Renewable Plant Oils Research Articles

Catalytic Biorefining of Natural Oils to Basic Olefinic Building Blocks of Proven Chemical Valorization Schemes.

Catalytic transformation of renewable plant oils including microalgae and waste oil into industrially relevant α-olefins in the C3 to C10 regime is demonstrated. The biorefinery concept is comprised of a catalytic sequence of ethenolysis, double bond isomerization, and a subsequent ethenolysis, thereby cutting and rearranging the fatty acid chains into valuable chemical building blocks. A benign extraction and reaction solvent, supercritical carbon dioxide (scCO2), is utilized.

Catalytic Biorefining of Natural Oils to Basic Olefinic Building Blocks of Proven Chemical Valorization Schemes

AbstractCatalytic transformation of renewable plant oils including microalgae and waste oil into industrially relevant α‐olefins in the C3 to C10 regime is demonstrated. The biorefinery concept is comprised of a catalytic sequence of ethenolysis, double bond isomerization, and a subsequent ethenolysis, thereby cutting and rearranging the fatty acid chains into valuable chemical building blocks. A benign extraction and reaction solvent, supercritical carbon dioxide (scCO2), is utilized.

Multifunctional WO3-ZrO2-Supported Platinum Catalyst for Remarkably Efficient Hydrogenolysis of Esters to Alkanes.

The hydrogenolysis of esters to alkanes is a key protocol for the synthesis of high-quality hydrocarbon fuels from renewable plant oils or fats. However, performing this process under mild energy-efficient conditions is challenging. Herein, we report a robust tungsten- and zirconium-oxide-supported platinum catalyst (Pt/WO3-ZrO2) for the hydrogenolysis of esters to alkanes at low temperatures (as low as 70 °C) and under ambient pressure (1 atm) of H2. For example, tristearin undergoes a complete conversion at 130 °C with more than 95% selectivity for the corresponding alkanes without carbon loss. In addition, the heterogeneous nature of the catalyst system reported herein permits multiple reuse of the catalyst without any significant loss of its high activity and selectivity. Mechanistic studies suggest that the multifunctional nature (acid and redox properties) of the WO3-ZrO2 support plays an important role in the high activity of the catalyst.

Discovery and Engineering of a Novel Baeyer-Villiger Monooxygenase with High Normal Regioselectivity.

Baeyer-Villiger monooxygenases (BVMOs) are remarkable biocatalysts for the Baeyer-Villiger oxidation of ketones to generate esters or lactones. The regioselectivity of BVMOs is essential for determining the ratio of the two regioisomeric products ("normal" and "abnormal") when catalyzing asymmetric ketone substrates. Starting from a known normal-preferring BVMO sequence from Pseudomonas putida KT2440 (PpBVMO), a novel BVMO from Gordonia sihwensis (GsBVMO) with higher normal regioselectivity (up to 97/3) was identified. Furthermore, protein engineering increased the specificity constant (kcat /KM ) 8.9-fold to 484 s-1 mM-1 for 10-ketostearic acid derived from oleic acid. Consequently, by using the variant GsBVMOC308L as an efficient biocatalyst, 10-ketostearic acid was efficiently transformed into 9-(nonanoyloxy)nonanoic acid, with a space-time yield of 60.5 g L-1 d-1 . This study showed that the mutant with higher regioselectivity and catalytic efficiency could be applied to prepare medium-chain ω-hydroxy fatty acids through biotransformation of long-chain aliphatic keto acids derived from renewable plant oils.

Genetic Manipulation of a Lipolytic Yeast Candida aaseri SH14 Using CRISPR-Cas9 System.

A lipolytic yeast Candida aaseri SH14 that can utilise long-chain fatty acids as the sole carbon source was isolated from oil palm compost. To develop this strain as a platform yeast for the production of bio-based chemicals from renewable plant oils, a genetic manipulation system using CRISPR-Cas9 was developed. Episomal vectors for expression of Cas9 and sgRNA were constructed using an autonomously replicating sequence isolated from C. aaseri SH14. This system guaranteed temporal expression of Cas9 for genetic manipulation and rapid curing of the vector from transformed strains. A β-oxidation mutant was directly constructed by simultaneous disruption of six copies of acyl-CoA oxidases genes (AOX2, AOX4 and AOX5) in diploid cells using a single sgRNA with 70% efficiency and the Cas9 vector was efficiently removed. Blocking of β-oxidation in the triple AOX mutant was confirmed by the accumulation of dodecanedioic acid from dodecane. Targeted integration of the expression cassette for C. aaseri lipase2 was demonstrated with 60% efficiency using this CRISPR-Cas9 system. This genome engineering tool could accelerate industrial application of C. aaseri SH14 for production of bio-based chemicals from renewable oils.

