The annual total consumption of organic raw materials in Germany is about 19 million ton; 82 % are based on crude oil, 8% on natural gas, 2 % on coal as well as 8 % on renewable feedstock. These 8 %, however, means 22 % of the value of all chemicals produced in the German chemical industry. Considering such figures for the use of renewables one has to realize that there is a big margin between the production costs and the sale prices resulting in high profit. Therefore and also due to the environmental constrains there is a strong interest in Europe to broaden the base for such feedstocks. Some examples will be presented:
1) The nature is the architekt of the carbon framework for the desired compounds
For example the selective conversion of mixtures of terpenes to the important intermediate p-cymene is of a high commercial interest. Such terpenes are widely and cheaply available as by-products from the orange and lemon juice production as well as from pulp and paper industry. The valuable p-cymene can be used, e.g. in the fragrance industry (non-nitrated musks), as a biodegradeable solvent and as intermediate for the production p-cresol. The investigation of the catalytic behavior over various Pd-modified silica catalysts results in yields of up to 98 % depending on the mixture of the starting material. In addition to this topic a flavor for the production of fragrances and aroms based on renewables will be presented, too. Among them the synthesis of the sandalwood fragrances, the grapefruit arom and the mangofruit arom will be discussed.
2) Oleoesters as feedstock for lubricants and biodiesel
By far the largest amount of lubricants and pressure media used world wide is produced on the basis of mineral oil. In 1999, the consumption of lubricants in Germany was 1.159,900 t. 10 % of that amount was employed for loss lubrication (e.g. for chain saws or as release agents). In total, 520.000 t of lubricants are released into the environment. Therefore the use of renewable feedstock is of high interest. The aim of our work presented is to improve the stability of rapeseed oil against oxidation and hydrolysis, by the addition of different carboxylic acids and alcohols to the double bonds in the presence of environmentally friendly heterogeneous catalysts resulting in high yields.
The 1st generation production of biodiesel FAME based on renewable feedstock such as palm oil, rapeseed oil, soya been oil and brown grease is a hot topic of our days . We have been able to develop a bifunctional catalyst with acid sites and basic sites based on La doped zirconia. This kind of catalyst enables us to carry out the transesterification of the oleoesters with methanol simultaneously with the estrification of the free fatty acid (FAA). The raffination of the oleoesters or the preesterification of the FAA can be avoided by this new catalysts yielding in a more economical procedure. The catalyst development, its characterization and catalytic performance as well as the up scale in a continous fixed bed reactor will be demonstrated.
The 2nd generation production of biodiesel will be illustrated on the conversion of oleic acid over Pd doped on amorphous silica alumina to achieve a mixture of hydrocarbons showing equal properties to conventional diesel
3) Glycerin as platform molecule for value added chemicals
In the biodiesel production of the 1st generation glycerol is produced as inevitable side product in 10%. In 2015 an amount of about 1 mio t/a glycerol is expected in Europe . As a result of that a lot of research is going on to convert that in high value added intermediates with a 3 C building block. The conversion of glycerol to acrolein and acrylic acid in high yields being competitive to the current technology based on propylene was developed in our group together with Arkema Comp. recently. That is a trend to get more independ from crude oil. This process is going to become commercialized.
In addition the possibility to convert glycerol to acrylonitrile will be discussed.
4) Sugar and starch as platform feedstock for polymers etc.
Metal-catalyzed oxidation of alcohols to carboxylic compounds is an important step for synthesis of fine chemicals. Particularly, the oxidation of the primary hydroxyl group in sugars and its derivatives such as starch and cellulose is important. The oxidized carbohydrates can be used as thickening, as gelling agents, in paints, as resins detergents co-builders, and as super absorbers (biodegradeable diapers). Only a few reports describe procedures for the oxidation of primary hydroxyl groups which leave the secondary hydroxyl groups still intact. Such regioselective oxidation can be mediated by 2,2,6,6,-tetramethylpiperidinyl-1-oxy (TEMPO), but unfortunately thereby an environmentally hazardous hypochlorite/bromide system is used . Therefore our investigations focus on heterogeneously Ag-catalyzed procedure. For example, 99 mol % selectivity to methyl-a-D-glucopyrasiduronic acid was obtained at 90 % conversion of the pyranoside over a silver-celite catalyst.
Other examples are a new 2nd generation PLA process and production of isosorbite.
Those examples will be discussed also in relation to chemical engineering aspects and its scale up procedures.
Wolfgang is a chemist who studied chemistry at the Technical University of Karlsruhe from 1968 – 1972, there he finished his dissertation in 1975. Afterwards in 1976 and 1977 he carried out Postdoctoral research at M.I.T., Cambridge, Massachusetts, USA. In 1978 he joined BASF SA.and was in charge of several leading positions in research of heteroge-neous catalysis. Among those he was the founder of the BASF zeolite group. Furthermore he was a member and the research representative in the 4 person steering committee of the BASF catalyst business profit center. On the 01st of April 1992 he followed the call of the State Nordrhein – Westfalien to become a University Professor and Director of the new founded Institute for Chemical Technology and Heterogeneous Catalysis at the Uni-versity of Technology RWTH-Aachen. After his retirement in 2011 he started his third career as head of TCHK Hoelderich Consultancy in Frankenthal, Germany. In addition he was visiting professor at NUS, Singapore and University of Lille, France from 2012 to 2014.as well as temporary scientific “ambassador” of UNIDO.
His major research topics are heterogeneously catalysed syntheses of fine and intermedi-ate chemicals as well as the use of renewable feeds as starting material and petrochemi-stry based on methane, alkylation and isomerisation processes as well as acid/base cata- lysis, in particular using zeolites and oxidation catalysis.
He wrotes more than 300 papers on heterogeneous catalysis and is inventor / co-inventor of 283 patent-families. In addition he is editor or co-editor of 6 books. He was involved in the commercialization of 26 industrial processes based on his patents.
He received several awards, among them the E.V. Murphree Award of the ACS for Industrial Chemistry and Chemical Engineering sponsored by ExxonMobil.