Patent ID: 7789939
Filing Date: 2010-09-07
Classification: B01D,F25J,G05B,Y02C

Abstract:
1. A method of controlling repressurization of adsorbent beds within an adsorption unit comprising: repressurizing one of the adsorbent beds while off-line with a repressurization stream during regeneration of the one of the adsorbent beds such that the one of the adsorbent beds is brought back to an operational pressure and is ready to be brought back to an on-line status; measuring product stream flow rate of a product stream produced by the adsorption unit and controlling the flow rate of the repressurization stream such that the product stream flow rate remains within a target range; during the repressurization of the one of the adsorbent beds, controlling a compressor feeding a compressed feed stream to the adsorption unit such that a feed flow rate of the compressed feed stream will increase from a nominal flow rate until a ratio of adsorbent bed pressures of the one of adsorbent beds and another of the adsorbent beds in the on-line status reaches a triggering pressure ratio and then will return back to the nominal flow rate after the triggering pressure ratio is reached over a target decrease time period; the feed flow rate being controlled with respect to each of the adsorbent beds in accordance with an increase rate function and a decrease rate function; tuning the increase rate function and the decrease rate function for each of the adsorbent beds such that deviations in the response of the product flow from the nominal flow rate during repressurization of each of the adsorbent beds is minimized and driven towards a value that is the same for all of the adsorbent beds; and adjusting the increase function for each of the adsorbent beds during operation of the adsorption unit such that repressurization times for each of the adsorbent beds is driven toward a target repressurization time.