPTION
The present invention relates to a process for preparing alcohols by gas phase hydrogenation of carboxylic acids or
esters thereof at temperatures in the range from 250 to 400° C. and pressures in the range from 5 to 100 bar in the
presence of a catalyst predominantly comprising oxides of main group IV and subgroup IV, in particular zirconium
dioxide, and in the presence of alcohols.
DE-A-2 519 817 discloses hydrogenating carboxylic acids in the liquid phase, e.g. in the presence of catalysts
comprising rhenium and/or elements of subgroup VIII, to give alcohols. This generally requires high temperatures
of 200° C. and more and high pressures of 200 bar and more. In many cases, the catalysts cannot be regenerated
after their deactivation. If the catalysts contain large amounts of expensive metals, they have to be worked up to
recover the metals. If a workup is impossible for technical reasons or economically inappropriate, the spent
catalysts have to be landfilled, which is usually very costly.
DE-A-2 543 673 discloses hydrogenating carboxylic esters in the liquid phase or in the gas phase, especially in the
presence of catalysts comprising predominantly copper, such as copper chromite catalysts or catalysts comprising
copper, manganese and aluminum, to give alcohols. Ester hydrogenations in the liquid phase generally require, like
carboxylic acid hydrogenations, temperatures above 200° C. and pressures above 200 bar (WO 97/31882). Ester
hydrogenations in the gas phase may be carried out at hydrogenating temperatures around 200° C., but in this
case the reaction pressures drop to around 50 bar (U.S. Pat. No. 5,395,990).
Copper catalysts have the disadvantages of being sensitive to halogen contaminants in the starting materials and
of a limited catalyst life. Regeneration is impossible in most cases, so that here too a subsequent workup or
landfilling of the spent catalysts is necessary.
It is an object of the present invention to develop a process for preparing alcohols by hydrogenation of carboxylic
acids and their esters at very low pressure using hydrogenation catalysts which can be regenerated.
2. First attempts to achieve this are described in the patent literature:
For instance, according to EPA 285 786, carboxylic acids and their esters can be hydrogenated using, as hydrogen
transfer agent, alcohols instead of hydrogen, in particular alcohols having 2-6 carbon atoms, to give the
corresponding alcohols. Particular preference is given to isopropanol. The reaction is carried out at 250-450° C. and
atmospheric pressure in the gas or liquid phase in the presence of only partially dehydrated oxides of zirconium, of
titanium or of tin which are prepared, for example, by heating the corresponding hydroxides to temperatures of up
to 300° C.
EPA 585 053 discloses reacting carboxylic acids and derivatives thereof, such as esters, nitriles or amides, with
alcohols as hydrogen transfer agent in the gas or liquid phase in the presence of TiO2 /ZrO2 catalysts to give the
corresponding alcohols. Comparative Example 1 describes, inter alia, the conversion of n-decanoic acid into n-
decanol in the presence of only partially dehydrated zirconium hydroxide using isopropanol. At 300° C. and
atmospheric pressure, the n-decanol yield is reported as 34% (100% conversion).
According to JP 060 651 25 and JP 060 634 01, it is also possible to use bismuth oxide/ZrO2 and tin
oxide/ZrO2 catalysts instead of TiO2 /ZrO2 catalysts.
The use of alcohols as sole hydrogen donor has the disadvantage that the alcohols used for the hydrogenation are
converted into the corresponding ketones and hence lost. Since 2 mol of alcohol are used per mole of carboxylic
acid or ester and the above-cited literature does not mention the particularly economical methanol as a preferred
hydrogenating alcohol, this method is only useful for the preparation of highly priced alcohols.
Finally, JP 6 2108-832-A describes the gas phase hydrogenation of aliphatic and cycloaliphatic carboxylic acids
using hydrogen at 200-500° C. and atmospheric pressure in the presence of zirconium dioxide calcined at 300-950°
C. and doped with further elements, such as especially chromium to give the corresponding aldehydes and/or
alcohols.
In all representation examples of JP 6 2108-832, the hydrogenation is carried out using hydrogen at atmospheric
pressure. Cycloaliphatic carboxylic acids such as cyclohexanecarboxylic acid are predominantly converted into
cyclohexanecarbaldehyde with 98-99% selectivity using undoped zirconium dioxide at 300-350° C. and
atmospheric pressure (Examples 1-7). The aliphatic carboxylic acid pivalic acid yields pivalaldehyde with 100%
selectivity (Example 8). However, aliphatic carboxylic acids or their esters having two alpha hydrogen atoms are
converted into the corresponding alcohols or mixtures of alcohols and aldehydes in moderate yields and
selectivities using chromium-doped zirconium dioxide at 320° C. and atmospheric pressure. For instance, n-
heptanoic acid and methyl n-heptanoate produce n-heptanol in a yield of 62% or 33.9%, respectively (Examples 9
and 10), propionic acid (Example 14) and valeric acid (Example 16) produce n-propanol in a yield of 34.6% and only
traces of n-pentanol (37.1% n-valeraldehyde yield). Buteric acid (Example 15) produces a mixture of n-
butyraldehyde (15.8% yield) and n-butanol (30% yield).
