Exxonmobil Chemical Patents Inc.

Mark A Rooney

James N McCoy

John R Messinger

David Jon Duhon

Barrington M Hammond

Robert David Strack

William A Aslaner

Walter F Filupeit

Darian E Orozco

James Richardson Lattner

David B Spicer

Reyyan Koc-Karabocek

Venkatesh Subramania

Robert C Thiets

Christopher Dillard

Yuti L Yang

Robert A D Strack

Robert A Strack

Processes and systems for quenching an effluent. In certain embodiments, the process can include contacting a pyrolysis effluent and a first quench medium to produce a first quenched effluent. A bottoms stream that can include tar and an overhead stream that can include ethylene and propylene can be obtained from the first quenched effluent. The first quench medium can include a first portion of the bottoms stream that can include a first portion of the tar. In certain embodiments, the process can also include hydroprocessing a second portion of the bottoms stream that can include a second portion of the tar to produce a hydroprocessed product. A hydroprocessed bottoms stream can be obtained from the hydroprocessed product. In certain embodiments, the process can also include contacting at least a portion of the hydroprocessed bottoms stream and the first portion of the bottoms stream to produce the first quench medium.

Processes and systems for quenching pyrolysis effluents

In some examples, coke, tar, or a mixture thereof can be removed from a furnace effluent. The furnace effluent can include coke, tar, or the mixture thereof and can be contacted with a first quench liquid to produce a quenched mixture, wherein the first quench liquid can include a first steam cracker naphtha, a first steam cracker gas oil, a first steam cracker quench oil, or a mixture thereof. The quenched mixture can be introduced into a first inlet of a centrifugal separator drum. A vapor product and a centrifugal separator drum bottoms can be separated from the quenched mixture, wherein the centrifugal separator drum bottoms can include at least a portion of the coke, tar, or the mixture thereof. The centrifugal separator drum bottoms can be recovered from a first outlet of the centrifugal separator drum.

Coke and tar removal from a furnace effluent

In some examples, a flow of hydrocarbon feed can be introduced into a pyrolysis furnace that includes a first radiant coil and a second radiant coil. At least a portion of the hydrocarbon feed can be pyrolysed in the first radiant coil and the second radiant coil to produce a pyrolysis effluent and to deposit coke on an inner surface of each of the first radiant coil and the second radiant coil. The flow of the hydrocarbon feed can be decreased into the first radiant coil and the flow of the hydrocarbon feed into the second radiant coil can be maintained, wherein the flow of the hydrocarbon feed into the pyrolysis furnace can be decreased by about 10 vol. % to about 90 vol. %. A decoking feed including steam at a pressure of &#x2265;690 kPag can be introduced into the first radiant coil of the pyrolysis furnace to remove at least a portion of the coke deposited on the inner surface of the first radiant coil.

Processes for on-stream decoking

Chromium particulate emissions in flue gas can be reduced or minimized by incorporating a thin layer bed of a catalyst within the flue gas flow path of a furnace, boiler, or other furnace environment that includes Cr-containing surfaces. The thin layer bed of catalyst can correspond to, for example, a honeycomb monolith with catalyst supported on the monolith surface, so as to provide a high contact area while forcing all of the flue gas to pass through the catalyst bed. The honeycomb monolith structure and the depth of the bed can be selected to provide a reduced or minimized pressure drop across the catalyst bed, such as a pressure drop of 0.25 kPa (1.0 inches of water) or less. Exposing the Cr-containing flue gas to the thin layer catalyst bed can result in a treated flue gas with a lower content of Cr.

Filtration of chromium from flue gas in furnace stacks

Methods and systems for using temperature measurements taken from a compact insulated skin thermowell to optimize a pyrolysis reaction are provided. In the present systems and methods, the upstream temperature and the upstream pressure of a pyrolysis reactor is measured through an adiabatic restriction in the inlet manifold of a parallel tube assembly to provide an absolute upstream temperature and an upstream pressure. The downstream temperature of the pyrolysis reactor is also measured following an adiabatic restriction to provide an absolute downstream temperature. The downstream pressure is then determined by multiplying the absolute upstream pressure with the quotient of the downstream temperature divided by the upstream temperature as taken to the power of k/k&#x2212;1, where k is the ratio of fluid specific heat at constant pressure (Cp) to fluid specific heat at constant volume (Cv).

Coke mitigation in hydrocarbon pyrolysis

Centralizing the handling and manipulating of vaporization medium to a single subsystem that supplies multiple ammonia vaporizers allows for efficient and effective production of a corresponding vaporized ammonia stream containing a controlled quantity of ammonia. These vaporized ammonia streams can then be used in conjunction with ammonia-consuming devices to reduce NOx in NOx-containing exhaust streams from multiple furnaces.

System and process for delivering controlled quantities of ammonia to ammonia-consuming devices

In a system for thermal cracking gaseous feedstocks, the system including a gas cracker for producing an effluent comprising olefins, at least one transfer line exchanger for the recovery of process energy from the effluent and a water quench tower system, a process for extending the range of system feedstocks to include liquid feedstocks that yield tar is provided. The process includes the steps of injecting a first quench fluid downstream of a primary transfer line exchanger to quench the process effluent comprising olefins, separating in a first separation vessel a cracked product and a first byproduct stream comprising tar from the quenched effluent, directing the separated cracked product to a water quench tower system and quenching the separated cracked product with a second quench fluid to produce a cracked gas effluent for recovery and a second byproduct stream comprising tar. An apparatus for carrying out such process is also provided.

Controlling tar by quenching cracked effluent from a liquid fed gas cracker

In a system for thermal cracking gaseous feedstocks, the system including a gas cracker for producing an effluent comprising olefins, at least one transfer line exchanger for the recovery of process energy from the effluent and a water quench tower system, a process for extending the range of system feedstocks to include liquid feedstocks that yield tar is provided. The process includes the steps of injecting a first quench fluid downstream of the at least one transfer line exchanger to quench the process effluent comprising olefins, separating in a separation vessel a cracked product and a first byproduct stream comprising tar from the quenched effluent, directing the separated cracked product to the water quench tower system and quenching the separated cracked product with a second quench fluid to produce a cracked gas effluent for recovery and a second byproduct stream comprising tar. An apparatus for cracking a liquid hydrocarbon feedstock that yield tar is also provided.

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Humble, TX, United States of America

Mark A Rooney