Scenario analysis on abating industrial process greenhouse gas emissions from adipic acid production in China

Adipic acid is an important petrochemical product,and its production process emits a high concentration of greenhouse gas N_2 O.This paper aims to provide quantitative references for relevant authorities to formulate greenhouse gas control roadmaps.The forecasting method of this paper is consistent with the published national inventory in terms of caliber.Based on the N_2 O abatement technical parameters of adipic acid and the production trend,this paper combines the scenario analysis and provides a measurement of comprehensive N_2 O abatement effect of the entire industry in China.Four future scenarios are assumed.The baseline scenario(BAUS) is a frozen scenario.Three emission abatement scenarios(ANAS,SNAS,and ENAS) are assumed under different strength of abatement driving parameters.The results show that China's adipic acid production process can achieve increasingly significant N_2 O emission abatement effects.Compared to the baseline scenario,by 2030,the N_2 O emission abatements of the three emission abatement scenarios can reach 207-399 kt and the emission abatement ratios can reach 32.5%-62.6%.By 2050,the N_2 O emission abatements for the three emission abatement scenarios can reach 387-540 kt and the emission abatement ratios can reach 71.4%-99.6%.

Kinetic study for the oxidation of cyclohexanol and cyclohexanone with nitric acid to adipic acid

The adipic acid is an important intermediate in the production of nylon,polyurethane and polye ster resin s.The industrial approach for preparing adipic acid is through the liquid catalytic oxidation of KA oil with nitric acid.In this work,a comprehensive model is developed for this reaction based on the kinetic study conducted in a continuous flow tubular reactor.The kinetic model fits well with the experimental results across the experimental conditions,and the average relative error between the calculated and experimental values is 5.7%.Results show that there was an induction period at the early stage of reaction.Moreover,it is found that at temperature range of 328-358 K,the formation rate of adipic acid strongly dependents on the temperature and nitric acid concentration.The developed model is used to predict the yield of adipic acid at 359-368 K.The work in this study could provide much knowledge for industrial tubular reactor design.

Highly dispersed metal incorporated hexagonal mesoporous silicates for catalytic cyclohexanone oxidation to adipic acid

Adipic acid is a dicarboxylic acid of great industrial importance,mainly used in the production of nylon-6,6 and polyurethane.The use of nitric acid as an oxidant in the industrial production of adipic acid poses significant carbon footprint to the environment.Clean adipic acid synthesis methods using a heterogeneous catalyst with H2O2 as oxidant and water as solvent have potential advantages of low catalyst cost,easy synthesis and recovery,cleanness and environmental protection.In this work,hexagonal mesoporous silicate materials were synthesized by a sol–gel method and evaluated for cyclohexanol/cyclohexanone oxidation to adipic acid.The physical and chemical properties of Fe-HMS were characterized by XRD,HR-TEM,BET and UV–Vis.The experimental results showed that Fe-HMS materials show pore sizes ranging from 2–3 nm.W-and Mo-based polyoxometalates were also evaluated and compared to the Fe-based HMS catalysts.To improve the adipic acid yield,the influence of the transition metal as well as the effect of metal loading,reaction temperature and catalyst amount on the catalytic performances of Fe-HMS have been investigated in details.When Si/Fe atomic ratio=100,Fe-HMS catalyst shows the highest activity,with a cyclohexanone conversion of 92.3%and adipic acid selectivity of 29.4%.The reaction pathway of cyclohexanone oxidation was further proposed based on experimental data.

Comparative Heat Transfer Data for Solid-Liquid Phase Change of D-Mannitol and Adipic Acid

The goal of this work was to measure the heat transfer rates from thermofluid, Therminol 66, to two phase change materials, D-mannitol and adipic acid. It concerns the determination of heat transfer coefficients for the design of a concentrated solar energy plant requiring PCM thermal energy storage and is part of a wider set of experiments, where several PCMs were tested. An experimental installation was used with a cylindrical vessel with three tubes disposed almost horizontally (5°inclination), containing the phase change material, around which the thermal fluid flowed almost perpendicular to the tubes. The experimental installation allowed to recreate heating and cooling cycles. In order to evaluate the influence of the flow on the rate at which the heating and cooling processes took place, tests were performed at different thermofluid mass flow rates, concluding that there is no great influence, since the thermal resistance inside the tubes is much higher than on the outside. D-mannitol and adipic acid, present different phase change temperatures, 164°C for D-mannitol and 152°C for adipic acid. The average heat transfer coefficient, during the phase change process, was of 340 W/(m2K) for D-mannitol and 1320 W/(m2K) for adipic acid.

