Economic Analysis of Pellet Production in Co-Digestion Biogas Plants

Abstract

In our paper we examine the economics of a technological process which utilizes the separated biogas plant digestate as the primary material and, as auxiliary material, the waste heat produced by the cogeneration process, to produce a marketable pellet which can be used in two ways (to supply soil nutrients and heat energy). Using multivariate linear regression model we developed an equation for the biogas yield from the modelled production recipe and expected nutrient pellet prices, and sensitivity analysis were also performed for the substrate dry matter content. We found that pellets can be produced at a cost of 88-90 EUR/ton with a 6 to 10% dry matter substrate content and that, primarily, sales of pellets for heating justify pelleting; producer's own use and use for nutrient purposes can only be justified in exceptional cases. In the case of dry solid content above 5%, the process does not require the total amount of waste heat; some of this can be used to cover other heat requirements.

Sustainability Evaluation of Municipal Solid Waste Management System for Hanoi (Vietnam)—Why to Choose the ‘Waste-to-Energy’ Concept

“…At the same time, developing countries need to expand their regional energy production processes, which can also be helped by waste-to-energy developments [50,51]. For developing countries, decision-makers prefer fast-track, cost-effective systems that have a life cycle that can be well understood and could be successful within five or a maximum of ten years [52,53].…”

Thermodynamic Fundamentals for Fuel Production Management

“…Pressure p n pressure in the chamber at the z-th instant of time after smoothing p(t z ) pressure in the chamber at the z-th instant of time p(t z−1 ) pressure in the chamber in z-1 instant of time p(t z+1 ) chamber pressure in z + 1 instant of time p cmax maximum pressure in the chamber m gas mass m p mass of burnt fuel or mass of injected fuel m z the mass of gas at the instant z m z−1 mass of gas at z-1 instant of time y 1 , y 2 , y 3 , y 4 , y 5 coefficients, individual for each gas dQ emitted heat xH mass share of hydrogen in the fuel…”

“…The needs for replacement of fossil fuels, and for mitigation of carbon dioxide emissions already became the challenge [4,5] that affects the World's economy [6]. New technologies in power engineering [7][8][9], promotion of electro-mobility, a departure from fossil fuels, and concern for sustainable development and energy security together with assuring the environmental protection are the factors that the fuel and energy industry must react to these changes and prepare for them [10][11][12].…”

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.…”

“…Cerone and Zimbardi [5] investigated the effect of air and steam supply on the overall process performance and syngas composition in a pilot updraft gasifier. Nagy et al [6] conducted an economic analysis of a process that utilized digestate and waste heat from a biogas plant as the raw materials to produce a pellet. The pellet can be subsequently used as a nutrient in soil or heat energy.…”