Production Of Adipic Acid Research Articles

A bio-based ‘green’ process for catalytic adipic acid production from lignocellulosic biomass using cellulose and hemicellulose derived γ-valerolactone

A bio-based ‘green’ process is presented for the catalytic conversion of corn stover to adipic acid (ADA) based on experimental studies. ADA is used for biobased nylon 6.6 manufacturing from lignocellulosics as carbon and energy source. In this process, the cellulose and hemicellulose fractions are catalytically converted to γ-valerolactone (GVL), using cellulose and hemicellulose-derived GVL as a solvent, and subsequently upgrading to ADA. Experimental studies showed maximal carbon yields (biomass-to-GVL: 41% and GVL-to-ADA: 46%) at low concentrations (below 16wt% solids) using large volumes of GVL solvents while requiring efficient interstage separations and product recovery. This work presents an integrated process, including catalytic conversion and separation subsystems for GVL and ADA production and recovery, and designs a heat exchanger network to satisfy the total energy requirements of the integrated process via combustion of biomass residues (lignin and humins). Finally, an economic analysis shows that 2000 metric tonnes (Mt) per day of corn stover feedstock processing results in a minimum selling price of $633 per Mt if using the best possible parameters.

Bifunctional H2WO4/TS-1 catalysts for direct conversion of cyclohexane to adipic acid: Active sites and reaction steps

Adipic acid production may account for 10% of the annual increase in atmospheric nitrous oxide level. Here we developed a hollow H2WO4/TS-1 bifunctional catalyst with excellent catalytic activity for the direct transformation of cyclohexane to adipic acid with 30% hydrogen peroxide by a non-HNO3 route. XRD diffraction, N2 physisorption, TEM, NH3-TPD and Raman, XPS, Infrared, and UV–visible spectroscopies were used to characterize catalysts to increase understanding of the structure of active species on the hollow TS-1 support. The enhanced catalytic activity in comparison of reference catalysts (H2WO4, H2WO4/Silicate-1 and TS-1) was explained in terms of their bifunctional catalytic sites and perfect hollow morphology with large intraparticle voids. Experimental results on the product distribution indicated that the tetrahedral Ti and surface W sites played important roles in the synergistic effect: tetrahedral Ti worked in oxidation of cyclohexane to intermediates (cyclohexanone and cyclohexanol) and surface W worked in further oxidation of late intermediates to adipic acid. Theoretical calculation results on catalytic activity of the TiOOH and WOOH active sites in the H2WO4/TS-1 for different reaction steps validate the experimental results. The catalytic activity was also correlated to the strong interaction between W sites and HTS-1 surface induced increase in acidity of the materials. Increasing calcination temperature led to structural evolution of supported active species and subsequent activity change. A cyclohexane conversion of 31% with 78% adipic acid selectivity was achieved over this catalyst calcinated at 500 ∘C. Based on the catalytic and characterization results, possible reaction pathways were thus proposed to explain high adipic acid yield over hollow H2WO4/TS-1 catalysts.

Supported Ni–Al–VPO/MCM-41 As Efficient and Stable Catalysts for Highly Selective Preparation of Adipic Acid from Cyclohexane with NO2

Developing an economic and efficient approach for the production of adipic acid is a grand challenge in the chemical industry. Toward this goal, we report a simple method for selective synthesis of adipic acid from cyclohexane with NO2 by using Ni–Al–VPO/MCM-41 as catalyst. The physical-chemical properties of supported Ni–Al–VPO/MCM-4 catalysts were characterized, the reaction conditions were optimized, and the reusability of the catalyst was examined. The results showed that the supported 30%Ni–Al–VPO/MCM-41 catalyst exhibited excellent catalytic performance with 65.1% of cyclohexane conversion and 85.3% of selectivity toward adipic acid, especially, its catalytic performance was still stable after five runs. Maybe this developed method has potential industrial application prospects for production of adipic acid.

