Abstract: Process for the preparation of n-butylamines where n-butenylamines are firstly prepared by reacting 1,3-butadiene in the form of a 1,3-butadiene-containing mixture obtained during the cracking of petroleum fractions or during the dehydrogenation of LPG or LNG or from GTL technology with a primary amine and/or a secondary amine under hydroaminating conditions, and the resulting butenylamine(s) are then reacted in a second process stage under hydrogenating and transalkylating conditions.

Abstract: The present invention relates to a method for operating a fuel metering system (11) of a direct-injection internal combustion engine (1), having a fuel supply container (12), at least one prefeed pump (13), a high-pressure pump assembly having at least two high-pressure pumps (14, 15) for pumping fuel out of the low-pressure region (ND) into at least one high-pressure reservoir (16; 16′, 16″), a control unit (22) for regulating an injection pressure (p_r) prevailing in the high-pressure reservoir (16; 16′, 16″), and having fuel injection valves (9) for injecting fuel out of the high-pressure reservoir (16; 16′, 16″) into combustion chambers (4) of the engine (1).

Abstract: A catalyst comprising at least one alkali metal and at least one metallic or semimetallic promoter selected from the group consisting of Ca, Sr, Ba, Ag, Au, Zn, Cd, Hg, In, Tl, Sn, As, Sb and Bi, on a support which may be doped with one or more compounds of an alkali metal and/or alkaline earth metal, where the alkali metal/support ratio by weight is from 0.01 to 5, the promoter/alkali metal ratio by weight is from 0.0001 to 5 and, when a dopant is present, the dopant/support ratio by weight is from 0.01 to 5.

Abstract: A process for preparing halogen-free, reactive polyisobutene having a terminal double bond content of more than 60 mol % and an average molecular weight Mn of 800-3000 dalton by cationic polymerization in the liquid phase of isobutene over an acidic, essentially halogen-free heterogeneous catalyst, where a) a hydrocarbon mixture of essentially C4-hydrocarbons comprising isobutene in an amount of from 10 to 80% by weight is used as the starting material and b) polymerization is carried out continuously at from −30 to 0° C. with average starting material residence times of one hour or less, where the temperature and the residence time are selected such that the isobutene conversion is less than 60% and, after separation from the resulting polyisobutene, the isobutene is either enriched in the partially converted hydrocarbon mixture and returned to the polymerization or passed to another isobutene reaction coupled with the polymerization.

Abstract: The invention is directed to a method and an arrangement for synchronizing at least two power-adjusting elements of an internal combustion engine which are electrically driven independently of each other. For carrying out the synchronization, the intervals between the respective combustions or the corresponding segment times of at least two cylinders are detected to which individual power-adjusting elements are allocated and their deviation is determined. At least one power-adjusting element is adjusted in order to maintain this deviation within a pregiven tolerance band. A correction of the control of the power-adjusting elements is derived in dependence upon the adjustment. The power-adjusting elements are adjusted in mutually opposite directions.

Abstract: A catalyst comprising at least one alkali metal and at least one metallic or semimetallic promoter selected from the group consisting of Ca, Sr, Ba, Ag, Au, Zn, Cd, Hg, In, Tl, Sn, As, Sb and Bi, on a support which may be doped with one or more compounds of an alkali metal and/or alkaline earth metal, where the alkali metal/support ratio by weight is from 0.01 to 5, the promoter/alkali metal ratio by weight is from 0.0001 to 5 and, when a dopant is present, the dopant/support ratio by weight is from 0.01 to 5.

Abstract: A catalyst comprising at least one alkali metal and at least one metallic or semimetallic promoter selected from the group consisting of Ca, Sr, Ba, Ag, Au, Zn, Cd, Hg, In, Tl, Sn, As, Sb and Bi, on a support which may be doped with one or more compounds of an alkali metal and/or alkaline earth metal, where the alkali metal/support ratio by weight is from 0.01 to 5, the promoter/alkali metal ratio by weight is from 0.0001 to 5 and, when a dopant is present, the dopant/support ratio by weight is from 0.01 to 5.

