Abstract: A reforming method of a metallurgical furnace generated exhaust gas includes reforming a high temperature exhaust gas discharged from a metallurgical furnace by adding a reducing agent to the gas, wherein addition of the reducing agent is initiated when an oxygen concentration in the exhaust gas is 1 vol % or less, and a reforming reaction is completed when a temperature of the exhaust gas is 800° C. or higher, and an apparatus thereof. The reducing agent is blown from a reducing agent blowing nozzle having a double pipe structure.

Abstract: A reforming method of a metallurgical furnace generated exhaust gas includes reforming a high temperature exhaust gas discharged from a metallurgical furnace by adding a reducing agent to the gas, wherein addition of the reducing agent is initiated when an oxygen concentration in the exhaust gas is 1 vol % or less, and a reforming reaction is completed when a temperature of the exhaust gas is 800° C. or higher, and an apparatus thereof. The reducing agent is blown from a reducing agent blowing nozzle having a double pipe structure.

Abstract: The improved process for preparing para-hydroxybenzoic acid comprises reacting potassium phenol with carbon dioxide in an inert reaction medium or without using a reaction medium in the presence of at least one compound selected from the group consisting of the compounds represented by the following general formula I or II: ##STR1## at a reaction temperature of 230.degree.-450.degree. C. and at a carbon dioxide pressure ranging from atmospheric pressure to 6 kg/cm.sup.2 (G). The process may comprise two stages and the first-stage reaction described above is followed by the second stage in which the reaction is further continued with the pressure of carbon dioxide in the system being reduced and/or the reaction temperature being elevated within the range specified above.Also, phenol may be used as the starting material instead of potassium phenolate.

Abstract: Para-hydroxybenzoic acid is prepared by reacting an alkali metal salt of phenol except the lithium and sodium salts with carbon dioxide in the presence of at least one compound selected from compounds of the following formulae (I) and (II): ##STR1## In formulae (I) and (II), M is an alkali metal except lithium and sodium; R is any substituent except an aliphatic hydroxy group having up to 4 carbon atoms, an aliphatic mercapto group having up to 4 carbon atoms, a substituent having at least one of them as its structural unit, and a hydrogen atom; R' is any substituent except an aliphatic hydroxy group having up to 4 carbon atoms, an aliphatic mercapto group having up to 4 carbon atoms, and a substituent having at least one of them as its structural unit; in formula (I) n is an integer of 1 to 5, and R groups may be the same or different when n is more than one; in formula (II) m is an integer of 1 to 5 and l is an integer of 0 to 4, and M alkali metals may be the same or different when m is one or more, and R'