Fuel and related compositions – Liquid fuels – Aluminum or heavy metal – other than lead – containing
Patent
1982-01-07
1983-11-15
Dees, Carl F.
Fuel and related compositions
Liquid fuels
Aluminum or heavy metal, other than lead, containing
44 24, 241 19, 241 24, C10L 908, C10L 900
Patent
active
044153350
DESCRIPTION:
BRIEF SUMMARY
This invention relates to an improved method of preparing mined coal for its end use and in particular to the preparation of mined coal as a feedstock for power generating stations.
Co-pending patent application No. 55574/80 relates to a process of deashing coal which comprises crushing mined coal into small sized particles, subjecting said mined coal to wetting with a hydrocarbon liquid and forming agglomerates of carbonaceous material in said coal, separating said carbonaceous agglomerates from non carbonaceous material present in said coal, subjecting said carbonaceous agglomerates to vapour separation treatment in the absence of oxidizing gases to separate the hydrocarbon liquid from said carbonaceous material to produce the deashed coal product and recycling said hyrocarbon liquid for use in wetting said mined coal.
The content of the disclosure of application No. 55574/80 is incorporated herein by reference.
This prior application was primarily concerned with recovery of oil from agglomerated coal pellets in a fuidized bed in which the integrity of the pellet is retained. This addresses the end use of the product as coke oven feed or similar application in which product handleability is of importance.
In applications within both the coking and steaming coal industries where charging or firing systems handling fine sized material are in use, the disintegration of the agglomerate pellet is necessary at some stage.
Further the residence times required and the heat input required were substantial in the disclosures of the prior patent application.
It is an object of this invention to provide a method in which low residence times are achieved in the steam stripping operation. To this end the present invention provides a method of separating an agglomerated mixture of coal particles and a liquid hydrocarbon to form finely divided coal and recover the hydrocarbon liquid which comprises disintegrating said agglomerates and subsequently and/or simultaneously subjecting agglomerates to vapourphase separation in the presence of steam and in the absence of oxidizing gases to recover the liquid hydrocarbon from the finely divided coal particles.
In a preferred form all of said agglomerates are above 1 mm in size, said steam temperature is above 200.degree. C., the residence time of the coal particles in the steam stripping zone is less than 5 seconds and at least 70% of the coal product comprises particles less than 0.3 mm and final product oil content less than 2.5%.
The exposure of the relatively high specific surface area of the particles after disintegration of the agglomerate pellet during the stripping process in this case offers the potential for the achievement of greatly enhanced heat and mass transfer rates.
Comminution of the agglomerates prior to the vapour phase separation may be carried out in any conventional comminution device. In a preferred method the agglomerates are subjected to initial attrition to reduce the particle size of the agglomerates and subsequently passing said agglomerates into the path of a high velocity stream of steam to further reduce the coal particle size and to separate such hydrocarbon liquid into a vapour phase.
Application of this invention to the use of coal-oil agglomerates offers several advantages over the alternative method of steam stripping in a fluidized bed. Foremost among these is the potentially large reduction in solids hold-up in the stripping system and subsequent improvement of response times due to the reduction in residence time in the steam stripping zone. Much of the complexity of the fluid bed system is removed and control functions are related to steam flow and inlet temperature and pressure alone.
Where the steam is introduced as a jet the velocity and the internal shape of the particle entrainer may be chosen to be sufficient to disintegrate the agglomerates. In this embodiment said agglomerates are passed into a high velocity stream of steam to simultaneously separate the hydrocarbon liquid and to form the finely divided coal particles.
The system
REFERENCES:
patent: 1628609 (1927-05-01), Newhouse
patent: 1734992 (1929-11-01), Barrows
patent: 2183924 (1939-12-01), Schoch
patent: 4209301 (1980-06-01), Nicol et al.
patent: 4239496 (1980-12-01), Cochran
Jones Charles U.
Mainwaring David E.
B. P. Australia Ltd.
Dees Carl F.
The Broken Hill Proprietary Company Ltd.
LandOfFree
Coal preparation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Coal preparation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coal preparation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-157700