Abstract: The present invention provides a method for the preparation of multi-nutrient potassic fertilizer, by recovering potassium from sugarcane molasses based alcohol distillery effluent (commonly known as ‘spent wash’). The process involves pre-treatment of spent wash to clarify the aqueous phase and utilization of the treated spent wash in production of potassic fertilizer. The present invention enables utilisation of spent wash for recovery of value-added product (viz., potash fertiliser of >99% purity) and improves ease of ‘Zero Liquid Discharge’ compliance by subjecting the relatively benign process effluent to industrially practiced techniques for water recovery and salt reclamation.

Abstract: Molasses based alcohol distilleries generate highly contaminated, dark coloured and foul smelling effluent (bio-methanated spent wash, BMSW, also known as post methanated effluent). While the prevailing practices for treatment of alcohol distillery effluents operate on the premises of “liability management”, high potassium content of spent wash (ca. 2% w/v in BMSW) offers an opportunity for its utilisation in production of potash fertilizers—a major agricultural input. The present invention provides process for potash recovery from BMSW with concomitant environmental remediation of effluent. The process involves pre-treatment of BMSW followed by potash recovery through selective precipitation technique to produce potash fertilizers and activated carbon while generating a relatively benign effluent (>80% remediation). It may further be possible for the alcohol distilleries to achieve ZLD status by incorporating commercially practiced water recovery techniques (viz.

Abstract: The present invention provides a method for the preparation of multi-nutrient potassic fertilizer, by recovering potassium from sugarcane molasses based alcohol distillery effluent (commonly known as ‘spent wash’). The process involves pre-treatment of spent wash to clarify the aqueous phase and utilization of the treated spent wash in production of potassic fertilizer. The present invention enables utilisation of spent wash for recovery of value-added product (viz., potash fertiliser of >99% purity) and improves ease of ‘Zero Liquid Discharge’ compliance by subjecting the relatively benign process effluent to industrially practiced techniques for water recovery and salt reclamation.

Abstract: Molasses based alcohol distilleries generate highly contaminated, dark coloured and foul smelling effluent (bio-methanated spent wash, BMSW, also known as post methanated effluent). While the prevailing practices for treatment of alcohol distillery effiuents operate on the premises of “liability management”, high potassium content of spent wash (ca. 2% w/v in BMSVV) offers an opportunity for its utilisation in production of potash fertilisers—a major agricultural input. The present invention provides process for potash recovery from BMSW with concomitant environmental remediation of effluent. The process involves pre-treatment of BMSW followed by potash recovery through selective precipitation technique to produce potash fertilisers and activated carbon while generating a relatively benign effluent (>80% remediation). It may further be possible for the alcohol distilleries to achieve ZLD status by incorporating commercially practiced water recovery techniques (viz.

Abstract: The present invention provides process for production of potassium ammonium sulfate compound fertilizer through the reaction of Epsom salt, obtained in course of chilling of concentrated sea bittern (32-33° Be), with potassium bitartrate, precipitated from such bittern, and ammonium hydroxide. While process integration was achieved through utilisation of Epsom salt; partial desulphatation of bittern, through crystallization of Epsom salt, resulted in about 17% improvement in K+ precipitation efficiency.

Abstract: Although U.S. Pat. No. 8,182,784 teaches the recovery of potassium chloride from schoenite end liquor (SEL) using dipicrylamine as extractant, and consequently simplifies the recovery of sulphate of potash (SOP) from kainite mixed salt employing the scheme disclosed in U.S. Pat. No. 7,041,268, the hazards associated with this extractant have thwarted practical utilization of the invention. Many other extractants for potash recovery have been disclosed in the prior art but none has been found suitable so far for practical exploitation. It is disclosed herein that the bitartrate ion, and particularly L-bitartrate, precipitates out potassium bitartrate very efficiently from SEL with ca. 90% utilization of the extractant. In contrast, recovery of potassium bi-tartrate from sea bittern directly is relatively much lower. It is further disclosed that this precipitate can be treated with magnesium hydroxide and magnesium chloride to throw out magnesium tartrate with ca.

