RAPID Funded Projects

Metal halide salts such as magnesium chloride have been demonstrated to be promising candidates for ammonia storage materials to enable applications such as intermittent energy storage, and distributed fertilizer production. Ammonia exiting a synthesis reactor can be separated from nitrogen and hydrogen by absorption into magnesium chloride. Compared with ammonia condensation seen in large-scale Haber-Bosch processes, ammonia absorption enables more complete separation at temperatures closer to the synthesis reactor, which can realize capital and energy savings that are necessary for cost-competitive distributed-scale modularization of ammonia production. This team has already fabricated a 1 kg/day modular synthesis protoype, funded by ARPA-E, being used to study this absorption process in a UMN exsisting wind-to-ammonia facility in western Minnesota. The project team has shown, in a preliminary techno-economic analysis (TEA), that absorption can offer competitive economics at small scale ammonia production relevant for distributed modular operations. Work with RAPID will include optimization and modeling of the prototype over a useful and relevant range of absorption cycling conditions - most importantly, the uptake and regeneration temperatures. The improved validated models provided by this optimized prototype will support better novel design, future optimization, and provide a step to safe and efficient further scaleup to commercial modular metric tonne per day capcities in the future. Additionally, longer-term testing with the protoype will be performed to produce useful stability and de-risking data.

Throughout the petrochemical and refining industry, the separation of olefins and paraffins is generally performed via distillation, a costly and capital intensive method, particularly for light olefins. This project uses a silver-incorporated custom amorphous fluoropolymer membrane to separate olefins and paraffins. Compared to previous attempts using facilitated transport membranes, this membrane has been shown to have very good longevity in laboratory settings and has been tested with reasonably-expected process poisons. The objective of this project is to gain a better understanding of the membrane performance in realistic operating conditions through both real world testing and fundamental modelling of the membrane system. It targets the case of integrating a membrane module in a process to recover propylene from propane in a polymerization reactor purge stream, with the propylene recycled to the reactor.

Ethane can represent up to 20 vol.% of shale-gas, exceeding the 10 vol. % allowed in “pipeline-quality” natural gas. Each year, over 210 million barrels (liquid equivalent) of ethane are rejected in the lower 48 states. Upgrading low- to negative-value ethane to easily transportable liquid fuels is a promising solution to this supply glut. The key to this process is development of modular systems that can operate economically at stranded sites. Conventional gas-to-liquids (GTL) technologies face significant challenges such as high capital cost and limited efficiency. This project will develop a fundamentally improved modular ethane-to-liquids (M-ETL) concept. The proposed M-ETL technology uses a modular Chemical Looping-Oxidative Dehydrogenation (CL-ODH) system to convert ethane and natural gas liquids (NGLs) efficiently into olefins (primarily ethylene) via cyclic redox reactions of highly-effective redox catalyst particles. The resulting olefins are converted to gasoline and mid-distillate products via oligomerization. The proposed project will also advance the M-ETL technology to make it ready for full-scale demonstration. A pilot-scale testbed will be designed and constructed for CL-ODH demonstration. The reactor channels of the testbed will be at a scale comparable to those of the proposed modular system.

This project will demonstrate conversion of a large-volume chemical commodities process from batch to continuous processing. It is focused to create an order of magnitude reduction in equipment size (and associated capital cost) by transitioning the traditionally batch production of dispersants, specifically succinimide dispersants, into a continuous process. Succinimide dispersants are a relatively large volume family of products that vary by molecular weight, and structure. Application and adoption of intensified, continuous processing principles offers the prospect of revolutionizing their manufacture. The project will look to establish a firm kinetic understanding of the proposed chemistry and to develop reactor modeling tools so that reaction and mass transfer requirements can be balanced while minimizing system volume, ultimately leading to construction and demonstration of an industrial pilot plant. Successful demonstration of a batch to continuous process at previously unrealized scales could open the door for a broader shift to continuous processing in the fine/ specialty chemical industries.

Ethane can represent up to 20 vol.% of shale-gas, exceeding the 10 vol. % allowed in “pipeline-quality” natural gas. Each year, over 210 million barrels (liquid equivalent) of ethane are rejected in the lower 48 states. Upgrading low- to negative-value ethane to easily transportable liquid fuels is a promising solution to this supply glut. The key to this process is development of modular systems that can operate economically at stranded sites. Conventional gas-to-liquids (GTL) technologies face significant challenges such as high capital cost and limited efficiency. This project will develop a fundamentally improved modular ethane-to-liquids (M-ETL) concept. The proposed M-ETL technology uses a modular Chemical Looping-Oxidative Dehydrogenation (CL-ODH) system to convert ethane and natural gas liquids (NGLs) efficiently into olefins (primarily ethylene) via cyclic redox reactions of highly-effective redox catalyst particles. The resulting olefins are converted to gasoline and mid-distillate products via oligomerization. The proposed project will also advance the M-ETL technology to make it ready for full-scale demonstration. A pilot-scale testbed will be designed and constructed for CL-ODH demonstration. The reactor channels of the testbed will be at a scale comparable to those of the proposed modular system.

The current approach to p-xylene production includes an isomerization step that gives a nearly equilibrium distribution of mixed xylenes, followed by a separate step to recover p-xylene, then recycling of p-xylene depleted product for further isomerization. This project aims to develop and validate para-xylene ultra-selective zeolite membranes and integrate them with an appropriately designed isomerization catalyst in a membrane reactor to accomplish selective para-xylene production. A successful membrane reactor will increase the yield of para-xylene beyond the limits of equilibrium by selectively removing para-xylene from the reactor as it is produced. Increased productivity and reduced separation energy, capital intensity, and greenhouse gas emissions are the key drivers for developing such an approach. Recent breakthroughs introduced by the University of Minnesota for the synthesis of zeolite membranes using ultrathin zeolite crystals (2-dimensional zeolites and zeolite nanosheets) enabled unprecedented mixture separation factors for para-xylene over its isomers (up to 10,000). This ultra-selective performance has been validated by measurements at ExxonMobil Research and Engineering Company and membranes are currently being tested at temperatures, compositions and pressures relevant to membrane reactor operation.

A significant portion of commodity products are manufactured in large facilities that operate at steady state. In many ways, the traditional chemical industry has reached a plateau in terms of productivity and energy efficiency in such facilities. Improvements based on existing technologies and unit operations are mostly incremental and unable to address fundamental transport limitations that drive process efficiency. Process intensification, largely based on reducing transport and transfer limitations, has the potential to take bulk and specialty chemical production to new levels of economic efficiency. However, process intensification has thus far largely focused on the redesign of process hardware, requiring significant capital investments to realize benefits. This project looks to use modeling and optimization to define PI opportunities in existing hardware. In particular, it takes a general look at dynamically forcing a process to take advantage of non-linear systems responses. In certain cases, this mode of operation can deliver significant improvements in performance. The goal of the project is to provide a general theoretical framework for dynamic intensification, as well as using divided wall column operation as a test case to practice dynamic intensification at the pilot scale.