JP 6 2108-832 A does not teach how to convert aliphatic and cycloaliphatic carboxylic acids and esters thereof into
the corresponding alcohols in high yields and selectivities. It is merely reported that more alcohol is obtained when
the number of carbon atoms in the carboxylic acid is small and that the amount of alcohol increases when the
reaction is carried out under pressure.
It is a particular object of the present invention to provide a process which does not have the disadvantages of the
abovementioned prior art and which makes it possible to prepare alcohols in very good yields at moderate
pressures.
We have found that this object is achieved according to the invention by a process for preparing alcohols by gas
phase hydrogenation of carboxylic acids or esters at elevated temperature and elevated pressure in the presence
of a catalyst consisting of or comprising, as hydrogenating components, oxides of main group IV and/or subgroup
IV, which comprises hydrogenating
a) at from 250° C. to 400° C. and from 5 bar to 100 bar in the presence of
b) primary or secondary alcohols, preferably methanol, the molar hydrogen/alcohol ratio being at most 800,
preferably from 10 to 300 and in particular from 20 to 200.
It was surprising that the specific combination of measures makes it possible to hydrogenate carboxylic acids and
esters thereof to give the corresponding alcohols in high yields and selectivities without requiring the high
pressures of JP 59106-431 and without dehydrogenating the added alcohols in amounts which would jeopardize
economic viability.
Starting materials which may be used in the process of the invention are saturated aliphatic, cycloaliphatic,
aromatic and heterocyclic mono- and polycarboxylic acids and esters thereof. Examples are acetic acid, n-hexanoic
3. acid, methyl n-hexanoate, n-decanoic acid, dimethyl valerate, cyclohexanecarboxylic acid, methyl
cyclohexanecarboxylate, dimethyl 1,4-cyclohexanedicarboxylate, n-butyl cyclohexanecarboxylate, terephthalic
acid, dimethyl terephthalate, methyl benzoate, benzoic acid, nicotinic acid, methyl nicotinate, tetrahydropyran-4-
carboxylic acid, methyl tetrahydropyran-4-carboxylate, methyl tetrahydrofuran-3-carboxylate or methyl furan-3-
carboxylate or methyl acrylate.
When esters are used as starting compounds, those containing C1 -C4 -alcohol components are preferred and those
containing C1 -and C2 -alcohol components are particularly preferred.
Useful alcohols are primary and secondary aliphatic, cycloaliphatic, aromatic or heterocyclic alcohols. They should
be easily volatilizable under the reaction conditions stated. Preference is given to aliphatic, primary and/or
secondary alcohols having 1 to 7 carbon atoms. Examples are methanol, ethanol, n-propanol, isopropanol, n-
butanol, sec-butanol, n-pentanol, cyclohexanol, benzyl alcohol. Particular preference is given to methanol, which is
not a preferred alcohol in the absence of hydrogen according to EP 585 053 and JP 6 2108-832.
Useful catalysts are oxides of main group IV and subgroup IV, particularly titanium dioxides, zirconium dioxides,
hafnium dioxides and tin oxides.
Preference is given to zirconium dioxides which may exist in the monoclinic, cubic or tetragonal crystal lattice
form. In particular, zirconium dioxide comprising 50-100%, preferably 60-98%, particularly preferably 70-95% of
monoclinic zirconium dioxide is used. These catalysts are commercially available or are obtainable in a
conventional manner (see e.g. Catal. Rev. Sci. Eng. 27, (1985), 341-372). They are obtained, for example, by
dissolving zirconium compounds, e.g. zirconium nitrate or zirconyl chloride, in water, precipitating zirconium
hydroxides using alkali metal hydroxides, alkaline earth metal hydroxides or ammonia, washing of the resulting
zirconium hydroxide hydrate, drying and calcining at 300-850° C.
The BET surface area of the zirconium dioxide used is typically from 5 to 150, preferably from 20 to 130, in
particular from 40 to 120, m2
/g, the term BET surface area as used herein meaning the catalyst surface area as
determined by the method of Brunauer, Emmett and Teller (see Z. Anal. Chem. 238 (1968), 187). The zirconium
dioxide should be neutral, i.e. contain very few basic and acidic sites. For instance, basic catalyst sites may lead to
yield losses, e.g. by aldol condensation of aldehyde intermediates. Acidic catalyst sites may reduce the yields of the
desired alcohols by dehydration to give olefins or by formation of ethers.
