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Microbial Control during Hydraulic Fracking Operations
Published in Kenneth Wunch, Marko Stipaničev, Max Frenzel, Microbial Bioinformatics in the Oil and Gas Industry, 2021
Renato De Paula, Irwan Yunus, Conor Pierce
Peroxy acids are related to hydrogen peroxide. Peroxy acids are synthesized by mixing hydrogen peroxide with carboxylic acids bearing various carbon chain lengths. Peracetic acid, from acetic acid and hydrogen peroxide, is the most prevalent of the peroxy acid oxidizing biocides in hydraulic fracturing operations. While it also generates hydroxyl radicals, peracetic acid is a more reactive molecule than hydrogen peroxide with a higher oxidation potential so is capable of oxidizing thiols and disulfide bonds in key cellular components without the need of a radical intermediate. An additional benefit of peracetic acid is the release of only environmentally benign byproducts: Acetic acid and water from the peracetic acid and oxygen from the hydrogen peroxide used to synthesize it (De Paula et al., 2013). Recent advances have introduced performic acid, from formic acid and hydrogen peroxide, as a more reactive peroxy acid variant. Mechanistically identical to peracetic acid but substantially more reactive, performic acid must be generated on-site. The byproducts of performic acid are also environmentally benign, forming only carbon dioxide and water due to the decreased amount of hydrogen peroxide required to generate it (Pierce and Peter, 2019).
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Published in Brajendra K. Sharma, Girma Biresaw, Environmentally Friendly and Biobased Lubricants, 2016
Kenneth M. Doll, Bryan R. Moser, Zengshe Liu, Rex E. Murray
Plant oils can be chemically modified for use in most of these applications. The most common chemical modification is epoxidation, where plant oils are subjected to the Prilezhaev reaction. A percarboxylic acid, such as peracetic or performic acid, is generated in situ by the acid-catalyzed reaction of formic or glacial acetic acid with hydrogen peroxide. The peracid then reacts with olefinic moieties to yield epoxidized plant oils containing three-membered ring epoxy structures, also called oxiranes [75]. Epoxidized triacylglycerols have shown promise for use in industrial applications such as in coatings, inks, and adhesives [167]. Epoxidized plant oils can also be polymerized in the presence of curing agents, such as diamines [168], or by ring-opening catalysts such as Lewis acids [169]. This curing process transforms the relatively low-molecular weight oil into a highly cross-linked network with properties ranging from a high-viscosity liquid to a solid composite panel [170]. Generally, the curing agent attaches to one of the carbons of the epoxide group to yield an ester, ether, or amine linkage. This results in the formation of a hydroxyl group on the other carbon of the epoxide moiety. The most successful use of an epoxidized triacylglycerol is epoxidized soybean oil (ESO), which is commercially available under the brand name Vikoflex 7170 (Arkema). ESO is widely used as a nontoxic stabilizer and plasticizer and potentially can replace phthalates in plastic plasticizers, where it imparts desired properties such as increased flexibility, stability, and improved processing conditions [171].
Liquid Chromatography
Published in Ernő Pungor, A Practical Guide to Instrumental Analysis, 2020
Performic Acid Oxidation. Freeze 100 μg of protein sample in drug ice and lyophilized acid and let it stand in a closed container for 2 h at ambient temperature, cool it to 0°C, and add 100 μl to the sample and allowed it to stand in a capped vial for 2.5 h at 0°C; add 0.9 cm3 of cold water, then lyophilize 200 μl from this mixture. The hydrolysis and derivatization with OPA must be done as described before.
