The sensible and latent heat of hot exhaust gases generated in fuel burning furnaces, roaster, cement kilns, and the like is transferred to a power fluid in the boiler of an external combustion engine. The cooled gases are purified by subliming or "freezing out" harmful, less volatile components. The purified gases are discharged to atmosphere without using flue gas stacks. The sublimed or "frozen out" impurities are collected and neutralized.
Solid waste, including municipal, agricultural, industrial, vegetable and animal matter, garbage and waste paper, is progressively converted by means of partial oxidation and distillation into gas under controlled temperature and pressure conditions and the gas is made suitable for industrial and chemical uses by being purified and separated into its main components or ingredients.
System For Treating And Recovering Energy From Exhaust Gases
A method and apparatus for improving the overall operating efficiency of a gas turbine system by purifying relatively hot turbine exhaust gas to remove environmentally harmful components therefrom, by converting a portion of the thermal energy of the exhaust gas to mechanical work and by reclaiming a portion of the thermal energy of the exhaust gas by transferring it to other fluids. Purification to remove harmful components is advantageously accomplished using regenerators. Conversion of thermal energy to mechanical work is usefully accomplished in a primary turbine motivated by hot combustion gas and in a helper turbine motivated by a relatively hot heat exchange fluid which has derived its thermal energy by exchange with heated solids in thermodynamically efficient regenerators.
System For Treating And Recovering Energy From Exhaust Gases
A method and apparatus for treating hot exhaust gas to purify the gas and/or to recover the heat values therein includes removing particulate matter from the gas, cooling the gas by transferring its heat to regenerators and purifying the cooled gas by subliming or "freezing out" harmful, less volatile components. The heat energy of the exhaust gas may be recovered by passing a heat exchange medium, such as compressed air and/or purified cooled gas, through the heated regenerators. A major advantage of this method and apparatus is that exhaust gases at 300. degree. -350. degree. C. may be purified and the heat energy recovered using thermodynamically efficient regenerators. As a result the air preheater stage of conventional boilers or combustion units, which comprise 60% to 70% of the heat exchange surface area, may be eliminated.
System For Treating And Recovering Energy From Exhaust Gases
A method and apparatus for treating hot exhaust gas to purify the gas and/or to recover the heat values therein includes removing particulate matter from the gas, cooling the gas by transferring its heat to regenerators and purifying the cooled gas by subliming or "freezing out" harmful, less volatile components. The heat energy of the exhaust gas may be recovered by passing a heat exchange medium, such as compressed air and/or purified cooled gas, through the heated regenerators. A major advantage of this method and apparatus is that exhaust gases at 300. degree. -350. degree. C. may be purified and the heat energy recovered using thermodynamically efficient regenerators. As a result the air preheater stage of conventional boilers or combustion units, which comprise 60% to 70% of the heat exchange surface area, may be eliminated.
System For Treating And Recovering Energy From Exhaust Gases
A method and apparatus for treating hot exhaust gas to purify the gas and to recover the heat values therein includes removing particulate matter from the gas, purifying the gas by subliming or "freezing out" harmful, less volatile components and discharging the more volatile components as purified gas. The sublimed or "frozen out" components are collected and neutralized or utilized. The heat values may be recovered prior or subsequent to purifying, such as by spraying a power fluid into the gas to cool and increase the volume of the gas and then expanding the gas in an expansion turbine to further cool the gas and to produce shaft work. Alternatively, the heat values may be recovered from purified, hot gas by transferring the heat energy of the gas to a power fluid which operates in a Rankine cycle external combustion engine to do shaft work.
Plant material containing hemicellulose and lignin is prehydrolyzed in the presence of steam and the vapors of a dilute acid solution having a pH of 1. 5-3. 5 at a temperature of 105. degree. C to 135. degree. C for 7-20 minutes to hydrolyze the hemicellulose into pentoses and hexoses and to leave a fibrous material and a liquid, said liquid containing said pentoses and hexoses. The liquid is separated from the fibrous material, and the pentoses and hexoses are recovered from the liquid. The fibrous material is digested with white liquor at a temperature of 105. degree. C to 135. degree. C.
A process for converting solid waste into a synthesis suitable for producing liquid fuel, comprising (a) partially oxidizing and combusting solid waste material in a closed combustion zone at a temperature of 800. degree. -1000. degree. C. and at a pressure below ambient to produce combustion gases by introducing into the combustion zone a gaseous oxidant comprising oxygen having a purity of at least 95% by volume and carbon dioxide in an oxygen to carbon dioxide ratio, by volume, of about 50:50, (b) conducting the combustion gases, oxygen and carbon dioxide through the solid waste material; (c) withdrawing a producer gas comprising the combustion gases and any unreacted oxygen and carbon dioxide; (d) removing particulate matter from the producer gas; (e) separating carbon dioxide from the producer gas and recycling a portion of the separated carbon dioxide to the combustion zone; (f) separating the less volatile, condensable components of the carbon dioxide-free producer gas, from the more volatile, non-condensable synthesis gas components thereof, and (g) compressing the producer gas at some time prior to the completion step (e). In a preferred embodiment, the more volatile components and at least a portion of the separated carbon dioxide from step (e) are admixed and the resulting admixed gas mixture is reacted to form methanol. Preferably, the less volatile components are converted by chemical reaction to hydrogen and the hydrogen is recycled into admixture with the producer gas at some time prior to the commencement of step (e).