The ZrO2 catalysts may be used as supported catalysts on a known inert support such as silicon dioxide or
aluminum oxide, and especially as unsupported catalysts. They can be used in the form of extrudates, preferably
with a maximum diameter of 1-5 mm, pellets or spheres. (All amounts relating to the composition of the catalysts
are based on their active mass, i.e. the support materials are not taken into account).
It may be advantageous to add small amounts of one or more elements to the zirconium dioxide to increase the
structural stability and the life of the catalyst. Such elements are present predominantly in oxidic form in the
finished zirconium dioxide catalyst and are, for example, lanthanide elements such as lanthanum, cerium,
praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium,
erbium, thulium, ytterbium and lutetium.
Compounds of lanthanum and praseodymium and also of cerium, samarium, neodymium and europium are
particularly suitable for use as components of the catalysts used according to the invention.
Other elements which may be included are chromium, manganese, zinc, indium, tin, lead, vanadium or iron.
Chromium is in particular indicated for the hydrogenation of aliphatic carboxylic acids and esters to give alcohols.
The atomic ratio of the added element to zirconium dioxide is generally in the range from 0.005 to 0.3, preferably
in the range from 0.05 to 0.2.
The catalysts may be arranged in a fixed bed reactor or in a fluidized bed reactor. The hydrogenation may be
carried out as a downflow or upflow process. It is advantageous to use at least such an amount of hydrogen as
hydrogenating agent and carrier gas that starting materials, intermediates and products never become liquid
during the reaction. Excessive hydrogen and nondehydrated alcohol are preferably recycled, it being possible for a
small part to be bled off as effluent gas in order to remove inert materials such as methane and carbon monoxide.
It is possible to use one reactor or more than one reactor, arranged in series or parallel to each other.
The hydrogenation temperature is in the range from 250° C. to 400° C., preferably from 270° C. to 370° C.,
particularly preferably from 300 to 350° C.
The reaction pressure is in the range from 5 bar to 100 bar, preferably from 10 bar to 60 bar, particularly
preferably from 25 bar to 50 bar, when undoped zirconium dioxide is used. The pressure is in the range from 20 to
4. 100 bar, preferably from 30 to 50 bar, when doped zirconium dioxide is used, since the hydrogenation to give the
alcohol is apparently retarded by the dopant.
The molar ratio of hydrogen to carboxylic acid or ester used is generally in the range from 20 to 300, preferably
from 50 to 150, particularly preferably from 70 to 130.
Deactivated zirconium dioxide catalysts may be regenerated many times e.g. by burning off in air at from 300° C. to
700° C.
The amount of alcohol is generally in the range from 0.5 to 10 mol, preferably from 1 to 5 mol, particularly
preferably from 2 to 4 mol, of alcohol per mole of acid or ester used.
The space velocity is usually in the range from 0.01 to 0.3, preferably from 0.05 to 0.2, particularly preferably from
0.05 to 0.15, kg of ester or acid to be hydrogenated per liter of catalyst per hour.
The hydrogenation is preferably carried out continuously. The hydrogenation effluents are condensed and then
preferably worked up by distillation.
The hydrogenation effluent consists essentially of the alcohol formed by hydrogenation, alcohol or water released
by hydrogenation of ester or acid groups, added alcohol and unconverted acid, ester or aldehyde intermediate. By-
products which may occur are olefins, hydrocarbons or ethers. New esters may be formed by esterification or
transesterification, but those may be hydrogenated to give the desired alcohols.
Excess added alcohol and, if conversion is incomplete, starting and intermediate compounds present in the
hydrogenation effluent may be separated off by distillation and recycled into the hydrogenation step.
EXAMPLES
a) Hydrogenation Apparatus:
The runs were conducted continuously in the hydrogenation apparatus shown diagrammatically in FIG. 1. The
apparatus consists of an evaporator (E), a 1.4 l tubular reactor (30×2000 mm) (R), two condensers C1 and C2 and a
pressure separator (S) for isolating the condensable components from the hydrogen stream, a recycle gas
compressor (K) for recycling the recycle hydrogen gas (3) and an effluent tank (T) for collecting the reaction
effluent (4).
b) Experimental Procedure:
The zirconium dioxide used in Examples 1 to 7, 9, 11 and 12 was obtained from Norton and had the designation XZ
16075. The zirconium dioxide was in the form of 3 mm extrudates and had a BET surface area of about 50 m2
/g.
More than 90% of the zirconium dioxide was monoclinic.
In Examples 8 and 10, La2 O3 (3% of La)/zirconium dioxide was used.