Highly crystalline core dominated the catalytic performance of carbon dot for cyclohexane to adipic acid reaction

Carbon dots(CDs)have uniquely structural,physicochemical and photochemical properties,suggesting a promising platform for catalysis applications.The in-depth understanding of the structure-activity relationship in the CDs-based catalyst system needs to know the effect of the crystalline core on their catalytic performance.The efficient catalytic oxidation of cyclohexane is an urgent challenge in current chemical industry,in which,adipic acid(AA)plays an important role in industry for synthesis of nylon6 and nylon-66.Here,we fabricated the pristine CDs by electrochemical etching graphite rod method and derived CDs with high crystalline core(CD-600,CD-800,and CD-1100)through a thermal treatment method in tube furnace.Furthermore,these CDs performed an outstanding catalytic performance for one-step synthesis of AA from cyclohexane.With the help of machine learning(ML),the deep correlations between features(structures of CDs,catalytic conditions)and catalytic performances were investigated by XGBoost(XGB)model.Then under the optimization and prediction of XGB,it was found that high crystalline core preceded the other features and CD-1100 could get the best conversion of 30.696%and selectivity to AA of 92.52%at reaction conditions of 130℃,1.5 MPa,and 10 h.This work pioneered the application of ML in industrial issues and demonstrated a comprehensive understanding on CDs as catalyst to realize one-step synthesis of AA.

Studies on QSAR of metalloporphyrin catalysts in the oxidation of cyclohexane to adipic acid

The catalysis of chloridized metalloporphyrins in the oxidation of cyclohexane to adipic acid was systemati-cally investigated.The turnover numbers(TON)data of 19 catalysts were obtained experimentally under optimal reac-tion conditions,and 2.4x106 TON for T(o-Cl)PP-MnIIICl catalyst at 2.0x10–6 mol/L of dosage was reached under the conditions of dioxygen pressure of 2.5 MPa at 150°C for 4 h.This was the best result reported for this reaction up to now.The QSAR models for each concerned metallopor-phyrin were established,where the catalytic activity was significantly correlated with the ELUMO(the energy level of the lowest unoccupied molecule orbit)and LM-N(the bond length between metal-nitrogen atoms).Using the QSAR models,four new metalloporphyrins with substituted nitro group were designed,and their catalytic activities were predicted.The experimental TON data of newly designed porphyrins were in good agreement with the predicted ones,and the square of their correlation coefficient was more than 0.958.The above results demonstrated that the proposed structure-activity relationship model could be applied to design some new metalloporphyrin catalysts,and to predict their catalytic activity in cyclohexane oxidation.

环己酮绿色氧化合成己二酸质谱分析

己二酸是合成尼龙-66的主要原料,同时在低温润滑油、合成纤维、油漆、聚亚胺酯树脂及食品添加剂的制备等方面也有重要用途,目前己二酸的世界年产量估计已达220万吨.工业上己二酸的生产是以环己烷经两步氧化合成,第一步为环己烷在金属离子催化下用氧气氧化为环己醇、环己酮,第二步用浓HNO3氧化环己醇、环己酮制得己二酸.……

Synthesis and Crystal Structure of a 2-D Framework Supramolecular Complex [Cd_2(phen)_2(adip)(NO_3)_2]

A novel binucleus complex [Cd2（phen）4（adip）（NO3）2] （phen = phenanthroline, H2adip = adipic acid） has been synthesized by the reaction of phen and H2adip with cadmium（Ⅱ） salt. Elemental analysis, IR spectra and X-ray crystal structure analysis were carried out to determine the crystal structure of the title complex. The crystal belongs to triclinic, space group P1^- with a = 9.638（7）, b = 10.315（7）, c = 13.109（10） A, α = 88.305（11）, β = 69.011（11）, γ = 75.818（11）°, C27H20N5O5Cd, Mr = 606.88, Z = 2, V = 1177.2（14）A^3, Dc = 1.712 g/cm^3,μ= 0.979 mm^-1, -8≤h ≤11, -12≤k≤ 12, -10≤l≤ 15, F（000） = 610, Rint = 0.0314, R = 0.0739 and wR = 0.1922 （Ⅰ〉 2σ（Ⅰ）. The cadmium atom is seven-coordinated in a distorted pentagonal bipyramidal configuration. The complex forms a 2-D supramolecular framework by C-H…O weak interactions and π-π stacking of neighbouring phen ligands.