Abstract: The present invention provides an integrated process for the recovery of sulphate of potash (SOP) and ammonium sulphate fertilizers from kainite mixed salt dispensing with magnesium hydroxide production. The process comprises, among other steps, producing calcium chloride from calcium carbonate through addition of hydrochloric acid; the calcium chloride being used for desulphatation of schoenite end liquor (SEL) obtained as liquid stream during decomposition of kainite mixed salt with water to obtain solid schoenite; using the resultant gypsum and carbon dioxide together with ammonia for the production of ammonium sulphate liquor and solid calcium carbonate, the latter being recycled in the process; producing carnallite from desulphated SEL; decomposing the carnallite to recover carnallite decomposed product (CDP) which is further refined under ambient conditions to obtain pure potassium chloride (KCl) utilized in the preparation of SOP from the schoenite.

Abstract: The invention relates to an integrated process for the production of 5-hydroxymethyl furfural (HMF), K2SO4, levulinic acid and formic acid from ?-carrageenan, the latter being obtained from fresh Kappaphycus alvarezii seaweed biomass after expelling the juice. Mg(HSO4)2 was used in HMF synthesis, with co-production of galactose. The aqueous stream after HMF extraction was treated with the seaweed juice which process facilitated recovery of K2SO4 in pure form. The galactose may be utilised for synthesis of levulinic acid and formic acid before or after K2SO4 recovery or, alternatively, utilised for other purposes. Catalysts required in the synthetic reactions are generated in the process itself while the process energy required is met out of additional supplies of the seaweed biomass which is subjected to combustion/gasification.

Abstract: A method of producing soda ash and ammonium sulphate by recycling by-products of Merseberg and Solvay processes includes treating brine with soda ash distiller waste for desulphatation of the brine to obtain gypsum, recovering pure salt from the desulphated brine and utilizing it in manufacture of soda ash in a Solvay process, washing the gypsum and reacting it with liquor ammonia and carbon dioxide to obtain CaCO3 and ammonium sulphate, separating the CaCO3 from the ammonium sulphate solution and recovering solid ammonium sulphate, washing the CaCO3 followed by calcination to generate CO2 and lime, recycling the CO2 in the Solvay process to obtain soda ash, recycling the lime with ammonium chloride generated in the Solvay process to recover ammonia and obtain distiller waste containing CaCl2 as a by-product, recycling the by-product distiller waste for the desulphatation of the brine, and recycling the ammonia recovered.

Abstract: The invention relates to an integrated process for the production of 5-hydroxymethyl furfural (HMF), K2SO4, levulinic acid and formic acid from ?-carrageenan, the latter being obtained from fresh Kappaphycus alvarezii seaweed biomass after expelling the juice. Mg(HSO4)2 was used in HMF synthesis, with co-production of galactose. The aqueous stream after HMF extraction was treated with the seaweed juice which process facilitated recovery of K2SO4 in pure form. The galactose may be utilised for synthesis of levulinic acid and formic acid before or after K2SO4 recovery or, alternatively, utilised for other purposes. Catalysts required in the synthetic reactions are generated in the process itself while the process energy required is met out of additional supplies of the seaweed biomass which is subjected to combustion/gasification.

Abstract: The present invention provides an integrated process for the recovery of sulphate of potash (SOP) and ammonium sulphate fertilizers from kainite mixed salt dispensing with magnesium hydroxide production. The process comprises, among other steps, producing calcium chloride from calcium carbonate through addition of hydrochloric acid; the calcium chloride being used for desulphatation of schoenite end liquor (SEL) obtained as liquid stream during decomposition of kainite mixed salt with water to obtain solid schoenite; using the resultant gypsum and carbon dioxide together with ammonia for the production of ammonium sulphate liquor and solid calcium carbonate, the latter being recycled in the process; producing carnallite from desulphated SEL; decomposing the carnallite to recover carnallite decomposed product (CDP) which is further refined under ambient conditions to obtain pure potassium chloride (KCl) utilized in the preparation of SOP from the schoenite.