Abstract: The catalyst comprises at least one alkali metal on a support which has the general formula (I) An′Tim′Zrp′Hfq′On′+2(m′+p′+q′)  (I) where A is a divalent metal, 20·(m′+p′+q′)>n′>0.05·(m′+p′+q′), and which may be doped with at least one compound of an alkali metal and/or alkaline earth metal, where the alkali metal/support ratio by weight is 0.01-5:1 and, when a dopant is present, the dopant/support ratio by weight is 0.01-5:1, and where the proportion of support phase corresponding to the ZrO2 structure or an alkaline earth metal oxide structure or consisting of ZrO2 or alkaline earth metal oxide is less than 10% by weight.

Abstract: A device for lowering boost pressure as a function of a defined setpoint engine torque (MMS) when the setpoint engine torque (MMS) or a setpoint engine performance quantity associated therewith is smaller than a corresponding engine performance quantity (MMFA) that is specified without boost pressure intervention. Thus, all performance quantities which require a specific engine torque are able to be controlled in open or closed loop by lowering boost pressure.

Abstract: A method and a device for controlling the exhaust temperature for a combustion engine with knock control by varying the air/fuel mixture supplied to the engine as a function of ignition-retard settings to prevent knocking, as are undertaken by a knock-control device, an increasingly retarded ignition (setting) entailing increasing enrichment; the procedure is such that a cylinder-selective enrichment follows in dependence upon the momentary ignition-retard (setting) in a cylinder.

Abstract: A process for determining the flow rate of a fluid, in particular of an air flow of an internal combustion engine, a temperature dependent resistor through which a heating current flows being arranged in the flow path of the fluid, the size of the heating current being a measure of the flow rate of the fluid, the temperature of the resistor being determined by a temperature sensor and being set to a constant value by means of a circuit arrangement which influences the heating current, and the fluid flow rate determined immediately after the start of the fluid flow being corrected by means of a correction value (k, k') in order to compensate for a measurement error which occurs when the heating current is switched on but when fluid is not yet flowing due to temperature deviation of the resistor.

Abstract: In the method for the adapted precontrol and feedback control of the air/fuel mixtures to be supplied to the two fuel-metering devices of an internal combustion engine, which has two separate exhaust-gas channels with a lambda probe and a catalytic converter in each channel, a common value of the precontrol manipulated variable and a common lambda desired value are determined for both fuel-metering devices. On the other hand, values of a control manipulated variable are determined separately for each fuel-metering device and values of precontrol adaptation variables, which are dependent upon the values of the control manipulated value, are determined and are superposed separately one after the other on the common precontrol value. This method makes it possible to manage with a single device for both cylinder banks which are to be operated in a stereo lambda control.

Abstract: A method is introduced of checking the drivability of a tank-venting valve (TEV) and of an idle actuator.After actuating the TEV, an additional air/fuel mixture is supplied to the intake region of an internal combustion engine having an air/fuel ratio which can be equal to that at which the engine usually operates (.lambda..sub.0) or greater or less than .lambda..sub.0. Reactions of a .lambda.-control and/or of an idle control can be evaluated in dependence thereon. It is advantageous that a check is made independently of how intense the additional air/fuel mixture is enriched with fuel.

Abstract: A tank-venting arrangement includes: a tank; an adsorption filter connected to the tank; a tank-venting valve interconnecting the adsorption filter and the intake pipe of the engine; a control unit for driving the tank-venting valve so that it closes or opens; a pressure difference sensor for measuring the pressure difference between the pressure in the tank and the ambient pressure; and, an integrating unit for determining the time integral of the pressure difference. With this tank-venting arrangement, a simple and reliable determination can be made as to when so much fuel vapor should have been adsorbed in the active charcoal filter so that when the tank-venting valve is opened thereafter, a lean correction by means of a lambda controller can be required. If this lean correction is not made, this is an indication that the fuel flowing from the tank has not reached the tank-venting valve so that the tank-venting arrangement leaks or is obstructed.

