PRELIMINARY ECONOMIC-ANALYSIS FOR PRODUCTION OF CALCIUM-MAGNESIUM ACETATE FROM ORGANIC RESIDUES

An engineering study was conducted to evaluate the engineering economi cs of producing calcium magnesium acetate (CMA), using different kinds of residue biomass as feedstock (sewage sludge, biomass, municipal so lid wastes, industrial wastes etc.). This study focused on bioconversi on of cellulose (as a model organic) to CMA based on 'suppressed metha ne' fermentation of the organic residue to produce acetic acid, follow ed by liquid ion exchange to recover the acetic acid from the fermente r broth, with subsequent reaction with dolime to form CMA, which is dr ied to a white crystalline salt. Preliminary economic analysis reveale d that the base line production cost for CMA was $358 (metric) tonne ( $325 per US ton). However, with the assumption of a 'credit' for the d isposal of the residue biomass, CMA can be more competitive. For examp le, it was found with a credit of $1210 per t ($1100 per US ton) for d isposal of sewage sludge, the costs result in a plus $825 per t ($750 per US ton) CMA produced.