The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 06, 1997
Filed:
Nov. 28, 1995
Matti A Hiltunen, Karhula, FI;
Jorma J Nieminen, Varkaus, FI;
Foster Wheeler Energia OY, Helsinki, FI;
Abstract
Method and apparatus for using biofuel or waste material or both for energy production. The biofuel or the waste material is gasified in a fluidized bed gasifier (10), preferably a circulating fluidized bed gasifier. The gas produced in the gasifier is introduced into a boiler (12) equipped with fossil fuel burners (28, 28'28'), typically burners for pulverized coal. The gas is introduced at a level above the burners. Ash from the boiler may be used to form the bed of the gasifier. For control of NO.sub.x, the gas is burned in the upper part of the boiler at a low temperature level of 800.degree.-1050.degree. C. (1472.degree.-1922.degree. F.), preferably 850.degree.-900.degree. C. (1562.degree.-1652.degree. F.), and with a small excess air content of about 5-10 percent. In a second embodiment, the raw gas may be cleaned of harmful or noxious components, and cooled if desired, between the gasifier and the boiler in an additional circulating fluidized bed reactor (152) having a bed of coal ash.