A flexible air separation process: 1. Design and steady‐state optimizations

Abstract

The flexible operation of energy-intensive processes, such as cryogenic air separation, has economic potential due to increasing fluctuations of the electricity markets. Multiproduct air separation processes with high ratios of liquid product are very promising for flexible operation due to storable products. We present a process design with an integrated liquefication cycle and liquid assist operation, that facilitates a high liquid product ratio and a flexible process operation. We use a mechanistic dynamic process model in steady-state process optimizations covering the wide operational range of the proposed process. The optimization results show that the power demand can be varied in a range from 3.5 to 28 MW without violating operational constraints by changing the nitrogen and oxygen production rates. Thus, the proposed process is a promising air separation candidate for flexible operation with respect to fluctuating electricity markets.

Nonlinear scheduling with time‐variable electricity prices using sensitivity‐based truncations of wavelet transforms

“…The considered process configuration has been tailored to a high load flexibility and is described in detail our in previous works. 31,35 Most importantly, the process configuration comprises an integrated liquefaction cycle enabling a high ratio of storable liquid products. Moreover, the configuration allows for liquidassisted operation, where stored cryogenic LIN is fed back to the rectification section.…”

“…The power consumption is calculated using an artificial neural network fitted to optimized steady-state operating points using a rigorous process model from literature. 31 ASU, air separation unit [Color figure can be viewed at wileyonlinelibrary.com]…”

“…Therein, we address the production planning subject to time-variable electricity prices for an industrial-scale air separation unit (ASU), which was designed for increased flexibility in previous work. 31 We utilize high-fidelity power consumption data from steady-state opti-…”

Separation Units 4.0 – Trennapparate heute und morgen

“…Ein ähnliches Vorgehen schlagen Caspari et al. , für Luftzerlegungsanlagen vor, die ebenfalls in Abhängigkeit des Strompreises in verschiedenen Modi betrieben werden können.…”

Power‐to‐X: Between Electricity Storage, e‐Production, and Demand Side Management

“…The latter responses consider electricity spot prices to reduce electrical energy costs. In addition to the economic benefits, environmental impacts, especially carbon footprint, can be mitigated by exploiting electricity with a high share of RES [34,35] electricity-intensive industrial processes such as air separation units (ASU) [36][37][38][39], chlor-alkali (CA) electrolysis [32,40], seawater reverse osmosis [41], and aluminum production processes [42], DSM is particularly worthwhile.…”