Processes and systems for making recycle content hydrocarbons, including olefins, using a cracker furnace having enhanced coil design. In some cases, the design of the furnace may prevent coking, so that the run length of the furnace is longer than conventional cracking furnaces. Cracker feed streams to the furnace can include recycle content pyrolysis oil and may be used to form olefin-containing effluent stream having recycle content.

In chemical processes for cracking hydrocarbons, reactors are subject to coking During the decoke process carburization of the metal substrate can occur, negatively impacting reactor life. Decokes are also costly due to down-time where costs are incurred without production of commercial products. Reducing the frequency of decokes provides an opportunity to reduce the financial impacts of downtimes. A start-up procedure is described herein that limits initial coke deposition, leading to a reduced tendency for carburization of the metal substrate, improving reactor life, and more importantly, extending reactor run length.

The invention relates to an ethylene plant, comprising a cracking furnace for converting a hydrocarbon feedstock into a cracked gas stream; a separation section to provide at least an ethylene-enriched product stream, a hydrogen-enriched fuel stream and a methane-enriched fuel stream from the cracked gas stream; a passage way for feeding at least part of the hydrogen-enriched fuel from the separation section to a burner of the cracking furnace and/or a passage way for feeding at least part of the hydrogen-enriched fuel from the separation section to a burner of a waste heat recovery boiler of a combined cycle gas turbine power plant(CCGT); a methane storage configured for storing methane-enriched fuel and a passage way for feeding at least part of the methane-enriched fuel from the separation section to the storage; the CCGT, comprising a gas turbine—comprising a combustor—and a passage way for feeding at least part of the methane-enriched fuel from the storage to the combustor of the gas turbine of the CCGT, which CCGT is configured to generate electric power and/or to generate high pressure steam to drive a steam turbine forming part of a steam generation circuit of the ethylene plant; and an electric power connection for providing part of the power for operating the plant, which is a connection to an electric power system to produce electric power from a renewable source.

The present application relates to a process for cracking a hydrocarbon feedstock, using to the largest extent electrically powered equipment where the power is obtained from renewable sources or low-carbon sources. In particular, it relates to a furnace for steam cracking a hydrocarbon feedstock, wherein the furnace comprises one or more tubes for transporting the hydrocarbon feedstock and dilution steam; and an electrically heated infrared emitter for transferring heat to the tubes. It also relates to a process for steam cracking a hydrocarbon feedstock using infrared radiation.

The present invention addresses to a system and methodology for evaluating the deposition in tubes of the furnaces of delayed coking unit (DCU) in order to reduce the costs involved with premature shutdowns. With this system, load rankings are obtained, influences of certain loads on processing are evaluated, and additives that reduce deposition are further evaluated. Consequently, the results obtained by such a system allow greater flexibility for the follow-up engineer to optimize his delayed coking unit in order to increase load or increase the unit campaign time, drastically reducing costs in premature shutdowns, or increasing its return by increasing load and shutdowns, since the load is limited by the degree of deposit formation, and that directly affects the wall temperature.

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−1, where k is the ratio of fluid specific heat at constant pressure (Cp) to fluid specific heat at constant volume (Cv).

Recycle content pyoil is cracked in a cracker furnace to make olefins and the coil outlet temperature of the r-pyoil fed coils can he lowered by adding r-pyoil to the cracker feedstock, or alternatively, the coil outlet temperature of the r-pyoil fed tubes can rise if the mass flow rates of the combined cracker stream containing r-pyoil are kept the same or lowered. Further, increasing the hydrocarbon mass flow rate by addition of r-pyoil can be achieved to also increase the output of ethylene and propylene in the cracker effluent. The cracker furnace can accept ethane and/or propane feedstocks in vapor form along with a liquid and/or vapor feed of r-pyoil.

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 ≥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.

A predominantly C.sub.2 to C.sub.4 hydrocarbon cracker stream is combined with recycle content pyrolysis oil to form a combined cracker stream and the combined cracker stream is cracked in a cracker furnace to provide an olefin-containing effluent. The r-pyoil can be fed to a first coil while a second cracker feed with none of the r-pyoil or less of the r-pyoil is fed to a second coil, and both are cracked in a cracker furnace to form an olefin-containing effluent stream. Alternatively, the r-pyoil can be fed and distributed across multiple coils along with the non-recycle cracker feed. The furnace can be a gas fed furnace, or split cracker furnace. Further, a first cracker stream with r-pyoil in a first coil can have a lower total molar flow rate than a second cracker stream in a second coil in the same furnace.

Equipment for producing ethylene and/or acetylene from hydrocarbons, including the reaction chamber (13), burner (11), common or separate fuel gas inlets (12) and oxygen inlets (18), preheating tubes (14), a gas distributor (15), cracking gas inlets (16), and a reaction product outlet (17); the gas distributor (15), which has multiple gas inlets and gas outlets, is arranged on the cross section of the reaction chamber (13), where the gas inlet is connected to the cracking gas inlet (16), and the gas outlet is connected to the preheating tube (14). The cracking gas is uniformly distributed through the gas distributor (15) and passed through the preheating tubes (14), which are hollow tubes; the opening at the other end of the hollow tube is close to or inserted into the combustion area of the gaseous fuel and oxygen.