3.2.3. Hydroformylation 2467 3.2.4. Dimerization 2468 3.2.5. Oxidative Cleavage and Ozonolysis 2469 3.2.6. Metathesis 2470 4. Terpenes 2472 4.1. Pinene 2472 4.1.1. Isomerization: R-Pinene 2472 4.1.2. Epoxidation of R-Pinene 2475 4.1.3. Isomerization of R-Pinene Oxide 2477 4.1.4. Hydration of R-Pinene: R-Terpineol 2478 4.1.5. Dehydroisomerization 2479 4.2. Limonene 2480 4.2.1. Isomerization 2480 4.2.2. Epoxidation: Limonene Oxide 2480 4.2.3. Isomerization of Limonene Oxide 2481 4.2.4. Dehydroisomerization of Limonene and Terpenes To Produce Cymene 2481

Chemical Routes for the Transformation of Biomass into Chemicals

This critical review provides a survey illustrated by recent references of different strategies to achieve a sustainable conversion of biomass to bioproducts. Because of the huge number of chemical products that can be potentially manufactured, a selection of starting materials and targeted chemicals has been done. Also, thermochemical conversion processes such as biomass pyrolysis or gasification as well as the synthesis of biofuels were not considered. The synthesis of chemicals by conversion of platform molecules obtained by depolymerisation and fermentation of biopolymers is presently the most widely envisioned approach. Successful catalytic conversion of these building blocks into intermediates, specialties and fine chemicals will be examined. However, the platform molecule value chain is in competition with well-optimised, cost-effective synthesis routes from fossil resources to produce chemicals that have already a market. The literature covering alternative value chains whereby biopolymers are converted in one or few steps to functional materials will be analysed. This approach which does not require the use of isolated, pure chemicals is well adapted to produce high tonnage products, such as paper additives, paints, resins, foams, surfactants, lubricants, and plasticisers. Another objective of the review was to examine critically the green character of conversion processes because using renewables as raw materials does not exempt from abiding by green chemistry principles (368 references).

Conversion of biomass to selected chemical products

Conversion of Biomass into Chemicals over Metal Catalysts

Epoxidation of cottonseed oil by aqueous hydrogen peroxide catalysed by liquid inorganic acids.

A novel process for the production of biodegradable lubricant-based stocks from epoxidized vegetable oil with a lower pour point via cationic ion-exchange resins as catalysts was developed. This involves two steps, first, ring-opening reactions by alcoholysis followed by esterification of the resultant hydroxy group in the first step. The ring-opening reaction of epoxidized soybean oil with different alcohols such as n-butanol, iso-amyl alcohol and 2-ethylhexanol was carried out in presence of Amberlyst 15 (Dry) as a catalyst; identity of products was confirmed by IR and NMR. Pour points of the products were observed in the range of -5 to - 15 degrees C. The hydroxy group of ring-opening product of n-butanol was further reacted with acetic anhydride in presence of catalyst Amberlyst 15 (Dry), which was previously used to carry out ring-opening reaction by alcoholysis and identity of the resulting product was confirmed by IR. Pour point of the resulting product was observed to be -5 degrees C. (c) 2006 Elsevier B.V. All rights reserved. (Less)

Green approach for the preparation of biodegradable lubricant base stock from epoxidized vegetable oil

Mesoporous and amorphous Ti–silicas on the epoxidation of vegetable oils

The effects of different alcohol molecular configurations and resin structures were analyzed on the acid-resin catalyzed addition of alcohols to epoxidized fatty esters. Emphasis was placed on the addition of α- and β-branched alcohols. Regarding the catalysts, the effect of the acid strength as well as that of the diffusion constraints on the reaction rate and products distributions, was determined. Reaction rate increases with the acid strength but the selectivity shows the opposite trend when highly branched alcohols are added. Epoxide ring-opening rate decreases by increasing the number of branches and size of the alcohol. Branches in α position introduce a higher steric hindrance than branches in β position. Low resin crosslinkage and/or high external surface area are necessary conditions to activate the epoxide when polystyrene-based resins are used as catalysts. The obtained by-products were the ketone, from epoxide rearrangement reaction, and trans-esterified products, when reaction times were relatively long.

