Completed Projects
2017
Oilivia: Screening of alternative oil plants
Olivia: Screening alternative oil plants
The research project “Olivia”, which is located at the Technolgoie- und Förderzentrum of the Free State of Bavaria, has set itself the goal of screening alternative oil plants for industrial use. The Department of Organic and Analytical Chemistry is the project partner for the analysis of the seed obtained in the test cultivation.
Funding:
- StMELF
Project team:
- TFZ: Dr. Mandy Fritz
- OAC: Prof. Dr. Herbert Riepl & Dr. Corinna Urmann
Project start:
- January 2015
End of project:
- March 2017
2016
Olefin conversion for the production of fuels - catalyst development and reaction conversion
In Germany, grassland accounts for about one third of the agriculturally used area and is thus a significant part of our cultural landscape. In addition to the use of green waste as animal feed, the use of these areas for the cultivation of renewable raw materials is becoming increasingly important.
In a joint project with the Straubing Science Centre, the farm biorefinery is to be used to develop a plant that makes special use of grass and grass silage as raw materials. In a modular and decentralised small plant, gaseous olefins such as ethene or isoprene are to be obtained from the biomass by fermentative digestion and conversion processes. These in turn are to be used as starting materials for other valuable products such as fuels. This is the main difference between the farm biorefinery and the biogas plant, whose product methane is so largely inert that it is not suitable for further chemical utilisation.
The aim of this subproject is the catalytic conversion of biotechnologically produced ethylene into liquid energy sources. As a gas, it can be easily separated in the preceding production step and then oligomerised into short-chain hydrocarbons with about 6-18 carbon atoms. Depending on the chain length and degree of branching, the product can be used as diesel or gasoline, but longer-chain molecules are no longer suitable for these fuels due to their excessively high boiling point.
For this purpose, a cost-effective catalyst is to be developed that operates under the mildest possible conditions and is highly resistant to impurities. The aim is also to ensure that the plant is operated as maintenance-free as possible and that high catalytic productivity is achieved in order to guarantee long production cycles. The catalysts used will be based on large-scale processes such as the Shell Higher Olefin process, but adapted to the milder conditions and smaller scale of the farm biorefinery.
The focus is on organometallic nickel complexes with bidentate P,O or N,O chelating ligands. The properties of the catalyst are significantly influenced by their size, structure and substitution pattern. Above all, the degree of oligomerization is a decisive parameter, since both short-chain and long-chain molecules are unsuitable for use as fuel. The coligands used, especially various phosphines, also play an important role here.
Initially, the catalysts are used in a homogeneous solution and the products are separated by distillation. In the further course of the project, a reactor prototype will also be developed and the process heterogenized by applying the catalyst to an inert carrier material.
Project team:
- Prof. Dr. Herbert Riepl (contact person)
- Felix Hiller (Project collaborator)
Project start:
- 2013
End of project:
- 2016
2015
Evaluation of hops prenylflavonoids with regard to their biological effects - Studies on the penetration of 8 prenylnaringenin and 6 prenylnaringenin via the blood-brain barrier
Xanthohumol, the highly concentrated prenyl flavonoid in the hop plant, is converted into flavanone isoxanthohumol during the brewing process. The most highly concentrated prenylflavanones in beer are therefore isoxanthohumol and 6 prenylnaringenin. Since isoxanthohumol is metabolized to 8 prenylnaringenin in the body and 6-prenylnaringenin is directly ingested, these substances ingested by beer were examined for their biological activities such as neurogenesis-inducing and anti-cancerogenic activity. Both compounds show differentiation-inducing activities on neuronal stem cells and have been identified as HDAC (histone deacelyase) inhibitors.
In order to have an effect on the neuronal stem cells in the brain, the substances have to cross the blood-brain barrier. Consequently, the penetration of the two flavonoids 6 prenylnaringenin and 8 prenylnaringenin through the blood-brain barrier will be investigated in a model system.
Advancement:
- Scientific Station for Breweries in Munich e.V.