Production of Adipic Acid from Sugar Beet Residue by Combined Biological and Chemical Catalysis

AbstractAdipic acid is one of the most important industrial dicarboxylic acids and is used mainly as a precursor to nylon‐6,6. Currently, commercial adipic acid is produced primarily from benzene by a chemical route that is associated with environmental, health, and safety concerns. Herein, we report a new process to produce adipic acid from an inexpensive renewable feedstock, sugar beet residue by combining an engineered Escherichia coli strain and Re‐based chemical catalysts. The engineered E. coli converted d‐galacturonic acid to mucic acid, which was precipitated easily with acid, and the mucic acid was further converted to adipic acid by a deoxydehydration reaction catalyzed by an oxorhenium complex followed by a Pt/C‐catalyzed hydrogenation reaction under mild conditions. A high selectivity to the free acid products was achieved by tuning the acidity of the Re‐based catalysts. Finally, adipic acid was produced directly from sugar beet residue that was hydrolyzed enzymatically with engineered E. coli and two chemical catalysts in a yield of 8.4 %, which signifies a new route for the production of adipic acid.

Pt catalysts for efficient aerobic oxidation of glucose to glucaric acid in water

Glucaric acid, a promising bio-based chemical for the production of adipic acid, is produced on a commercial Pt/C catalyst via aerobic oxidation of glucose in water.

Engineering a Polyketide Synthase for In Vitro Production of Adipic Acid.

Polyketides have enormous structural diversity, yet polyketide synthases (PKSs) have thus far been engineered to produce only drug candidates or derivatives thereof. Thousands of other molecules, including commodity and specialty chemicals, could be synthesized using PKSs if composing hybrid PKSs from well-characterized parts derived from natural PKSs was more efficient. Here, using modern mass spectrometry techniques as an essential part of the design-build-test cycle, we engineered a chimeric PKS to enable production one of the most widely used commodity chemicals, adipic acid. To accomplish this, we introduced heterologous reductive domains from various PKS clusters into the borrelidin PKS' first extension module, which we previously showed produces a 3-hydroxy-adipoyl intermediate when coincubated with the loading module and a succinyl-CoA starter unit. Acyl-ACP intermediate analysis revealed an unexpected bottleneck at the dehydration step, which was overcome by introduction of a carboxyacyl-processing dehydratase domain. Appending a thioesterase to the hybrid PKS enabled the production of free adipic acid. Using acyl-intermediate based techniques to "debug" PKSs as described here, it should one day be possible to engineer chimeric PKSs to produce a variety of existing commodity and specialty chemicals, as well as thousands of chemicals that are difficult to produce from petroleum feedstocks using traditional synthetic chemistry.

Engineering Escherichia coli for the production of adipic acid through the reversed β-oxidation pathway

The current study aimed to construct a functionally reversed β-oxidation cycle in Escherichia coli for the production of adipic acid, one of the most important dicarboxylic acids. Starting from the condensation of acetyl-CoA and succinyl-CoA, a synthetic pathway mimicking a reversed β-oxidation cycle was constructed in E. coli to produce adipyl-CoA, consisting of four enzymatic steps. Products of the synthetic pathway were confirmed by liquid chromatography-tandem mass spectrometry. To convert adipyl-CoA into adipic acid, a putative adipyl-CoA thioesterase (encoded by Acot8 from Mus musculus) was selected, and its functional expression in E. coli was confirmed by gas chromatography-mass spectrometry. Finally, when the reversed β-oxidation cycle and Acot8 were co-expressed in E. coli, the resulting strain produced 12μg/L of adipic acid from glucose. These results suggest that the synthetic adipic acid pathway functions in E. coli but requires further optimization for increased production of adipic acid.

