172 results about "Chemical recovery" patented technology

A method and an apparatus for optimizing the combustion air system in a power boiler or chemical recovery boiler by improving fluid flow and gas mixing are disclosed, whereby one can increase boiler capacity and combustion uniformity and reduce particulate and gaseous emissions. The method involves interlacing of the secondary and, where applicable, the tertiary air supply through opposing air ports on all four walls of the boiler, and is implemented by alternately opening wide or partially closing a port damper on one side, while partially closing or opening wide a port damper on the opposite side, such that a 70-100% open damper on one side opposes a partially closed (10-40% open) damper on the other and vice versa in an alternating fashion, along opposing walls. In a preferred embodiment, the optimization is further enhanced by balancing primary air flow, achieved by adjusting port dampers and windbox pressures so that the primary air flow is evenly distributed between opposite walls, between all four walls of the boiler and between individual airports on each wall. Windbox pressure and other key measurements of boiler operation ensure proper balancing and an adequate interlacing of air flows at the primary, secondary and tertiary elevations, respectively.

The present invention relates to a process for chemical recycling of PET waste that comprises, among other stages, a saponification reaction stage, wherein PET waste particles are reacted with stoichiometric or excessive amounts of a strong base metal in an alcoholic reaction media, the reaction being brought to the boiling temperature of the alcoholic reaction media, preferably at atmospheric pressure, thereby obtaining as reaction products a salt of terephthalic acid with the base metal and ethylene glycol, the latter being incorporated to the alcoholic reaction media. From this reaction it is possible to afford ethylene glycol, terephthalic acid and salts thereof, which are products with a high commercial value.

The invention relates to a recovery method for mortar in a wire cutting technology, in particular to a chemical recovery method for the mortar in the wire cutting technology. The chemical recovery method comprises the following operation steps: firstly, solid-liquid separation is carried out on the mixed mortar containing cutting liquid A, silicon powders, metal filings and silicon carbide abrasives after wire cutting to obtain a liquid part B and a solid part C; secondly, the silicon powders and the metal filings in the solid part C are removed by adopting a chemical treatment method to obtain a solid part D which is rich in the silicon carbide abrasives; and thirdly, the solid part D which is rich in the silicon carbide abrasives is directly and uniformly stirred with cutting liquid E to obtain mixed materials G, and the mixed materials G are used for wire cutting again. The invention removes metal impurities and the silicon powders, can be used for secondary cutting without drying the silicon carbide abrasives, and enables the silicon carbide abrasives and water soluble cutting liquid to be repeatedly and reasonably utilized. The use effect of recovered mortar is nearly same with the use effect of new mortar, therefore, the cost of chemical recovery of the mortar is greatly lowered.

The invention relates to a novel method for generating bisphenol A and dialkyl carbonate by chemical degradation of waste polycarbonate (PC) to realize chemical recycling of the bisphenol A and the dialkyl carbonate. The method is characterized in that reusable ionic liquid such as chloridized 1-allyl-3-methylimidazole and bromized 1-butyl-3-methylimidazole is taken as a reaction medium and catalyst, and subjected to hydrolysis reaction or alcoholysis reaction at a temperature of between 60 and 170 DEG C; after reaction is over, bisphenol A products are obtained after extraction, distillation and other operations (as for alcoholysis reaction, the dialkyl carbonate is obtained simultaneously); reclaimed ionic liquid is directly reused without any treatment; and the yield of the bisphenol A is more than 93 percent. Compared with the prior art, the method has the characteristics that: firstly, the method overcomes the defects in the prior art that high-concentration inorganic strong acid/strong alkali is applied and can not be recycled; and secondly, due to adoption of the ionic liquid which has certain solubility on the PC as the reaction medium and the catalyst, the method relieves the reaction conditions on one hand and can realize reutilization of the ionic liquid on the other hand, and obviously solves the problems of equipment corrosion and environmental pollution.

