Systems/methods for continuous operation of fixed bed reactors using gaseous fuels for power generation through integration with a combined cycle power plant are provided. The fixed bed reactors are assumed to operate in a semi-batch mode composed of reactor modules integrated into module trains that comprise the chemical-looping combustion island of the power plant. The scheduling of each reactor train is cast as an optimization problem that maximizes thermodynamic efficiency subject to constraints imposed to each reactor and the entire island. When the chemical-looping reactors are arranged cyclically, each feeding to or being fed from another reactor, in an operating scheme that mimics simulated moving bed reactors, the thermodynamic efficiency of the reactor island can be improved. Allowing the reversal of module order in the cyclically arranged reactor modules further improves the overall thermodynamic efficiency, while satisfying constraints imposed for carbon capture, fuel conversion, power plant safety and oxygen carrier stability.

A process for producing a polyol block copolymer in a multiple reactor system including a first and second reactor in which a first reaction takes place in the first reactor and a second reaction takes place in the second reactor. The first reaction is the reaction of a carbonate catalyst with CO.sub.2 and epoxide, in the presence of starter and/or solvent to produce polycarbonate polyol copolymer and the second reaction is the reaction of DMC catalyst with the polycarbonate polyol compound of the first reaction and epoxide to produce polyol block copolymer. The product of the first reaction is fed into the second as crude reaction mixture, the epoxide and the polycarbonate polyol compound of the first reaction are fed in a continuous or semi-batch manner, and/or the product of the first reaction has neutral or alkaline pH on addition to the second. The invention further relates to the copolymers and products incorporating such copolymers.

A process for producing a polyol block copolymer in a multiple reactor system including a first and second reactor in which a first reaction takes place in the first reactor and a second reaction takes place in the second reactor. The first reaction is the reaction of a carbonate catalyst with CO.sub.2 and epoxide, in the presence of starter and/or solvent to produce polycarbonate polyol copolymer and the second reaction is the reaction of DMC catalyst with the polycarbonate polyol compound of the first reaction and epoxide to produce polyol block copolymer. The product of the first reaction is fed into the second as crude reaction mixture, the epoxide and the polycarbonate polyol compound of the first reaction are fed in a continuous or semi-batch manner, and/or the product of the first reaction has neutral or alkaline pH on addition to the second. The invention further relates to the copolymers and products incorporating such copolymers.