Modularized System and Method for Urea Production Using A Bio-Mass Feedstock

Abstract

A modular system and method for producing urea from bio-mass includes means and steps for “homogenizing” a biomass feedstock stream having components with different bulk density BTU content into a stream having a consistent bulk density BTU content. The steps include cleaning the incoming bio-mass feedstock stream to remove non-organic matter, blending the cleaned bio-mass feedstock stream to obtain a homogeneous blend having a consistent bulk density BTU content, and milling the homogeneous blend bio-mass feedstock stream to a predetermined size no greater than 12 mm.

What is claimed is: 
     
         1 . A method for producing urea from bio-mass, the method comprising the steps of:
 cleaning a bio-mass feedstock to remove substantially all non-organic matter;   blending the cleaned bio-mass feedstock to obtain a substantially homogeneous blend;   pelletizing the blended bio-mass feedstock to a substantially uniform size;   gasifying the pellets in a gasifier; and   combining a resultant CO 2  stream from the gasifier with NH 3  to form urea.   
     
     
         2 . A method according to  claim 1  wherein the bio-mass feedstock includes at least two bio-mass feedstocks each having at least one different processing characteristic. 
     
     
         3 . A method according to  claim 1  further comprising the step of mixing pellets from at least two bio-mass feedstocks each having at least one different processing characteristic to produce a single substantially homogeneous pellet blend. 
     
     
         4 . A method according to  claim 1  wherein the bio-mass feedstock has a moisture content of less than about 15% by weight. 
     
     
         5 . A method according to  claim 1  wherein the cleaned bio-mass feedstock includes no more than 1% non-organic matter by weight. 
     
     
         6 . A method according to  claim 1  further comprising the pelletizing step resulting in pellets having substantially the same density. 
     
     
         7 . A method according to  claim 1  further comprising the pelletizing step resulting in pellets having substantially the same calorific burn value. 
     
     
         8 . A method according to  claim 1  further comprising the step of cleaning including the sub-step of sizing the bio-mass feedstock to a predetermined size. 
     
     
         9 . A method according to  claim 1  further comprising the gasifying step including the sub-step of pulverizing the pellets to a fine particle size. 
     
     
         10 . A method according to  claim 9  wherein the fine particle size is about 1 mm. 
     
     
         11 . A method according to  claim 1  further comprising the gasifying step including at least one of the sub-steps of injecting an organic oil into an input bio-mass feed stream and varying a feed rate to the gasifier to maintain a substantially constant burn temperature. 
     
     
         12 . A method according to  claim 1  wherein a burn temperature of the gasifier when gasifying the pellets does not vary by more than about ±25° C. 
     
     
         13 . A method according to  claim 1  further comprising a burn temperature of the gasifier being in a range of from 600° to 850° C. 
     
     
         14 . A method according to  claim 1  wherein the gasifier is effective for a conversion efficiency of about 98%. 
     
     
         15 . A method according to  claim 1  further comprising the step of cleaning a resultant syngas stream from the gasifier. 
     
     
         16 . A method according to  claim 1  further comprising the step of compressing a resultant syngas stream from the gasifier to a high pressure of about 6,000 to 7,000 psi. 
     
     
         17 . A method according to  claim 1  further comprising the step of processing the NH 3  in a bypass recycling loop at a 30% conversion rate at a high pressure of about 6,000 to 7,000 psi. 
     
     
         18 . A method according to  claim 1  wherein at least one of the cleaning step, pelletizing step, and gasifying step occurs at a geographical location different from where at least one of the other steps occurs. 
     
     
         19 . A method according to  claim 1  wherein all equipment associated with at least one of the cleaning step, pelletizing step, and gasifying step is contained within a footprint of a standard flatbed truck trailer. 
     
     
         20 . A method according to  claim 1  wherein all equipment associated with at least one of the cleaning step, pelletizing step, and gasifying step is skid mounted.