Project team:
- Dr. Corinna Urmann (contact person)
Project start:
- January 2015
End of project:
- December 2015
New production processes for monomers for polyamide production from domestic vegetable oils
The material class of polyamides is characterized by the repeating carbonamide group in the main chain, which is responsible for the physical differences compared to most other polymeric materials. The formation of hydrogen bonds by the carbonamide function contributes to the outstanding mechanical properties, chemical resistance and water absorption capability of polyamide materials.
Various methods are known for the production of polyamide monomers from petrochemical sources. As in many other areas, the synthesis of polyamide monomers attempts to replace or supplement these petroleum-based raw materials with renewable ones. In this project, aliphatic, unsaturated fatty acids will serve as starting materials. Oleic acid is of particular interest due to its low price and availability. To produce a carbonamide, a nitrogen functionality must be introduced.
In the current project, the unsaturated fatty acids are to be converted into the corresponding furoxanes with the aid of dinitrogen trioxide N2O3, which can then be split into the desired amines.
Promotion:
- BayReChem2050
Project team:
- Prof. Dr. Herbert Riepl (contact person)
- Dipl.-Chem. Christian Beck (Project collaborator)
Project start:
- March 2012
End of project:
- December 2015
Process development for the extraction and fractionation of waxes from plant fibres
Waxes are esters of long-chain fatty acids and long-chain alcohols. They can be found on the surface of plants and serve as a protective layer. The composition of the surface wax varies from plant to plant. The wax layer consists of alkanes, alcohols, fatty acids, esters, ketones, aldehydes and sterols and is often highly structured. In this project the composition of different surface waxes as well as the quantity shall be investigated. Different solvents for extraction and different analytical methods will be tested.
Figure 1: Water droplets on hydrophobic leaf surface (Photo: daisy/pixelio.de)
Another point is the synthesis of such wax compound classes. In maritime organisms, which are difficult to access deep in the sea, long-chain ethers and oligomers can be found. The synthesis of these long-chain ethers and their subsequent oligomerisation could make them more easily accessible. The properties of their use in plastics, thermoplastic elastomers (TPE), can then be determined.
Promotion:
- BayReChem2050
Project team:
- Prof. Dr. Herbert Riepl (contact person)
- Veronika Huber M. Sc. (Project collaborator)
Project start:
- March 2012
End of project:
- December 2015
Evaluation of the biological effects of hop prenyl flavonoids - influence on histone deacetylases
Xanthohumol, the highly concentrated prenyl flavonoid in the hop plant, is converted into flavanone isoxanthohumol during the brewing process. The most highly concentrated prenylflavanones in beer are therefore isoxanthohumol and 6 prenylnaringenin. Since isoxanthohumol is metabolized in the body to 8 prenylnaringenin and 6-prenylnaringenin is taken up directly, these substances taken up by beer consumption are to be examined for their biological activities such as neurogenesis-inducing and anti-cancerogenic activity. In particular, the extent to which these substances influence histone deacetylases will be investigated.
Promotion:
- Scientific station for breweries in Munich e.V.
Project team:
- Dr. Corinna Urmann (contact person)
Project start:
- January 2014
End of project:
- December 2014
Terpenes as renewable raw materials
Terpenes are very common constituents of plants, some of which have considerable
commercial significance, e.g. the camphor or the collophonium called terpene mixture
from tree resins. Others are currently more commonly used in the pharmaceutical industry or in the
fragrance area, e.g. limonene obtained from citrus fruit peel.
Terpenes have an enormous variety of chemical structures, which can hardly be described by a simple denominator.
but one characteristic feature is that they often deliver pure stereoisomers.
One speaks of a chiral pool of natural substances.
Until now, terpenes have hardly been used in the field of plastics. An important
The plasticizers, which help to reduce brittleness, also contribute to the polymer properties.
to avoid. Camphor was already a very common plasticizer in the early days of plastics,
has quickly become out of use due to its easy evaporation.
