Hydrothermal Oxidation of Industrial Alkali Lignin for Producing Small Molecular Organic Acids

2012 ◽  
Vol 608-609 ◽  
pp. 1399-1406 ◽  
Author(s):  
Guang Yi Zhang ◽  
Ju Wei Zhang ◽  
Jian Yu ◽  
Yin Wang
Keyword(s):  
Acetic Acid ◽  
Organic Acids ◽  
Paper Industry ◽  
Black Liquor ◽  
Total Yield ◽  
Reaction Times ◽  
Hydrothermal Conditions ◽  
Alkali Lignin ◽  
Hydrothermal Oxidation ◽  
Acetic Acids

To control the serious pollution caused by alkaline pulping in paper industry and utilize alkali lignin – the main organic ingredient residing in black liquor, an experimental research on hydrothermal oxidation of industrial alkali lignin for producing small molecule organic acids (mostly formic and acetic acids) was conducted using batch reactors. The results showed that the yields of acetic acid almost entirely increased and then decreased with oxygen supplies, reaction times and reaction temperatures, while the yields of formic acid fell in a narrow range of ~ 4% irrespective of all the hydrothermal conditions. A highest total yield of formic and acetic acids of 23.0% was achieved at the conditions of 300 °C, a 100% oxygen supply and a 60 s reaction time, and at the same time a highest yield of acetic acid of 20.3% was obtained. Based on the products recognized, the main pathways for producing small molecular organic acids, particularly formic and acetic acids were discussed.

Comparative Analysis on the Epoxidation of Soybean Oil using Formic and Acetic Acids

2018 ◽  
Vol 26 (4) ◽  
pp. 289-298 ◽  
Author(s):  
Shatori Meadows ◽  
Mahesh Hosur ◽  
Yusuf Celikbag ◽  
Shaik Jeelani
Keyword(s):  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Comparative Analysis ◽  
Soybean Oil ◽  
Oxygen Carrier ◽  
Reaction Times ◽  
Oxirane Oxygen ◽  
Stoichiometric Ratio ◽  
Oxygen Carriers ◽  
Acetic Acids

The objective of this study was to make a comparative analysis of the effect of formic and acetic acids as oxygen carriers on the epoxidation of soybean oil used with hydrogen peroxide as the oxygen donor. Comparative analysis between the use of formic acid (FA) and acetic acid (AA) was studied to obtain the most effective oxygen carrier that yielded high oxirane oxygen contents (OOC). The epoxidation reaction was carried out using a stoichiometric ratio of 1:0.5:1, 1:0.5:0.5, and 1:0.5:2 of soybean oil: formic/acetic acid: hydrogen peroxide. The synthesis was performed at three reaction times (2, 4 and 6 h) at a constant temperature of 50°C. Samples prepared using FA and AA were characterized using ASTM D1652-11 and confirmed by Fourier transform infrared (FTIR) spectroscopy. The result of this study proved FA to be an effective oxygen carrier compared to that of AA based on the high OOC and percent yield achieved. The optimum epoxidized soybean oil (ESO) sample using FA was obtained at a reaction time of 6 h using 2 moles of H2O2, yielding an OOC of 7.45 at a relative conversion to oxirane of 98%. Samples of FA were further characterized to prove the optimum parameters that gave the highest OOC using rheology and gel permeation chromatography (GPC). Rheology data revealed an increase in the viscosity that implied an increase in the degree of epoxidation. GPC indicated an increase in the molecular weight at low reaction times, then a decrease resulting in a change in the structure of the triglyceride and consequently an increase in the extent of epoxidation.