Mechanically strong plant oil-derived thermoplastic polymers prepared via cellulose graft strategy

The design of polymers from renewable plant oils is gaining more attention within sustainable development. Most plant oils based thermoplastic polymers exhibit poor mechanical properties. In this paper, we reported the mechanically strong cellulose-graft-soybean oil copolymers, which combined two natural biomasses in one. The soybean oil-based monomers with secondary amide groups (SOM1) and tertiary amide groups (SOM2) were prepared and copolymerized. The mechanical properties of the P(SOM1-co-SOM2) copolymers were investigated. Cellulose-g-P(SOM1-co-SOM2) copolymers with 0.5 wt% cellulose were prepared via atom radical transfer polymerization. FT-IR, 1H NMR, and TGA measurements demonstrated that the Cellulose-g-P(SOM1-co-SOM2) copolymers were successfully prepared. Tensile test results demonstrated that the mechanical properties of the as-prepared Cellulose-g-P(SOM1-co-SOM2) copolymers were superior to the linear P(SOM1-co-SOM2) copolymers.

Functional polymers from renewable plant oils

This focus review addresses recent progress on plant oil-based functional polymers and composites. Plant oils are one of the most ideal chemical feedstocks to replace fossil resources for a variety of industrial chemicals in the polymer industry. In this focus review, an environmentally benign coating system is demonstrated using plant oils as the starting substrate for the preparation of artificial urushi with high hardness and a high gloss surface. Epoxidized plant oils, mainly epoxidized soybean oil, are polymerized with designed inorganics, cellulose, and biodegradable aliphatic polyesters to afford functional biobased polymers and composites. Castor oil is used as the core of branched poly(lactic acid) to improve the physical properties of biobased plastics. These plant oil-based materials are significant for the molecular design of functional and high-performance biobased products for industrial applications to contribute to the reduction of greenhouse emissions. This focus review addresses recent progress on plant oil-based functional polymers and composites. An environmentally benign coating system is demonstrated using plant oils as the starting substrate for the preparation of artificial urushi with high hardness and a high gloss surface. Epoxidized plant oils are polymerized with designed inorganics, cellulose, and biodegradable aliphatic polyesters to afford functional biobased polymers and composites. Castor oil is used as the core of branched poly(lactic acid) to improve the physical properties of biobased plastics.

Seed-specific RNAi in safflower generates a superhigh oleic oil with extended oxidative stability.

SummaryVegetable oils extracted from oilseeds are an important component of foods, but are also used in a range of high value oleochemical applications. Despite being biodegradable, nontoxic and renewable current plant oils suffer from the presence of residual polyunsaturated fatty acids that are prone to free radical formation that limit their oxidative stability, and consequently shelf life and functionality. Many decades of plant breeding have been successful in raising the oleic content to ~90%, but have come at the expense of overall field performance, including poor yields. Here, we engineer superhigh oleic (SHO) safflower producing a seed oil with 93% oleic generated from seed produced in multisite field trials spanning five generations. SHO safflower oil is the result of seed‐specific hairpin‐based RNA interference of two safflower lipid biosynthetic genes, FAD2.2 and FATB, producing seed oil containing less than 1.5% polyunsaturates and only 4% saturates but with no impact on lipid profiles of leaves and roots. Transgenic SHO events were compared to non‐GM safflower in multisite trial plots with a wide range of growing season conditions, which showed no evidence of impact on seed yield. The oxidative stability of the field‐grown SHO oil produced from various sites was 50 h at 110°C compared to 13 h for conventional ~80% oleic safflower oils. SHO safflower produces a uniquely stable vegetable oil across different field conditions that can provide the scale of production that is required for meeting the global demands for high stability oils in food and the oleochemical industry.