Synthesis,Crystal Structure and Characterization of a New Coordination Polymer Based on Trinuclear Mn(Ⅱ) Cluster:[Mn_3(L)_2(adip)_3]·2H_2O

The coordination polymer,[Mn3（L） 2（adip） 3]·2H2O（L = 2-（4-fluorophenyl） -1H-imidazo[4,5-f] [1,10]phenanthroline and H2adip = adipic acid） ,has been synthesized under hydro-thermal conditions and characterized by elemental analysis,IR and single-crystal X-ray diffraction. It crystallizes in triclinic,space group P1^- with a = 8.4085（11） ,b = 11.1273（14） ,c = 14.5758（18） ,α = 78.528（2） ,β = 75.425（2） ,γ = 78.143（2） °,V = 1276.0（3） A^3,Z = 1,C56H50F2Mn3N8O14,Mr = 1261.86,Dc = 1.642 g/cm^3,F（000） = 647,μ（MoKa） = 0.819 mm^-1,R = 0.0446 and wR = 0.1008. The backbones of the two types of adip dianions link the neighboring trinuclear Mn（Ⅱ） clusters to yield a two-dimensional layer structure. The large conjugated L ligands are located on both sides of the two-dimensional layers. Additionally,the O-H···O,O-H···N and N-H···O hydrogen bonds further stabilize the structure.

The Influence of Aziridine on the Aging of Composite Solid Rocket Propellant

Aging of a solid composite propellant containing HTPB/AP/AL was performed in order to validate the conformance of the accelerated aging data to the Arrhenius law. The main objective of the work was to examine the influence of the aziridine bonding agents family on the propellant aging. Aging of the prepared propellant samples was conducted as follows: 1. Four samples, one free of bonding agents, and three containing aziridine based bonding agents MAPO,HX-752, MAT4 were aged at 65°C. 2. Another four samples based on HX-752, MAT4 with different curing agents were aged at 65°C. The measured mechanical properties of the free bonding agent propellant samples were very far from the specifications and this illustrates the importance of the bonding agents in both the preparation and the aging phases.The prepared bonding agent 'MAT4' gave remarkable improvements of the mechanical properties comparing with HX-752 and MAPO. The aziridine bonding agents family inhibited the rate of decomposition of the propellant during the aging periods and supported the propellant matrix against decomposition at the elevate temperatures. Using of HMDI as curing agent gave slight better mechanical properties to the IPDI.

Tailoring the microstructure and properties of PES/SPSf loose nanofiltration membranes using SPES as a hydrophilic polymer for the effective removal of dyes via steric hindrance and charge effect

Herein,polyethersulfone(PES)and sulfonated polysulfone(SPSf)blend membranes were prepared with addition of sulfonated polyethersulfone(SPES)as a hydrophilic polymer and adipic acid as a porogen via non-solvent induced phase separation method for effective fractionation of dyes based on the influence of steric hindrance and charge effect.Raman spectroscopy and molecular dynamic simulation modeling confirmed that hydrogen bonds between PES,SPSf,SPES,and adipic acid were crucial to membrane formation and spatial arrangement.Further addition of hydrophilic SPES resulted in a membrane with reduced pore size and molecular weight cut-off as well as amplified negative charge and pure water permeance.During separation,the blend membranes exhibited higher rejection rates for nine types of small molecular weight(269.3–800 Da)dyes than for neutral polyethylene glycol molecules(200–1000 Da).This was attributed to the size effect and the synergistic effect between steric hindrance and charge repulsion.Notably,the synergistic impact decreased with dye molecular weight,while greater membrane negative charge enhanced small molecular dye rejection.Ideal operational stability and anti-fouling performance were best observed in M2(PES/SPSf/SPES,3.1 wt%).Summarily,this study demonstrates that SPES with–SO3‒functional groups can be applied to control the microstructure and separation of membranes.