Economy, environmental assessment and energy conservation for separation of isopropanol/diisopropyl ether/water multi-azeotropes via extractive distillation coupled pervaporation process

This wok proposed the extraction distillation coupled pervaporation(ED+PV) technology process using two different solvents to separate isopropanol(IPA) and diisopropyl ether(DIPE) from DIPE/IPA/H_(2)O ternary heterogeneous azeotropes in industrial wastewater from the synthesis of isopropanol in this study.Based on strict design specifications, simulation and sequential iteration methods are used for process design and optimization. Compared to the ethylene glycol(EG)-EG+H_(2)O process and the 1,3-propanediol(PDO)-IPA+H_(2)O process, the total annual cost(TAC) of the EG-IPA+H_(2)O process decreased by 20.76% and 7.86%(PDO). Compared to the EG-EG+H_(2)O process, the TAC of the PDO-IPA+H_(2)O process reduced 14%, but the global warming potential(GWP) and human toxicity of the PDO-IPA+H_(2)O process increased 11.3% and 4.07% respectively. Compared to the PDO-IPA+H_(2)O process, the EG-IPA+H_(2)O process saves 7.86%(TAC), 9.78%(GWP) and 9.85%(human toxicity). The ED+PV process with EG is superior to PDO in factors of TAC, energy consumption, human toxicity and environment. The EG-IPA+H_(2)O process changed the separation order of the products of the multi-azeotropic system, reduced the cost and energy conservation of the system, and enhanced the environmental protection evaluation of the process, is the best process through life cycle assessment for analyzing the economy, energy conservation, environmental assessment and human toxicity, designing cleaner products, controlling waste discharge, and promoting the chemical purification industry. This work provides a new process design and optimized separation ideas, will have a good guiding significance for the research and application separation of multi-azeotropic mixture with mixed solvents in organic wastewater from the cleaner chemical production, has been up to standard wastewater discharge process, and realized the development goal of carbon peak and carbon neutrality in the sustainable development of chemical clean industry.

A novel carbon cycle process assisted by Ni/La_(2)O_(3) catalyst for enhanced thermochemical CO_(2) splitting

Thermochemical two-step CO_(2) splitting is a potential approach that fixes the sustainable resource into transportable liquid fuels.However,the harsh CO_(2) splitting conditions,the limited oxygen release kinetics and capacity of metal oxides block further promoted the CO yield and solar-to-fuel energy efficiency.Here,we propose a different carbon cycle assisted by Ni/La_(2)O_(3) via coupling methane decomposition with thermochemical CO_(2) splitting,replacing conventional metal oxides cycle.Superior performance was demonstrated with methane conversion reached around 94%with almost pure H_(2) generation.Encouragingly,CO_(2) conversion of 98%and CO yield of 6.9 mmol g^(-1) derived from CO_(2) were achieved,with peak CO evolution rate(402 mL min^(-1) g^(-1))of orders of magnitude higher than that in metal oxide process and outstanding thermodynamic solar-to-fuel energy efficiency(55.5%vs.18.5%).This was relevant to the synergistic activation of La_(2)O_(3) and Ni for CO_(2) in carbon cycle,thus improving CO_(2) splitting reaction with carbon species.

Multiobjective-Multicriterion Decision Making for Selecting Design Scheme of an Absorption Refrigeration System

In this paper, first, a biobjective thermodynamics model of minimizing comprehensive quantity of boiler vapour consumption and maximizing thermodynamics efficiency of an absorption refrigeration system is established, solved by a multiobjective optimization method to generate a non-inferior scheme set. Then, applying fuzzy multicriterion decision method, a best compromise scheme is selected by taking account of five factors-investment, operation cost, total water consumption, compactness of apparatus and difficulty of operation and maintenance. In addition, other complex factors are considered simultaneously which can hardly be treated by classical methods. The decision thought and method in this paper is of certain universal significance to problems of scheme optimization.