1. A process for alkylating aromatics under at least partial liquid phase conditions which comprises:
(i) contacting a feed comprised of an alkylatable aromatic and an alkylating agent with an alkylation catalyst in a reactor maintained under liquid phase alkylating conditions to produce an alkylated aromatic product;
(ii) simultaneously contacting said feed and alkylation catalyst with a polar compound in said reactor maintained under said liquid phase alkylating conditions during which catalyst poisons deposited on said alkylation catalyst are desorbed, said catalyst poisons selected from the group consisting of nitrogen compounds, sulfur compounds and oxygen compounds;
wherein said alkylation catalyst is selected from the group consisting of MCM-22, MCM-36, MCM-49, and MCM-56; and
wherein said polar compound is selected from the group consisting of water, carbon monoxide, and formic acid.
2. The process of claim 1, wherein said alkylatable aromatic is selected from the group consisting of benzene, toluene, xylenes, alkylbenzenes, naphthalene and substituted naphthalenes and said alkylating agent is selected from the group consisting of C2-C16 olefins and substituted aromatics having 8 carbon atoms or more.
3. The process of claim 2, wherein said alkylatable aromatic is benzene and said alkylating agent is ethylene or propylene.
4. The process of claim 1, wherein said liquid phase alkylating conditions comprise a temperature ranging from about 100 to 300 C, a pressure ranging from 0.2 to 25 atmospheres, an WHSV of from 0.1 to 10 and an alkylatable aromatic compound to alkylating agent mole ratio of from about 0.1:1 to 50:1.
5. A process for producing ethylbenzene or cumene in a fixed bed reactor maintained under at least partial liquid phase alkylation conditions which comprises:
(i) contacting benzene with ethylene or propylene in said fixed bed reactor maintained under said liquid phase alkylating conditions in the presence of an alkylation catalyst selected from the group consisting of MCM-22, MCM-36, MCM-49, and MCM-56 to provide an ethylbenzene or cumene product, during which contacting said alkylation catalyst becomes at least partially deactivated by sorbing catalyst poisons present, said catalyst poisons selected from the group consisting of nitrogen compounds, sulfur compounds and oxygen compounds;
(ii) collecting said alkylated aromatic product; and
(iii) then treating said at least partially deactivated alkylation catalyst from step (ii) in said fixed bed reactor by contacting said alkylation catalyst with at least one polar compound selected from the group consisting of water, carbon monoxide, and formic acid, under treatment conditions of temperature, pressure and time which are sufficient to at least partially desorb said catalyst poisons from said at least partially deactivated alkylation catalyst.
6. The process of claim 5, wherein said polar compound is water in the form of steam.
7. A process for at least partial liquid phase production of ethylbenzene or cumene comprising the step of supplying a feed comprised of benzene, ethylene or propylene, catalyst poisons and water to a reactor having an alkylation catalyst selected from the group consisting of MCM-22, MCM-36, MCM-49 and MCM-56 and said reactor maintained under liquid phase alkylating conditions to produce ethylbenzene or cumene and whereby said catalyst poisons that are deposited on said alkylation catalyst are at least partially desorbed, said catalyst poisons selected from the group consisting of nitrogen compounds, sulfur compounds and oxygen compounds.
8. The process of claim 7, wherein the water content of the feed is less than about 100 ppm.
9. The process of claim 7, wherein said liquid phase alkylating conditions comprise a temperature ranging from about 100 to 300 C, a pressure ranging from 0.2 to 25 atmospheres, an WHSV of from 0.1 to 10 and an alkylatable aromatic compound to alkylating agent mole ratio of from about 0.1:1 to 50:1.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. In a temperature sensor, a method of matching transistors to generate currents of a known ratio, said method comprising:
generating a control signal from a control circuit, wherein said control signal comprises a value that defines a configuration;
detecting whether said value of said control signal has changed; and
provided said value has changed, switching a plurality of transistors from one configuration to a different configuration, wherein there are at least four transistors in said plurality of transistors and wherein a first configuration comprises connecting said at least four transistors in parallel and a second configuration comprises connecting the same said at least four transistors in series, wherein said first configuration produces a first current in a first circuit and in a second circuit, wherein said second configuration produces a second current in said first circuit and in said second circuit, wherein the ratio of said first current to said second current is said known ratio, and wherein said ratio of said first current to said second current is used to determine a temperature at a device coupled to said plurality of transistors.
2. The method as recited in claim 1 wherein the ratio of any error attributable to said first configuration to any error attributable to said second configuration is also equal to said known ratio.