Provided is a process for manufacturing shaped cellulose materials from lignocellulose where a dissolving grade pulp is manufactured and dissolved in an aqueous alkaline or acidic solvent system forming a solution suitable for shaping new cellulose structures including fibers, films and cellulose derivatives. At least a part of the spent cellulose dissolving or cellulose shaping chemicals are recovered in one or more unit operations in a pulp mill chemical recovery cycle.

The invention discloses a recovery technology and a separation device of a waste lithium iron phosphate battery cathode material. The recovery technology is characterized by firstly separating a lithium iron phosphate material from an aluminum foil by adopting a physical method of heating treatment and mechanical force separation, and then obtaining a novel lithium iron phosphate material by adopting the technologies of fine smashing, dissolving and impurity removing, and roasting, repairing and lithium supplementing; separating and obtaining a lithium iron phosphate recovery material by the separation device through a grinding mode of a millstone. The safe and industrial recovery method and the separation device are provided for recycling of the waste lithium iron phosphate battery cathode material, the material recovery rate can be increased, the cost is reduced, a chemical recovery technology is simplified, the resources are saved, and environment pollution is reduced.

In one embodiment, a system comprises a filter and at least one electrodeionization (EDI) unit for chemical recovery. The filter is adapted to receive a fluid and to remove a selected chemical element or contaminant from the fluid. The EDI unit is coupled to the filter and adapted to recover a chemical element from the fluid and to separate the recovered chemical element from the fluid.

A method and an apparatus for preparing cellulose pulp, in which a lignin-containing raw material is impregnated with impregnation liquor and the impregnated raw material is cooked. The black liquor obtained by cooking is concentrated in an evaporation plant integrated in a chemical recovery plant. In the impregnation, the lignin-containing raw material is impregnated with a circulating alkaline impregnating liquor, which impregnating liquor is concentrated by evaporating water from it in at least one evaporator unit of the evaporation plant arranged in the chemical recovery plant of a pulp mill.

This invention provides a method for applying carbothermic method to prepare Sn Sb alloy negative material of Li ionic batteries characterizing in matching the oxide of Sn and Sb according to the Sn and Sb proportion in their generated alloy, then introducing a proper proportion of carbon powder as the reducer to get a mixture to be ground and put in N or Ar atmosphere to increase the temperature with the speed of 5-30deg.C/minute to arrive at different temperatures and keep them cut off to be cooled to the room temperature. Compared with the method of liquid phase chemical recovery and powder metallurgy, this invented method costs less, the particles of SnSb alloy powder are fine and uniform and good at crystallinity, the produced negative material has high specific capacity and stable circulation.

Exhaust gas, produced in a thermal reactor (1) that is fed with solid fuel can be cooled and in a gas cooler (4) which produce a condensate that is further cooled in a condensate cooler (7) which produce energy. By using air moisturizing and particle separation technology the exhaust gas and the excess condensate can be clean and the energy efficiency of the plant can be increased. The method can be used for a broad spectrum of fuels and conversion technologies.

The invention discloses an electrochemical lithium recovery method. Lithium in a solution is enriched through an electrochemical process by iron phosphate (FePO4), and the obtained lithiated iron phosphate material undergoes heat treatment to prepare a lithium iron phosphate positive electrode material. The electrochemical method which is used to extract lithium has a high lithium extraction selectivity, and is not influenced by other ions in the solution, and the electrochemical product lithiated iron phosphate can be directly converted to the lithium iron phosphate material after processing. So the method is very suitable for the direct extraction of lithium from the ionic solution having low values, and has the advantages of simple process, easy control and low cost, substantial practical values and good application prospect.

The invention provides a preparation technology of ethylene glycol terephthalate and a preparation method of a polyester. The preparation technology of the ethylene glycol terephthalate (BHET) comprises the steps of: pretreatment of polyester waste, pre-alcoholysis reaction, deep alcoholysis reaction, impurity removal of an alcoholysis product and the like. The polyester (PET) can be prepared again from the obtained BHET; by adopting the preparation technology of the BHET, a chemical recovery method is utilized; an industrial production technology with low energy consumption is provided; the index of the product can achieve the standards of food grade and environmental wire grade.

