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Neue regenerativ hergestellte Kraftstoffe, sogenannte reFuels, konnen schon kurzfristig zur CO2-Reduktion der Bestandsflotte beitragen. Das Karlsruher Institut fur Technologie (KIT) zeigt, welche Bausteine bei der Entwicklung CO2-neutraler Mobilitat zusammenwirken mussen. Wesentlicher Faktor bei der Einfuhrung von reFuels ist der hohe Zeitvorlauf bei der Projektierung und beim Bau der Produktionsanlagen. Zudem ist zeitnah eine gesetzlich verankerte Planungssicherheit und Anerkennung dieser neuen Kraftstoffe unabdingbar.

Oligomeric oxymethylene dimethyl ethers (DMEs; OMDMEn) are acetals of the type CH3O(CH2O)nCH3 with a high oxygen content and without carbon–carbon bonds in the molecular structure. Therefore, formation of soot and NOx emissions is largely suppressed during combustion. Oligomers with n = 3–5 exhibit properties similar to conventional diesel fuel and this stimulated extensive research in this field. Reactions of OMDME1, the corresponding ethyl derivative OMDEE1 and dimethyl ether (DME) with trioxane have been carried out employing zeolite BEA25 as acidic catalyst. Thus, oligomer mixtures with n = 1–5 are obtained and very small amounts of higher oligomers are also formed. OMDMEn- or OMDEEn-forming reactions from the starting materials take place as well as subsequent transacetalization reactions which lead usually to a product distribution according to a Schulz–Flory distribution. Several transacetalization reactions have been studied, e.g. reactions of OMDME1 with OMDME3 and OMDEE1 with OMDEE3, which lead to the typical mixtures with n = 1–5. Reactions of OMDME1 with OMDEE1 yielded ethoxymethoxymethane, i.e. the acetal with mixed end groups. This allows for the tuning of oligomer mixtures and adjustment of properties according to the required demands of the respective application. Regarding DME as starting compound, the transacetalization reaction with OMDME3 yielded only small amounts of OMDME1–5 while the reaction of DME with trioxane yielded considerable amounts of the oligomers. The reaction is comparatively slow enabling a kinetic control of the oligomer distribution which exhibits an elevated selectivity for the desired OMDME3–5 fraction in the beginning of the reaction.

Lignocellulosic biomasses are strongly connected composites of cellulose, hemicelluloses, and lignin. A pretreatment is required in order to make these components available for their later conversion into chemicals. At this point, two strategies have to be considered: to either produce chemicals via microorganism or enzymes (1), or by chemical conversion (2). The focus of this article is the second strategy, which is chemical conversion, performed in water to produce the final products furfural and 5-hydroxymethylfurfural (HMF). Reviewed first is the composition of cellulose and hemicelluloses as well as their degradation chemistry in water. Then, fundamental modes of action and process parameters of pretreatment methods in aqueous solution are summarized. The pretreatment methods discussed here are steam explosion, treatment with hot liquid water, diluted and concentrated acids, as well as alkaline solutions. Finally, the advantages and disadvantages of these pretreatments are discussed for lignocellulosic biomass.

Gasification in supercritical water can be assisted with heterogeneous catalysts. Effective salt separation upstream of the catalyst is important to avoid poisoning of the catalyst and to recover nutrients. Recovery of phosphorus and nitrogen as well as gasification of a significant portion of the organic carbon were demonstrated on the pilot plant scale. A Ru/C catalyst was applied to catalyze the formation of CH4, which was the desired primary gasification product. On top of the catalyst, a bed of ZnO was used as sulfur adsorbent to protect the catalyst from deactivation. As feedstock for the process, glycerol, ethanol, and digestate sludge were studied. The results confirm the activity of the catalyst under the applied conditions. At a reaction temperature of 420 °C and a pressure of 280 bar, a gas composition close to thermodynamic equilibrium was achieved. Salt separation performed at 470 °C was effective, but the separation efficiency was less for potassium than for phosphorus. Fifty-six percent of the ash contained in digestate sludge was separated and recovered. Sulfur partly escaped the salt separation system and reached the reactor. The ZnO layer trapped most of this remaining sulfur. The remaining sulfur contamination was low enough not to poison the Ru/C catalyst completely. In total, 326 kg of glycerol, 334 kg of digestate sludge, and 167 kg of ethanol were gasified without any operational issues.

In the literature the frequency of splenic metastasis is documented very inconsistently. Only metastases of ovarial cancer are recommended for a surgical therapy. We examined the frequency of splenic metastasis in our hospital. The data of the Tumorboard Schwerin has been analyzed for splenic metastases. Based on hospital documents and contact via telephone the clinical course of the patients was also examined. A total of 6,137 of 29,364 patients with malignant tumors developed metastases (20.9%). We found 59 of these patients with splenic metastases (0.96%; 0.002% of all patients with malignant tumors). Men were more frequently concerned then women. The median age of the patients was 62 (26–88) years. There are only a few primary tumors metastasized in more than 1% into the spleen. A total of 47% of these metastases were synchronous, 53% metachronous. Only three patients had isolated splenic metastasis. Two further patients also had lymph node metastasis in the splenic hilus. Two other patients developed liver metastases after splenectomy. We performed four splenectomies because of splenic metastasis. The survival of splenic metastasis was median 3 (0–61) months. The published studies of the frequency of the splenic metastasis are autopsy studies, which are not usable for epidemiological statements because of selection bias. We show that splenic metastases arise in less than 1% of all metastases. A splenectomy in case of splenic metastases makes sense, if the metastases are isolated. It is also meaningful as a debulking procedure that would be followed by a chemotherapy, e.g. in case of an ovarial carcinoma. As a result the survival is increased for patients undergoing splenectomy (median survival 19.5 vs. 3 months).