摘要:
The invention relates to a process for the preparation of an alkali metal catalyst by mixing an alkali metal with pulverulent, solid potassium carbonate as support, wherein the potassium carbonate has a specific surface area of at least 0.3 m2/g, and to the use thereof for the side-chain alkylation of alkylbenzenes.
摘要:
In a process for reducing the formation of polymers during side-chain alkylation or side-chain alkenylation of alkylaromatic compounds by reaction with olefins or diolefins in the presence of an alkali metal catalyst followed by distillation in order to isolate the alkylated or alkenylated compound, the alkali metal is present in the catalyst on an inorganic support, and the catalyst is mechanically separated from the reaction mixture after the reaction and before the distillation.
摘要:
The present invention describes a process for the preparation of ethyldimethylamine and triethylamine with the following steps: (i) reaction of a mixture of diethylamine and dimethylamine with ethylene in the presence of a catalyst from the group of alkali metal dimethylamides, alkali metal diethylamides and alkali metal hydrides (ii) removal of the catalyst (iii) distillation separation of the resulting mixture in triethylamine and ethyldimethylamine and optionally diethylamine and dimethylamine (iv) optional return of the catalyst and of the starting amines to the reaction. The process according to the invention permits the coproduction of ethyldimethylamine and diethylamine in a simple process.
摘要:
A process for preparing dialkylamides of the alkali metals by reacting the corresponding dialkylamine with the corresponding alkali metal in the presence of an electron-donating substance selected from the group consisting of 1,3-butadiene, isoprene, naphthalene and styrene with formation of small amounts of butenyldialkylamine comprises suspending the corresponding alkali metal in a solvent and subsequently adding dialkylamine and electron-donating substance in such a way that the dialkylamine is present in an amount of up to 45% by weight, preferably up to 25% by, weight, in particular up to 15% by weight, and the butadiene is present in an amount of up to 5% by weight, preferably up to 3% by weight, in particular up to 1.5% by weight.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. With the aid of the check valve and the difference pressure sensor which measures the pressure difference between the pressure in the tank and the ambient pressure, the tank-venting arrangement can be so operated that at least for a running engine, a desired maximum overpressure in the tank can be obtained relative to the ambient pressure independently of the extent of the underpressure in that part of the arrangement forward of the check valve.
摘要:
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.
摘要:
A method and a device for controlling fuel injection in multi-cylinder internal combustion engines, includes means for computing a time shift of a common time point for ignition start in respective cylinders to a new value at which pressure differentials in respective intake pipes are approximately equal and consequently .lambda.-dispersion is minimized.