Production of Formic Acid and Acetic Acid by Hydrothermal Oxidation of Alkali Lignin

2010 ◽  
Author(s):  
Xu Zeng ◽  
Fangming Jin ◽  
Jianglin Cao ◽  
Guodong Yin ◽  
Yalei Zhang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Alkali Lignin ◽  
Hydrothermal Oxidation

Study on Mechanism of Action of Catalysts on Liquefaction of Bagasse Alkali Lignin

2011 ◽  
Vol 383-390 ◽  
pp. 6145-6150 ◽  
Author(s):  
Xin Jin Sui ◽  
Shu Bin Wu
Keyword(s):  
Mechanism Of Action ◽  
Black Liquor ◽  
Total Yield ◽  
Structural Rearrangement ◽  
Hydroxyl Groups ◽  
Use Value ◽  
Optimal Conditions ◽  
Alkali Lignin ◽  
H Nmr ◽  
Ft Ir

Bagasse alkali lignin is the primary constituent of pulping black liquor. The phenolic products such as phenol, 2,6-dimethoxy-phenol and 2-methoxy-phenol were obtained by catalytic liquefaction from bagasse alkali lignin, with the aim of enhancing its use value. In the investigation, under optimal conditions, using SiO2-Al2O3 or FeS as catalyst, the phenols yield reached 54.10% and 55.18%, respectively. HPLC spectrum showed that the phenolic products of them were different. FT-IR and H-NMR spectrums showed that, using SiO2-Al2O3 as the catalyst, the α-O-4 and β-O-4 ether bonds and C-Cα bonds of lignin units were prone to break, forming 2,6-dimethoxy-phenol, 2-methoxy-phenol and phenol. While FeS action was more difficult, the α-O-4 and β-O-4 ether bonds and Cα-Cβ bonds of lignin units broke down. Then, the introduction of additional hydroxyl groups from glycols consequently increased the final product solubility. At the same time, Cα–C bond of the phenylpropane linkage was broken to produce phenolic chemicals. Third, part of the phenylpropane linkage was prone to break Cα–Cβ bond and structural rearrangement occurred. So the content of 2-methoxy-4-methyl-phenol and the total yield of phenols were high.

scholarly journals Banana Vinegars Production Using Thermotolerant Acetobacter pasteurianus Isolated From Ivorian Palm Wine

2015 ◽  
Vol 4 (2) ◽  
pp. 92
Author(s):  
Moussa Konate ◽  
Eric E. Akpa ◽  
Goualie G. Bernadette ◽  
Louis B. Koffi ◽  
Ouattara G. Honore ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Organic Acids ◽  
Acid Production ◽  
Elaeis Guineensis ◽  
Total Acidity ◽  
Acid Fermentation ◽  
Acetobacter Pasteurianus ◽  
Fermentation Efficiency ◽  
Acid Producing Bacteria ◽  
Acetic Acids

<p>Vinegar or sour wine is a product of alcoholic and subsequent acetous fermentation of sugary precursors. Among acetic acid producing bacteria, only few genera (<em>Acetobacter and Gluconobacter</em>) are used in vinegar industry. In this paper, we intended to produce vinegar at 37 °C using two <em>Acetobacter</em> <em>pasteurianus</em> strains (S3 and S32). These species were isolated from palm (<em>Elaeis guineensis</em>) wine and presented potentialities for industrial vinegar production at 37 °C. Successive fermentations were carried up and semi-continuous acetous fermentation was performed to increase acid production. Concentrated bananas (<em>Musa ssp.</em>) juice (11°Brix) was fermented using <em>Saccharomyces cerevisae</em> within 7 days, yielding 6.4% alcohol. After fermentation, 60 and 58 g/L acetic acid were produced in vinegars obtained using S3 and S32 stains respectively in 34 days and 5 flow cycles. Malic and acetic acids were the most substantial acids produced in alcoholic juice with 5 631.473 and 2 833.055 mg/L respectively. Among the eight organic acids responsible for vinegars total acidity, acetic acid was major compound with 23 459.416 and 21 268.407 mg/L for S3 and S32 strains respectively. Alcohol and acetic acid fermentation efficiency were 90.9% and 85.39 - 87.63% respectively. All the results above showed that S3 and S32 strains revealed great potentialities for successful industrial vinegar production from overripe banana.</p>

