Comparative early stage assessment of multiproduct biorefinery systems: An application to the isobutanol platform.

An early stage assessment method is applied to the production of isobutanol from lignocellulosic biomass, and to three multiproduct portfolios from the conversion of isobutanol: Case 1: production of isobutyl acetate and glycerol tert-butyl ether (GTBE), Case 2: production of isobutyl acetate and ketones, and Case 3: production of isobutyl acetate alkanes. The method screens and compares each route with its equivalent petrochemical counterpart. The method is composed by different indicators involving economic and environmental aspects. Sensitivity analyses were carried out to account for variation in prices, weighting factors and distribution of isobutanol to isobutyl acetate (in multiproduct portfolios). Results show that bio-based isobutanol has advantages over fossil-based isobutanol. In multiproduct systems, case 1 performs better, followed by cases 2 and 3. Screening using economic or environmental aspects show to have a significant effect on the results, where bio-based systems tend to perform better when environmental aspects are included.

Techno-economic analysis for brewer's spent grains use on a biorefinery concept: the Brazilian case.

A techno-economic analysis for use of brewer's spent grains (BSG) on a biorefinery concept for the Brazilian case is presented. Four scenarios based on different levels of heat and mass integration for the production of xylitol, lactic acid, activated carbon and phenolic acids are shown. A simulation procedure using the software Aspen Plus and experimental yields was used. Such procedure served as basis for the techno-economic and environmental assessment according to the Brazilian conditions. Full mass integration on water and full energy integration was the configuration with the best economic and environmental performance. For this case, the obtained economic margin was 62.25%, the potential environmental impact was 0.012 PEI/kg products, and the carbon footprint of the processing stage represented 0.96 kg CO2-e/kg of BSG. This result served as basis to draw recommendations on the technological, economic and environmental feasibility for implementation of such type of biorefinery in Brazil.

Techno-economic analysis of bioethanol production from lignocellulosic residues in Colombia: a process simulation approach.

In this study a techno-economic analysis of the production of bioethanol from four lignocellusic (Sugarcane bagasse, Coffee cut-stems, Rice Husk, and Empty Fruit Bunches) residues is presented for the Colombian case. The ethanol production was evaluated using Aspen Plus and Aspen Process Economic Analyzer carrying out the simulation and the economic evaluation, respectively. Simulations included the composition of lignocellulosic residues, which was determined experimentally. It was found that empty fruit bunches presents the highest ethanol yield from a dry basis point of view (313.83 L/t), while rice husk produced less ethanol (250.56 L/t). The ethanol production cost was assessed for the standalone ethanol plant and the ethanol plant coupled with a cogeneration system. Moreover, ethanol production cost using EFB was the lowest with (0.49 US$/L) and without (0.58 US$/L) cogeneration scheme.

Techno-economic analysis for a sugarcane biorefinery: Colombian case.

In this paper a techno-economic analysis for a sugarcane biorefinery is presented for the Colombian case. It is shown two scenarios for different conversion pathways as function of feedstock distribution and technologies for sugar, fuel ethanol, PHB, anthocyanins and electricity production. These scenarios are compared with the Colombian base case which simultaneously produce sugar, fuel ethanol and electricity. A simulation procedure was used in order to evaluate biorefinery schemes for all the scenarios, using Aspen Plus software, that include productivity analysis, energy calculations and economic evaluation for each process configuration. The results showed that the configuration with the best economic, environmental and social performance is the one that considers fuel ethanol and PHB production from combined cane bagasse and molasses. This result served as the basis to draw recommendations on technological and economic feasibility as well as social aspects for the implementation of such type of biorefinery in Colombia.