Abwässer,Schlämme sowie feste Rückstände der chemischen Industrie — Aufbereiten,Verbrennen, Deponieren

Waste Water, Sludges and Solid Residues of the Chemical Industry — Processing, Combustion, Deposition The importance of waste control policy in large chemical plants is emphasized, and waste collection, transportation, treatment and disposal systems are described. The Uerdingen Works of Bayer AG are discussed as an example to demonstrate the nature, origin and treatment of individual types of waste materials (waste water, combustible and incombustible residues). The total waste water quantity generated consists of 80% cooling water, 10% waste water from inorganic production lines, and 10% waste water from organic production lines. The waste water which is laden with organic matter is purified in a mechanical, two-stage, biological waste water treatment plant (η > 96%). Waste water with a high organic loading is already specially treated during the operational process, in order to separate the greater part of organics (recycling). The combustible residues, 1/3 of which consists of refuse and 2/3 of residues having a solid, pasty, or almost liquid consistency, are fed to an incinerator. The mixed sludge from the central waste water treatment plant is also regarded as combustible residue. Following dehydration, this sludge is incinerated in a fluid-bed furnace, at the same time adding liquid residues. The incombustible residues (special wastes) are dumped onto controlled tipping grounds. These residues are made up of building rubble, cinder and slag discharged from incinerators and other installations. During the manufacture of inorganic pigments, other non-combustible residues are generated. These are neutralized and subjected to a secondary treatment process, in which the oxidisable components are reduced and are then precipitated in an insoluble form. The sludge produced is loaded on barges and used for filling-in exhausted gravel pits on the Lower Rhine. Residues which are particularly critical are filled into drums and stored underground in the caverns of a shut-down salt mine.     

Lysolecithin aus Getreidestärke,ein gut zugängliches,natürliches Lysophosphatid

Lysolecithin from Cereal Starch - An Easily Accessible Natural Lysophosphatide From cereal starch, especially wheat starch, a well defined lysolecithin is obtained preparatively by relatively simple means. The lipids are quantitatively extracted with butanol-water (65:35). After purification one obtains a lysolecithin having the fatty acid rest in 1-position. Linoleic acid is the major fatty acid, followed by palmitic acid. The lysolecithin isolated is highly sensitive towards autoxidation, however, as clathrate with amylose it is well protected against alterations.     

Latentwärmespeicher: Speichermaterialien,Wärmeübertragung und Anwendungen

Phase change materials (PCMs) can absorb/release heat during the phase change. They are frequently used in thermal storage systems due to their large latent heat und isothermal nature. This paper provides an overview of the various inorganic and organic PCMs. Techniques for improving their thermophysical properties and the corrosion of metallic construction materials by inorganic PCMs are discussed. Finally, typical applications for latent‐heat storage systems are presented.     

Darstellung,Struktur und Reaktivität quartärer Ammoniumcellulosate

Tetraalkylammonium cellulosates were prepared by means of an exchange reaction between cellulose and tetraalkylammonium methoxides in anhydrous methanol and dimethylsulfoxide up to a degree of substitution of about 0,7 without chain degradation. The course of this reaction and the structure of the cellulosates in comparison to lithium and sodium cellulosate has been studied. The reaction rate and the equilibrium substitution decreased with increasing size of the cation in the methoxide. The distribution of the alcoholate groups in equilibrium at C-2, C-3 and C-6 of the glucopyranosyl unit in the cellulosates, which was investigated by methylation, hydrolysis of the methylcelluloses, and analysis of the methylglucoses by gas chromatography, was independent of the nature of the cation. Under the given reaction conditions the hydroxyl group at C-2 was more acidic than those at C-3 and C-6, while for the latter practically no difference was found. The tetraalkylammonium cellulosates are highly reactive intermediates for the preparation of cellulose derivatives. The reactivity of the cellulosates increased with increasing size of the cation, Li^⊕ < Na^⊕ < N(CH₃)₄^⊕ <[(CH₃)₃N? CH₂? C₆H₅]^⊕.     

Wärmeübergang in kurzen,wandgängig gerührten Apparaten

Scraped surface heat exchanger are often used in industrial settings for the treatment of systems with solid particle formation or higher viscosities. In reactors with a small length‐diameter ratio, the backmixing has thereby a significant influence on the heat transfer. In the experiments presented here, it can be shown that the heat transfer coefficient strongly depends on the flow pattern within the laminar flow regime, and that, depending on the running conditions, an increased rotor speed may have a negative effect on the heat transfer rate.     

Dithiocarbonsäuren,Dithiocarbonsäureester oder Thiocarbonsäureamide aus methylenaktiven Chlormethylverbindungen und Schwefel

Dithiocarboxylic Acids, Dithiocarboxylic Esters, or Thiocarboxylic Amides by Reaction of Methylene-active Chloromethyl Compounds with Sulfur With a mixture of sulfur and amine in DMF at room temperature halomethyl compounds ( 1 , 5 – 10 ) can be oxidized to give thiocarboxylic acids ( 2 , 11 – 16 ) and their derivatives ( 3 , 4 , 17 – 35 ). We studied this reaction in detail especially with chloroacetic derivatives ( 11 – 15 ) or chloromethyl heterocycles ( 16 ) formally derived from chloroacetic acid. The resulting thiooxalic acid derivatives ( 11 – 27 ) represent activated acids and very useful C₂-synthons, especially for the synthesis of heterocycles. Oxidation in the presence of triethyl amine leads to dithiocarboxylates ( 11 – 16 ) which can be alkylated to dithioesters ( 17 – 27 ) in high yields. As a rule, with different primary and secondary amines instead of tertiary amines these dithiocarboxylates or dithiocarboxylic esters can be transformed already at low temperatures to thioamides ( 28 – 35 ).     

Über Viskositäten und das Viskosität-Temperatur-Verhalten von Alkylcycloalkanen,Alkylbenzolen, Alkenen und einigen Äthylenglykoläthern im Vergleich zu den n-Alkanen

Viscosities and Viscosity-Temperature-Relationships of Alkyl Cycloalkanes, Alkyl Benzenes, Alkenes and some Ethyleneglycol Ethers Compared to n-Alkanes Kinematic viscosities of a few alkyl cycloalkanes were determined at different temperatures. The viscosities at 20°C and the viscosity-temperature-relationship of alkyl cycloalkanes are compared to those of alkyl benzenes, alkenes, alkanes and some ethyleneglycol ethers.