Methodology for the optimal thermo-economic, multi-objective design of thermochemical fuel production from biomass

Abstract

This paper addresses a methodology for the optimal conceptual design of thermochemical fuel production processes from biomass. A decomposed modelling approach with separate energy-flow, energy-integration and economic models is presented and coupled to multi-objective optimisation, which allows to generate a set of optimal process flowsheets that constitute a sound basis for the synthesis of a viable process.

Optimal process design for the polygeneration of SNG, power and heat by hydrothermal gasification of waste biomass: Thermo-economic process modelling and integration

“…In this formulation, the utility cost C UT (eqn 23) cancels out if the plant produces net electricity (i.e. _ E + ¼ 0, _ E À > 0), the maintenance cost C M is supposed to amount to 5% of the investment per year and the catalyst cost C cat is determined from its replacement rate _ m cat with respect to the sulfur loading as calculated by eqn (20), (21). Expressing the annualised investment as a depreciation cost C GR,d by discounting with the capital recovery factor at an interest rate i r over the economic lifetime n of the plant, the total expenses C tot [$ MWh biomass ] are obtained by:…”

“…20 Similar to a classical design procedure, the analysis of raw material characteristics, product specifications and feasible production pathways allows for identifying suitable technology for the process unit operations and energy recovery that are assembled in a process superstructure. A decomposition-based modelling approach is then adopted to systematically develop candidate flowsheets.…”

“…1 that is required to reach the targeted conversion. 20 Following classic process design procedures, 26,43 the process vessels for reaction and separation are roughly sized for the specific operating conditions. Costing data from the same sources is then used to determine the investment required for the plant.…”

“…In order to assess the catalyst poisoning in the gasifier by residual sulfur, the salt concentration at the separator outlet is estimated with the solubility correlation of Leusbrock et al 39 for Na 2 20) in whichc Na2SO4 is the molar fraction of diluted salt,R the ideal gas constant, and T ss , r ss andm the temperature, density and molar weight of the saturated fluid at the separation temperature, respectively. Due to the lack of data for organic mixtures at these conditions, the correlation with respect to the fluid's molar density r ss /m is applied without modification.…”

Multi-product biorefineries from lignocelluloses: a pathway to revitalisation of the sugar industry?

“…In the context of sugar industry, a biorefinery could be annexed to a sugar mill to increase diversification and support regional and rural development. A number of economic assessments have been published on biofuel production from 2G waste biomass, considering biochemical [21, 22] or thermochemical technologies [23–26]. Production of value-added chemicals and polymers from lignocellulosic waste biomass has been also explored in the past few years [10, 27–29].…”