A heat-integrated prefractionator arrangement is studied for a ternary separation of a propane–butane–pentane mixture. These types of integrated prefractionator arrangements have large energy savings ...compared with the best of the direct or indirect sequence with no heat integration. However, a heat-integrated distillation system can be more difficult to control than a non-integrated arrangement, so good control systems are essential. In this work, the focus is on selecting control variables that will ensure that the promised energy savings are achieved. The method of self-optimizing control (Skogestad, 2000) has been used to provide a systematic procedure for the selection of controlled variables, based on steady state economics. The results show that the integrated prefractionator arrangement can have large energy savings compared with non-integrated arrangements and that controlling the ratio of the distillate flow to the feed flow has good self-optimizing properties.
A multi-effect distillation where the condenser of a high pressure column is integrated with the reboiler of a low pressure column has been studied. The method of self-optimizing control has been ...used to provide a systematic procedure for the selection of controlled variables, based on steady-state economics. The system has 10 degrees of freedom at steady state. The heat integrated distillation system was optimized to find the nominal operating point. It was found that the constraints on the product composition, area in the combined reboiler/condenser, the purity constraint in the low pressure column and the pressure in the low pressure column are active constraints. For the remaining unconstrained variable it was found that a temperature in the low-pressure column has good self-optimizing properties. The study also shows how there can be multiplicities in the objective function for certain variables in the system.
The muon-proton and muon-deuteron inclusive deep inelastic scattering cross sections were measured in the kinematic range 0.002 < x < 0.60 and 0.5 < Q(2) < 75 GeV2 at incident muon ...energies of 90, 120, 200 and 280 GeV. These results are based on the full
Results are presented for F-2(d)/F-2(p) and R(d) - R(p) from simultaneous measurements of deep inelastic muon scattering on hydrogen and deuterium targets, at 90, 120, 200 and 280 GeV. The difference ...R(d) - R(p), determined in the range 0.002 < x < 0.4 at
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