Design, Implementation and Simulation of a Small-Scale Biorefinery Model

Abstract

Second-generation biomass is an underexploited resource, which can lead to valuable products in a circular economy. Available locally as food waste, gardening and pruning waste or agricultural waste, second-generation biomass can be processed into high-valued products through a flexi-feed small-scale biorefinery. The flexi-feed and the use of local biomass ensure the continuous availability of feedstock at low logistic costs. However, the viability and sustainability of the biorefinery must be ensured by the design and optimal operation. While the design depends on the available feedstock and the desired products, the optimisation requires the availability of a mathematical model of the biorefinery. This paper details the design and modelling of a small-scale biorefinery in view of its optimisation at a later stage. The proposed biorefinery comprises the following processes: steam refining, anaerobic digestion, ammonia stripping and composting. The models’ integration and the overall biorefinery operation are emphasised. The simulation results assess the potential of the real biowaste collected in a commune in Flanders (Belgium) to produce oligosaccharides, lignin, fibres, biogas, fertiliser and compost. This represents a baseline scenario, which can be subsequently employed in the evaluation of optimised solutions. The outlined approach leads to better feedstocks utilisation and product diversification, raising awareness on the impact and importance of small-scale biorefineries at a commune level.

Special Issue: Mathematical Modeling and Control of Bioprocesses

“…At a more macroscopic scale, four papers of the SI on MMCB focus on dynamic models for describing different processes, i.e., production of biopolymers [4], production of biopesticides [5], biodegradation [6] and biorefinery of second-generation biomass [7]. Duvigneau et al [4] propose a new kinetic model for describing the production of the bio-copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), which has a broad range of applications and is easier to process than the classical homopolymer poly(3hydroxybutyrate).…”

“…The global stabilizability of the model dynamics towards equilibrium points is analyzed and illustrated with numerical examples. Sbarciog et al [7] propose a biorefinery model that integrates several processes, among which are steam refining, anaerobic digestion, ammonia stripping and composting. The overall goal is the model-based optimization of the process.…”

Critical analysis of the use of white-box versus black-box models for multi-objective optimisation of small-scale biorefineries

“…In this contribution, the multi-objective optimisation of a smallscale and flexi-feed biorefinery is considered. The considered biorefinery design was previously presented by Sbarciog et al (2022) and is specifically tailored for the considered Flemish setting. Small-scale biorefineries outperform their large-scale counterparts by being specifically designed for the (small) local area they serve.…”

“…In order to be able to make a sufficiently accurate assessment of the consumed energy of the proposed biorefinery design, an Aspen Plus model is developed. The considered biorefinery network was previously presented in Sbarciog et al (2022) is re-considered in this contribution. The Aspen Plus (A+) model is based on the mass-balance models presented in Sbarciog et al (2022) and, in combination with the latter, will allow for simultaneously modelling the biorefinery's mass yields as well as its energy consumption.…”

“…The considered biorefinery network was previously presented in Sbarciog et al (2022) is re-considered in this contribution. The Aspen Plus (A+) model is based on the mass-balance models presented in Sbarciog et al (2022) and, in combination with the latter, will allow for simultaneously modelling the biorefinery's mass yields as well as its energy consumption. Notwithstanding major efforts have already been made in the context of modelling the energy consumption of a multitude of biorefinery designs (e.g., Davis et al (2016) developed an Aspen Plus model of an algal biorefinery; Humbird et al (2011); Davis et al (2015) developed Aspen Plus models for the dilute-acid and enzymatic treatment of lignocellulosic biomass; Nguyen (2014) developed an Aspen Plus model of the anaerobic digestion process (which is considered in the studied biorefinery network)), a thorough literature review did not reveal any energy, or Aspen Plus models, of the additional processes of the considered biorefinery network.…”