Metabolic engineering of a novel muconic acid biosynthesis pathway via 4-hydroxybenzoic acid in Escherichia coli.

cis,cis-Muconic acid (MA) is a commercially important raw material used in pharmaceuticals, functional resins, and agrochemicals. MA is also a potential platform chemical for the production of adipic acid (AA), terephthalic acid, caprolactam, and 1,6-hexanediol. A strain of Escherichia coli K-12, BW25113, was genetically modified, and a novel nonnative metabolic pathway was introduced for the synthesis of MA from glucose. The proposed pathway converted chorismate from the aromatic amino acid pathway to MA via 4-hydroxybenzoic acid (PHB). Three nonnative genes, pobA, aroY, and catA, coding for 4-hydroxybenzoate hydrolyase, protocatechuate decarboxylase, and catechol 1,2-dioxygenase, respectively, were functionally expressed in E. coli to establish the MA biosynthetic pathway. E. coli native genes ubiC, aroF(FBR), aroE, and aroL were overexpressed and the genes ptsH, ptsI, crr, and pykF were deleted from the E. coli genome in order to increase the precursors of the proposed MA pathway. The final engineered E. coli strain produced nearly 170 mg/liter of MA from simple carbon sources in shake flask experiments. The proposed pathway was proved to be functionally active, and the strategy can be used for future metabolic engineering efforts for production of MA from renewable sugars.

Combined neutralization of nitrogen(I), (II), and (IV) oxides in production of adipic acid

Compositions of a catalyst and a chemisorbent for effective purification of oxygen-containing effluent gases in production of adipic acid to remove N2O, NO, and NO2 were developed. Their use enables catalytic decomposition of N2O as the prevalent component at temperatures of up to 500°C and chemisorption purification to remove microimpurities of NO and NO2 at 20°C and in excess amount of oxygen. The optimization of the catalyst and chemisorbent compositions made it possible to diminish the content of the expensive ruthenium and cerium to 4.5 and 4.2 wt %, respectively, with the developed service characteristics preserved.

Production of adipic acid by the native-occurring pathway in Thermobifida fusca B6.

To identify the native-occurring adipate pathway in a previously engineered Thermobifida fusca B6 strain and optimize the adipic acid production of this strain on glucose and corncob. The native-occurring adipate pathway in T. fusca B6 was identified to be the reverse adipate degradation pathway, including five steps: β-ketothiolase (Tfu_0875), 3-hydroxyacyl-CoA dehydrogenase (Tfu_2399), 3-hydroxyadipyl-CoA dehydrogenase (Tfu_0067), 5-Carboxy-2-pentenoyl-CoA reductase (Tfu_1647) and succinyl-CoA synthetase (Tfu_2576, Tfu_2577). The cell lysates of T. fusca wild-type strain with the addition of the Tfu_1647 protein produced trace adipic acid, while no adipic acid was produced in the absence of this protein. The above results prove that the low expression of Tfu_1647 in the wild-type strain was the reason why it did not produce any adipic acid. We then demonstrated that in T. fusca B6, the maximal titre of adipic acid on 50 g l(-1) glucose was 2·23 g l(-1) with 0·045 g g(-1) -glucose yield and 0·22 g l(-1) adipic acid was produced from 19·38 g l(-1) milled corncob. The reverse adipate degradation pathway was found to be responsible for the adipate synthesis in T. fusca B6 and Tfu_1647 was the regulatory node on this pathway. Thermobifida fusca B6 was the first reported micro-organism using its native-occurring pathway to accumulate adipic acid. It had the highest reported yield and titre of adipic acid so far.

Production of Adipic Acid from Mixtures of Cyclohexanol-Cyclohexanone using Polyoxometalate Catalysts

Adipic acid production through catalytic conversion of cyclohexanol-cyclohexanone using polyoxometalate H 5 [ a -BW 12 O 40 ] and H 4 [ a -SiW 12 O 40 ] as catalysts was carried out systematically. Polyoxometalates H 5 [ a -BW 12 O 40 ] and H 4 [ a -SiW 12 O 40 ] were synthesized using an inorganic synthesis method and were characterized using Fourier transform infrared spectroscopy (FTIR). Adipic acid was formed from conversion of cyclohexanol-cyclohexanone and was characterized by using melting point measurement, identification of functional group using FTIR spectrophotometer, analysis of gas chromatography-mass spectrometry (GC-MS), and 1 H and 13 C NMR (nuclear magnetic resonance) spectrophotometer. This research investigated the influence of reaction time and temperature on the conversion. The results showed that adipic acid was formed successfully with a yield of 68% by using H 5 [ a -BW 12 O 40 ] as the catalyst with a melting point of 150-152 ° C after optimization. In contrast, using H 4 [ a -SiW 12 O 40 ] as the catalyst, the formation was only 3.7%. Investigation of time and temperature showed 9 h as the optimum reaction time and 90 ° C as the optimum temperature for conversion of up to 68%. Identification using FTIR, 1 H, and 13 C NMR showed that the adipic acid from conversion of cyclohexanol-cyclohexanone was in agreement with the standard adipic acid data in the literatures. GC-MS analysis indicated that several by-products were formed in conversion of cyclohexanol-cyclohexanone using H 5 [ a -BW 12 O 40 ] and H 4 [ a -SiW 12 O 40 ] as the catalysts.

