Increasing Profits in Food Waste Biorefinery—A Techno-Economic Analysis

Abstract

The present manuscript highlights the economic profit increase when combining organic waste anaerobic digestion with other mixed culture anaerobic fermentation technologies, e.g., lactic acid fermentation and dark fermentation. Here we consider the conversion of 50 tonnes/day of food waste into methane, power generation (from CHP of biomethane), lactic acid, polylactic acid, hydrogen, acetic acid and butyric acid. The economic assessment shows that the basic alternative, i.e., anaerobic digestion with methane selling to the grid, generates 19 USD/t_VS (3 USD/t_foodwaste) of profit. The highest profit is obtained by dark fermentation with separation and purification of acetic and butyric acids, i.e., 296 USD/t_VS (47 USD/t_foodwaste). The only alternative that presented losses is the power generation alternative, needing tipping fees and/or subsidy of 176 USD/t_VS (29 USD/t_foodwaste). The rest of the alternatives generate profit. From the return on investment (ROI) and payback time, the best scenario is the production of polylactic acid, with 98% ROI, and 7.8 years payback time. Production of butyric acid ROI and payback time was 74% and 9.1 years.

A critical review: emerging bioeconomy and waste-to-energy technologies for sustainable municipal solid waste management

“…Thus, following the idea of the circular economy from the EU it is clear that the development of separate collection structures and recycling capacity should be a top priority. From the technological perspective, without proper waste sorting, the costs for substances-separation can easily transcend the value of the final bio-products [159,160]. Separation technologies are required to isolate cellulose, antioxidants, amino acids, or any other unwanted substances from the chain of refinery processes.…”

BioEnergy and BioChemicals Production from Biomass and Residual Resources

“…The twenty-one published papers cover a variety of biomass or waste residuals that have been converted into different types of energy, biofuels or biochemicals including heat [1,11,16], methane [2,4,[7][8][9]17,[19][20][21], electricity [2,11,16], short chain fatty acids [2,19], ethanol [3,12,19], syngas [5,19], nutrient pellets [6], hydroxymethylfurfura [15], and hydrogen [2,10,14,18,19]. The key information including biomass or residuals, products, and technology for the production and type of research are summarized in Table 1.…”

“…Bastidas-Oyanedel and Schmidt [2] conducted a techno-economic analysis of a food-waste-based biorefinery process. It was found in their study that dark fermentation with separation and purification of acetic and butyric acids could gain the highest profit among other scenarios.…”

Techno-Economic Analysis of Bio-Based Lactic Acid Production Utilizing Corn Grain as Feedstock

“…Lactic acid production using sugarcane bagasse feedstock showed that cellulose-based processes have larger lactic acid production rates and lower production costs than hemicellulose-based processes; and gypsum-free scenarios had the lowest production costs [9]. Few other studies have evaluated the techno-economics of lactic acid production using other feedstocks such as sugarcane juice, food waste, and different technologies [10][11][12][13][14][15]. Lactic acid from starch-based biomass resources, such as corn grain, can be an attractive option for biorefineries in the U.S. Corn grain contains large fraction of starch, which can be hydrolyzed using enzymes to produce sugars, which can then be fermented to produce lactic acid [16].…”