Transport of aqueous coal slurries

{
  "publication_number": "US4242098A",
  "country": "US",
  "kind": "A",
  "title": "Transport of aqueous coal slurries",
  "abstract": "Compositions containing small amounts of named water soluble polymers in an aqueous coal slurry permit the extrusion, pumping and transport of higher solids content aqueous coal slurries.",
  "claims": [
    "1. In an aqueous coal slurry composition comprising water and coal, the improvement of having present therein up to about 10 weight percent based on the total weight of the composition of a water-soluble polymer from the group consisting of hydroxyethyl cellulose, the quaternary nitrogen-substituted cellulose ethers, xanthan gum, hydroxypropyl guar gum and carboxymethyl hydroxypropyl guar gum.",
    "2. A composition as claimed in claim 1 wherein the said water-soluble polymer is hydroxyethyl cellulose having an intrinsic viscosity in 3 percent aqueous sodium chloride solution at 25° C. of from 1 to 10 dl/gm.",
    "3. A composition as claimed in claim 1 wherein the said water-soluble polymer is xanthan gum having an intrinsic viscosity in 3 percent aqueous sodium chloride solution at 25° C. of from 10 to 15 dl/gm.",
    "4. A composition as claimed in claim 1 wherein the said water-soluble polymer is hydroxypropyl guar gum having an intrinsic viscosity in 3 percent aqueous sodium chloride solution at 25° C. of from 10 to 15 dl/gm.",
    "5. A composition as claimed in claim 1 wherein the said water-soluble polymer is carboxymethyl hydroxypropyl guar gum having an intrinsic viscosity in 3 percent aqueous sodium chloride solution at 25° C. of from 10 to 15 dl/gm.",
    "6. A composition as claimed in claim 1 wherein the said water-soluble polymer is a quaternary nitrogen-substituted cellulose ether having a molecular weight from 100,000 to 3,000,000.",
    "7. In a method for transporting or pumping an aqueous coal slurry, the improvement of having present in the aqueous coal slurry a water-soluble polymer from the group consisting of hydroxyethyl cellulose, the quaternary nitrogen-substituted cellulose ethers, xanthan gum, hydroxypropyl guar gum and carboxymethyl hydroxypropyl guar gum in a concentration of up to 10 weight percent based on the total weight of the composition.",
    "8. In an aqueous coal slurry composition consisting essentially of water and coal, the improvement of having present therein up to about 10 weight percent based on the total weight of the water and coal composition of a water-soluble poly(ethylene oxide) polymer.",
    "9. In a method for transporting or pumping an aqueous coal slurry, the improvement of having present in the aqueous coal slurry a water-soluble poly(ethylene oxide) polymer in a concentration of up to 10 weight percent based on the total weight of the composition; said water-soluble polymer reducing the dewatering of the aqueous coal slurry composition.",
    "10. The coal slurry composition of claim 8 wherein coal is present in a concentration of over 50 weight percent based on the total weight of the composition.",
    "11. The method of claim 9 wherein coal is present in a concentration of over 50 weight percent based on the total weight of the composition.",
    "12. A composition as claimed in claim 8 wherein the concentration of said water-soluble polymer is from 0.05 weight percent to 5.0 weight percent.",
    "13. A composition as claimed in claim 8 wherein the said water-soluble polymer is poly(ethylene oxide) having an intrinsic viscosity in water at 30° C. of from 1 to 50 dl/gm and an average molecular weight of from 100,000 to 10,000,000."
  ],
  "description_excerpt": "Coal is a major source of energy in the United States and is increasing in importance because of the abundance within the United States and because of the security and balance of payments problems which arise from our reliance on foreign oil. A very promising process is the gasification of coal to produce gas for pollution free combustion and as a petrochemical feedstock but this requires the need to pump large quantities of coal into the reactor. Transport problems constitute one of the major difficulties in the use of coal. Aqueous slurries of finely ground coal containing more than about 55 weight percent solids are difficult to transport using conventional slurry pumps because as the solids level is increased above about 50 weight percent the water and solids tend to separate causing coal particles to build up in various areas throughout the pumping system. This dewatering of the slurry causes blockage and jamming of the pumping system. For similar reasons coal slurries containing above about 65 weight percent solids have not heretofore been capable of being extruded continuously using an extruder.\n\nIt is desirable to decrease the weight percent of water in aqueous coal slurries because water is a major contributor to the cost of transport and processing operations. The less water transported the greater is the volume of coal that can be moved, resulting in transport efficiencies. Also during coal gasification a significant amount of heat is required to vaporize the water vehicle. As the weight percent of the water vehicle decreases, the efficiency of the coal gasification process increases.",
  "cpc": [
    "F17D 1/16",
    "B65G 53/30",
    "C09K 3/00",
    "C10L 1/326",
    "Y10T 137/0391"
  ],
  "ipc": [
    "B65G 53/30",
    "C09K 3/00",
    "C10L 1/32",
    "C10L 5/00",
    "F17D 1/16"
  ],
  "assignees": [
    "UNION CARBIDE CORP"
  ],
  "inventors": [
    "BRAUN DAVID B",
    "DRAP STEPHEN",
    "FRITZ HENRY E",
    "INGBERMAN ARTHUR K"
  ],
  "filing_date": "1978-07-03",
  "publication_date": "1980-12-30",
  "grant_date": "1980-12-30",
  "priority_date": "1978-07-03",
  "application_number": "US-92180778-A",
  "family_id": "25446001",
  "citations": [
    "US3524682A",
    "US3996026A",
    "US4090853A"
  ]
}