Degree Type

Dissertation

Date of Award

2018

Degree Name

Doctor of Philosophy

Department

Mechanical Engineering

Major

Mechanical Engineering

First Advisor

Mark M. Wright

Abstract

Climate change is leading to concerning fluctuations in weather patterns mainly due to anthropogenic activities such as deforestation and burning of fossil fuels which are and will affect different sectors such as food chains, wildlife and most importantly the human life. The upcoming generations must be left with an environment worth to live in thus humans must intervene to reduce the emissions of greenhouse gases and that is why sustainable means must be used to provide clean energy and renewable-based chemicals. For the U.S., the USDOE and USDA proposed a 25% and 20% vision for biomass-based chemicals and fuels respectively by the year 2030.

The different chapters of this dissertation are: 1) introduction, 2) literature review, 3) “more than ethanol: a techno-economic analysis of corn stover-ethanol biorefinery integrated with hydrothermal liquefaction (HTL) process to convert lignin into biochemicals”, 4) “techno-economic analysis of 2,5-dimethylfuran (DMF) production using an electrolyzer/electrochemical reactor”, 5) “electrochemical production of 2-methylfuran (MF) from furfural: a techno-economic analysis”, and 6) “electrochemical processing of CO2 into Fischer Tropsch (FT) fuels using renewable electricity: a techno-economic analysis”, 7) general conclusions, and 8) recommendations for future work.

The project of integrating corn stover biorefinery with HTL evaluates a 2000 metric tonne per day (MTPD) corn stover biorefinery producing 61 MMgal/yr. of ethanol and different yields of lignin-based biochemicals. A minimum ethanol selling price (MESP) of $1.03±0.19 per gal was estimated considering the production of lignin-derived catechol, phenol, cresols, acetic acid, formic acid, furfural, and acetaldehyde. The most influential factors on MESP are fixed capital investment, internal rate of return, feedstock price, cresols, catechol, and acetic acid prices. In terms of costs, the total purchased equipment cost is $114.5 million (MM), total installed cost (TIC) is $345.7 MM, and total capital investment is $624.5 MM. Producing lignin-derived biochemicals using hydrothermal liquefaction (HTL) is in the early stages of development thus more research is needed to establish its commercialization potential.

The 2,5-dimethylfuran (DMF) project evaluates the techno-economic feasibility of producing DMF using an electrolyzer/electrochemical reactor. A 300-metric ton per day (MTPD) fructose biorefinery was considered producing 34 MTPD levulinic acid as a byproduct and 174 MTPD of hydroxymethylfurfural/5-hydroxymethylfurfural (HMF). The HMF is further converted to DMF through an electrochemical process producing 95 MTPD of 2,5-dimethylfuran (DMF) and the byproducts being 59 MTPD 2,5-bis(hydroxymethyl)furan and 21 MTPD 5-methylfurfuryl alcohol. A minimum product-selling price (MPSP) of $12.51/gal of DMF was estimated. The sensitivity analysis results showed that DMF yield, fixed capital investment, internal rate of return (IRR), 2,5-bis(hydroxymethyl)furan price, and fructose feedstock price are the most influential parameters on the MPSP. The biorefinery considered in this analysis requires a total purchased equipment cost (TPEC) of $146 MM, $442 MM of total installed cost (TIC), and $799 MM as the total capital investment. Using an electrolyzer/electrochemical reactor process to produce bioproducts is promising though in the early stages of development thus more research should be done to enable commercialization of the electrochemical process.

The 2-methyfuran project investigated the techno-economic feasibility of producing 2-methylfuran (MF) from furfural using an electrolyzer that utilizes renewable electricity. Furfural flowrate assumed was 300 MTPD producing over 239 MTPD with byproducts of furoic acid (30 MTPD) and furfuryl alcohol (30 MTPD). MPSP is $9.07/gal and its mostly influenced by MF yield, fixed capital investment, furfural price, and acetonitrile price. The different cost are $79 MM, $240 MM, and $433 MM for total purchased equipment cost, total installed cost, and total capital invest cost respectively.

The CO2 project, analyzed a 2000 MTPD biorefinery producing Fischer Tropsch biofuel gasoline gallon equivalent (GGE). The electrochemical conversion of CO2 into biofuels is an alternative to carbon sequestration and/or its release into the atmosphere that causes global warming. The biorefinery considered produces 70.7 MM gal/yr GGE (1236 MTPD, C8 and C16 hydrocarbons) and 253 MTPD of propane (CH4 – C3 hydrocarbon mixture). The estimated investments are $388 MM as total purchased equipment cost (TPEC), $1.2 BB for total installed costs (TIC), $1.8 BB as fixed capital investment (FCI) and $2.1 BB as the total investment cost. The estimated MPSP is $4.69/gal GGE and is mostly influenced by F-T GGE yield ($3.91 – 5.86/GGE), fixed capital investment ($3.86 – 5.53/GGE), IRR ($4.11 – 5.28/GGE), and income tax rate ($$4.51-4.91/GGE). Electrochemical conversion of CO2 is a promising technology to combat global warming though more research is needed to ascertain the electrolyzer functionality in converting CO2.

The overall conclusion is that techno-economic analysis (TEA) is a good method to evaluate the feasibility of a project before being scaled-up from a laboratory to a pilot scale and then to a commercial facility. The evaluation provides insights of the minimum product selling price(s) and the factors that affect it most. This helps in comparison of biomass-based verses fossil-based products. Also, TEA provides estimates of total purchased equipment costs, total installation cost, and total capital investment. Overall, to have a bioeconomy, biofuels must be produced with biochemicals and CO2 capture and conversion into useful products will minimize and/or eliminate global warming.

DOI

https://doi.org/10.31274/etd-180810-5946

Copyright Owner

Denis Bbosa

Language

en

File Format

application/pdf

File Size

167 pages

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