Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/96—Regeneration, reactivation or recycling of reactants
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/46—Removing components of defined structure
  • B01D53/48—Sulfur compounds
  • B01D53/50—Sulfur oxides
  • B01D53/508—Sulfur oxides by treating the gases with solids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/04—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of alkali metals, alkaline earth metals or magnesium
  • B01J20/043—Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28002—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their physical properties
  • B01J20/28004—Sorbent size or size distribution, e.g. particle size
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/34—Regenerating or reactivating
  • B01J20/3433—Regenerating or reactivating of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2220/00—Aspects relating to sorbent materials
  • B01J2220/50—Aspects relating to the use of sorbent or filter aid materials
  • B01J2220/56—Use in the form of a bed

Definitions

• the present invention relates to a method of regenerating carbonate granules used in gas purification plants, for instance mineral granules rich in limestone, such as lime ⁇ stone and dolomite in accordance with the preamble of Claim 1.
• the limestone granules are passed to a separation zone where they are regenerated and cleaned mechanically with the aid of a rotating drum which causes the limestone granules to rub against one another and therewith wear away the surface coatings on the granules.
• This abrasion results in separation of the surface coating, although only after a relatively long granule residence time in the separation zone.
• the fine-grain material rubbed from the granules can then be sieved and subsequently dumped.
• the object of the present invention is to provide a novel and improved technique for removing chemical compounds that have formed on the mineral surfaces, therewith to enable essen ⁇ tially optimal use of regenerated carbonate granules in a simple and economic manner.
• Coatings that are formed by chemical reaction with compounds in the gas being cleaned can be relatively hard and the energy input needs to be rela- tively high in order to clean the carbonate granules effec ⁇ tively.
• SO ⁇ -compounds for instance, can be relatively hard and the energy input needs to be rela- tively high in order to clean the carbonate granules effec ⁇ tively.
• coating separation can be controlled and guided in a completely different fashion with the aid of different procedures, as described below with reference to the modus operandi of the mill.
• the energy input per unit volume of attrition or grinding space is very large in comparison with the energy input of rotating drums, meaning that the mill installation requires relatively little space for the same energy input.
• the mill can be constructed on both a small and a large scale to no detriment, and the carbonate granules that have been cleaned of their coatings in the mill can be recycled to the gas purification plant with optimal results both with regard to the degree of separation and to a suitable particle-size distribution.
• the contaminated material is transported through an agitated mill in a dry system, which is preferred in this case, with the aid of gravitational forces.
• the rate at which the contaminated material passes through the mill can be varied by commensurate adjustment of the devices that feed the mineral granules into the mill and the devices that discharge said minerals therefrom.
• the attrition principle to which the invention refers can also be characterized as containing an intrinsic dynamic classification function, which contributes towards effective separation of the chemical compounds that form on the surfaces of the granules.
• Smaller granules will, in princi ⁇ ple, move more quickly through the mill than larger granules. Since sulphur compounds are adsorbed on the surfaces of the granules, the amount of substances that coat the granules per unit of surface area is essentially the same on both large and small granules in the present context. In follows from this that larger granules will have a slightly greater abrading effect than smaller granules.
• the illustrated plant includes a gas cleansing vessel 1 which includes a filling or bed of carbonate granules having a size of approximately 5-10 mm.
• the fresh, unused mineral granules are fed to the upper part of the vessel through the medium of feeder means, as indicated by arrow 2, and used, contaminated granules are discharged from the lower part of the vessel through the medium of discharge means 3.
• a given proportion of the discharged granules can be returned to the gas cleansing plant without separating the contaminated coatings from the granules, as indicated by the material flow 4.
• the devices referenced 1-4 are not embraced by the invention, and are merely shown to provide a better under ⁇ standing of the invention.