Resin catalyzed alcoholysis of epoxidized fatty esters: Effect of the alcohol and the resin structures

The heterogeneously catalyzed nucleophilic addition of carboxylic acid to the epoxide center in the epoxidized methyl- cis -9-octadecenoate (eOME) was attempted and the lubricant properties of the resulted hydroxy esters are reported It is demonstrated that solid acid catalysts like Nafion, Nafion–silica composites (SAC), Amberlyst 15, Amberlite IR 120, zeolite H-Y and montmorillonite were promising and selective catalysts for hydroxy ester formation at reaction temperature 30 °C The lubricant properties of various hydroxy esters were evaluated by rotary bomb testing, which indicates higher oxidation stability of the hydroxyl di esters than the starting material, methyl oleate The viscosity index calculation shows that the viscosities of the hydroxy esters are significantly influenced by the size of the carbon chain and nature of the carboxylic acid

Heterogeneous catalysts for the production of new lubricants with unique properties

Most lubricants and functional fluids worldwide are based on mineral oil. These fluids contain up to 10% of a wide variety of additives for the improvement of their tribological properties. Several of these are still ecologically hazardous.



From an environmental point of view, the use of renewable feedstock is of great interest. In Europe rape seed oil is available in substantial amounts and its esters (triglycerides, esters with saturated or partly unsaturated acids) to some extent display better tribological properties than conventional lubricants. The aim of the work which is presented here has been to improve the stability of these types of ester and their derivatives with regard to oxidation and hydrolysis. This can be done by the addition of different carboxylic acids and alcohols, of various complexities, to the double bonds. This paper deals with the indirect addition of different alcohols, such as methanol, isobutanol, and neopentanol, to the double bond of methyl oleate, and the addition of methanol to the double bonds of glycerin trioleate using the corresponding epoxides as intermediates. The reactions were carried out with environmentally friendly heterogeneous catalysts. Several tests, such as for viscosity, oxidation stability, and biodegradability, were carried out to demonstrate the potential of these newly developed fluids for use as lubricants.

Investigations into the epoxidation and alcoholysis of oleochemicals for use as lubricants

The influence of Nafion content (5–80 wt%) in different Nafion/silica composite materials (SAC) as well as the effect of different solvents was studied in liquid phase Friedel-Crafts acylation of 2-methoxynaphthalene (2-MN) with acetic anhydride. The higher the Nafion content, the higher are conversion and selectivity (up to 69%) to the desired product 2-acetyl-6-methoxynaphthalene (2,6-ACMN). Unpolar solvents such as toluene or methylene chloride favour the formation of 1-acetyl-2-methoxynaphthalene (1,2-ACMN) while polar solvents like nitrobenzene or sulfolane promote the 2,6-ACMN formation. Further investigations are related to the influence of metal ions, e.g. Al 3+ , Fe 3+ , Zn 2+ , Cu 2+ and Ag + in ion-exchanged Nafion–silica composite on the formation of the desired 2,6-ACMN. An increase in selectivity to 2,6-ACMN in comparison with the pure acidic Nafion–silica was observed. Zeolites containing Lewis acid sites created by ion-exchange with Fe 3+ , Cu 2+ and Ag + were investigated in the heterogeneously catalysed acylation of methoxynaphthalene for comparison reasons.

Hans Schuster

Papers

Mesoporous and amorphous Ti–silicas on the epoxidation of vegetable oils

Resin catalyzed alcoholysis of epoxidized fatty esters: Effect of the alcohol and the resin structures

Heterogeneous catalysts for the production of new lubricants with unique properties

Investigations into the epoxidation and alcoholysis of oleochemicals for use as lubricants

The acylation of 2-methoxynaphthalene with acetic anhydride over Nafion/silica composites and BEA zeolites containing Lewis acid sites