The Mixed Biomass Firing and Energy-efficient Stoves in Tofu Production: Biomass Cost Savings and Carbon Emission Reduction

Abstract

Mixed biomass firing and energy-efficient stove technology may improve fuel-use efficiency in household-scale tofu production while lowering biomass costs and associated carbon emissions. This study evaluated the combined effects of mixed biomass firing and energy-efficient stoves on biomass costs and estimated carbon emissions in tofu agro-industries in Mataram City. Cross-sectional data were collected from 37 business units in Sekarbela and Sandubaya districts using observation, surveys, in-depth interviews, and literature review. Multiple linear regression, cross-tabulation, and graphical analysis were used. Of the sampled units, 27 used mixed biomass firing with firewood and corncobs, while 10 additionally used sawdust; 13 units used energy-efficient stoves and 24 used non-energy-efficient stoves. The biomass-cost model showed that mixed biomass firing and stove technology were significantly associated with biomass costs. Mixed biomass firing with firewood and corncobs was associated with a reduction of IDR 717 per kilogram of soybean raw material, while energy-efficient stove technology was associated with a reduction of IDR 755 per kilogram. Energy-efficient stoves reduced biomass use from 2.306 to 1.362 kg per kilogram of soybean raw material, equivalent to 40.94%. Estimated carbon emissions were calculated to decrease from 10.561–11.364 tons/day to 6.238–6.712 tons/day. These findings support the use of energy-efficient stoves and appropriate biomass mixtures to reduce fuel costs and biomass consumption in tofu production.