SBIR-STTR Award

Over the past decade, the growth of unconventional oil and gas has resulted in discovery and availability of vast quantities of natural gas across the United States. In many regions, lack or deficit of adequate infrastructure results in gas being stranded, or, in case of oil-associated gas, wastefully vented or flared, needlessly contributing to GHG emissions and global warming. Although manufacturing sector as a whole benefitted from lower energy costs, the effect on the chemical industry remained relatively small. The chemical industry is one of the largest energy-consuming sub-sectors of the manufacturing industry in the U.S. The bulk of the energy consumption and corresponding GHG emissions (as much as 2% of GHG emissions worldwide) is associated with production of many intermediate compounds, such as ethylene, which are used as the basis for a wide range of other chemicals and many industrial and consumer products. Low-cost unconventional gas has enabled use of ethane, a cheaper ethylene feedstock, which accounts for 3%-5% (10% in associated gas) of the natural gas stream. However, energy consumption is not altered, while the bulk of natural gas stream, methane, remains underutilized by the chemical industry. Practical and cost-effective technologies for conversion of methane into petrochemicals, liquid fuels, and materials in distributed, small-scale, low-cost plants with reduced or eliminated greenhouse gas footprint, have the potential to materially change the structure of the chemical industry and significantly reduce its greenhouse footprint. It’s proposed that fluidized catalytic bed of carbon and/or metal-based catalysts can be used to facilitate the rapid and selective conversion of methane to ethylene with a thermal efficiency >65%. The proposed study will develop a proof-of-concept microwave-enhanced catalytic fluidized bed reactor to facilitate the non-equilibrium plasma activation of methane. This reactor will be used to evaluate the selectivity and efficiency of direct methane conversion over various catalytic materials and the role of mild oxidants as a means to improve the stability of methane conversion to ethylene. Experimental testing combined with plasma diagnostics will enable Phase II development of a refined and industrially representative microwave fluidized bed reactor for the direct and efficient conversion of methane to value-added chemicals. Phases I and II will lead to subsequent deployment of a demonstration 1-3 ton/day pilot ethylene conversion plant within the next 2-4 years, and an industrial 60,000 ton/year ethylene conversion plant within 7 years.

With the discovery of vast quantities of natural gas in shale formations in the U.S. comes the opportunity to convert this gas into value-added chemicals. Practical and cost-effective conversion technologies are needed to more wisely, cleanly (without CO2 production or water consumption) and efficiently use natural gas. As the capital cost of state-of-the art chemical plants continues to grow, smaller distributed modular plants that can be deployed closer to rural gas fields offer economic advantages. Advanced conversion concepts are especially needed to utilize "economically stranded" gas associated with oil production which is wastefully and harmfully flared. These challenges will be addressed by utilizing a novel non-thermal (microwave) plasma process to convert methane into industrial chemicals such as ethylene, acetylene, and others with virtually zero process CO2 emissions, no water consumption, high methane conversion yield, high selectivity, and lower capital costs than existing state of the art. Phase I demonstrated rapid, continuous, direct (single-step) conversion of methane to acetylene, hydrogen, and carbon, as well as the ability to catalytically hydrogenate and/or polymerize acetylene to higher hydrocarbons including C3s and C4s in an integrated reactor stage without the need for extra hydrogen. This electrically-powered process has low bulk temperatures, proceeds at ambient pressures, emits zero CO2, and can be powered by renewable electricity. The process can target different stream compositions via a change of parameters (e.g. energy inputs, gas flows, compositions, mixing patterns, residence times, and specific reactor configuration). Co-production of high-value, premium carbon products (including graphene platelets) has been demonstrated with clear economic and process advantages over existing state of the art. In the first 6 months of Phase II, a skid-mounted pilot system will be designed and built to evaluate process parameters for industrial scale-up. The system will integrate a modular microwave reactor system without microwave plasma containment (already demonstrated during Phase I) with adequately sized and powered microwave and process gas inputs. In the following 9 months, extensive testing will (i) evaluate key process parameters such as energy efficiency and product yields across a range of conditions and (ii) demonstrate the stability of the process in an industrially relevant setting. Finally, conceptual designs and techno-economics will be developed for several commercial scales, including a next scale demonstration system targeting platform chemicals and premium carbons. The pilot will support future studies and feasibility tests, and will be capable of commercial carbon production at 2 metric ton/year capacity. With lower-energy requirements than conventional thermal plasmas, reactions in microwave plasmas are driven by electron kinetics rather than thermodynamics, and their non-uniform, non-equilibrium energy distributions allow reaction pathways that are unavailable with conventional chemical or thermal plasma processes. Microwave plasmas also offer reaction intensification that enables reductions in system costs and the production of smaller, portable, modular, reactor systems that can produce industrial chemicals and premium carbons directly from natural gas with less capital and infrastructure expenditure than state of the art. This process could also displace the GHG-intensive ethane and/or naphtha-cracking and steam-methane reforming processes for industrial production of ethylene, hydrogen, and other chemicals.