Corrosion monitoring and root cause identification in high solids concentrators

TAPPI Journal ◽  
2016 ◽  
Vol 15 (7) ◽  
pp. 467-477
Author(s):  
PASI NIEMELAINEN ◽  
MARTTI PULLIAINEN ◽  
JARMO KAHALA ◽  
SAMPO LUUKKAINEN
Keyword(s):  
Paper Industry ◽  
Black Liquor ◽  
Construction Materials ◽  
Open Circuit ◽  
Process Conditions ◽  
Potential Range ◽  
Corrosion Monitoring ◽  
General Corrosion ◽  
High Solids ◽  
Passive Area

Black liquor high solids (about 80%) concentrators have often been found to suffer from aggressive corrosion. In particular, the first and second effect bodies are susceptible to corrosion attacks resulting in tube leaks and wall thinning, which limit the availability and lifetime of evaporator lines. Corrosion dynamics and construction materials have been studied extensively within the pulp and paper industry to understand the corrosion process. However, it has been challenging to identify root causes for corrosion, which has limited proactive measures to minimize corrosion damage. Corrosion of the first phase concentrator was studied by defining the potential regions for passive area, stress corrosion cracking, pitting corrosion, and general corrosion. This was achieved by using a technique called polarization scan that reveals ranges for the passive area in which the equipment is naturally protected against corrosion. The open circuit potential, also known as corrosion potential, and linear polarization resistance of the metal were monitored online, which allowed for definition of corrosion risks for stainless steel 304L and duplex stainless steels 2205 and SAF 2906. An online temperature measurement added insight to the analysis. A process diagnostics tool was used to identify root causes of the corrosion attacks. Many of the root causes were related to process conditions triggering corrosion. Once the metal surface was activated, it was difficult to repassivate the metal naturally unless a sufficient potential range was reached.

scholarly journals Characterization of Aerosol Composition, Aerosol Acidity and Organic Acid Partitioning at an Agriculture-Intensive Rural Southeastern U.S. Site

2018 ◽  
Author(s):  
Theodora Nah ◽  
Hongyu Guo ◽  
Amy P. Sullivan ◽  
Yunle Chen ◽  
David J. Tanner ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Organic Acids ◽  
Organic Acid ◽  
Organic Aerosol ◽  
Water Soluble ◽  
Molar Concentration ◽  
Particle Phase ◽  
Aerosol Composition ◽  
Phase Water ◽  
Acetic Acids

Abstract. The implementation of stringent emission regulations has resulted in the decline of anthropogenic pollutants including sulfur dioxide (SO2), nitrogen oxides (NOx) and carbon monoxide (CO). In contrast, ammonia (NH3) emissions are largely unregulated, with emissions projected to increase in the future. We present real-time aerosol and gas measurements from a field study conducted in an agricultural-intensive region in the southeastern U.S. during the fall of 2016 to investigate how NH3 affects particle acidity and SOA formation via the gas-particle partitioning of semi-volatile organic acids. Particle water and pH were determined using the ISORROPIA-II thermodynamic model and validated by comparing predicted inorganic HNO3-NO3− and NH3-NH4+ gas-particle partitioning ratios with measured values. Our results showed that despite the high NH3 concentrations (study average 8.1 ± 5.2 ppb), PM1 were highly acidic with pH values ranging from 0.9 to 3.8, and a study-averaged pH of 2.2 ± 0.6. PM1 pH varied by approximately 1.4 units diurnally. Formic and acetic acids were the most abundant gas-phase organic acids, and oxalate was the most abundant particle-phase water-soluble organic acid anion. Measured particle-phase water-soluble organic acids were on average 6 % of the total non-refractory PM1 organic aerosol mass. The measured molar fraction of oxalic acid in the particle phase (i.e., particle-phase oxalic acid molar concentration divided by the total oxalic acid molar concentration) ranged between 47 and 90 % for PM1 pH 1.2 to 3.4. The measured oxalic acid gas-particle partitioning ratios were in good agreement with their corresponding thermodynamic predictions, calculated based on oxalic acid’s physicochemical properties, ambient temperature, particle water and pH. In contrast, gas-particle partitioning of formic and acetic acids were not well predicted for reasons currently unknown. For this study, higher NH3 concentrations relative to what has been measured in the region in previous studies had minor effects on PM1 organic acids and their influence on the overall organic aerosol and PM1 mass concentrations.

