Development of a Novel Helical-Ribbon Mixer Dryer for Conversion of Rural Slaughterhouse Wastes to an Organic Fertilizer and Implications in the Rural Circular Economy

Organic wastes of rural slaughterhouses in developing countries comprise blood and undigested rumen contents harboring infectious microbial pathogens having impermissible BOD5 COD values. Previously we demonstrated valorization through drying conversion to an efficacious organic fertilizer which was free from heavy metals. Here describe fabrication a novel helical-ribbon mixer dryer for transition the current small-scale household cooking equipment-driven sustainable production. Blood digesta mixed 3:1 ratio, initial moisture 85%, were dried at 90–110 °C 3–4 h attain 15.6% final moisture-containing fertilizer. Energy consumption extraction rate 49.4 MJ per batch 18.9 kg h−1 respectively. Using this method, small abattoir owners could emerge as multi-product producers enhance earnings while farmers source locally farming. The two activities can be complementary each other become circular economy model. We applied spreadsheet-based model calculation cash flow, breakeven point conducted financial cost–benefit analysis on projected operation dryer. Fertilizer production parallel with meat trade should profitable slaughterhouse apart generating local employment opportunities.