3. The method as recited in claim 1 wherein said at least four transistors comprises a first transistor and a second transistor, and wherein said switching comprises:
inverting said control signal to produce a first switching signal;
inverting said first switching signal to produce a second switching signal;
controlling a first switching device with said second switching signal, wherein said first switching device is coupled between a first node and a first terminal of said first transistor;
controlling a second switching device with said second switching signal, wherein said second switching device is coupled between a second terminal of said first transistor and a second node;
controlling a third switching device with said first switching signal, wherein said second switching device is coupled between a third node and said first terminal of said first transistor;
controlling a fourth switching device with said first switching signal, wherein said fourth switching device is coupled between said second terminal of said first transistor and a seventh switching device;
controlling a fifth switching device with said second switching signal, wherein said fifth switching device is coupled between said first node and a first terminal of said second transistor;
controlling a sixth switching device with said second switching signal, wherein said sixth switching device is coupled to a second terminal of said second transistor and said second node;
controlling said seventh switching device with said first switching signal, wherein said seventh switching device is coupled between said fourth switching device and said first terminal of said second transistor; and
controlling an eighth switching device with said first switching signal, wherein said eighth switching device is coupled between said second terminal of said second transistor and a fourth node.
4. The method as recited in claim 1 wherein said pre-determined ratio is a square-number.
5. An apparatus for matching transistors to generate currents to a known ratio comprising:
a plurality of transistors, wherein there are at least four transistors in said plurality;
a switching circuit coupled to said transistors, said switching circuit for switching said transistors from one configuration to a different configuration in response to a control signal, wherein a first configuration comprises connecting all of said at least four transistors in parallel and a second configuration comprises connecting all of said at least four transistors in series, wherein said first configuration produces a first current in a first circuit and in a second circuit and said second configuration produces a second current in said first circuit and in said second circuit, wherein the ratio of said first current to said second current is said known ratio;
a control circuit coupled to said switching circuit, wherein said control circuit sends said control signal to said switching circuit; and
an additional transistor coupled to said plurality of transistors, wherein said ratio of said first current to said second current and the difference between a first base-emitter voltage of said additional transistor measured with said plurality of transistors in said first configuration and a second base-emitter voltage of said additional transistor measured with said plurality of transistors in said second configuration are used to determine a temperature of a chip that includes said transistor.
6. The apparatus as recited in claim 5 wherein said first configuration produces a first error current in said first circuit and said second circuit, wherein said second configuration produces a second error current in said first circuit and said second circuit, and wherein the ratio of said first error current and said second error current is also equal to said pre-determined ratio.
7. The apparatus as recited in claim 5 wherein said plurality of transistors comprises a first transistor and a second transistor, and wherein said switching circuit comprises:
a first inverter having an input coupled to said control signal;
a second inverter coupled to said first inverter;
a first switching device coupled between a first node and a first terminal of said first transistor, wherein said first switching device is controlled by an output of said second inverter;
a second switching device coupled between a second terminal of said first transistor and a second node, wherein said second switching device is controlled by said output of said second inverter;
a third switching device coupled between a third node and said first terminal of said first transistor, wherein said third switching device is controlled by an output of said first inverter;
a fourth switching device coupled between said second terminal of said first transistor and a seventh switching device, wherein said fourth switching device is controlled by said output of said first inverter;
a fifth switching device coupled between said first node and a first terminal of said second transistor, wherein said fifth switching device is controlled by said output of said second inverter;
a sixth switching device coupled between a second terminal of said second transistor and said second node, wherein said sixth switching device is controlled by said output of said second inverter;
said seventh switching device coupled between said fourth switching device and said first terminal of said second transistor, wherein said seventh switching device is controlled by said output of said first inverter; and
an eighth switching device coupled between said second terminal of said second transistor and a fourth node, wherein said eighth switching device is controlled by said output of said first inverter.
8. The apparatus as recited in claim 7 wherein said first transistor and said second transistor are controlled by a bias signal.
9. The apparatus as recited in claim 5 wherein said pre-determined ratio is a square number.
10. An apparatus for measuring the temperature of a transistor comprising:
a circuit for changing a collector current of said transistor between a first collector current and a second target collector current, said circuit comprising:
a plurality of transistors, wherein there are at least four transistors in said plurality;
a switching circuit coupled to said transistors, said switching circuit for switching said transistors from one configuration to a different configuration in response to a control signal, wherein a first configuration comprises connecting said at least four transistors in parallel and a second configuration comprises connecting the same said at least four transistors in series, wherein said first configuration produces a first current and said second configuration produces a second current, wherein the ratio of said first current to said second current is N2-to-one; and
a control circuit coupled to said switching circuit, wherein said control circuit sends said control signal to said switching circuit; and
a circuit for measuring a first base-emitter voltage of said transistor corresponding to said first collector current of said transistor and measuring a second base-emitter voltage of said transistor corresponding to said second collector current, wherein said first and second base-emitter voltages and the ratio of said first current to said second current are used to determine said temperature.