Integrated Techno-economic and Environmental Analysis in Support of Biorefinery Technology Commercialization and Product Scheme Decision-making.

摘要

The bioeconomy is a relatively new market sector comprising bio-energy, bioplastics, biofuels, bio-based textiles and packaging, and pharmaceuticals. Government support for the bioeconomy has incentivized the production of bioproducts for companies endeavoring to bring bio-based products to market. Critical tools for predicting the commercialization feasibility of a bioproduct or biorefining scheme include process modeling and techno-economic analysis, bench- and pilot-scale experimental results, and market analysis. Whereas financial and technical metrics are good predictors of operational and economic feasibility at commercial scale, these metrics lack the ability to quantify essential product or system utility functions as mandated for governmental incentives, which require positive socio-economic and environmental outcomes. Unfortunately, once numerous criteria are measured for scenarios and bioproducts under comparison, the complexity of subsequent scenario comparison disallows objective, normative decision-making. Decision science, specifically methodologies classified as multi-criteria decision-making analysis (MCDA) allow for systematic, objective scenario comparison via weighted single-scoring.;The objective of this research is to employ MCDA as an integrated analysis and decision-making tool to evaluate the holistic feasibility of various biorefinery conversion technologies and bioproduct schema using technological, economic, social, logistical, environmental and financial criteria. This MCDA tool may facilitate more objective decision-making for biorefinery investors and operators; the success of which will promote the continued growth of the U.S. bioeconomy. This integrated assessment will present data from many robust modeling and analysis tools and methodologies and will explore the integration of these data and methodologies to develop a clearer picture of holistic biorefinery feasibility and conversion technology scalability for stakeholders.;Past research has identified biomass production prior to biorefining as a major cost and technical driver which is known to contribute substantively to net environmental impacts for conversion technologies such as gasification to mixed alcohols. In Chapters 2, 3, and 4, indepth biomass supply system models were developed for eighteen biomass types including primary agricultural and forestry crops as well as agricultural and forestry residues in order to better measure feasibility metrics for biomass supply. Cradle-to-gate feasibility analysis was conducted as a truncated assessment of unspecified product biorefining feasibility. Experimental weight sets were developed which weighted feasibility criteria differently in order to approximate a stakeholder's values during decision-making. Results of this biomass supply analysis were used to select scenarios which are more likely to be feasible for cradle-to-grave analysis of biosugar, bioethanol oxygenate, fuel pellet, and transportation fuels conversion technologies and biorefining/bioprocessing scenarios.;Conversion technologies assessed herein include (a) various pretreatment options followed by enzymatic hydrolysis and distillation to biosugar (biochemical conversion, Chapter 5 and Chapter 6), (b) fast pyrolysis followed by hydrodeoxygenation, catalytic cracking, and distillation to gasoline range molecules (Chapter 7), (c) biochemical saccharification and fermentation of corn to bioethanol (Chapter 5 and Chapter 8), (d) biochemical saccharification and fermentation of cellulosic biomass to bioethanol (Chapter 5 and Chapter 8), and (e) densification to fuel pellets for bioenergy production via combustion (Chapter 8).;Outcomes of this completed research include evidence of the successful integration of disparate feasibility analysis methodologies and the identification of technologies which are most feasible and which provide the greatest utility for stakeholders. Implications of conversion platform, biomass feedstock, product scheme, weight set, and MCDA method, among other study parameters, for scenario ranking and normative decision-making were analyzed. While some bioproducts are not directly comparable (such as bioethanol versus biosugar or bioenergy versus pellets), a systematic comparison on the biorefinery rather than bioproduct basis harmonizes the functional units and enables a fair comparison.