Separation Propane to Acrylic Acid design plant proses

33 conversion is increased. Selectivities of acetic acid and carbon dioxide remain relatively constant. 15 Figure 5.1: Product Selectivity Profiled for Propane Oxidation Over Diluted MoVTeNb Mixed Oxide Catalyst Aspen Plus Simulation The APSEN Plus simulations use the NRTL-RK property method. Due to the complex interactions between acrylic acid, acetic acid, and water, three separate azeotropes form. In order to accurately model these azeotropes, 5 additional binary interaction databanks needed to be loaded. VLE-RK, VLE-HOC, VLE-IG, LLE-Aspen, and VLE-LIT were loaded to improve the complex interaction modeling. Catalyst Assumptions This process uses a mixed metal oxide catalyst that is not commercially produced at the time of this report. While conversions and selectivities, which were used in modeling the reactor for scale-up, are known, there is no market information on cost. In order to estimate a cost, it was recommended to price the catalyst as bismuth molybdate. This estimation would give a reasonable frame of reference and allow for the catalyst cost to be included in the economic 15 Widi, R. K. 2012. Kinetic Investigation of Carbon Dioxid, Acetic Acid, Acrylic Acid Formation on Diluted and Leached MoVTeNb Catalyst. Indonesian Journal of Chemistry, 122, 131-134. 34 analysis of this process. It is also assumed that the catalyst needs to be replaced every two years. Additionally, it is estimated that the spent catalyst can be sold back to the supplier as raw material for 15 of the purchase price. Propane Supply Based on the proposed site location, it is assumed that propane will be supplied via pipeline for 0.213 per pound. It is further assumed that the propane is arriving in liquid form at standard ambient temperature 75°F, which sets its pressure at 150 psia. Pure Oxygen Supply Based on the proposed site location, it is also assumed that pure oxygen can be accessed via pipeline at 500 psig and standard ambient temperature 75°F for 0.03 per pound. Wastewater Treatment It is assumed that a wastewater treatment system already exists on site or nearby. Therefore, the economic analysis of this design does not include the installation of a wastewater treatment plant. Instead, the analysis includes the cost associated with wastewater treatment based on the hydro-loading and organic compositions of the wastewater streams. Purge It is assumed that a furnace for burning the purge gas stream already exists on site or nearby. Therefore, this design does not include the installation cost of a furnace in the economic analysis. The heating value for this stream was calculated, as well as its dollar value should it be sold to another local facility. The heating value can be used as a credit to offset the utility demand of the plant. Utility Usage It is assumed that utilities are readily available for purchase from public or private entities in the Gulf Coast Region where the plant would be located. Utility prices are estimated using Table 23.1 of Product and Process Design, by Seider, Seader, and Lewin. The figures are adjusted to 2013 prices using a CE value of 575. 35 Section 6 Equipment List Unit Descriptions