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US 5,843,298 AGranted
Method of production of solids-free coal tar pitch
AssigneeUCAR Carbon Technology Corporation
InventorsThomas Harry Orac, Ching F. Chang, Irwin C. Lewis, Richard L. Shao
Life of this patent
Estimating the term…
Abstract
A process for converting coal tar containing quinoline-insoluble particles (Q.I.) produces a substantially Q.I.-free coal tar pitch and a separate, Q.I.-containing coal tar pitch. Dehydrated coal tar, soft coal tar pitch or hard coal tar pitch are subjected to continuous cross flow filtration in a circulation loop to obtain a substantially Q.I.-free stream and, concurrently, a Q.I.-containing stream. The two streams are then separately subjected to further fractionation, if any, to produce the substantially Q.I.-free hard coal tar pitch and separate Q.I.-containing hard coal tar pitch.
Claims35
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.), to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- continuously feeding the heated dehydrated tar into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the heated dehydrated tar to obtain (i) a substantially Q.I.-free permeate stream exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing stream;
- thereafter continuously, and concurrently with the feeding of additional heated dehydrated tar into said circulation loop, releasing a portion of said Q.I.-containing stream from said circulation loop;
- and thereafter separately fractionating the substantially Q.I.-free permeate stream and the Q.I.-containing stream to separate and remove tar distillate fractions and produce a substantially Q.I.-free coal tar pitch and a separate, Q.I.-containing coal tar pitch.
1 more element
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.) to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- fractionating the dehydrated tar to separate and remove tar distillate fractions to produce a soft coal tar pitch;
- continuously feeding the soft coal tar pitch into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the soft coal tar pitch to obtain (i) a substantially Q.I.-free permeate stream exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing stream;
- thereafter continuously, and concurrently with the feeding of additional soft coal tar pitch into said circulation loop, releasing a portion of said Q.I.-containing stream from said circulation loop;
- and thereafter separately fractionating the substantially Q.I.-free permeate stream and the Q.I.-containing stream to separate and remove additional tar distillate fractions and produce a substantially Q.I.-free coal tar pitch and a separate, Q.I.-containing coal tar pitch.
2 more elements
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.) to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- fractionating the dehydrated tar to separate and remove tar distillate fractions to produce a hard coal tar pitch;
- continuously feeding the hard coal tar pitch into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the hard coal tar pitch to obtain (i) a substantially Q.I.-free pitch exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing pitch;
- thereafter continuously, and concurrently with the feeding of additional hard coal tar pitch into said circulation loop, releasing a portion of said Q.I.-containing pitch from said circulation loop;
- and thereafter separately cooling the substantially Q.I.-free pitch and the Q.I.-containing pitch to produce a substantially Q.I.-free coal tar pitch and a separate, Q.I.-containing coal tar pitch.
2 more elements
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.), to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- continuously feeding the heated dehydrated tar at a temperature above about 140.degree. C. into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the heated dehydrated tar and maintain said heated dehydrated tar at a pressure above about 40 psig to obtain (i) a substantially Q.I.-free permeate stream exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing stream;
- thereafter continuously, and concurrently with the feeding of additional heated dehydrated tar into said circulation loop, releasing a portion of said Q.I.-containing stream from said circulation loop;
- and thereafter separately fractionating the substantially Q.I.-free permeate stream and the Q.I.-containing stream to separate and remove tar distillate fractions and produce a substantially Q.I.-free coal tar pitch and a separate, Q.I.-containing coal tar pitch.
1 more element
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.) to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- fractionating the dehydrated tar to separate and remove tar distillate fractions to produce a soft coal tar pitch;
- continuously feeding the soft coal tar pitch at a temperature above about 250.degree. C. into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the soft coal tar pitch and maintain said soft coal tar pitch at a pressure above about 40 psig to obtain (i) a substantially Q.I.-free permeate stream exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing stream;
- thereafter continuously, and concurrently with the feeding of additional soft coal tar pitch into said circulation loop, releasing a portion of said Q.I.-containing stream from said circulation loop;
- and thereafter separately fractionating the substantially Q.I.-free permeate stream and the Q.I.-containing stream to separate and remove additional tar distillate fractions and produce a substantially Q.I.-free coal tar pitch and a separate, Q.I.-containing coal tar pitch.