The present invention relates to a new and environmentally sound process for the manufacturing of a chemical pulp from lignocellulosic material with an integrated recovery system for recovery of pulping chemicals. The process is carried out in several stages involving a pre-treatment stage followed by one or more delignification stages using an alkaline buffer solution comprising alkali metaborate and sodium carbonate as major components. The alkaline components of the pulping liquor are recovered from a chemicals recovery furnace and at least a portion of the alkali is recycled and used for delignification without any prior reactions with lime or calcium compounds for generation of alkali hydroxide. A quinone based delignification catalyst may be added to be present during delignification.

The present invention relates to biological method of processing waste water containing heavy metal, and is especially biological method of processing waste water containing heavy metal with residual active sludge from city domestic sewage processing yard or waste industrial sludge as carrier. The biological method features that the sludge is mixed with nutritive N and P containing matter essential for microbes to grow to form efficient micro ecological system after directional activating culture inside reactor; waste water containing heavy metal is then introduced into the reactor for anaerobic treatment; and the upper layer sludge with rich heavy metal then flows into precipitator for partial reflux, enriching and biological or chemical recovery of heavy metal while draining the supernatant. The method has wide applicable range, high purifying efficiency, short period, low cost and simple technological process.

Process for chemical recycling of post consumption poly(ethylene terephthalate) and equipment to perform the chemical recycling of post consumption poly(ethylene terephthalate) comprising a chemical process performing the depolymerization of poly(ethylene terephthalate)—PET—with the purpose of promoting the post consumption chemical recycling of this polymer. It also describes the equipment required for its performance. Such process is based on hydrolysis reaction, which causes the rupture in of the ester bonds formed between the polymer precursors (terephthalic acid and ethylene glycol) at the time of polymerization. The purpose is to recover, from the PET wastes and post consumption PET, terephthalic acid and ethylene glycol. The advantage of this patent are the working conditions at low to moderate pressure, at temperatures of 215 to 450oC, allowing to reach the energy level required to the PET hydrolysis desired, and simultaneously promoting the separation and purification of the terephthalic acid and ethylene glycol and/or another glycol present in the formulation of the PET formed in this hydrolysis reaction. The product obtained in this recycling is the terephthalic acid and the ethylene glycol, that thereby closes the cycle of life of the PET returning it to its raw materials, avoiding its accumulation in the planet biosphere.

The invention relates to a recyclable eugenol-based epoxy resin Vitrimer material and a preparation method of the recyclable eugenol-based epoxy resin Vitrimer material. Biomass-based eugenol is used as a raw material, an eugenol-based epoxy resin matrix similar to DGEBA is prepared through a two-step method including an allyl bromide substitution reaction and a m-chloroperoxybenzoic acid oxidation reaction, then the eugenol-based epoxy resin matrix is mixed with a dicarboxylic acid curing agent system containing and not containing dynamic bonds, curing is conducted in a gradient heating mode, and theeugenol-based epoxy resin Vitrimer material with a dynamic reversible exchange key anddisulfide bond is otained. The epoxy resin Vitrimer material has the advantages of high physical remodeling reprocessability, high chemical recovery efficiency and the like, and overcomes the defects that the traditional epoxy resin takes petrochemical resources as raw materials and is difficult to recycle after being used; and green development and sustainable utilization of the thermosetting polymer material are promoted.

The invention belongs to the technical field of chemical recovery and degradation, and particularly relates to a method for catalytically degrading polyethylene glycol terephthalate. The method comprises the following steps: (1) uniformly mixing polyethylene glycol terephthalate fragments and a catalyst to obtain a mixture; and (2) heating the mixture, carrying out degradation reaction under the combined action of water vapor and a catalyst, and obtaining a solid-phase product and a liquid-phase product after the reaction is completed; wherein the catalyst is a zinc compound. Zinc oxide or a compound which can be decomposed to generate zinc oxide in the heating process is used as a catalyst, then the zinc oxide activates a C=O bond in a PET polymer chain to generate terephthalic acid and ethylene glycol, the method is green and environmentally friendly, and a new path is provided for high-added-value conversion and reutilization of waste PET.