Ash removal from coal: process to avoid large quantities of hydrogen fluoride on-site

A system for treating coal containing fly ash with hydrogen fluoride and regenerating the hydrogen fluoride used in said system, comprising:

• a reaction vessel sized to receive a prescribed amount of coal containing fly ash;
• a first fluid transport mechanism sized to feed aqueous hydrogen fluoride into said reaction vessel in an amount sufficient to react with said fly ash to form a first reaction mixture of soluble reaction products, insoluble fluoride compounds and initially clean coal;
• a second fluid transport mechanism sized to feed nitric acid into said reaction vessel in an amount sufficient to react with fly ash remaining in said initially clean coal to form a second reaction mixture of additional soluble reaction products, insoluble nitrate compounds and ultra clean coal;
• a discharge line sized to remove said soluble reaction products and said insoluble fluoride and nitrate compounds from said reaction vessel;
• a storage tank for holding said first and second reaction mixtures;
• and
• a hydropyrolizer for regenerating substantially all of the hydrogen fluoride fed into said reaction vessel.

A method for continuously producing ultra clean coal using multiple reaction vessels connected in series and sized to receive and treat coal containing fly ash, comprising:

• sequentially charging each of said reaction vessels with coal containing fly ash;
• reacting said coal containing fly ash with hydrogen fluoride in each of said reaction vessels to form soluble reaction products, insoluble fluoride compounds and initially clean coal;
• separating said soluble reaction products and insoluble fluoride compounds in each of said reaction vessels from said initially clean coal;
• reacting fly ash remaining in said initially clean coal in each of said reaction vessels with nitric acid to form additional soluble reaction products, insoluble nitrate compounds and ultra clean coal;
• separating said ultra clean coal in each of said reaction vessels from said additional soluble reaction products and insoluble nitrate compounds;
• and
• regenerating substantially all hydrogen fluoride used in said method.