2 more elements
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.) to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- fractionating the dehydrated tar to separate and remove tar distillate fractions to produce a hard coal tar pitch;
- continuously feeding the hard coal tar pitch at a temperature above about 300.degree. C. into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the hard coal tar pitch and maintain said hard coal tar pitch at a pressure above 40 psig to obtain (i) a substantially Q.I.-free permeate stream exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing stream;
- thereafter continuously, and concurrently with the feeding off additional hard coal tar pitch into said circulation loop, releasing a portion of said Q.I.-containing stream from said circulation loop;
- and thereafter separately cooling the substantially Q.I.-free permeate stream and the Q.I.-containing stream to produce a substantially Q.I.-free coal tar pitch and a separate, Q.I.-containing coal tar pitch.
2 more elements
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.), to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- continuously feeding the heated dehydrated tar into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the heated dehydrated tar to obtain (i) a substantially Q.I.-free permeate stream exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing stream;
- thereafter continuously, and concurrently with the feeding of additional heated dehydrated tar into said circulation loop, releasing a portion of said Q.I.-containing stream from said circulation loop;
- and thereafter separately fractionating the substantially Q.I.-free permeate stream to separate and remove tar distillate fractions and produce a substantially Q.I.-free coal tar pitch.
1 more element
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.) to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- fractionating the dehydrated tar to separate and remove tar distillate fractions to produce a soft coal tar pitch;
- continuously feeding the soft coal tar pitch into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the soft coal tar pitch to obtain (i) a substantially Q.I.-free permeate stream exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing stream;
- thereafter continuously, and concurrently with the feeding of additional soft coal tar pitch into said circulation loop, releasing a portion of said Q.I.-containing stream from said circulation loop;
- and thereafter separately fractionating the substantially Q.I.-free permeate stream to separate and remove additional tar distillate fractions and produce a substantially Q.I.-free coal tar pitch.
2 more elements
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.) to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- fractionating the dehydrated tar to separate and remove tar distillate fractions to produce a hard coal tar pitch;
- continuously feeding the hard coal tar pitch into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the hard coal tar pitch to obtain (I) a substantially Q.I.-free pitch exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing pitch;
- thereafter continuously, and concurrently with the feeding of additional hard coal tar pitch into said circulation loop, releasing a portion of said Q.I.-containing pitch from said circulation loop;
- and thereafter separately cooling the substantially Q.I.-free permeate pitch to produce a substantially Q.I.-free coal tar pitch.
2 more elements
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.) to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- fractionating the dehydrated tar to separate and remove tar distillate fractions to produce an internal tar distillation intermediate stream at a processing temperature;
- continuously feeding the intermediate stream at the intermediate stream processing temperature into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the intermediate stream to obtain (i) a substantially Q.I.-free permeate stream exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing stream;
- thereafter continuously, and concurrently with the feeding of additional intermediate stream into said circulation loop, releasing a portion of said Q.I.-containing stream from said circulation loop;
- and thereafter separately fractionating the substantially Q.I.-free permeate stream to separate and remove additional tar distillate fractions and produce a substantially Q.I.-free coal tar pitch.
2 more elements
A process for converting an internal stream in a coal tar distillery containing quinoline-insoluble particles (Q.I.) to produce coal tar pitch which comprises:
- heating Q.I.-containing coal tar to a temperature sufficient to remove therefrom substantially all water to produce a heated dehydrated tar;
- fractionating the dehydrated tar to separate and remove tar distillate fractions to produce a coal tar pitch;
- continuously feeding the coal tar pitch into a circulation loop which includes a cross-flow filtration membrane filter and a pump to circulate continuously the coal tar pitch to obtain (i) a substantially Q.I.-free coal tar pitch exiting the circulation loop via said cross-flow filter and (ii) a Q.I.-containing pitch;
- thereafter continuously, and concurrently with the feeding of additional coal tar pitch into said circulation loop, releasing a portion of said Q.I.-containing stream from said circulation loop to produce a substantially Q.I.-free coal tar pitch.
1 more element
Dependencies are inferred from the claim text.