Renewable atom-efficient polyesters and thermosetting resins derived from high oleic soybean oil

We report an atom-efficient approach to the preparation of sustainable polyesters and their corresponding thermosetting resins (RESINs) from renewable plant oils.

Green polymer chemistry: new methods of polymer synthesis using renewable starting materials

The present article reviews the recent results reported mainly from our group on “green polymer chemistry”. Characteristic important aspects of green polymer chemistry include herein, typically (1) using renewable resources as starting materials for polymer production, and (2) employing green method for the polymer synthesis. As renewable starting materials, the following materials were employed; lactic acid, itaconic anhydride, renewable plant oils, and cardanol. Polymer production using these materials contributes to mitigate the carbon dioxide emission because of their “carbon neutral” nature. As green method, lipase enzyme was mainly used for polymerization catalyst, since lipase is a natural benign catalyst, showing a specific catalysis as well as recyclable character. Polymer synthesis from these materials and the catalyst provided various value-added functional polymers, demonstrating good examples of green polymer chemistry.

4D printing smart biomedical scaffolds with novel soybean oil epoxidized acrylate.

Photocurable, biocompatible liquid resins are highly desired for 3D stereolithography based bioprinting. Here we solidified a novel renewable soybean oil epoxidized acrylate, using a 3D laser printing technique, into smart and highly biocompatible scaffolds capable of supporting growth of multipotent human bone marrow mesenchymal stem cells (hMSCs). Porous scaffolds were readily fabricated by simply adjusting the printer infill density; superficial structures of the polymerized soybean oil epoxidized acrylate were significantly affected by laser frequency and printing speed. Shape memory tests confirmed that the scaffold fixed a temporary shape at −18 °C and fully recovered its original shape at human body temperature (37 °C), which indicated the great potential for 4D printing applications. Cytotoxicity analysis proved that the printed scaffolds had significant higher hMSC adhesion and proliferation than traditional polyethylene glycol diacrylate (PEGDA), and had no statistical difference from poly lactic acid (PLA) and polycaprolactone (PCL). This research is believed to significantly advance the development of biomedical scaffolds with renewable plant oils and advanced 3D fabrication techniques.

Production of Long-Chain α,ω-Dicarboxylic Acids by Engineered Escherichia coli from Renewable Fatty Acids and Plant Oils.

Long-chain α,ω-dicarboxylic acids (LDCAs, ≥ C12) are widely used as a raw material for preparing various commodities and polymers. In this study, a CYP450-monooxygenase-mediated ω-oxidation pathway system with high ω-regioselectivity was heterologously expressed in Escherichia coli to produce DCAs from fatty acids. The resulting engineered E. coli produced a maximum of 41 mg/L of C12 DCA and 163 mg/L of C14 DCA from fatty acids (1 g/L), following 20 h of whole cell biotransformation. Addition of a heme precursor and the hydroxyl radical scavenger, thiourea, increased product concentration (159 mg/L of C12 DCA and 410 mg/L of C14 DCA) in a shorter culture duration than that of the corresponding controls. DCAs of various chain lengths were synthesized from coconut oil hydrolysate using the engineered E. coli. This novel synthetic biocatalytic system could be applied to produce high value DCAs in a cost-effective manner from renewable plant oils.

Green Nanocomposites from Renewable Plant Oils and Polyhedral Oligomeric Silsesquioxanes

Green nanocomposites based on renewable plant oils and polyhedral oligomeric silsesquioxanes (POSS) have been developed. An acid-catalyzed curing of epoxidized plant oils with oxirane-containing POSS derivatives produced transparent nanocomposite coatings with high gloss surface, in which the organic and inorganic components were linked via covalent bonds. The hardness and mechanical strength were improved by the incorporation of the POSS unit into the organic polymer matrix. Nanostructural analyses of the nanocomposites showed the formation of homogeneous structures at the micrometer scale. On the other hand, such improvements of the coating and mechanical properties were not observed in the composite without covalent bonds between the plant oil-based polymer and POSS unit. The study demonstrates the correlation between the nanostructure of composites and macroscopic properties.