Muconic acid production from glucose using enterobactin precursors in Escherichia coli.

Muconic acid (MA) is a promising bulk chemical due to its extensive industrial applications in the production of adipic acid and other valuable, biodegradable intermediates. MA is heretofore mainly produced from petrochemicals by organic reactions which are not environmentally friendly or renewable. Biological production processes provide a promising alternative for MA production. We designed an artificial pathway in Escherichia coli for the biosynthesis of MA using the catechol group of 2,3-dihydroxybenzoate, an intermediate in the enterobactin biosynthesis pathway. This approach consists of two heterologous microbial enzymes, including 2,3-dihydroxybenzoate decarboxylase and catechol 1,2-dioxygenase. The metabolic flow of carbon into the heterologous pathway was optimized by increasing the flux from chorismate through the enterobactin biosynthesis pathway and by regulating the shikimate pathway. Metabolic optimization enabled a concentration of 605.18 mg/L of MA from glucose in a shaking flask culture, a value nearly 484-fold higher than that of the initial recombinant strain. The results indicated that the production of MA from this pathway has the potential for further improvement.

Adipic acid production from lignin

Biological funneling is used to convert lignin-derived species to muconic acid, which is separated and catalytically upgraded to adipic acid.

A non-nitric acid method of adipic acid synthesis: organic solvent- and promoter-free oxidation of cyclohexanone with oxygen over hollow-structured Mn/TS-1 catalysts

A novel hollow-structured Mn/TS-1 catalyst has been reported as a non-nitric acid route for adipic acid production from oxidative cleavage of cyclohexanone.

Green Approach To Adipic Acid

A new route to adipic acid that uses ozone and ultraviolet light to eliminate the problematic nitrous oxide by-product has researchers intrigued. But once again, issues of scale-up and safety with a greener route to this chemical intermediate—used to make nylon, polyurethane, and plasticizers—temper the good news. Right now, 95% of the world’s adipic acid production uses nitric acid as an oxidant, which releases N2O as a by-product. The gas eats away at Earth’s protective ozone layer and ranks behind only carbon dioxide and methane when it comes to greenhouse gas emissions. Some producers trap and destroy N2O, and emissions have been cut in half since 1990. But significant emissions remain. Chemists have been exploring N2O-free routes to adipic acid for years by using O2 or H2O2 or employing enzymes. These methods tend to be more energy efficient, have better yields, and avoid corrosion problems from using nitric acid, but ...

One-pot room-temperature conversion of cyclohexane to adipic acid by ozone and UV light.

Nitric acid oxidation of cyclohexane accounts for ~95% of the worldwide adipic acid production and is also responsible for ~5 to 8% of the annual worldwide anthropogenic emission of the ozone-depleting greenhouse gas nitrous oxide (N2O). Here we report a N2O-free process for adipic acid synthesis. Treatment of neat cyclohexane, cyclohexanol, or cyclohexanone with ozone at room temperature and 1 atmosphere of pressure affords adipic acid as a solid precipitate. Addition of acidic water or exposure to ultraviolet (UV) light irradiation (or a combination of both) dramatically enhances the oxidative conversion of cyclohexane to adipic acid.

