Topic
Wet oxidation
About: Wet oxidation is a research topic. Over the lifetime, 3094 publications have been published within this topic receiving 61536 citations.
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TL;DR: Wet oxidation is a suitable pre-treatment for the conversion of organic waste carbohydrates into ethanol and that compatible conversion yields (60-65%) can be achieved at moderate enzyme loadings.
Abstract: Organic municipal solid waste enriched with wheat straw was subjected to wet-oxidation as a pre-treatment for subsequent enzymatic conversion and fermentation into bio-ethanol. The effect of temperature (185-195 °C), oxygen pressure (3-12 bar) and sodium carbonate (0-2 g l-1) addition on enzymatic cellulose and hemicellulose convertibility was studied at a constant wet oxidation retention time of 10 minutes. An enzyme convertibility assay at high enzyme loading (25 filter paper unit (FPU) g-1 dry solids (DS) added) showed that up to 78% of the cellulose and up to 68% of the hemicellulose in the treated waste could be converted into respectively hexose and pentose sugars compared to 46% for cellulose and 36% for hemicellulose in the raw waste. For all wet oxidation conditions tested, total carbohydrate recoveries were high (> 89%) and 44-66% of the original lignin could be converted into non-toxic carboxylic acids mainly (2.2-4.5 % on DS basis). Simultaneous saccharification and fermentation (SSF) of the t...
33 citations
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TL;DR: The results reveal that the conversion of ammonia by wet oxidation in the presence of Cu-ACF catalysts was a function of the metal loading weight ratio of the catalyst.
33 citations
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TL;DR: In this article, a review of existing and cutting-edge reaction pathways for the conversion of agricultural waste biomass into formic acid is presented, and the authors conclude that catalytic oxidation has the highest sustainability score in terms of yield, waste emissions, feedstock cost and innovation potential.
33 citations
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TL;DR: Wet air oxidation (WAO) is effective in the oxidation of 5-nitro-o-toluenesulfonic acid (NTSA); the WAO reaction is first-orde r with respect to NTSA as mentioned in this paper.
Abstract: Wet air oxidation (WAO) is effective in the oxidation of 5-nitro-o-toluenesulfonic acid (NTSA); the WAO reaction is first-orde rwith respect to NTSA. Sulfur intially present is almost stoichiometrically converted to sulfate. A significant amount of nitrogen gas and ammonium are present in the reactor off gas and WAO effluent, respectively. No NO x or SO x is detected. Proposed reaction pathways are presented for the WAO of NTSA, based on the intermediates and end products identified. NTSA concentration up to 150 mg/L does not show inhibitory effects on enriched Nitrosomonas. However, WAO-treated NTSA does show some adverse effect on the nitrite production capability of the Nitrosomonas, thus indicating that same byproducts formed during WAO of NTSA may be more toxic than NTSA itself
33 citations
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TL;DR: In this paper, a comparison of a wide range of caustic waste treatment methods in terms of their economic costs and efficiency is presented, focusing on the mechanisms and prominent parameters that affect the chemical oxygen demand (COD) reduction processes.
Abstract: Spent caustics contain compounds such as mercaptans, sulfides, and phenols. In addition, spent caustic solutions are highly alkaline and have high chemical oxygen demand. There are different ways to treat caustic waste. This paper for the first time, presents a comparison of a wide range of caustic waste treatment methods in terms of their economic costs and efficiency. Wet air oxidation, advanced oxidation processes, electrochemical processes, as well as biological and membrane systems are among technologies used to treat spent caustic solutions. This review focuses on the mechanisms and prominent parameters that affect the chemical oxygen demand (COD) reduction processes. The membrane process enjoys high efficiency (80–98 %) and is important because of advantages such as low energy consumption and easy design, compared to other methods. Nevertheless, it is not affordable because of the cost of cleaning the membranes and producing waste caused by the chemicals used to cleanse the membranes. The WAO process has high efficiency (70–96 %) but is not recommend due to severe operating conditions. Production of the Fenton reagent in an electrochemical cell using electricity as an energy source is one of the best options. The use of electricity as a source of energy prevents pollution and increases the process efficiency (90–99 %).
33 citations