United States of America, As Represented by the Secretary of Agriculture

Renewable Spirits LLC

Mark Wilkins

Karel Grohmann

David Alexander Stewart

Wilbur W Widmer

Method for producing ethanol from solid citrus waste by reducing the concentration of limonene in citrus waste to allow fermentation. In one embodiment ground solid citrus waste is partially hydrolyzed and pasteurized by heating using a jet cooker and then injected into a flash tank to remove limonene. The heated citrus waste is then cooled, hydrolyzed with enzymes and fermented to ethanol. The remaining solids and liquids may be processed further to yield other byproducts. More particularly, the solids may be dried and pressed for use in cattle feed and the liquids may be further fermented or processed to yield additional ethanol, acetate, galacturonic acid monomers and polymers, five carbon sugars and other products.

Ethanol production from solid citrus processing waste

Method of pretreating citrus waste to break cell structure, pasteurize or sterilize citrus waste solids and remove inhibitory peel oil components (e.g., limonene) involving optionally reducing the particle size of the citrus waste prior to preheating, preheating the citrus waste through indirect heating in a preheater reactor to form preheated citrus waste and conveying the preheated citrus waste to a main reactor, heating the citrus waste through a combination of (simultaneous) indirect heating and direct heating to produce treated citrus waste solids that are pasteurized and a vapor containing water and peel oil components, separating the pasteurized citrus waste solids and the vapor containing water and peel oil components, and collecting the separated vapor containing water and peel oil components by condensation. The method optionally includes cooling the pasteurized citrus waste solids followed by saccharifying with enzymes and fermentation to produce ethanol or other products.

Growing community of inventors

Stillwater, OK, United States of America

Mark Wilkins