Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “coproducts”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2

Economic perspective of ethanol and biodiesel coproduction from industrial hemp

Herein, the economics of producing biofuels from an industrial hemp (Cannabis sativa) genotype e 19m96136 was investigated. A lignocellulosic biofuel plant, hourly consuming 85 metric tons of hemp biomass was modeled in SuperPro Designer®. The integrated bioenergy plant produced hemp biodiesel and bioethanol from lipids and carbohydrates, respectively. The structural composition of the industrial hemp plant was analyzed in a previous study. The data obtained was used to simulate feedstock composition in SuperPro Designer®. The simulation results indicated that Hemp containing 2% lipids can yield up to 3.95 million gallons of biodiesel annually. On improving biomass lipid content to 5 and 10%, biodiesel production increased to 9.88 and 19.91 million gallons, respectively. The breakeven unit production cost of hemp biodiesel with 2, 5, and 10% lipid containing hemp was $18.49, $7.87, and $4.13/gallon, respectively. The biodiesel unit production cost when utilizing 10% lipid-containing hemp was comparable to soybean biodiesel at $4.13/ gallon. Furthermore, sensitivity analysis revealed the possibility of a 7.80% reduction in unit production cost upon a 10% reduction in hemp feedstock cost. Furthermore, industrial hemp was capable of pro- ducing between 307.80 and 325.82 gallons of total biofuels per hectare of agricultural land than soybean.

09 BIOMASS FUELS↗

Reinterpreting the infrared spectrum of H + HCN: Methylene amidogen radical and its coproducts

The methylene amidogen radical (H 2 CN) plays a role in high-energy material combustion and extraterresterial atmospheres. Recent theoretical work has struggled to match experimental assignments for its CN and antisymmetric CH 2 stretching frequencies (ν 2 and ν 5 ), which were reported to occur at 1725 and 3103 cm –1 . Herein, we compute the vibrational energy levels of this molecule by extrapolating quadruples-level coupled- cluster theory to the complete basis limit and adding corrections for vibrational anharmonicity. This level of theory predicts that ν 2 and ν 5 should occur at 1646 and 2892 cm –1 , at odds with the experimental assignments. To investigate the possibility of defects in our theoretical treatment, we analyze the sensitivity of our approach to each of its contributing approximations. Our analysis suggests that the observed deviation from experiment is too large to be explained as an accumulation of errors, leading us to conclude that these transitions were misassigned. To help resolve this discrepancy, we investigate possible byproducts of the H + HCN reaction, which was the source of H 2 CN in the original experiment. In particular, we predict vibrational spectra for cis -HCNH, trans -HCNH, and H 2 CNH using high-level coupled-cluster computations. Based on these results, we reassign the transition at 1725 cm –1 to ν 3 of trans-HCNH, yielding excellent agreement. Supporting this identification, we assign a known contaminant peak at 886 cm –1 to ν 5 of the same conformer. Our computations suggest that the peak observed at 3103 cm –1 , however, does not belong to any of the aforementioned species. To facilitate further investigation, we use structure and bonding arguments to narrow the range of possible candidates. Furthermore, these arguments lead us to tentatively put forth formaldazine [(H 2 CN) 2 ] as a suggestion for further study, which we support with additional computations.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Metagenome-assembled genomes from microbiomes fermenting dairy coproducts

ABSTRACT To advance knowledge of microbial communities capable of fermenting agro-industrial residues into value-added products, we report metagenomes of microbial communities from six anaerobic bioreactors that were fed a mixture of ultra-filtered milk permeate and cottage cheese acid whey. These metagenomes produced 122 metagenome-assembled genomes that represent 34 distinct taxa.

Walters, Kevin A.↗

Data from Economic Perspective of Ethanol and Biodiesel Coproduction from Industrial Hemp

In this study, the economics of producing biofuels from an industrial hemp (Cannabis sativa) genotype – 19m96136 was investigated. A lignocellulosic biofuel plant, hourly consuming 85 metric tons of hemp biomass was modeled in SuperPro Designer®. The integrated bioenergy plant produced hemp biodiesel and bioethanol from lipids and carbohydrates, respectively. The structural composition of the industrial hemp plant was analyzed in a previous study. The data obtained was used to simulate feedstock composition in SuperPro Designer®. The simulation results indicated that Hemp containing 2% lipids can yield up to 3.95 million gallons of biodiesel annually. On improving biomass lipid content to 5 and 10%, biodiesel production increased to 9.88 and 19.91 million gallons, respectively. The breakeven unit production cost of hemp biodiesel with 2, 5, and 10% lipid containing hemp was $18.49, $7.87, and $4.13/gallon, respectively. The biodiesel unit production cost when utilizing 10% lipid-containing hemp was comparable to soybean biodiesel at $4.13/gallon. Furthermore, sensitivity analysis revealed the possibility of a 7.80% reduction in unit production cost upon a 10% reduction in hemp feedstock cost. Furthermore, industrial hemp was capable of producing between 307.80 and 325.82 gallons of total biofuels per hectare of agricultural land than soybean.

