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:
Nov. 18, 2014
Filed:
May. 24, 2013
Japan Pionics Co., Ltd., Hiratsuka, JP;
Japan Pionics Co., Ltd., Kanagawa, JP;
Abstract
There are provided methods capable of easily and efficiently recovering and recycling ammonia from exhaust gas containing a small amount of ammonia, the exhaust gas being exhausted from a production process of a gallium nitride compound semiconductor. The method of recovering ammonia includes filtering exhaust gas containing ammonia, hydrogen, nitrogen, and a solid compound with a filter to remove the solid compound from the exhaust gas; pressurizing and cooling the filtered exhaust gas with a heat pump to liquefy ammonia contained in the filtered exhaust gas; and separating liquefied ammonia from hydrogen and nitrogen to recover liquefied ammonia. The method of recycling ammonia includes evaporating recovered liquid ammonia; mixing the evaporated ammonia with another crude ammonia to obtain mixed gas; purifying the mixed gas; and supplying the purified gas to the production process of a gallium nitride compound semiconductor.