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Ammonia (NH3) production is of global concern for today's food supply security and as future energy vector. Plasma technology can add to supply‐chain resilience of fertilizer production and improve the environmental profile using renewable energy; allowing distributed NH3 production. With the objective to provide process intensification of small‐capacity reactors for local supply, a novel micropyramid‐disk plasma reactor operated in micro‐arc mode was developed. NH3 was synthesized from N2, nitrogen, and H2, hydrogen over Ru/MCM‐41 catalyst at atmospheric pressure. The microplasma brings plasma and catalyst surface close together and intensifies the electric field. The arc plasma elevates temperature, 'nonthermal', releasing high‐energy free electrons, known to be effective in converting low‐reactive molecules. The study demonstrates that microplasma, with reduced electrode‐to‐electrode dimensions and a microstructured reaction environment, enhances the performance of the NH3 synthesis and opens novel process windows. This is detailed on the impact of feed ratio (N2/H2), applied voltage, frequency, electrode gap, and the flow distribution by which the gas is fed in. Optical emission spectroscopy (OES) was used to identify vibrationally and other excited species generated by the microplasma and confirms the catalyst is in symbiosis with the radicals. [ABSTRACT FROM AUTHOR]

Turning carbon dioxide (CO2) into fuels and chemicals using chemical, photochemical, electrochemical, and enzymatic methods could be used to recycle large quantities of carbon. The enzymatic method, which is inspired by cellular CO2 metabolism, has attracted considerable attention for efficient CO2 conversion due to improved selectivity and yields under mild reaction conditions. In this review, the research progress of green and potent enzymatic conversion of CO2 into useful fuels and chemicals was discussed. Furthermore, applications of the enzymatic conversion of CO2 to assist in CO2 capture and sequestration were highlighted. A summary including the industrial applications, barriers, and some perspectives on the research and development of the enzymatic approach to convert CO2 were introduced. [ABSTRACT FROM AUTHOR]

Thethermally coupled distillation sequence (TCDS) has attractedincreasing interest in a range of chemical processes because of itspotential energy and capital cost savings in multicomponent separations.In addition, the TCDS has attracted particular attention in retrofitprojects because of its lower energy requirements compared to theexisting conventional column sequence, easy design, and small modification.This, however, can create a bottleneck in the column. The main aimof this study was to identify bottlenecks in a retrofitted TCDS systematicallyusing a hydraulic performance indicator and fractional utilizationof area (FUA), and to propose a novel strategy for the use of a sidereboiler or a side condenser for debottlenecking of the column. Apractical method using the response surface methodology (RSM) is proposedfor TCDS design and optimization. The optimum TCDS structure can beobserved in a practical manner while minimizing the simulation runs.The use of a side reboiler or a side condenser in a retrofitted TCDScould debottleneck the column and increase the process capacity. Thiscan reduce the temperature difference between the top and side reboilerlocation, or between the bottom and side condenser location, whichhas potential use as a heat pump by utilizing the heat from the topvapor stream or side vapor stream, respectively. The column grandcomposite curve (CGCC) was used to indicate the thermodynamic feasibilityof the implementation of the heat pump system into the TCDS. The resultsshowed that the operating cost could be reduced dramatically throughnovel combinations of internal and external heat integration, suchas TCDS using a top vapor recompression heat pump. [ABSTRACT FROM AUTHOR]

ABSTRACT The depropanizing, debutanizing, and deisobutanizing fractionation steps of processing natural gas liquids were improved through studying complex distillation arrangements, including the double prefractionator arrangement (DPA), the double dividing wall column (DDWC) arrangement, and the Agrawal arrangement. The DPA and DDWC arrangements were obtained from an initial conventional column sequence, and both offer benefits by decreasing reboiler and condenser power consumption. Reducing the number of columns and their diameters in the DDWC arrangement can potentially reduce construction costs. Inter-reboiling of the bottom section of the second dividing wall column improved the performance of the DDWC. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents the different process schemes used for known NGL recovery methods with respect to their economic performance. The original turbo-expander (ISS) was considered as base case plant. The GSP, CRR and RSV process schemes focus on improvement at the top of the demethanizer column. The IPSI-1 and IPSI-2 schemes focus on the bottom of the demethanizer column. All the process schemes were initially built using Aspen HYSYS with a common set of operating criteria. Numerous simulation runs were made by taking various typical feed compositions classified as lean and rich. The economic assessment for each process scheme was later made by considering the capital cost, operating cost and profitability analysis. Results showed that the IPSI-1 process scheme gives the best economic performance with lowest TAC and payback time compared to the other process schemes. On the other hand, the RSV process gives higher TAC and payback time compared to others. [ABSTRACT FROM AUTHOR]