Abstract: A tank-venting arrangement includes: a tank having a tank closure; an electrically drivable check valve; an adsorption filter; connecting lines for interconnecting the above components; a difference pressure sensor which measures the pressure difference between the pressure in the tank and the ambient pressure and supplies a pressure difference signal; a comparator which, at least for a running engine, compares the pressure difference signal to upper and lower threshold values and supplies an opening signal to the check valve to open the latter when the pressure difference signal is greater than the upper threshold value and a closure signal for closing the check valve when the pressure difference signal drops below the lower threshold value; and, a detector unit which supplies an opening signal to the check valve for opening the check valve when the sensor determines a possible opening of the tank and a closure signal for closing the check valve when the sensor determines a possible closure of the tank.

Abstract: A tank-venting system has an adsorption filter (AF) with a venting line (BL) which can be shut off by means of a controllable shut-off valve (AV). The shut-off venting valve makes it possible to set underpressures and overpressures in the system in a concerted manner in order to check its operability. As a result, particularly reliable information relating to the operability can be obtained.

Abstract: A tank-venting arrangement for a motor vehicle includes a fuel tank KT having a HC (hydrocarbon)-sensor, an adsorption filter AF and a tank-venting valve TEV. If the HC-sensor annouces that fuel vapor above a pregiven concentration is present in the tank, then it is expected that a lambda correction in the lean direction is required when the tank-venting valve is opened. If such a correction is not determined, this shows that either the arrangement leaks or the tank-venting valve does not open correctly. For carrying out the mentioned testing method, this arrangement requires only a single additional sensor, namely, the HC-sensor mounted in the tank. The arrangement is therefore simpler than known arrangements and nonetheless permits carrying out a reliable method for checking the operability.

Abstract: A method is disclosed for obtaining output values for actuating a tank venting valve connected to the intake pipe of an internal combustion engine. A control factor is supplied by a lambda controller computing step and modifies a loading factor until a regenerating fuel quantity leading to no deviation from the lambda desired value is supplied via the tank venting valve. The controlled loading factor modifies precontrol values for the regenerating fuel quantity which is supplied in an operating condition. The method takes into consideration the pressure conditions at the tank venting valve. This makes it possible to place the opening of the tank venting pipe into the intake pipe of an internal combustion engine behind the throttle flap where there is a great negative pressure, which, however, can fluctuate within wide limits.

Abstract: The invention is directed to a method and an apparatus for controlling the overrun mode of operation of an internal combustion engine, wherein instantaneous values of the relevant negative speed change of the internal combustion engine are sensed and evaluated to control the overrun mode. In this arrangement, a higher resume speed which is selected on commencement of the overrun mode and reduced to a lower speed limit after a predetermined time function, can be shifted additionally in dependence on the negative speed change. Further, to keep an internal combustion engine from stalling, the actual value of the negative speed change can be compared with a predetermined desired value; if it exceeds that value, the decision for a resume of fuel delivery can be made without delay.

Abstract: A method of and a device for regulating air-fuel ratio of an internal combustion engine includes an oxygen or lambda probe and a signal processing unit connected to the lambda probe. The change-overs of the lambda signal at the output of the lambda probe are compared with a succession of adjustable first time intervals t.sub.1 and, when no change-over is detected during the first time interval, the output signal from the signal processing unit which controls the air-fuel ratio is abruptly changed in a jump. To avoid overshoot of the output control signal, there is provided a resetting unit by means of which the jump of the control signal is reversed when the change-over of the lambda signal occurs in an additional monitoring time interval t.sub.2 following the first monitoring time interval t.sub.1.