Conversion↗

A Comparative Life-Cycle Assessment of Briquetting Logging Residues and Lumber Manufacturing Coproducts in Western United States

Abstract. Timber harvest activities in the western United States have resulted in large volumes of low- to no-value logging (forest) residues. Alternatives to pile-and-burning are needed to best utilize this material and to mitigate the resultant environmental impacts. Briquetting (densifying) forest residues near-woods is one such option and is the focus of this study. This study presents a cradle-to-grave life-cycle assessment (LCA) performed to evaluate the overall environmental impacts associated with briquetting post-harvest forest residues and dry sawmill residues (sawdust) in the Pacific Northwest (PNW) region of the United States. Environmental impacts resulting from the two briquette production systems were compared with firewood and propane production, which are common residential heating sources in rural areas of the PNW, on a per 1 MJ of useful energy for domestic heating. In the briquetted post-harvest forest residue system, the feedstock preparation stage had the largest share in global warming (GW) impact, mainly resulting from the drying process (69.5%), followed by transportation. Valorization of post-harvest forest residues, in combination with a briquetter, to produce a bioenergy carrier was revealed to be advantageous in smog, acidification, and eutrophication impact categories, with considerable environmental benefits from avoided pile-and-burn emissions. With all scenarios investigated, briquette production from post-harvest forest residues with high dryer efficiency showed lowest GW impact compared to briquetting sawmill residues and firewood supply chain. For a scenario analysis, LCA showed that using a diesel generator to support the forest residue briquetter operation resulted in 45% higher GW impact compared to use of a wood-gas-powered generator. Keywords: Bioenergy, Biomass densification, Briquette, Forest residues, Life-cycle assessment, Sawdust.

Agriculture↗

Ediesel: Diesel Additive production from ethanol and bio-diesel coproducts

This project has focused on supporting and expanding the U.S. ethanol industry by developing new conversion routes and products from ethanol and the byproducts made in ethanol fermentation. The work is relevant to the DOE program goals of developing high-margin chemical products in the biorefinery to economically support large-scale biofuel production. The higher alcohols from condensation of ethanol, alkylated amine compounds made by electrocatalytic alkyation, and fusel alcohols produced by modified fermentation microorganisms are all existing or potentially large-scale commodity or specialty chemicals with well-defined uses in industry. The formation of higher alcohols from ethanol in the condensed phase developed several catalysts, first in stirred batch autoclave reactors and then in a continuous flow reactor system, to achieve significant yields of n-butanol and higher alcohols. The best selectivity to higher alcohols exceeded 80% of theoretical at ethanol conversions of 30-40%. From the laboratory experiments and analysis of the phase equilibria of the species involved, a process concept was generated and simulated in AspenPlus to determine the specifications of the various equipment involved in the process. Results show that for the conversion and selectivity described above, the required n-butanol selling price of ~$1.60/kg is in the range of current n-butanol selling price in the marketplace. Several additional permutations of the process, along with evaluation of higher conversion and selectivities to desired alcohol products, showed that the production of n-butanol from ethanol should be competitive in the marketplace as the science and engineering behind the process improves with continued development. A second aspect of the project focused on producing fusel alcohols in increased quantities during ethanol fermentation. Fusel alcohols, which are composed primarily of isoamyl alcohol and minor quantities of C3-C6 alcohols, have potential as higher value feed stocks for specialty chemical production. Several strains of yeast were evaluated for fusel alcohol production, and the most efficient process for separating and purifying fusel alcohols was developed from both experiments and simulation. Finally, model fusel alcohol mixtures were subjected to condensation reactions with ethanol to prepare higher alcohols that again have potential for specialty chemical or solvent applications. In this preliminary work, measurable quantities of several species were observed, including some species that were previously unknown or uncharacterized in the literature. The third aspect of the project involved the electrocatalytic alkylation of amines with alcohols to form alkyl amines. Ethanol has been demonstrated to serve as an effective ethyl group transfer agent to the nitrogen centers of amines, a reaction with only water as a byproduct. Mild reaction conditions (60 °C, aqueous solution) are enabled by the novel use of simple, undivided electrochemical cell reactors that include long-lived, low cost catalytic electrodes. Direct polyalkylation of ammonia and isolation of the resulting triethylamine product was readily achieved in high yield. Though classical high temperature and pressure industrial scale alkylations reactions will likely continue to be used for production of simple product such as triethylamine, this approach has opened the door to the low cost, low waste use of ethanol and related primary and secondary alcohols to alkylate more delicate amines that were heretofore difficult to synthesize.

