Results Unit 800 produces ethylene and acetic acid through the partial oxidation of ethane. Ethylene, the most abundant product from the unit, is partitioned such that half of the product is used as a feed source for Unit 600 and the other half is sold on the market. Ethylene purity must reach at least 99.5% to be sold as reagent grade. The second desired product, acetic acid, is also sold on the market, at 99% purity.
Unit 800 consists of a fired heater to preheat the reactants, an isothermal reactor to produce ethylene and acetic acid, a series of heat exchangers to cool the product, and a separation train to distill products to an economically sustainable purity. Due to the complex kinetic expressions for the several reactions taking …show more content…
The feed consists of ethane and air, which is compressed, mixed, preheated to 285°C, and then sent to an isothermal packed bed reactor to form the desired products. The products then are sent through a series of heat exchangers to cool the product down to -30°C, creating a two phase flow which facilitates separation of the effluent. The output from the final heat exchanger is thus separated rather easily using a flash vessel. The vapor stream, containing the unreacted ethane feed and inert nitrogen as well as any ethylene and carbon dioxide formed in the reactor, is compressed then separated in a distillation column. The liquid stream from the flash vessel, primarily consisting of acetic acid and water, is heated and expanded before being sent to a distillation column to be separated into reagent grade (99% purity) acetic acid and a wastewater stream (Figure …show more content…
However, thanks to a MoV type catalyst, acidic acid is also produced at a rate comparable to that of ethylene (Faizur et al., 2010). Although most of the Unit was modelled in CHEMCAD, due to the complexity of the reaction rate expressions, simulation of the reactor could not be done directly in CHEMCAD, meaning that using MATLAB was necessary to model the reactor. For more information about kinetic parameters used, see appendix H. All the data needed to cost the equipment was found using the CHEMCAD simulation, in addition to extra calculations used to find the cooling loop necessary to keep the reactor to a constant
Unit 800 consists of a fired heater to preheat the reactants, an isothermal reactor to produce ethylene and acetic acid, a series of heat exchangers to cool the product, and a separation train to distill products to an economically sustainable purity. Due to the complex kinetic expressions for the several reactions taking …show more content…
The feed consists of ethane and air, which is compressed, mixed, preheated to 285°C, and then sent to an isothermal packed bed reactor to form the desired products. The products then are sent through a series of heat exchangers to cool the product down to -30°C, creating a two phase flow which facilitates separation of the effluent. The output from the final heat exchanger is thus separated rather easily using a flash vessel. The vapor stream, containing the unreacted ethane feed and inert nitrogen as well as any ethylene and carbon dioxide formed in the reactor, is compressed then separated in a distillation column. The liquid stream from the flash vessel, primarily consisting of acetic acid and water, is heated and expanded before being sent to a distillation column to be separated into reagent grade (99% purity) acetic acid and a wastewater stream (Figure …show more content…
However, thanks to a MoV type catalyst, acidic acid is also produced at a rate comparable to that of ethylene (Faizur et al., 2010). Although most of the Unit was modelled in CHEMCAD, due to the complexity of the reaction rate expressions, simulation of the reactor could not be done directly in CHEMCAD, meaning that using MATLAB was necessary to model the reactor. For more information about kinetic parameters used, see appendix H. All the data needed to cost the equipment was found using the CHEMCAD simulation, in addition to extra calculations used to find the cooling loop necessary to keep the reactor to a constant