Model of Steady State Cyclohexane Oxidation for Ketone-Alcohol (K-A) Oil Production

Cylohexane oxidation is of great industrial importance in the production of intermediates for the manufacture of nylon-6 and nylon-6,6. Most cyclohexane is commercially converted into a cyclohexanone–cyclohexanol mixture (known as K-A oil) by catalytic oxidation. K-A (Ketone-Alcohol) oil is then used as a raw material for adipic acid and caprolactam production. Practically, if the cyclohexanol content of KA oil is higher than that of cyclohexanone, it is more profitable to convert it into adipic acid; otherwise caprolactam production is more likely. The steady state cyclohexane oxidation reaction model in a stirred tank reactor for K-A oil production is presented and solved in this paper. The model was derived based on the mass balance and mass transfer equations using the kinetic equation. The set of algebraic equations was solved using non linear programming. The advantage of this method is that the relationship among variables can be better understood and an appropriate solution to the equation set can be obtained more quickly. Simulation results are particularly useful for process design such as in determining reactor dimensions and operating conditions.

Direct biosynthesis of adipic acid from a synthetic pathway in recombinant Escherichia coli.

The C6 dicarboxylic acid, adipic acid, is an important platform chemical in industry. Biobased production of adipic acid is a promising alternative to the current petrochemical route. Here, we report biosynthesis of adipic acid using an artificial pathway inspired by the reversal of beta-oxidation of dicarboxylic acids. The biosynthetic pathway comprises condensation of acetyl-CoA and succinyl-CoA to form the C6 backbone and subsequent reduction, dehydration, hydrogenation, and release of adipic acid from its thioester. The pathway was first tested in vitro with reconstituted pathway enzymes and then functionally introduced into Escherichia coli for the biosynthesis and excretion of adipic acid into the culture medium. The production titer was increased by approximately 20-fold through the combination of recruiting enzymes that were more suitable to catalyze the synthetic reactions and increasing availability of the condensation substrates. This work demonstrates direct biosynthesis of adipic acid via non-natural synthetic pathway, which may enable its renewable production.

Reducing nitrous oxide emissions to mitigate climate change and protect the ozone layer.

Reducing nitrous oxide (N2O) emissions offers the combined benefits of mitigating climate change and protecting the ozone layer. This study estimates historical and future N2O emissions and explores the mitigation potential for China's chemical industry. The results show that (1) from 1990 to 2012, industrial N2O emissions in China grew by some 37-fold from 5.07 to 174 Gg (N2O), with total accumulated emissions of 1.26 Tg, and (2) from 2012 to 2020, the projected emissions are expected to continue growing rapidly from 174 to 561 Gg under current policies and assuming no additional mitigation measures. The total accumulated mitigation potential for this forecast period is about 1.54 Tg, the equivalent of reducing all the 2011 greenhouse gases from Australia or halocarbon ozone-depleting substances from China. Adipic acid production, the major industrial emission source, contributes nearly 80% of the industrial N2O emissions, and represents about 96.2% of the industrial mitigation potential. However, the mitigation will not happen without implementing effective policies and regulatory programs.

Highly Efficient Chemical Process To Convert Mucic Acid into Adipic Acid and DFT Studies of the Mechanism of the Rhenium‐Catalyzed Deoxydehydration

AbstractThe production of bulk chemicals and fuels from renewable bio‐based feedstocks is of significant importance for the sustainability of human society. Adipic acid, as one of the most‐demanded drop‐in chemicals from a bioresource, is used primarily for the large‐volume production of nylon‐6,6 polyamide. It is highly desirable to develop sustainable and environmentally friendly processes for the production of adipic acid from renewable feedstocks. However, currently there is no suitable bio‐adipic acid synthesis process. Demonstrated herein is the highly efficient synthetic protocol for the conversion of mucic acid into adipic acid through the oxorhenium‐complex‐catalyzed deoxydehydration (DODH) reaction and subsequent Pt/C‐catalyzed transfer hydrogenation. Quantitative yields (99 %) were achieved for the conversion of mucic acid into muconic acid and adipic acid either in separate sequences or in a one‐step process.