39 results about "Recycling by product" patented technology

The invention provides a heat pump evaporation process for recycling flue gas cleaning byproducts. The process is characterized by comprising the following steps: feeding waste liquor subjected to wet cleaning into a reactor to have reaction with ammonium bicarbonate; after the reaction is finished, carrying out solid-liquid separation on feed liquid, cooling and crystallizing liquid to obtain clear liquid serving as raw material liquid, pumping the raw material liquid into a preheater, feeding the preheated raw material liquid into a heat exchanger, heating the raw material liquid by using shell pass steam in a tube pass of the heat exchanger so that the temperature of the raw material liquid is increased; pushing the raw material liquid into a crystal separator by using a forced circulation pump, performing flash evaporation in the crystal separator so that the raw material liquid is supersaturated and crystallized to obtain ammonium salt crystals which can be recycled; compressing secondary steam (generated by flash evaporation) by a compressor and feeding the compressed secondary steam serving as a heat source into the shell pass of the heat exchanger. The process is particularly suitable for processing sodion waste liquid generated after flue gas desulfurization and denitration and the aims of changing waste material into things of value is achieved and steam consumption is reduced.

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.

The invention discloses a method for preparing a paint raw material from a paint waste residue, and the method comprises the following steps of: preprocessing the paint waste residue, classifying, removing impurities, then adding an additive and a protecting agent, and uniformly dispersing; sending the preprocessed paint waste residue to an organic waste recycling system, setting a proper temperature and then carrying out separation modification; recycling solid components to form thick plaster-shaped modified resin and packaging; collecting mixed steam of a solvent and water through gas and then condensing so as to separate gas from liquid, carrying out tail gas purification on the gas part and discharging the gas part when the gas part reaches the standard, carrying out oil-water separation on the liquid part to ensure that water is separated from the solvent, collecting the solvent for concentrated utilization, and carrying out wastewater treatment on the water and then discharging when the gas part reaches the standard. A large quantity of organic solvent is not adopted in the method, water can be well separated from the paint waste residue, and the prepared paint raw material has the advantages of lower organic solvent content, lower danger and the like, thus the paint raw material can be safely used in various medium- and low-end coating raw materials.

The present invention relates to a method of producing Rebaudioside A in a high yield by recycling by-products produced when Rebaudioside A is produced from leaves of Stevia Rebaudiana Bertoni containing a sweetening material.

The invention relates to a method for preparing iron oxalate, belonging to the field of chemical engineering. The method for preparing iron oxalate can recycle by-product of copperas generated when preparing titanium pigment with titanium concentrate. The method for preparing iron oxalate takes the by-product of copperas generated when preparing the titanium pigment with the titanium concentrate as raw materials, and comprises the following steps of: a. adding water to the copperas for dissolution to obtain a ferrous sulfate solution, adjusting pH value to be 5.6 to 6.5 by utilizing ammonia, filtering the solution; b. extracting the filtrate by utilizing P2O4, separating the filtrate to obtain an organic phase and a water phase; c. and adding a solution containing F to the water phase so as to deposit Mg<2+>, filtering the solution, adding an oxalic acid solution to the filtrate, and filtering the solution to obtain iron oxalate crystallization. The invention not only solves the problem of stacking the copperas, but also enhances the economic value of the copperas, provides a new choice for treating the by-product of copperas generated when preparing titanium pigment with a sulfuric acid method, and has wide application prospect.

There is provided a method and system for recycling by-products containing large amounts of useful components and discharged in the form of dust and sludge from a coal-based molten iron making process to reuse the by-products in a reduced iron agglomeration process. The system includes: a fluidized reduction furnace reducing fine iron ore; a reduced iron tank connected to the fluidized reduction furnace through a reduced iron discharge pipe for storing the reduced iron and supplying the reduced iron in an agglomeration system; an agglomeration system agglomerating the reduced iron transferred from the reduced iron tank; and a transfer unit transferring compactions of by-products discharged from a molten iron making process through a by-product supply pipe. The compactions of the by-products are supplied to at least one selected from the group consisting of the fluidized reduction furnace, the reduced iron supply pipe, and the reduced iron tank.

The invention provides a preparation method of highly optically pure L-carnitine, comprising step 1): taking ethyl 4-chloroacetoacetate as a raw material, and obtaining ethyl 4-chloro-3-hydroxybutyrate through hydroboration reduction reaction; Step 2): Using ethyl 4-chloro-3-hydroxybutyrate obtained in step 1) as the reaction starting material, under the catalysis of immobilized lipase, carry out asymmetric esterification reaction with acyl donor to obtain (R )‑4‑chloro‑3‑hydroxybutyrate ethyl ester and (S)‑4‑chloro‑3‑hydroxybutyrate ethyl ester; step 3): (R)‑4‑chloro‑3‑hydroxybutyrate obtained in step 2) 3-Hydroxybutyrate ethyl ester is the reaction starting material, and after condensation with trimethylamine, the hydrolysis reaction is carried out to obtain L-carnitine. In the preparation method provided by the invention, the reaction raw materials are easy to obtain, the product yield is high, the optical purity is high, by-products can be recycled, and the method is suitable for industrial production.