Deep desulfurization of real fuel oils over tin-impregnated graphene oxide-hydrogen peroxide and formic acid catalyst-oxidant system
Published in Journal of Sulfur Chemistry, 2023
Muhammad Yaseen, Sidra Subhan, Kifayatullah Khan, Muhammad Usman Farooq, Waqas Ahmad, Humaira Seema, Rafia Naz, Fazle Subhan
The concentration of oxidants greatly influences the efficiency and the economy of the ODS process [35]. Oxidation processes driven by Le Chatelier’s principle shift the reaction in the forward direction with the increase in the molar concentration of oxidizing species [25]. Hydrogen peroxide and formic acid as oxidants were used for the ODS of the model and commercial oil sample with different catalyst loadings. During the reaction, hydrogen peroxide acts as a co-oxidant that reacts with formic acid to give performic acid, which then converts DBT molecules to their respective oxides [36]. Figure S3 shows the effect of oxidant dose in the presence of GO and Sn/GO catalyst using different volumes i.e. 2, 4, 6, and 8 mL, 0.03 g/10 mL DBT solution. The results show that combining a 2:2 concentration (mL) of hydrogen peroxide and formic acid gives maximum DBT removal of 82% and 97% for GO and Sn/GO, respectively. Further increase in oxidant ratio increases the number of oxidizing species that cause competition with the catalytic active species instead of reacting DBT molecules, thus leading to lower DBT conversion [37,38].
Amino acid preparation and recovery from refractory sludge by the oxidative acid hydrolysis process
Published in Environmental Technology, 2022
Wenlong Hui, Jiti Zhou, Ruofei Jin
Every hydrolysis bottle containing 1.0 g freeze-dried refractory sludge was filled with 10 ml cooled performic acid solution (the volume ratio of 30% hydrogen peroxide and formic acid was 1:9). The reaction was carried out in the refrigerator at 0∼4°C for 24 h. After standing at room temperature, the hydrolysis bottle was put into 100 ml hydrochloric acid solutions (HCl concentration: 0, 2, 4, 6, and 8 M). Then it was filled with nitrogen for 1 min and the cap was tightened. The hydrolytic tube was hydrolysed in a thermostatic (temperature: 80, 90, 100, 110, and 120°C) drying oven for some time (0, 8, 16, 24, and 32 h). After the reaction, the sludge hydrolysate was cooled, centrifuged, and filtered with a 0.22 um membrane. The orthogonal test was conducted based on the critical process parameters of the temperature (100, 110, and 120°C), the reaction times (16, 24, and 32 h), and the HCl concentration (4, 6, and 8 mol/L). Each hydrolysis experiment was repeated three times with the same procedure with the average value as the final results.
Desulfurization and de-ashing of low-rank coal by catalytic oxidation using Sn as catalyst loaded in different forms
Published in International Journal of Coal Preparation and Utilization, 2022
Waqas Ahmad, Ishraq Ahmad, Imtiaz Ahmad, Muhammad Yaseen, Nisar Muhammad, Muhammad Salman
The oxidation of coal was carried out using H2O2/HCOOH oxidation system. The mechanism of oxidative desulfurization has been extensively studied in literature, which reveals that during simple oxidation of coal, the sulfur compounds present in coal are changed to leachable forms, among different forms of sulfur present in coal, the organic sulfur is changed to sulfoxides and sulfones that may easily be washed out with water, while the pyritic sulfur is changed to sulfatic form (Hayvanovych and Pysh’yev 2003; Yaman and Küçükbayrak 1997), which are then washed in the washing step. During the current oxidation system, the hydrogen peroxide dissociates to hydroxyl radical (HO.) which combines with formic acid and form performic acid, which carry out the oxidation of sulfur (Guimarães et al. 2008). Whereas the pyritic form of sulfur can also be removed by oxidation of coal, wherein, the pyrite form (FeS2) is converted to ferric sulfate (FeSO4) and elemental sulfur. The elemental form of sulfur is further oxidized to sulfuric acid (H2SO4). Because these sulfate compounds are hydrophilic in nature, therefore are easily removed by washing with water (Fan 1984). Beside due to acidic nature of the reagents involved in oxidation, many other minerals are also assumed to be leached out from coal. Initially the oxidation parameters were optimized and later the oxidation of coal is investigated in the presence of catalyst under optimized conditions (Saikia, Khound, and Baruah 2014).