Sustainability Assessment for Energy Systems and Chemical Process Industries

Sustainability has become an important factor in the chemical process and energy industries with a strong drive for process improvements towards more environmentally conscious solutions. However, there are many ways of defining sustainability and even more ways of trying to determine how sustainable a process is. This work looks into applying a conjunction of tools including; process simulation, multi-criteria decision matrices and life-cycle assessment to more quantitatively determine sustainability metrics. We have applied these tools for the production of electricity, methanol and dimethyl ether. A novel method of electricity production, in chemical looping combustion (CLC), was used that inherently involves carbon dioxide capture. Experimental work was conducted for two different oxygen carriers, CaSO4 and CuO, using thermogravimetric analysis (TGA). Process simulations were developed for both coal and natural gas (NG) feedstocks to produce power and heat. Sustainability metrics were developed based on simulated data showing electricity prices of 23.7 ¢/kWhr (NG) and 7.8 ¢/kWhr (coal) while reducing CO2 emissions 0.38 (NG) and 3.38 (coal) metric ton/MWhr electricity. Renewable methanol production was also simulated in Aspen Plus. This process used wind based electrolytic hydrogen and captured CO2 as feedstocks. This work presents a multi-criteria decision matrix for the inclusion of sustainability metrics alongside economic indicators in feasibility analysis. A comparison of renewable methanol to NG based methanol using this matrix shows that the renewable process is feasible. We continued this work to conduct a full (cradle-to-grave) life-cycle assessment of alternative fuels based on this renewable methanol and its conversion to dimethyl ether. Using renewable methanol as a fuel reduces greenhouse gas emissions 86% and fossil fuel use by 91% compared to conventional gasoline. Using dimethyl ether reduces greenhouse gas emissions 80% and fossil fuel use 81% when compared to ultra-low sulfur diesel. This whole work focuses on developing sustainability metrics helps identify a quantified measure of sustainability that can be used along economic indicators in a multi-criteria decision matrix for a better and comprehensive feasibility evaluation of energy systems and chemical processes. Advisor: Yaşar Demire

Methanol and dimethyl ether from renewable hydrogen and carbon dioxide: Alternative fuels production and life-cycle assessment

In this work we investigate two renewably based alternative fuels; methanol and dimethyl ether. The ultimate feedstocks for production are wind-based electrolytic hydrogen and carbon dioxide captured from an ethanol fermentation process. Dimethyl ether production was modeled in ASPEN Plus using a previously simulated methanol production facility. The facilities use 18.6 metric tons (mt) of H2 and 138.4 mt CO2 per day. Methanol is produced at a rate 96.7 mt/day (99.5 wt%) and dimethyl ether is produced at a rate of 68.5 mt/day (99.6 wt%). A full comparative life-cycle assessment (cradle-to-grave) of both fuels was conducted to investigate their feasibility and sustainability. Renewable methanol and dimethyl ether results were independently compared and this renewable process was also compared to conventional production routes. Results show that production of dimethyl ether impacts the environment more than methanol production. However the combustion of methanol fuel evens out many of the emissions metrics compared to dimethyl ether. The largest environmental impact was found to be related to the fuel production stage for both fuels. Both biofuels were shown to be comparable to biomass-based gasification fuel production routes. Methanol and dimethyl ether from CO2 hydrogenation were shown outperform conventional petroleum based fuels, reducing greenhouse gas emissions 82–86%, minimizing other criteria pollutants (SOx, NOx, etc.) and reducing fossil fuel depletion by 82–91%. The inclusion of environmental impacts in feasibility analyses is of great importance in order to improve sustainable living practices. The results found here highlight the favorable feasibility of renewably produced methanol and dimethyl ether as alternative fuels

Methanol and dimethyl ether from renewable hydrogen and carbon dioxide: Alternative fuels production and life-cycle assessment

In this work we investigate two renewably based alternative fuels; methanol and dimethyl ether. The ultimate feedstocks for production are wind-based electrolytic hydrogen and carbon dioxide captured from an ethanol fermentation process. Dimethyl ether production was modeled in ASPEN Plus using a previously simulated methanol production facility. The facilities use 18.6 metric tons (mt) of H2 and 138.4 mt CO2 per day. Methanol is produced at a rate 96.7 mt/day (99.5 wt%) and dimethyl ether is produced at a rate of 68.5 mt/day (99.6 wt%). A full comparative life-cycle assessment (cradle-to-grave) of both fuels was conducted to investigate their feasibility and sustainability. Renewable methanol and dimethyl ether results were independently compared and this renewable process was also compared to conventional production routes. Results show that production of dimethyl ether impacts the environment more than methanol production. However the combustion of methanol fuel evens out many of the emissions metrics compared to dimethyl ether. The largest environmental impact was found to be related to the fuel production stage for both fuels. Both biofuels were shown to be comparable to biomass-based gasification fuel production routes. Methanol and dimethyl ether from CO2 hydrogenation were shown outperform conventional petroleum based fuels, reducing greenhouse gas emissions 82–86%, minimizing other criteria pollutants (SOx, NOx, etc.) and reducing fossil fuel depletion by 82–91%. The inclusion of environmental impacts in feasibility analyses is of great importance in order to improve sustainable living practices. The results found here highlight the favorable feasibility of renewably produced methanol and dimethyl ether as alternative fuels