Acyclic triene metathesis (ATMET) miniemulsion polymerization of linseed oil produces polymer nanoparticles with comparable molecular weight to that of bulk reactions

Acyclic triene metathesis (ATMET) polymerizations of linseed oil were performed in bulk and miniemulsion to evaluate the activity of different types of ruthenium‐based catalysts (Grubbs 1st and 2nd generations, Hoveyda–Grubbs 2nd generation and Umicore M2) in both systems. Miniemulsion polymerizations with a nonionic surfactant resulted in polymer nanoparticles with an average size around 200 nm. The number‐average molecular weight (Mn) of the polymers, approximately 6 kDa, obtained by linseed oil metathesis miniemulsion polymerizations was found to be comparable to linseed oil metathesis bulk reactions if Umicore M2 and Hoveyda–Grubbs 2nd generation catalysts and nonionic surfactants were used. The presence of oleic acid moieties and saturated fatty acids in linseed oil limited the molecular weight increase and cross‐linking, since they act as chain‐stoppers. On the other hand, ATMET homopolymerization of glyceryl triundec‐10‐enoate (UDTG) with terminal double bonds led to a massive gel formation due to the three highly reactive terminal double bonds per molecule. Increasing the amount of linseed oil in ATMET copolymerization between linseed oil and UDTG resulted in lower gel content.Practical applications: Naturally occurring renewable plant oils as raw materials, without prior chemical modifications, are a very attractive alternative to fossil reserves. Linseed oil contains about 90% unsaturated fatty acids. This property makes it suitable for ATMET polymerization, including the miniemulsion technique, allowing the synthesis of branched macromolecular nanoparticles. The ratio of linseed oil and glyceryl triundec‐10‐enoate (UDTG) in ATMET copolymerization can tune the gel content, as the presence of oleic acid moieties and saturated fatty acids in linseed oil limits the cross‐linking.Branched macromolecule nanoparticles were obtained by ATMET miniemulsion polymerization of linseed oil.

Multistep Enzymatic Synthesis of Long‐Chain α,ω‐Dicarboxylic and ω‐Hydroxycarboxylic Acids from Renewable Fatty Acids and Plant Oils

A multistep enzyme catalysis was successfully implemented to produce long-chain α,ω-dicarboxylic and ω-hydroxycarboxylic acids from renewable fatty acids and plant oils. Sebacic acid as well as ω-hydroxynonanoic acid and ω-hydroxytridec-11-enoic acid were produced from oleic and ricinoleic acid.

Multistep Enzymatic Synthesis of Long‐Chain α,ω‐Dicarboxylic and ω‐Hydroxycarboxylic Acids from Renewable Fatty Acids and Plant Oils

Eine mehrstufige Enzymkatalyse überführt erneuerbare Fettsäuren und pflanzliche Öle in langkettige α,ω-Dicarbonsäuren und ω-Hydroxycarbonsäuren. Sebacinsäure sowie ω-Hydroxynonansäure und ω-Hydroxytridec-11-ensäure werden ausgehend von Öl- und Ricinolsäure erzeugt. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Performance, emission and combustion characteristics of an indirect injection (IDI) multi-cylinder compression ignition (CI) engine operating on neat jatropha and karanj oils preheated by jacket water

Renewable non-edible plant oils such as jatropha and karanj have potential to substitute fossil diesel fuels in CI engines. A multi-cylinder water cooled IDI type CI engine has been tested with jatropha and karanj oils and comparisons made against fossil diesel. The physical and chemical properties of the three fuels were measured to investigate the suitability of jatropha and karanj oils as fuels for CI engines. The engine cooling water circuit and fuel supply systems were modified such that hot jacket water preheated the neat plant oil prior to injection. Between jatropha and karanj there was little difference in the performance, emission and combustion results. Compared to fossil diesel, the brake specific fuel consumption on volume basis was around 3% higher for the plant oils and the brake thermal efficiency was almost similar. Jatropha and karanj operation resulted in higher CO2 and NOx emissions by 7% and 8% respectively, as compared to diesel. The cylinder gas pressure diagram showed stable engine operation with both plant oils. At full load, the plant oils gave around 3% higher peak cylinder pressure than fossil diesel. With the plant oils, cumulative heat release was smaller at low load and almost similar at full load, compared to diesel. At full load, the plant oils exhibited 5% shorter combustion duration. The study concludes that the IDI type CI engine can be efficiently operated with neat jatropha (or karanj) oil preheated by jacket water, after small modifications of the engine cooling and fuel supply circuits.