The La2 O3 (3% of La2 O3)/ZrO2 was prepared by impregnating 3 mm ZrO2 exdrudates made of ZrO2 from Norton (SN
9516321) with La(NO3)3 solution, drying at 120° C. for 4 hours and calcining at 400° C. for 6 hours.
In Example 14, Cr2 O3 (5% of Cr)/zirconium dioxide was used.
The Cr2 O3 (5% of Cr)/ZrO2 was prepared by impregnating 3 mm ZrO2 extrudates made of ZrO2 from Norton (SN
9516321) with Cr(NO3)3 solution, drying at 120° C. for 4 hours and calcining at 400° C. for 6 hours.
The catalyst zone was bounded by a layer of quartz rings at the upper and lower ends. In all cases, recycle gas was
used, with 10% of the recycle gas (5) being bled off and replaced by an equal amount of fresh hydrogen.
A pump (P) was used to meter the starting compounds (1), (7), (12) and added alcohol into the evaporator where
they were evaporated and passed into the reactor in gaseous form, mixed with preheated hydrogen (2). The molar
starting compound/hydrogen ratio of inlet streams 1 and 2 was determined by weighing the amount of starting
material added and measuring the hydrogen streams.
The hydrogenation effluent was condensed and then weighed. Its composition was quantitatively determined by
gas chromatography using an internal standard (diethylene glycol dimethyl ether). The runs were each conducted
for several days without any changes, and only then was the hydrogenation effluent analyzed.
TABLE 1__________________________________________________________________________ #STR1## -
Methanol Space addition Selectivity [%] Temperature Pressure Molar ratio velocity [mol per Conversion
Cyclohexane Cyclohexane Ester EtherExample [° C.] [bar] ester/H2 (N2) [kg/l · h] mol (1)] [%] methanol (2) aldehyde
(3) (4) (5) (6)__________________________________________________________________________1
(Comparative) 350 1 H2 (25) 0.1 0 81.9 34.6 43.7 14.5 0.7 0.2 2 (Comparative) 3 73.9 68.2 14.7 8.7 0.2 1.0 3
(Comparative) 330 10 N2 (50) 3 21.0 48.7 6.0 31.9 0.9 0.8 4 H2 (120) 3 98.9 90.9 2.0 0.4 0 3.6 5 (Comparative) 330
20 N2 (50) 3 23.8 46.5 3.8 32.2 0.9 0.8 6 H2 (120) 3 99.2 95.0 1.3 0.3 0 5.0 7 330 20 H2 (120) 0.1 .sup. 31
) 99.4 43.3
1.3 0 17.6 82
) 305 20 H2 (120) 0.1 3 99.7 96.0 1.9
5. 0__________________________________________________________________________ 0.4 1
) Three moles of
isopropanol instead of methanol 2
) La2 O3 /ZrO2 instead of ZrO2 -
TABLE 2__________________________________________________________________________ #STR2## -
Selectivity [%] Space Methanol Benzyl Benz- Temperature Pressure Molar ratio velocity addition Conversion
alcohol aldehyde Ester Ether Example [° C.] [bar] ester/H.sub. 2 (N2) [kg/l · h] [mol per mol (1)] [%] (8) (9) (10)
(11)__________________________________________________________________________9 330 20 H2 (120)
0.1 3 99.2 80.7 4.4 0.4 7.5 101
) 300 20 H2 (120) 0.1 3 100 85.0 5.2 0
2.2__________________________________________________________________________ 1
) La2 O3 /ZrO2
instead of ZrO2- Benzyl alcohol by hydrogenation of methyl benzoate
TABLE 3__________________________________________________________________________ #STR3## -
Methanol Space addition Selectivity [%]Temperature Pressure Molar ratio velocity [mol per Conversion
Cyclohexane Cyclohexane Ester EtherExample[° C.] [bar] acid/H2 (N2) [kg/l · h] mol (1)] [%] methanol (2) aldehyde
(3) (4) (5) (6)__________________________________________________________________________11 330 20
H2 (120) 0.1 3 97.7 92.0 0.9 0.3 0.3 12 330 45 H2 (120) 0.1 3 100 90.8 5.6 0.2
0.8__________________________________________________________________________
Cyclohexanemethanol by hydrogenation of cyclohexancarboxylic acid
EXAMPLE 13
Methyl tetrahydropyran-4-carboxylate was hydrogenated as described in Example 6, but at 310° C./45 bar. The
selectivity to 4-hydroxymethyltetrahydropyran was 76.4% (97.4% conversion), the selectivity to 4-
formyltetrahydropyran was 2%.
EXAMPLE 14
Methyl n-hexanoate was hydrogenated as described in Example 6, but at 300° C./45 bar and over a
Cr2 O3 /ZrO2 catalyst. The n-hexanol yield was 70% (100% conversion), the selectivity to n-hexanal was 0.5%.