Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Olefins”

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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Systems Analysis Approach to Polyethylene Terephthalate and Olefin Plastics Supply Chains in the Circular Economy: A Review of Data Sets and Models

The environmental and economic impacts of implementing a circular economy in plastic waste supply chains are not well understood. The proposed systems analysis framework assesses environmental, social, and economic impacts of plastic waste supply chains in a circular economy. The first objective of this article is to identify datasets, models and knowledge gaps associated with waste plastic supply chain processes, mainly in the U.S. Our literature review indicated that the best datasets exist for virgin plastic resin production, mechanical recycling, landfilling, and incineration, with materials recovery facility being intermediate, and with chemical recycling the lowest. The second objective of this article is to develop an illustrative application of the framework by conducting a preliminary systems analysis of PET bottles with closed-loop recycling. Here, the preliminary systems analysis of PET bottles utilized a linear programming optimization method. Our optimization model indicated that both chemical and mechanical recycling processes are needed to achieve a true circular economy of PET bottles with the least greenhouse gas emissions, specifically reductions of 24% when compared with the linear economy. Good quality and standardized life cycle assessment and techno-economic analysis studies are needed to better understand the environmental, economic, and social impacts of advanced sorting and chemical recycling technologies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Cyclic(alkyl)(amino)carbene ruthenium complexes for Z -stereoselective (asymmetric) olefin metathesis

The first Z-stereoselective catechodithiolate ruthenium complexes containing cyclic(alkyl)(amino)carbene ligands are reported. Isolated in nearly quantitative yields or in situ generated, these catalysts demonstrated remarkable Z selectivity (Z/E ratio up to >98/2) in ring-opening metathesis polymerization (ROMP), ring-opening-cross metathesis (ROCM) and cross-metathesis (CM). Thanks to the efficient chiral HPLC resolution of racemic CAAC-complex precursors, optically pure dithiolated complexes were also synthesized allowing to produce enantioenriched Z-ROCM products in >99/1 Z/E with good levels of enantioselectivity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Hydroselenation of olefins: elucidating the β-selenium effect

We report a light-promoted hydroselenation of alkenes with high anti -Markovnikov selectivity. Blue light activates an aryl diselenide to generate a seleno radical with subsequent addition into an alkene to form a β-seleno carbon radical. Hydrogen atom transfer (HAT) from the selenol to the carbon radical generates the linear selenide with high selectivity in preference to the branched isomer. These studies reveal a unique β-selenium effect, where a selenide β to a carbon radical imparts high anti -selectivity for radical addition through delocalization of the HAT transition state.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Direct conversion of Light Hydrocarbons to Olefins (Final report)

Reaction35 is developing a new industrial process that is substantially different from the traditional standalone dehydrogenation process practiced in industry such as Oleflex® and Catofin®. Those processes have substantial energy consumption and loss of feed constraints. The Reaction35 process is based on using molecular bromine to activate the alkane (e.g., nbutane) by forming highly reactive butyl bromides. The butyl bromides are easily converted to nbutylenes (final product) and hydrogen bromide. The hydrogen bromide generated in bromination and dehydrobromination is oxidized with air, recovering the molecular bromine which is reused. The overall result is a process with a favorably low energy consumption and less than 1 % overall loss of feed compared to more than 5 % for the direct dehydrogenation processes. During the grant period, several important aspects of the technology have been developed further. The major effort was the hydrogenation catalyst step development. The hydrogenation catalyst is used for recovery of the polybromobutanes to the bromobutanes intermediates. The scientific field regarding dibromo- and polybromoalkanes has not been extensively studied, which necessitated that Reaction35 performs a full study of a number of catalysts and the various experimental conditions that influence the hydrogenation reaction. Currently, Reaction35 has completed its catalyst selection and preliminary experimental parameters optimization. This will allow for the construction of an engineering model for a pilot unit testing.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Cyclic Olefin Copolymer based Alkaline Exchange Polymers and Reinforced Membranes