Abstract: A method of producing soda ash and ammonium sulphate by recycling by-products of Merseberg and Solvay processes includes treating brine with soda ash distiller waste for desulphatation of the brine to obtain gypsum, recovering pure salt from the desulphated brine and utilizing it in manufacture of soda ash in a Solvay process, washing the gypsum and reacting it with liquor ammonia and carbon dioxide to obtain CaCO3 and ammonium sulphate, separating the CaCO3 from the ammonium sulphate solution and recovering solid ammonium sulphate, washing the CaCO3 followed by calcination to generate CO2 and lime, recycling the CO2 in the Solvay process to obtain soda ash, recycling the lime with ammonium chloride generated in the Solvay process to recover ammonia and obtain distiller waste containing CaCl2 as a by-product, recycling the by-product distiller waste for the desulphatation of the brine, and recycling the ammonia recovered.

Abstract: A highly pure 3,5-dibromo-4-hydroxybenzonitrile (bromoxynil) has been prepared in high yield from 4-hydroxybenzonitrile using eco-friendly brominating reagent comprising of 2:1 mole ratio of bromide to bromate salts in aqueous acidic medium without any catalyst under ambient conditions with no work up procedure. The product 3,5-dibromo-4-hydroxybenzonitrile was obtained in 91-99% yield with melting point 189-191° C. and more than 99% purity by gas chromatographic analysis without any purification.

Abstract: Although U.S. Pat. No. 8,182,784 teaches the recovery of potassium chloride from schoenite end liquor (SEL) using dipicrylamine as extractant, and consequently simplifies the recovery of sulphate of potash (SOP) from kainite mixed salt employing the scheme disclosed in U.S. Pat. No. 7,041,268, the hazards associated with this extractant have thwarted practical utilization of the invention. Many other extractants for potash recovery have been disclosed in the prior art but none has been found suitable so far for practical exploitation. It is disclosed herein that the bitartrate ion, and particularly L-bitartrate, precipitates out potassium bitartrate very efficiently from SEL with ca. 90% utilization of the extractant. In contrast, recovery of potassium bi-tartrate from sea bittern directly is relatively much lower. It is further disclosed that this precipitate can be treated with magnesium hydroxide and magnesium chloride to throw out magnesium tartrate with ca.

Abstract: Kainite mixed salt is treated with water to obtain solid schoenite and a schoenite end liquor. The latter is desulphated using recycled CaCl2 and thereafter evaporated to obtain camallite crystals, from which KCl is recovered, and a liquor rich in MgCl2. Gypsum produced during desulphatation is reacted with aqueous ammonia and CO2 to produce ammonium sulphate and calcium carbonate. The calcium carbonate is calcined to obtained CaO and CO2. The CaO is slaked and reacted with the MgCl2-rich liquor generated above to produce slurry of Mg(OH)2 in aqueous CaCl2. To this surface modifying agent is added while hot and, after cooling, the slurry yields surface modified Mg(OH)2. The filtrate rich in CaCl2 is recycled for desulphatation process above. The solid surface modified Mg(OH)2 may he calcined to produced MgO. The schoenite and KCl are reacted to produce solid sulphate of potash.

Abstract: A highly pure 3,5-dibromo-4-hydroxybenzonitrile (bromoxynil) has been prepared in high yield from 4-hydroxybenzonitrile using eco-friendly brominating reagent comprising of 2:1 mole ratio of bromide to bromate salts in aqueous acidic medium without any catalyst under ambient conditions with no work up procedure. The product 3,5-dibromo-4-hydroxybenzonitrile was obtained in 91-99% yield with melting point 189-191° C. and more than 99% purity by gas chromatographic analysis without any purification.

Abstract: The present invention provides an integrated process for the recovery of sulphate of potash (SOP), ammonium sulphate and surface modified magnesium hydroxide and/or magnesium oxide utilizing kainite mixed salt and ammonia as the only consumable raw materials. The process involves treating kainite mixed salt with water to obtain solid schoenite and a schoenite end liquor. The latter is desulphated using CaCl2 generated in the process itself and thereafter evaporated to obtain carnallite crystals from which KCl is recovered while the liquor rich in MgCl2 serves as a source of MgCL. The gypsum produced during desulphatation is reacted with aqueous ammonia and CO2 to produce ammonium sulphate and calcium carbonate. The calcium carbonate so obtained is then calcined to obtained CaO and CO2. The CaO is then slaked in decarbonated water and reacted with the MgCl2-rich liquor generated above to produce slurry of Mg(OH)2 in aqueous CaCl2.