THE FEASIBILITY OF A RESIDUE BIOMASS BIOCONVERSION PROCESS TO PREPARE CALCIUM MAGNESIUM ACETATE DEICING SALT

Using residue biomass as feedstock for conversion to calcium magnesium acetate (CMA) as an alternative road salt has been investigated. This salt is less corrosive to bridge decks and vehicles than sodium chloride, the traditional road salt. CMA derived from residue biomass is expected to be less costly than that derived from petroleum or natural gas. The residue biomass may be woody biomass residues not suitable for lumber or paper pulp, industrial residues such as whey, municipal solid waste (MSW), or sewage sludge. This study focused on bioconversion of sewage sludge to CMA based on "suppressed methane" fermentation to produce acetic acid followed by liquid ion exchange to recover acetic acid from the fermenter broth prior to reaction with limestone. Overall feasibility was evaluated using results from laboratory work and cost estimates from a preliminary engineering process model. Percent bioconversion and kinetics to acetic acid were confirmed in small batch fermenters. Equilibrium constants for acetic acid recovery via liquid ion exchange were measured. Rates of conversion to CMA were determined. © 1990.