ASH REMOVAL FROM COAL: PROCESS TO AVOID LARGE QUANTITIES OF HYDROGEN FLUORIDE ON-SITE

• Main Authors: DRAPER SAM DAVID, SONWANE CHANDRASHEKHAR GANPATRAO, KAUFMAN ERIC STEPHEN, NEWKIRK MICHAEL DAVID
• Format: Patent
• Language: English
• Published: 07.04.2011
• Subjects: ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE ORUNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOUNDS THEREOF; FIRELIGHTERS; FUELS; FUELS NOT OTHERWISE PROVIDED FOR; INORGANIC CHEMISTRY; LIQUEFIED PETROLEUM GAS; LUBRICANTS; METALLURGY; NATURAL GAS; NON-METALLIC ELEMENTS; PEAT; PERFORMING OPERATIONS; PETROLEUM, GAS OR COKE INDUSTRIES; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BYSUBCLASSES C10G, C10K; TECHNICAL GASES CONTAINING CARBON MONOXIDE; THEIR RELEVANT APPARATUS; TRANSPORTING

A method and system for treating coal with hydrogen fluoride to remove fly ash and thereafter regenerating substantially all of the hydrogen fluoride used during the process (thereby significantly reducing the amount of HF on site). An exemplary method includes the steps of charging at least one reaction vessel with coal containing fly ash; feeding hydrogen fluoride into the reaction vessel to form a first reaction mixture of soluble reaction products, insoluble fluoride compounds and initially clean coal; separating out the first soluble and insoluble reaction products; feeding nitric acid into the same reaction vessel to react with any remaining fly ash components and separating out those second reaction products; and regenerating substantially all of the hydrogen fluoride used in the first fluoride reaction.