02 PETROLEUM↗

Pretreatment of Algae for the Production of Fuels and Chemical Coproducts

Algal biomass is a promising resource for producing renewable fuels and chemicals, but despite decades of research, algal biorefining remains in a pre-commercial state. Recent economic analyses have indicated that high-value co-products are necessary to offset the cost of fuel production, implying the need for algae fractionation technology. One promising fractionation approach is Combined Algal Processing (CAP), which pretreats and extracts algal biomass to produce a fermentable aqueous hydrolysate, an organic lipid fraction, and a residual solids fraction. The CAP approach has historically employed a dilute acid pretreatment to lyse cells and solubilize algal carbohydrates for fermentation of the hydrolysate phase, but we recently identified alternative pretreatments with the potential to decrease costs and environmental impacts, including different implementations of dilute acid pretreatment, dilute alkali pretreatment, enzymatic pretreatment, and flash hydrolysis. We conducted a screening of six different pretreatment approaches across nine algae strains of varying composition, and measured pretreatment effectiveness as a combination of carbon and nitrogen solubilization, lipid extraction yield, and lipid speciation. In this screening, we found traditional dilute acid pretreatment to provide the most robust pretreatment performance, though other pretreatments were competitive, and some performed better for certain strains of algae. These results highlight the interplay between algae composition and pretreatment effectiveness.

algae↗

Towards cost-competitive middle distillate fuels from ethanol within a market-flexible C2 platform-based biorefinery concept

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 (similar to 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.

Zhang, Junyan↗

Life-cycle energy use and greenhouse gas emissions of palm fatty acid distillate derived renewable diesel

This study aims to quantify life-cycle fossil energy use and greenhouse gas (GHG) emissions for palm fatty acid distillate (PFAD) derived renewable diesel (RD) taking into consideration different feedstock classifications that are applicable to PFAD (residue, byproduct, or coproduct), and incorporating updated data for key processes. Under the three classifications, the PFAD to RD pathway was modeled using the Greenhouse gases, Regulated Emissions, and Energy Use in Technologies (GREET®) model. PFAD-derived RD could reduce fossil energy consumption by 77%–88%, relative to petroleum diesel. GHG emissions are very sensitive to PFAD classification and coproduct handling methods. Considering the production of palm oil and PFAD and economic value, we maintain that PFAD should be treated as a byproduct in palm oil refineries. With this treatment, PFAD-derived RD could achieve 84% GHG emissions reductions, compared to the emissions of petroleum diesel. We also employed a substitution method to address the substitution of PFAD by other materials in the marketplace. Compared to coproduct allocation results, we found substituting PFAD by tallow, soy oil, barley, and canola oil results in lower GHG emissions. Due to high induced land-use change emissions associated with palm farming, if PFAD is treated as a coproduct with refined palm oil, PFAD-derived RD may not deliver GHG reductions. A sensitivity analysis identified key parameters such as palm fruit yield, oil extraction efficiency in oil mills, and energy use intensity for RD production affects LCA results significantly; future efforts to improve these parameters could result in further GHG reductions.

09 BIOMASS FUELS↗

A Hybrid Pathway to Biojet Fuel via 2,3-Butanediol

Production of biomass-derived sustainable alternative jet fuels (SAJF) has been considered as an important approach to decarbonize the aviation industry but still possesses various challenges in technology advancement, particularly in achieving high carbon efficiency. Here we report a hybrid pathway to SAJF from 2,3-butanediol (2,3-BDO), integrating biologically converting biomass to 2,3-BDO with catalytically upgrading of 2,3-BDO to jet-range hydrocarbons. This pathway is demonstrated to have a high carbon recovery to liquid hydrocarbons from corn stover (25–28%) (74–82% of the theoretical maximum efficiency). The catalytic conversion steps involve 2,3-BDO to C3+ olefins, oligomerization, and hydrogenation where the first two steps are the focus of this study. Under optimum reaction conditions (523 K, 115 kPa, 1.0 h-1 weight hourly space velocity), 2,3-BDO conversion and C3+ olefin selectivity are >97% and 94–98% during 40 h time on stream, respectively. To demonstrate the adaptability of this technology with bio-derived 2,3-BDO, we also investigated the impact of water and other organic coproducts (acetoin and acetic acid) inherited from the fermentation broth on the catalyst performance and product selectivities. We have shown that the catalyst can handle a significant amount of water in the liquid feed (40 wt% water/60 wt% 2,3-BDO) and maintain catalyst stability for ~40 h. Acetoin can be converted to similar C3+ olefins as 2,3-BDO with complete conversion of acetoin. Co-feeding 10 wt% acetoin with 2,3-BDO is found to have no impact on 2,3-BDO conversion, C3+ olefin selectivity, and catalyst stability. The utilization of organic coproduct like acetoin can help to improve overall carbon conversion efficiency when using real biomass-derived 2,3-BDO. On the other hand, the presence of 10 wt% acetic acid is shown to drastically inhibit methyl ethyl ketone (MEK) hydrogenation and butene oligomerization as revealed by the increased MEK and butene selectivities, implying the importance of separating organic acids when feeding bio-derived 2,3-BDO. The formed C3–C6 olefins from 2,3-BDO are further oligomerized over Amberlyst-36 catalyst to longer-chain hydrocarbons with >70 wt% jet-range hydrocarbons including predominantly iso-olefins/iso-paraffins. The overall carbon efficiency for the jet-range hydrocarbons is 19–22%, exceeding most of the reported biojet pathways, which makes it a promising approach for SAJF production.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