Propylene/propane separation by vacuum swing adsorption using 13X zeolite

Abstract

A vacuum swing adsorption process using 13X zeolite pellets with jice steps was designed to split an equimolar mixture of propylene/propane: pressurization with feed; high-pressure feed; high-pressure puige with product; cocurrent blowdown; and countercurrent vacuum blowdown, where the enriched propylene product is withdrawn. In the process, the partial pressure of the C,-mixture is controlled with nitrogen, which is used as inert gas. With an equimolar feed of C, diluted to 50% with nitrogen, the column is fed at 5 bar and 423 K and the product is obtained when the total pressure is lowered to 0.1 bar. After 15-20 cycles, the cyclic steady-state condition is achieved, a propylene-enriched stream of 98 % mol relative to propylene/propane mixture, with 3.2 % of nitrogen, a recovery of 19% (molar basis), and a productivity of 0.785 mol/kg-h is obtained, The experimental work was complemented with numerical simulations, and the effect of different operating parameters on the pe@ormance of the VSA was considered.

Advances in Pressure Swing Adsorption for Gas Separation

“…This step was called "rinse." Although the rinse step aimed to provide a solution to concentration of low-per cent light compounds, it has been widely used for other purposes: concentration of the more adsorbed species [32,[120][121][122][129][130][131][132].…”

“…Co-n-current depressurization was also used to remove the less adsorbed gas from the column in order to increase the content of most-adsorbed gas inside the column (aiming to its concentration) [32,[120][121][122].…”

Separation of Carbon Dioxide from Flue Gas Using Adsorption on Porous Solids

“…The PSA experimental setup consisted of one fixed-bed adsorption that simulated the operation of a unit with several fixed-beds, for which more details are given elsewhere (Da Silva & Rodrigues, 2001). The solid adsorbent used was the commercial activated carbon which was pre-treated by passing helium at a flow rate of 1.0 L.min -1 and at 150°C for 12 hours.…”

New momentum and energy balance equations considering kinetic energy effect for mathematical modelling of a fixed bed adsorption column

“…The second simplified energy balance, hereinafter referred to as Simplified 2 model, has the following formula (Da Silva et al 1999, 2001Ribeiro et al 2008;Kim et al 2006).…”

“…Meanwhile, several researchers have included mathematical terms describing the pressure change with time in the energy balance in order to simulate the pressure-varying steps more accurately (Da Silva et al 1999, 2001Ribeiro et al 2008;Kim et al 2006). Furthermore, a separate momentum equation, e.g.…”