In this project, a team of researchers from Rensselaer Polytechnic Institute developed high performance, low-cost alkaline conductors which can improve efficiency and lower cost of energy storage and conversion technology. The Rensselaer Polytechnic Institute team has developed a highly ion conductive, chemically stable, and mechanically durable alkaline membrane materials. Such membranes will serve as a critical component in electrochemical devices when energy is generated from renewable sources (e.g., sun and wind) or hydrogen fuel. The use of alkaline membrane in electrochemical reactions allows us to replace expensive platinum catalysts with less expensive, earth abundant metals as catalysts, offering huge economic advantages in renewable energy technology.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2025

Understanding and Developing Dual-Wavelength Olefin Metathesis Polymerizations for the Rapid, Continuous Additive Manufacturing of High-Performance Thermosets

This report details the goals, approach, results, and future needs of a three-year Laboratory Directed Research and Development project funded by Sandia’s Materials Science Research Foundation. In this project, we established basic principles and mechanistic understanding of orthogonal or sequential chemistries for fabricating multi-material or robust materials. We developed numerous additive manufacturing, or 3D-printing, techniques including volumetric solid-state printing, dual-wavelength printing, and lithographic regulation of polymer crystallinity. We leveraged these new printing motifs to expand upon what is possible with manufacturing to give bespoke optical and mechanical performance. Moreover, we discovered new techniques for depolymerization enabling recovery of pristine carbon-fiber and high value electronics under moderate conditions.

36 MATERIALS SCIENCE↗
DOE OSTI2022

A 100+ RON Gasoline Blendstock for High Efficiency, Low Emission Vehicles Engines - CRADA 493 (Final Report)

This study aimed at demonstrating production of a 100+RON gasoline fraction from a linear olefins feedstock to help improve further the viability and flexibility of the Pacific Northwest National Laboratory/ LanzaTech alcohol-to-jet (ATJ) patented process that converts ethanol from LanzaTech’s syngas fermentation process to low aromatic jet-range iso-paraffins. To achieve a high RON gasoline and ultimately a 100+RON, the technical approach consisted of converting the linear olefins into an iso-olefins rich mixture and then oligomerizing the iso-olefins rich mixture into high RON compounds in a single bed loaded with an acid catalyst that allows conversion at low reaction temperature. Three families of acid catalysts labeled as type A, B and C were investigated for the single-bed conversion of linear olefins into high RON gasoline range compounds. The effects of the nature of the catalyst, acid sites concentration and operating conditions were investigated. Fuel properties measurements and engine testing were conducted for the most promising catalyst. For type A catalysts, we demonstrated that the conversion increases with the increase of the Brönsted acid site concentration and that lower reaction temperature favors the formation of desired highly branched compounds. The highest dRON obtained with type A catalyst was equal to 94 (from NMR and IQT). Type B catalysts appear very effective for producing dimethyl-olefins compounds when operating at low reaction temperature (i.e., < 100°C). The highest dRON obtained with type B catalyst was equal to 92. The results suggest that type B catalysts are less favorable to internal conversion of linear olefins into iso-olefins compared to type A catalysts which leads to the formation of a gasoline blendstock with a lower dRON. A Type C catalyst that is less commonly used for production of gasoline range compounds from linear olefins was investigated due to its ability to favor conversion of linear olefins into iso-olefins. Compared to type A and type B catalyst, type C favors the formation of highly branched compounds (i.e., with 3+ methyl groups) in the gasoline range. Indeed, a gasoline blendstock containing about 33 wt.% of highly branched compounds was produced with type C catalyst while maintaining a high linear olefins conversion (i.e., 70%). A large quantity of this gasoline blendstock was produced and fuel properties measurements including engine testing for Research Octane Number (RON), Motor Octane Number (MON) and octane sensitivity (S) were conducted. A high RON = 97, MON = 82.7, S =14.3, AKI = 90 and HoV = 334.1kJ/kg were measured. While a RON of 100 was not achieved, the fuel properties of the gasoline blendstock are very acceptable as compared to current premium gasoline. Overall, these results highlight the potential for producing a high RON/ premium gasoline blendstock starting from a linear olefins feedstock.

02 PETROLEUM↗
DOE OSTI2020

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↗