Environmental Enhancement through Corn Stover Utilization

Tom Miles

Environmental Enhancement through Corn Stover Utilization
Robert Brown, Iowa State University

Technical Relevance and Merit

We propose a new system for maintaining soil fertility that employs cornstover or corn fiber for production of a nitrogen-rich, biologically active char that both enriches the soil and sequesters carbon from the atmosphere. In this system, cornstover or corn hulls are collected and preprocessed locally to yield fine, porous char and energy-rich bio-oil. The bio-oil, which can be thought of as densified biomass, is transported by tanker truck to a central facility for steam reforming to hydrogen followed by some part of it being converted to anhydrous ammonia (the process yields excess hydrogen for other applications). Using existing infrastructure of the agricultural fertilizer industry, anhydrous ammonia is transported back to the distributed preprocessing facilities where it is reacted with carbon dioxide, water, and char, which are byproducts from pyrolysis of biomass, to yield ammonia bicarbonate (NH4HCO3) precipitated within the pores of the char. The nitrogen-rich char is injected into the soil where it serves three purposes: nitrogen fertilizer, biologically-active soil amendment, and a means for sequestering carbon from the atmosphere.