• the proportion of carbonate granules that are to be de-coated are passed down into a vessel 5.
• the supply of mineral granules to an agitating, stationary mill is regulated with the aid of a feeder 6, which is preferably a screw feeder.
• the mineral granules are led to the mill 7, which in the present case is an agitated mill in which abrading and attrition are achieved by virtue of agitating the mineral granules, indicated at 7', with the aid of a highspeed, movable rotor 7" provided with rods 7 .
• the grinding and attrition effect is thus achieved by pressure and shear forces and by movement between the carbonate granules themselves, said forces being generated by means of the aforesaid rotor or agitator, which will normally rotate at a speed of about 80 rpm and deliver a high power per unit of mill volume.
• the desired degree of abrasion and attrition of the carbonate granules in the mill 7 can be adapted to the requirements placed on the gas cleansing capacity of the thus regenerated material, i.e. by increasing or decreasing the quantity of sieved fine-fraction. This is also an important factor, since carbonate minerals can have mutually different hardnesses, different sulphur adsorption capacities, etc., which may require corrections in order to achieve suitable process properties.
• the mill 7 may be provided conveniently with a speed regula ⁇ tor which will enable the desired energy outtake from the mill to be controlled in a simple manner.
• the energy consumed per unit of weight of processed material controls the amount of fine-fraction formed when working the material.
• the amount of energy consumed per unit of weight is also a function of the level of the medium in the mill with a rotor that includes a given number of outwardly projecting ele ⁇ ments, suitably rods.
• energy consumption can also be regulated by decreasing or increasing the level of the mineral granules in the mill 7, thereby increasing or decreasing the number of rods 7" ' that come into contact with the mill charge.
• the balance between abrading and grinding the granules can be influenced in accordance with the particular requirements prevailing in each individual case, by appropriate configura ⁇ tion of the grinding tools, i.e. the rods, or by appropriate selection of the spacing therebetween.
• the extent to which the carbonate granules 7' are abraded and/or ground is determined partly by the amount of sulphur to be adsorbed, partly to the cleanliness requirement of these granules subsequent to the regeneration process, and partly by the requirement to perform the granule regeneration process in a manner in which the delivery of fresh material will compensate for the amount of separated material as far as possible.
• this inter ⁇ play will result in the gas resistance in the sulphur- cleansing vessel to be held as constant as possible, by taking appropriate measures in accordance with the afore- going. From an economical aspect, it is also important to keep material separation to the lowest possible level, so as to avoid unnecessary losses of carbonate material.
• the discharge of material from the mill 7 and delivery of the material to a sieve or screen 9 is regulated with the aid of a discharge feeder 8, suitably a disc feeder.
• the screen 9 separates a fine-fraction 10 containing the impurities, said fine-fraction normally corresponding to 5% of the weight of carbinate granules, while oversize granules 11 captured by the sieve are returned to the sulphur cleansing process.
• the sieve 9 may have two or three tiers. A two or three tier sieve will enable the separation and possible abrasion of an intermediate fraction 12 of selected particle size. In some cases, this may be an appropriate procedure in maintaining the desired average granule size in the sulphur cleansing plant, which is preferred with regard to obtaining suitable resistance to the gases that flow through the vessel 1.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Analytical Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Biomedical Technology (AREA)
• Environmental & Geological Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Inorganic Chemistry (AREA)
• Sustainable Development (AREA)
• Treating Waste Gases (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Industrial Gases (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20397013

Family Applications (1)

Country Status (6)

Cited By (3)

Citations (5)

• 1995
  • 1995-01-30 SE SE9500323A patent/SE510535C2/sv not_active IP Right Cessation
• 1996
  • 1996-01-24 WO PCT/SE1996/000074 patent/WO1996023577A1/en not_active Application Discontinuation
  • 1996-01-24 CZ CZ972298A patent/CZ229897A3/cs unknown
  • 1996-01-24 AU AU46374/96A patent/AU4637496A/en not_active Abandoned
  • 1996-01-24 PL PL96321320A patent/PL321320A1/xx unknown
• 1997
  • 1997-07-29 FI FI973141A patent/FI973141A0/fi unknown

Patent Citations (5)

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