China 
Africa 
Explore chapters and articles related to this topic
Carbon Dioxide Conversions
Published in Saeed Sahebdelfar, Maryam Takht Ravanchi, Ashok Kumar Nadda, 1 Chemistry, 2022
Saeed Sahebdelfar, Maryam Takht Ravanchi, Ashok Kumar Nadda
With phenol salts (alkali phenolates), CO2 brings about substitution of hydrogen with a carboxyl ( −COOH ) group (Kolbe or Kolbe-Schmitt reaction) which is important in commercial production of salicylic acid (Scheme 6.2). The ionization of the salt activates the ring for electrophile attack such that feeble electrophiles such as CO2 can react.
Other Feedstocks—Coal, Oil Shale, and Biomass
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Naphthalene and several tar acids are the important products extracted from volatile oils from coal tar. It is necessary to first extract the phenolic compounds from the oils and then to process the phenol-depleted oils for naphthalene recovery. Tar acids are produced by extraction of the oils with aqueous caustic soda at a temperature sufficient to prevent naphthalene from crystallizing. The phenols react with the sodium hydroxide to give the corresponding sodium salts as an aqueous extract known variously as crude sodium phenate, sodium phenolate, sodium carbolate, or sodium cresylate. The extract is separated from the phenol-free oils which are then taken for naphthalene recovery.
Treatment of Coal Industry Effluents
Published in Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang, Treatment of Industrial Effluents, 2019
Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang
All the pollutants of the spent ammoniacal liquor affect the ecology of the waste-receiving water. During the process, phenol is considered to be the most hazardous pollutant. The other objectionable substances include thiocyanate, thiosulfate, cyanide, etc. In some plants, spent ammoniacal liquor is utilized for quenching of hot coke, this practice destroys the toxic matters like phenols in the liquor, but as this causes heavy corrosion in the quenching cars and in other quenching equipment, the method is not generally favored. Being a valuable chemical by-product, phenol may be recovered instead of destroying it. For the recovery of phenol by liquid extraction methods, several techniques have been developed. Most of these processes use benzene as a solvent to extract phenol from the crude ammoniacal liquor, before entering for ammonia stripping. Other solvents used include light oil, petroleum oil, etc. The extracted phenols from all absorption process can be recovered by washing with sodium hydroxide solution. Phenol reacts with a caustic solution to produce sodium phenolate. The crude phenol is then liberated from it using gases containing carbon dioxide. The phenols, thiocyanates, thiosulfates, and ammonia can be biologically oxidized using certain microorganisms such as bacteria and yeast. When optimum pH and temperature are maintained, sufficient nutrients are added, and the reactor is suitably seeded, the proper loading of this phenolic substrate to the reactor may result in a desirable reduction of the pollution load of the waste. Phenol concentrations of ~800 mg/L may be treated biologically. In all practical cases, the phenol concentration in the waste ammoniacal liquor is too high to be treated directly by biological means.
Extraction of phenolic pollutants from industrial wastewater using a bulk ionic liquid membrane technique
Published in Environmental Technology, 2022
Khalid Farhod Chasib, Anwer Jassim Mohsen, K. J Jisha, Ramesh L. Gardas
Solvent obtained after the extraction process was allowed to mix appropriately with the prepared NaOH solution (called as strip solution) and then the stripping was performed. The solvent volume ratio used for the stripping was noted down for further references. Phenolate forms of phenols and chlorophenols were formed after the stripping as the molecules reacted with the sodium hydroxide solution. Concentrations of the components present in the strip phase were determined with the help of UV-Visible spectrophotometer by checking the absorbance of each molecule. The wavelength chosen for different components were different, and the list is as follows: sodium phenolate (290 nm), sodium 4-chlorophenolate (294 nm), sodium 2,4-dichlorophenolate (288 nm), sodium 2,4,6-trichlorophenolate (312 nm) and sodium pentachlorophenolate (345 nm). Other than the formed phenolates, pure phenol was also present in the solvent phase, which was obtained after the stripping, and the quantitative analysis of the phenol component was investigated using material conservation.
Application of phenol-cresol-formaldehyde resin as an adhesion promoter for bitumen and asphalt concrete
Published in Road Materials and Pavement Design, 2021
Volodymyr Gunka, Yuriy Demchuk, Iurii Sidun, Denis Miroshnichenko, Bemgba B. Nyakuma, Serhiy Pyshyev
The extraction of phenols from the wide phenolic fraction (WPhF) was performed using 20% NaOH solution. The alkali removal of phenols was based on the ability of phenol and its derivatives to form water-soluble phenolates. Typically, the latter is separated from the hydrocarbon fraction after extraction before conversion to phenols by 38% hydrochloric acid (concentrated HCl). The composition of «raw» phenols in WPhF is typically about 32.3 wt. %.