Microwave Irradiated Acetylation of p-Anisidine: A Step towards Green Chemistry

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Mousumi Chakraborty ◽  
Vaishali Umrigar ◽  
Parimal A. Parikh
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Green Chemistry ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Organic Solvent ◽  
Reaction Times ◽  
Microwave Energy ◽  
Operating Parameters ◽  
Feed Composition

The present study aims at assessing the effect of microwave irradiation against thermal heat on the production of N-acetyl-p-anisidine by acetylation of p-anisidine. The acetylation of p-anisidine under microwave irradiation produces N-acetyl-p-anisidine in shorter reaction times, which offers a benefit to the laboratories as well as industries. It also eliminates the use of excess solvent. Effects of operating parameters such as reaction time, feed composition, and microwave energy and reaction temperature on selectivity to the desired product have been investigated. The results indicate as high as a 98% conversion of N-acetyl-p-anisidine can be achieved within 12-15 minutes using acetic acid. The use of acetic acid as an acetylating agent against conventionally used acetic anhydride eliminates the handling of explosive acetic anhydride and also the energy intensive distillation step for separation of acetic acid. Organic solvent like acetic anhydride are not only hazardous to the environment, they are also expensive and flammable.

AN ADAPTABILITY POTENTIAL ANALYSIS OF THE VICIA SATIVA VARIETIES ON THE GREEN MASS YIELD IN THE SOUTH EASTERN ZONE OF THE KAMCHATKA TERRITORY CONDITIONS

1970 ◽  
pp. 33-37
Author(s):  
А. А. Zhdanova ◽  
М. B. Kochneva
Keyword(s):  
Total Yield ◽  
Vicia Sativa ◽  
Thermal Coefficient ◽  
The South ◽  
Hydrothermal Conditions ◽  
Environmental Index ◽  
Limit Values ◽  
South Eastern ◽  
Green Mass ◽  
Eastern Zone

The article presents the results of a four-year collection study of promising varieties of spring-sown vetch, Vicia sativa L., for zoning in the conditions of the south-eastern zone of the Kamchatka Territory according to statistical parameters. The aim of the study was to identify stress-resistant, environmentally plastic, stable and adaptive varieties of vetch seed calculated by the yield of green mass. The experimental field of the Kamchatka Research Institute of Agriculture is located in the area of the Pacific influence with a cold summer without a dry season. Hydrothermal conditions during the periods of green mass formation in 2014-2017 were characterized by excessive moisture content, hydrothermal coefficient = 2.0-4.6. The environmental index ranged from -12.08 to 13.2. The correlation analysis revealed a direct relationship between the total yield and the sum of active temperatures, r = 0.9. An inverse correlation was determined between the environmental conditions index and the hydro-thermal coefficient, r = -0.79. The average annual yield of green mass for 4 years was 18.7 t/ha. The level of the average yield of green mass varied from 10.0 to 26.8 t/ha, the limit values varied within 5.5-34 t/ha. In the course of work, 18 varieties of spring vetch were studied, of which 5 valuable varieties were identified for cultivation in the region: Lyudmila (Yср = 26.8 t/ha), Yubilejnaya 110 (25.5), Uzunovskaya 91 (22.8), Tayozhnaya (21.8) and the zoned variety Lugovskaya 85 (18.0 t/ha), capable of producing stable yields in favorable and extreme conditions.

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