Today’s polymers are often copolymers that are tailor-made with regard to their properties.
are. Different chain sections of the polymer have different functions.
Thermoplastic elastomers consist e.g. of sections of longer simple hydrocarbon chains.
– which provide the elasticity – followed by sections of crystallizing molecular chains,
which, however, soften at higher temperatures and thus ensure deformability during processing.
I’m not going to worry about you.
In a project of the Fraunhofer Project Group Terpene we are dealing with the possibility of
camphor derivatives which are capable of being polymerized as comonomers.
Such bifunctionalised terpene alcohols or amines would, due to their molecular shape
have a softening effect, but at the same time be an integral part of the polymer.
Project partner:
- Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB)
Project team:
- Prof. Dr. Herbert Riepl (contact person)
- Dipl-Chem. Florian Kinzl (Project collaborator)
Project start:
- 2010
End of project:
- 2014
Investigation of the isomerization of the internal olefinic double bond in natural fatty acids
For the production of nylon-11 (Rilsan®), ω-aminoundecanoic acid is produced to a considerable extent from ricinus oil. This makes this type of nylon one of the few plastics based on renewable raw materials. Due to the special chemistry of ricinoleic acid, however, this is a special case that cannot be generalized. Characteristic for the other natural unsaturated fatty acids is the special position of their double bond in the middle of the molecule at the position of the 9th carbon atom or higher. For applications of these fatty acids in the chemical industry, a position of the double bond at the ω-terminal end would be more advantageous because terminal olefins react more easily and specifically. A process to isomerize the internal double bond in commercial oleic acid derivatives from rapeseed or sunflower to a terminal double bond would therefore be desirable. An FNR joint project coordinated by Wacker Chemie was looking for catalysts that could be used in this way. At the Straubing site, precious metal catalysts were produced and tested on a small scale for their suitability. Particular attention was paid to intercepting any terminal olefins with silylation reagents in order to develop silicon-containing oleochemicals as an interesting new product group.
In the subproject under consideration, all silicon-containing target compounds first had to be synthesized independently as reference substances. Furthermore, metal-based catalyst systems were screened, which allow both a shift of the double bond to the terminal position and the subsequent addition of a silane to the double bond. It could be shown that such reactions with iridium-based catalysts in good yields are possible for the group of trialkylsilanes. However, this could not easily be transferred to the trialkoxysilane group: these silanes probably require combined catalyst systems. The investigations showed, however, that a side-reaction to the silyl ether was more pronounced.
Promotion:
- Agency for Renewable Resources (FNR)
Project partner:
- Agency for Renewable Resources; Wacker Chemie AG; Fraunhofer ICT; Umicore AG
Project team:
- Prof. Dr. Herbert Riepl (contact person)
- Thimo Huber M. Sc. (Project collaborator)
Project start:
- July 2010
End of project:
- December 2013
Evaluation of hop prenyl flavonoids with regard to their biological effects
Xanthohumol, the highly concentrated prenyl flavonoid in the hop plant, is converted into flavanone isoxanthohumol during the brewing process. The most highly concentrated prenylflavanones in beer are therefore isoxanthohumol and 6 prenylnaringenin. Since isoxanthohumol is metabolized in the body to 8 prenylnaringenin and 6-prenylnaringenin is taken up directly, these substances taken up by beer consumption are to be examined for their biological activities such as neurogenesis-inducing and anti-cancerogenic activity.
Promotion:
- Scientific station for breweries in Munich e.V.
