A gas-phase reactor with reversible exothermic reactions is the classical example of the many tradeoffs between operating costs and capital costs. Because per-pass conversion is limited by chemical equilibrium, recycle is almost always needed, and this gas recycle is expensive because of the high capital cost and high energy cost of gas compression. At low temperatures, conversion is limited by...

Gas holdup and mixing time were characterized in a forced circulation internal loop draft-tube reactor (unaerated aspect ratio≈ 6, downcomero-riser cross-sectional area ratio = 0.493) as functions of the forced liquid superficial velocity in the riser (ULr) and the gas superficial velocity in he riser (UGr). Data were obtained in air–water system. The operation ranges were 0≤ULr ≤ 0.051 m/s and...

Robust static feedback stabilization of linear systems with uncertainties and bounded control inputs is studied. Necessary and sufficient conditions of positive invariance of polyhedral domains with respect to motion of uncertain linear systems are formulated together with conditions ensuring the asymptotic stability of uncertain linear systems with bounded control inputs. The problem of robust...

A circular (close-loop) biorefinery, which integrates wastewater treatment with the generation of an energy precursor and organic fertilizer, tested at level a pilot plant treating 54,000 L per day (LPD) sewage, is described. In biorefinery’s first stage, sewage was treated in novel SHEFROL® (sheet-flow-root-level) bioreactor very rapid rate, indicated by hydraulic retention time mere 6 h, to t...

In this contribution, a theoretical study of the dynamic behaviour (open- and closed-loop) Feed-Effluent Heat Exchanger (FEHE) / Reactor system for catalytic combustion Volatile Organic Compounds (VOCs) is carried out. An additional supply energy provided by means furnace to achieve desired reactor inlet temperature. The positive feedback source instability that leads pronounced limit cycles in...

A simplified model of a direct current arcjet-assisted diamond chemical vapor deposition reactor is presented. The model is based upon detailed theoretical analysis of the transport and chemical processes occurring during diamond deposition, and is formulated to yield closed-form solutions for diamond growth rate, defect density, and heat flux to the substrate. In a direct current arcjet reacto...

The performances of a laboratory PhotoCatalytic Oxidation (PCO) device were determined using a recirculation closed-loop pilot reactor. The closed-loop system was modeled by associating equations related to two ideal reactors: a perfectly mixed reservoir with a volume of VR = 0.42 m³ and a plug flow system corresponding to the PCO device with a volume of VP = 5.6 × 10-3 m³. The PCO device was c...

In this paper inventory control is applied to a particulate system. The performance of inventory control is guaranteed only if the zero dynamics of the closed loop system is stable. Mathematical analysis for the stability of the particulate system is derived to show that the zero dynamics is stable. The approach is illustrated by the application to thermal deposition of silicon in a fluid bed r...

This work concerns the synthesis of discrete-time nonlinear controllers for nonlinear processes that make the closed-loop system linear in an input/output sense. The synthesis of state feedback controllers is studied first, followed b.y the synthesis of dynamic output feedback controllers. Both problems are solved within the globally linearizing control ( GLC) framework. Precise theoretical con...