TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The tar cracking catalyst is added to the syngas stream prior to entry of the syngas into the catalytic filter. The process is conducted in a coal gasification unit. The process further comprises a source of nitric oxide. The metal sorbent is added to the syngas prior to passing the syngas through a cracking catalyst. The catalyst in the step (b) further promotes a water gas shift reaction thus adjusting the ratio of hydrogen gas to carbon monoxide gas present in the purified syngas. The process comprises: (a) contacting raw syngas with a mixture of sorbents comprising (i) kaolin clays or kaolin-containing materials, amorphous aluminosilicates, aluminates, and silicates, and calcium-based sorbents that capture trace metals such as lead, cadmium, arsenic and selenium, sodium, and potassium, (ii) calcium-based sorbents that capture sulfur-containing species such as hydrogen sulfide, carbonyl sulfide and carbon disulfide, (iii) calcium-based or magnesium-based sorbents that capture halides-containing contaminants comprising chlorine, bromine, fluorine, iodine, hydrogen chloride, hydrogen bromide, hydrogen fluoride, and hydrogen iodide, and (iv) sorbents that can remove more than one of the contaminants listed in (i)-(iii); at high temperatures of greater than or equal to 700 degrees C thus capturing onto sorbent particles of one or more contaminates comprising metals, sulfur species, and halides, where the sorbent particles are captured in a downstream filter to form a decontaminated syngas; (b) passing the decontaminated syngas formed in step (a) through a catalytic cracking filter element thus removing the sorbent particles, ash, cracking tars and other hydrocarbon components, where the cracking filter comprises a rare earth metal oxide or salt and/or a transition metal oxide or salt, thus forming a sulfur-free, metal-free, cracked syngas; (c) passing the sulfur-free, metal-free, cracked syngas into a cooling zone for where the syngas is cooled to a temperature of at least 370 degrees C to form a cooled sulfur-free, metal-free, cracked syngas; and (d) passing the cooled, sulfur-free, metal-free, cracked syngas into a vessel comprising a source of nitric oxide, where the nitric oxide reacts with ammonia contaminants present in the sulfur-free, metal-free, cracked syngas to produce a purified syngas. The tar cracking catalyst from dolomite or other containing compound is injected into the syngas prior to entry of the syngas into the catalytic filter. Preferred Components: The metal sorbent is kaolin clays, kaolin-containing materials and/or calcium-based sorbents. The sulfur sorbent is calcium-based or calcium comprising material, a magnesium-based sorbent, and/or an alkaline-based sorbent. The halide sorbent is calcium-based or calcium comprising material, a magnesium-based sorbent, and/or an alkaline-based sorbent. The sulfur sorbent is: lime, crushed lime, limestone or crushed limestone; and calcium hydroxide, calcium carbonate, calcium oxide, dolomite, magnesium oxide, recycled pulp or paper waste material. The sorbent for each contaminant is the same sorbent or combinations of sorbents that can absorb more than one contaminant. The sulfur sorbent comprises calcium and the amount of sulfur sorbent added is such that the number of moles of calcium to the number of moles of sulfur is 0.5:1-5:1. The catalytic filter comprises nickel, nickel oxide or a nickel-comprising compound. The cracking catalyst is a rare earth metal or transition metal oxide or salt. The cracking catalyst is an oxide or salt of platinum, palladium, iridium, osmium, rhodium, ruthenium, rhenium, lanthanum, vanadium and/or nickel. The catalytic filter comprises a nickel catalyst deposited upon a substrate and further comprises one or more promoters comprising lithium, potassium, calcium and magnesium.