Project team:
- Dr. Corinna Urmann (contact person)
Project start:
- January 2013
End of project:
- December 2013
Recyclability of polyphenols from residues of olive oil production
The production of olive oil is economically one of the most important downstream industries of the agricultural sector of the Mediterranean countries. Two types of processes are currently in use to produce “extra virgin” oil. The three-phase system (Israel, Palestine, Greece etc.) provides two separate types of waste, OMSW = olive mill solid waste and OMW = olive mill waste water, while the two-phase system (Spain) provides a pasty mass of olive meat containing all the water. Especially the waste water is an acute problem in the partly arid region. Worldwide 1.4 -1.8 million tons of olive oil are produced per year, whereby 30 million m3 waste water result. This water has an extremely high chemical & biological oxygen demand (COD, BOD), which is due to the polyphenols it contains as an organic substance. Due to this high load of organic antimicrobial chemicals as constituents of the olive, this water cannot simply be disposed of in sewage treatment plants. Also the solids of the olive oil pressing are not easily biodegradable. Although some research has already been done on the subject of disposal of olive residues, no economically attractive solution has been found so far. However, the substances are also very desirable in the final products (oil) and contribute to their value. Polyphenols in the diet can be used as antioxidants to prevent a number of civilization diseases. Plant antioxidants also have a preservative value and can therefore be a model for technical use. In addition to further medical research, this technical use also requires technological efforts in the field of extraction methods, e.g. in the treatment of residual water.
Promotion:
- Federal Ministry of Education and Research
Project team:
- Prof. Dr. Herbert Riepl (contact person)
- Dipl.-Chem. Doris Brunner (Project collaborator)
Analysis of ingredients of commercial plant extracts
Xanthohumol as the most prominent polyphenol of hops has proven to be a potent antioxidant, cancer protective and even weak cytostatic flavonoid. As one of the main ingredients of hops, it is, however, not dissolved much in commercial hop extracts and remains in the hop grains as a valuable product. As a constituent of beer, which probably gives it considerable added value, it has also attracted the attention of beverage manufacturers, who are striving to improve the xanthohumol content somewhat. From this perspective, hop processors are also interested in new extracts rich in such substances in order to be able to provide products suitable for seasoning beer, as conventional carbon dioxide extracts contain very little xanthohumol. Xanthohumol and related substances belong chemically to the chalcones and are partially unstable in aqueous solution. They can cyclize to flavanones. These chemical reactions depend on the medium, thermal load, pH value, etc. Hop flavanones partly have oestrogen-like effects. The composition of the extracts should therefore be known exactly. The aim of the project is to determine the conversion kinetics. These data are used to establish a quality management system for novel hop extracts.
Promotion:
- Hallertauer Hopfenveredelungsgesellschaft mbH; Scientific station for breweries in Munich e.V.; Klinge Foundation
Project team:
- Prof. Dr. Herbert Riepl (contact person)
- Dipl.-Chem. Corinna Urmann (Project collaborator)
Use of vegetable oils in the production of thermoplastic elastomers
The project aims to develop a process for the production of segmented thermoplastic elastomers (TPE) based on renewable raw materials. The aim is to develop copolyesters and copolyamides based on monomer building blocks of oils, fats and sugars. TPE consist of amorphous, thermoplastic segments (“soft segment”) and crystalline segments (“hard segment”). TPE have the ability to be repeatedly melted and processed. TPE is currently produced on a petrochemical basis (based on terephthalic acid). In the first step, suitable components for the hard segment are to be synthesized from sugar, while suitable components for the soft segment are to be obtained by olefin metathesis followed by hydroformylation / reduction of unsaturated fatty acids. Metathesis is a metal-catalyzed reaction in which formal substituents on a double bond are exchanged for another radical. According to a suggestion by Chauvin, however, the radicals do not migrate but the double bond is completely broken and reformed, whereby intermediate metal-carbon double bonds are formed, so-called metal-carbene complexes. Possible metal centres have been used up to now: Tungsten, molybdenum, rhenium, more rarely tantalum and niobium, whereby some systems have found technical application especially with tungsten. In the last decade, ruthenium has made a name for itself as a metal of the metathesis catalyst, as the Ru carbene complexes have proven to be extremely robust and do not require activation with aluminum or tin alkylene.
Promotion:
- Agency for Renewable Resources (FNR)
Project team:
- Prof. Dr. Herbert Riepl (contact person)
- Dipl.-Chem. Jürgen Pettrak (Project collaborator)
