Experimental,equilibrium modelling,and column design for the reactive separation of biomass-derived 2-furoic acid

Electrochemical conversion of biomass to value-added chemicals has gained impetus in recent years. Herein, we present a methodology for recovering biomass-derived 2-furoic acid from the dilute aqueous stream by reactive extraction. The reactive extraction was performed using a chemical extractant, trioctylamine (TOA), with diluents (octanol, chloroform, and diethyl ether). Equilibrium parameters influencing the recovery of 2-furoic acid were evaluated. Using TOA in various diluents, the 2-furoic acid was recovered with 85%–99% efficiency. A 1:1 complex of the 2-furoic acid—TOA was formed in the organic phase, and the experimental equilibrium complexation constant was compared with that obtained from the relative basicity and Langmuir models. The equilibrium parameters were used for column design to estimate the solvent to feed ratio (S/F) and the number of theoretical stages (NTS). The NTS required is 12 to attain 99% recovery of 2-furoic acid in counter-current extraction. The present study sheds light on the reactive extraction process adopted for process intensification with electrochemical conversion, paving the way for the commercialization of valuable products obtained from biomass.     

Air Oxidation of Benzene to Biphenyl – A Dual Catalytic Approach

Facile oxidative homocoupling of benzenes to the respective biphenyls is effected under moderate conditions, using air or oxygen in the presence of catalytic PdCl₂ and AcOH/AcONa as solvent. The fast regeneration of the active Pd ²⁺ species is accomplished by combining several oxygen‐binding catalysts, such as Zr(IV), Mn(II), and Co(II) acetates. In this way, it is possible to increase the content of active oxygen in solution so that the rate of catalyst regeneration is faster than the rate of aggregation of the „spent catalyst”︁, Pd(0), to palladium black. The effects of various process parameters are studied and some mechanistic implications are discussed.     

FlexBeamOpt: Hybrid solution methodologies for high-throughput GEO satellite beam laydown and resource allocation

Modern satellite communication systems are required to serve heterogeneous and geographically dispersed user demands with limited resources. In this paper, we investigate methodologies for dynamic resource allocation in Geosynchronous Earth Orbit (GEO) High-throughput Satellite (HTS) systems. We designed three solution approaches FlexBeamOpt v1 , FlexBeamOpt v2 , and FlexBeamOpt v3 , each as a hybridization of custom heuristics, integer linear programming, and/or constraint programming. We test the performance of the three approaches on 12 test instances that vary in user distribution (realistic, random, and clustered), user numbers (500 vs. 5000 users), and demand distribution (uniform vs. random). We observed that FlexBeamOpt v1  consistently outperformed FlexBeamOpt v2  and FlexBeamOpt v3  in terms of demand coverage and number of users covered for realistic and random user distribution test instances but at the cost of computation time. FlexBeamOpt v3  is the fastest in these instances. For clustered user distribution instances, FlexBeamOpt v3  performed better in terms of demand coverage and number of users covered, at the cost of using more beams. For these test instances, FlexBeamOpt v2  is the fastest in terms of computation time while providing a comparable solution quality.