Sulphuric acid is a major raw material in the phosphate fertiliser industry and one of the largest-volume industrial chemicals produced in the world with large-scale industrial uses. Other important applications are in petroleum refining, steel pickling, rayon and staple fiber, alum, explosives, detergents, plastics and fibers etc
We manufacture Sulphuric Acid from our own plants at Biccavolu in Andhra Pradesh and Koppal in Karnataka. Sulphuric Acid produced is used for captive consumption and for industrial supply.
Second stream of SO3 gases gets absorbed in oleum tower and solubility depends upon temperature and concentration of circulating oleum. Oleum concentration rises to 30% where circulation of oleum in oleum tower is carried out with proper cooling of oleum in plate heat exchanger. 30% oleum from the oleum process tank is passed through a ‘shell & tube’ type heat exchanger before feeding to oleum boilers. In oleum boilers, 30% oleum is heated with steam (4-5 kg/cm2) and pure SO3 gas is stripped off. 30% oleum gets reduced to 20% oleum. SO3 gas is liquefied in condensers. Hot 20% oleum is returned to oleum tower via ‘shell & tube’ type heat exchanger called pre-heater. Water is used to liquefy the gas in condenser. We primarily produce 23% grade Oleum. To produce 23% oleum, sulphuric acid and 30% oleum are mixed in 23% oleum process tank in requisite proportions. After thorough mixing 23% oleum is cooled in a trombone M.S. pipe cooler and then transferred to 23% storage tanks. With the help of dispatch pumps, 23% oleum may be filled in tankers directly.
Dimethyl Sulphate (“DMS”) is used as a methylation agent and is essential in several chemical applications. It is also used as a solvent, stabilizer, sulfonation agent and catalyst. Its end applications is found in crop protection products, pharmaceuticals, water treatment and rubber chemicals, surfactants, fabric softeners, colouring agents, etc.
DMS is produced by synthesis of methanol with liquid SO3. Methanol is pumped continuously into methanol vaporizer and the resulting vapours of methanol are fed into a reactor containing alumina catalyst. At 250oC, methanol vapours on reacting with alumina gets converted to Di-methyl-Ether (“DME”). These vapours of DME are fed into a stripping column along with water and unreacted methanol (15 to 20%). The resultant compound is pure DME which is retrieved from the top of the column and water plus methanol mixture that is retrieved from the bottom of the column which is further taken to methanol recovery column to get pure methanol for re-use. The pure DME gas is then fed into a sulphonater containing liquid SO3 to get Technical Di-Methyl Sulphate (“TDMS”) (min 94 to 95%). This TDMS is purified by vaccum distillation to get pure DMS (min. 99.5%).
Linear Alkyl Benzene Sulphonic Acid
Linear Alkyl Benzene Sulphonic Acid (“LABSA”) is one of the major active ingredients for the production of soaps, synthetic detergent powders and liquids like laundry powders, laundry liquids, dish washing liquids, other house hold cleaners, etc. It is also used as an industrial application like emulsifier and for use in herbicides, wetting agent with other surfactant in soap for foaming and emulsion polymerization. Further, it finds application in crop protection products to improve the spray ability.
Our Company produces LABSA with 90% active ingredient. LABSA is produced by reaction of Linear Alkyl Benzene (“LAB”) with Sulphuric Acid. LABSA is produced in a two stage reaction process. The first stage consists of exothermic reaction of LAB with Sulphuric acid into a reactor for around 8 hours at a temperature ranging between 300C to 600C. On reaching 600C, the compound is cooled till temperature reaches 500C. To control the temperature, cool water from the chilling towers is passed through the jackets of the reactors. On reaching 500C, the second stage of hydrolysis is commenced by slowly adding water to the compound and the temperature is increased up to 700C. At this temperature, the reaction process will be stopped and the compound will be allowed to settle. During hydrolysis, excess SO3 present in the compound may be converted into dilute acid. After hydrolysis in the reactor, the compound will form in two layers based on specific gravities viz., diluted acid and LABSA. The diluted acid will first be decanted out into a dilute acid batch tank and then to dilute acid storage tank. The second layer i.e., LABSA will be transferred to the LABSA storage tank.