Abstract
Ethanol to middle distillates (ETMD) is a promising pathway to produce sustainable liquid fuels to decarbonize the hard-to-electrify transportation sectors due to (1) the abundant sugar/starch and lignocellulosic biomass, (2) the existing deployment scale of fuel ethanol production (∼29 billion gallons per year globally), and (3) emerging opportunities in C2+ alcohol synthesis from CO2. Here we report a conceptual market-responsive biorefinery centered around a new ETMD pathway based on one-step ethanol to butene-rich olefins (ETO) over a Cu-Zn-Y/Beta catalyst. Specifically, this ethanol conversion pathway comprises one-step ETO, oligomerization, and hydrotreating. This ETO is distinct from that in the conventional ethanol-to-jet process which is based on two-step ethanol to ethylene and ethylene oligomerization to butenes. Butene-rich olefins can be shifted to butadiene-rich products by simply changing the reaction atmosphere from hydrogen to inert gas over the same ETO catalyst. Leveraging the experimental results, baseline techno-economic analysis (TEA) and sensitivity analysis indicate that the ethanol conversion cost is $0.60 per gallon gasoline equivalent (GGE), with opportunities for further cost reduction via improving the liquid hydrocarbon yield and space velocities, and process optimization on balancing dewatering of ethanol feed prior to the ETO step. The minimum fuel selling price (MFSP) of liquid hydrocarbons derived from corn starch ethanol with butadiene as coproduct is $1.64 per GGE, in the range that is cost competitive with petroleum kerosene-type jet fuel. Projected MFSP for cellulosic ethanol (corn stover) derived hydrocarbons is below $3.00 per GGE and co-production of butadiene further reduces the MFSP to $1.70 per GGE. The Well-to-Wake life-cycle analysis indicates that 85% greenhouse gas emission reduction can be achieved when using corn stover compared to petroleum reference and the associated carbon credits will provide significant economic incentives to favor the cellulosic ethanol-derived hydrocarbon fuels. This study demonstrates a low-cost pathway to middle distillate fuels leveraging existing ethanol infrastructure, where catalysis innovation drives the reduction of process complexity and flexible coproduction of a value-added chemical product.
| Original language | English |
|---|---|
| Pages (from-to) | 9534-9548 |
| Number of pages | 15 |
| Journal | Green Chemistry |
| Volume | 23 |
| Issue number | 23 |
| DOIs | |
| State | Published - Dec 7 2021 |
Funding
J. Z., B. H. D. and Z. L. were sponsored by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies Office (BETO), under contract DE-AC05-00OR22725 (ORNL) with UT-Battle, LLC, and in collaboration with the Chemical Catalysis for Bioenergy (ChemCatBio) Consortium, a member of the Energy Materials Network. The work was also supported by the U.S. Department of Energy’s Bioenergy Technologies Office under Contract No. DE-AC36-08GO28308 with the National Renewable Energy Laboratory. B. H. D. and Z. L. were also supported by the Center for Bioenergy Innovation, a DOE Bioenergy Research Center supported by the Office of Biological and Environmental Research in the DOE Office of Science and led by Oak Ridge National Laboratory. The views and opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. The authors acknowledge Dr Todd Toops and Dr Sreshtha Majumdar for experimental assistance with the DRIFTS analysis.
| Funders | Funder number |
|---|---|
| Chemical Catalysis for Bioenergy | |
| DOE Bioenergy Research Center | |
| U.S. Department of Energy | |
| Office of Energy Efficiency and Renewable Energy | |
| Biological and Environmental Research | |
| Oak Ridge National Laboratory | |
| National Renewable Energy Laboratory | |
| Bioenergy Technologies Office | DE-AC05-00OR22725, DE-AC36-08GO28308 |
| Center for Bioenergy Innovation |
