Abstract: A process for preparing C9-alcohols comprises a) providing a C4-hydrocarbon stream comprising butene and butane; b) subjecting the C4-hydrocarbon stream to oligomerization over an olefin oligomerization catalyst and fractionating the resulting reaction mixture to give an octene-containing stream and a butene-depleted C4-hydrocarbon stream; c) subjecting the butene-depleted C4-hydrocarbon stream to steam reforming or partial oxidation to give carbon monoxide and hydrogen; d) hydroformylating the octene-containing stream by means of carbon monoxide and hydrogen in the presence of a hydroformylation catalyst to form C9-aldehydes, where the carbon monoxide used and/or the hydrogen used originate at least in part from step c); and e) catalytically hydrogenating the C9-aldehydes by means of hydrogen.

Abstract: A process for preparing C9-alcohols comprises a) providing a C4-hydrocarbon stream comprising butene and butane; b) subjecting the C4-hydrocarbon stream to oligomerization over an olefin oligomerization catalyst and fractionating the resulting reaction mixture to give an octene-containing stream and a butene-depleted C4-hydrocarbon stream; c) subjecting the butene-depleted C4-hydrocarbon stream to steam reforming or partial oxidation to give carbon monoxide and hydrogen; d) hydroformylating the octene-containing stream by means of carbon monoxide and hydrogen in the presence of a hydroformylation catalyst to form C9-aldehydes, where the carbon monoxide used and/or the hydrogen used originate at least in part from step c); and e) catalytically hydrogenating the C9-aldehydes by means of hydrogen.

Abstract: Method and device for determining contact between a tool and a workpiece clamped on a processing machine. A signal, such as a high-frequency electrical current signal or an acoustic signal, is supplied between a location at the tool and a location at the workpiece. For as long as the tool and the workpiece are not in contact with each other, the signal has a specific amplitude. As soon as the tool and the workpiece make contact with each other, the two locations are additionally connected through a resistor connected parallel to the resistance of the machine. Thereby the amplitude changes significantly. The process can be performed manually and automatically. It can also be employed at a quasi-standstill of tool and/or workpiece, but also when the elements are moving.

Abstract: The invention relates to methods for removing gaseous contaminants and aerosols from a vapor-saturated gas stream, in which method a gas stream containing a) at least one gaseous contaminant which is soluble in a scrubbing liquid, with or without salt formation, and b) at least one aerosol with a particle size from 0.01 to 10 &mgr;m, is brought into contact, in a scrubber column, with a scrubbing liquid, the temperature of which is lower by at least 2° C. than the temperature of the gas stream, resulting in the formation of a vapor phase, the degree of saturation S of which is greater than 1, and in the removal of the gaseous and particulate contaminants from the gas stream.

Abstract: The invention is directed toward preparation of (meth)acrylic acid, comprising condensation of a gas comprising (meth)acrylic acid, absorption with water, and extraction with an aqueous solution forming a miscibility gap.

Abstract: A method of controlling the positioning and/or speed of axes on a machine tool as well as an apparatus for carrying out the method. The inventive method controls the positioning and/or speed of fast-rotating, high-accuracy orbital axes (i.e. rotational axes) of a gear-manufacturing machine, wherein a standard NC is used. The inventive method and apparatus are realized by the inclusion of a second control system which is provided in addition to the standard NC and is structured such that the known aliasing effects generated by underscanning and the limitation of the dynamics by the cycle times are avoided or considerably reduced. By application of the inventive method, higher accuracy can be attained while maintaining the full functional scope of the standard NC.

Abstract: The method is used for measuring and/or controlling the position of a rotating reference element of a machine tool as a function of the position of a rotating main guide element. The two elements execute a basic movement with a transmission ratio which is constant in the ideal case. From the elements executing the basic movements pulse sequences are derived and their frequencies are made equal. The reference element executes an additional movement which, compared with the basic movement, occurs slowly and is predetermined as a function of the position of another moving element. To superimpose the additional movement, at least one of the signals describing the basic movement is shifted in phase relative to the reference element and a phase comparison is executed between the signals obtained, in such a manner that the resolution of the phase shift is distinctly finer than the distance between adjacent pulses of the signals derived from the main guide element and from the reference element.