Replacing Fossil Oil with Plant Oils - for What?

The value of the products and chemicals made from the 10% of fossil oil that is used as feed stock in the chemical industry is the same as the value of all fuel made from the remaining 90%. Using plant oil instead of fossil oil as feed stock for the materials and chemicals could capture much of this added value, if the plant molecules are optimized in-planta for the end use and thereby minimizing the downstream processing costs. I have a vision that within 20 years time replace 40% of the fossil oil used in the chemical industry with renewable plant oils, whilst ensuring that growing demand for food oils is also met. This will require a trebling of global plant oil production from current levels of 135 MT to about 400 MT annually. Realisation of this potential will rely on application of plant biotechnology to (a) tailor plant oils to have high purity (preferably > 90%) of single desirable fatty acids, (b) introduce unusual fatty acids that have speciality end-use functionalities, (c) increase plant oil production capacity by increased oil content in current oil crops, and conversion of other high biomass crops into oil accumulating crops. Using plant oils in the chemical industry will not only enable replacement of fossil oil but will, at least equally importantly, enable substantial overall energy savings and generate added-value for agricultural products that cannot be captured by using them for energy production. I will in this presentation outline research strategies for the replacement of a significant portion of the fossil oil used in the chemical industry with plant oils by extrapolating on the present state of the art of science in the area.

Replacing fossil oil with fresh oil – with what and for what?

Industrial chemicals and materials are currently derived mainly from fossil-based raw materials, which are declining in availability, increasing in price and are a major source of undesirable greenhouse gas emissions. Plant oils have the potential to provide functionally equivalent, renewable and environmentally friendly replacements for these finite fossil-based raw materials, provided that their composition can be matched to end-use requirements, and that they can be produced on sufficient scale to meet current and growing industrial demands. Replacement of 40% of the fossil oil used in the chemical industry with renewable plant oils, whilst ensuring that growing demand for food oils is also met, will require a trebling of global plant oil production from current levels of around 139 MT to over 400 MT annually. Realisation of this potential will rely on application of plant biotechnology to (i) tailor plant oils to have high purity (preferably >90%) of single desirable fatty acids, (ii) introduce unusual fatty acids that have specialty end-use functionalities and (iii) increase plant oil production capacity by increased oil content in current oil crops, and conversion of other high biomass crops into oil accumulating crops. This review outlines recent progress and future challenges in each of these areas.Practical applications: The research reviewed in this paper aims to develop metabolic engineering technologies to radically increase the yield and alter the fatty acid composition of plant oils and enable the development of new and more productive oil crops that can serve as renewable sources of industrial feedstocks currently provided by non-renewable and polluting fossil-based resources. As a result of recent and anticipated research developments we can expect to see significant enhancements in quality and productivity of oil crops over the coming decades. This should generate the technologies needed to support increasing plant oil production into the future, hopefully of sufficient magnitude to provide a major supply of renewable plant oils for the industrial economy without encroaching on the higher priority demand for food oils. Achievement of this goal will make a significant contribution to moving to a sustainable carbon-neutral industrial society with lower emissions of carbon dioxide to the atmosphere and reduced environmental impact as a result.

Organic-inorganic hybrids from renewable plant oils and clay.

This study deals with the preparation and properties of a new class of organic-inorganic hybrids from renewable resources. The hybrids were synthesized by an acid-catalyzed curing of epoxidized triglycerides in the presence of an organophilic montmorillonite (a modified clay). The mechanical properties were improved by the incorporation of clay in the oil-based polymer matrix. The reinforcement effect due to the addition of clay was confirmed by dynamic viscoelasticity analysis. The hybrids showed relatively high thermal stability. The co-curing of epoxidized soybean and linseed oils in the presence of clay produced hybrids with controlled mechanical and coating properties. The barrier property of the hybrid towards water vapor was superior to that of the oil polymer. The development of the present hybrids consisting of inexpensive renewable resources, triglyceride and clay is expected to contribute to global sustainability.