Chemical storage of wind energy by renewable methanol production: Feasibility analysis using a multi-criteria decision matrix

This study is for the technoeconomic analysis of an integral facility consisting of wind energy-based electrolytic hydrogen production, bioethanol-based carbon dioxide capture and compression, and direct methanol synthesis. ASPEN Plus was used to simulate the facility producing 97.01 mt (metric tons) methanol/day using 138.37 mt CO2/day and 18.56 mt H2/day. A discounted cash flow diagram for the integral facility is used for the economic analysis at various hydrogen production costs and methanol selling prices. The feasibility analysis is based on a multi-criteria decision matrix consisting of economic and sustainability indicators comparing renewable and non-renewable methanol productions. The overall energy efficiency for the renewable methanol is around 58%. Fixation of carbon reduces the CO2 equivalent emission by around –1.05 CO2e/kg methanol. The electrolytic hydrogen production cost is the largest contributor to the economics of the integral facility. The feasibility analysis based on multi-criteria shows that renewable methanol production may be feasible

Use of natural ores as oxygen carriers in chemical looping combustion: A review

Chemical looping combustion (CLC) has gained considerable ground in energy production due to its inherent carbon capture with a minimal energy penalty. The choice of metal oxide used as an oxygen carrier (OC) in CLC has a substantial weight on the overall efficiency of energy production as well as the ultimate cost per MW. While much work has gone into manufacturing synthetic OCs with high fuel conversions, harsh operating conditions and process limitations cause some unavoidable loss of the oxygen carrier. With low production costs and minimal conditioning required, natural ores have grown in interest as cheap alternative oxygen carriers. This work provides a substantial literature review of recent works studying the use of natural ores in CLC. Iron-based, manganese-based, copper-based and calcium based ores were found to be the main ores researched, along with mixtures of these ores and natural ores with minor additional compounds. Typical parameters have been collected for each study including; fuel conversion, stability, physical characteristics, and carbon capture efficiency. Natural ores are compared with purified metal oxides to highlight strengths and weaknesses of each ore and recommendations for future studies are made

The roles of pyroxenite and peridotite in the mantle sources of oceanic basalts

Subduction of oceanic crust generates chemical and lithological heterogeneities in the mantle. An outstanding question is the extent to which these heterogeneities contribute to subsequent magmas generated by mantle melting, but the answer differs depending on the geochemical behaviour of the elements under investigation: analyses of incompatible elements (those that preferentially concentrate into silicate melts) suggest that recycled oceanic crust is an important contributor, whereas analyses of compatible elements (those that concentrate in crystalline residues) generally suggest it is not. Recently, however, the concentrations of Mn and Ni—two elements of varying compatibility—in early-crystallizing olivines, have been used to infer that erupted magmas are mixtures of partial melts of olivine-rich mantle rocks (that is, peridotite) and of metasomatic pyroxene-rich mantle rocks (that is, pyroxenite) formed by interaction between partial melts of recycled oceanic crust and peridotite. Here, we test whether melting of peridotite alone can explain the observed trend in olivine compositions by combining new experimental data on the partitioning of Mn between olivine and silicate melt under conditions relevant to basalt petrogenesis with earlier results on Ni partitioning. We show that the observed olivine compositions are consistent with melts of fertile peridotite at various pressures—importantly, melts from metasomatic pyroxenites are not required. Thus, although recycled materials may well be present in the mantle source regions of some basalts, the Mn and Ni data can be explained without such a contribution. Furthermore, the success of modelling the Mn–Ni contents of olivine phenocrysts as low-pressure crystallization products of partial melts of peridotite over a range of pressures implies a simple new approach for constraining depths of mantle melting

Laser-plasma weapons-effects-simulation progress report

The present goal of the Laser-Plasma Weapons-Effects-Simulation Program is the study of the conversion of laser radiation to x-radiation. The purpose is ultimately to make an intense pulsed source of x-rays to be useful in simulation programs. The requirement of a large conversion efficiency (from Laser to x-radiation) is important in order to minimize the energy requirements, size, and expense of the laser system

Cellular Ser/Thr-Kinase Assays Using Generic Peptide Substrates

High-throughput cellular profiling has successfully stimulated early drug discovery pipelines by facilitating targeted as well as opportunistic lead finding, hit annotation and SAR analysis. While automation-friendly universal assay formats exist to address most established drug target classes like GPCRs, NHRs, ion channels or Tyr-kinases, no such cellular assay technology is currently enabling an equally broad and rapid interrogation of the Ser/Thr-kinase space. Here we present the foundation of an emerging cellular Ser/Thr-kinase platform that involves a) coexpression of targeted kinases with promiscuous peptide substrates and b) quantification of intracellular substrate phosphorylation by homogeneous TR-FRET. Proof-of-concept data is provided for cellular AKT, B-RAF and CamK2δ assays. Importantly, comparable activity profiles were found for well characterized B-Raf inhibitors in TR-FRET assays relying on either promiscuous peptide substrates or a MEK1(WT) protein substrate respectively. Moreover, IC50-values correlated strongly between cellular TR-FRET assays and a gold standard Ba/F3 proliferation assay for B-Raf activity. Finally, we expanded our initial assay panel by screening a kinase-focused cDNA library and identified starting points for >20 cellular Ser/Thr-kinase assays

Understanding the degradation of methylenediammonium and its role in phase-stabilizing formamidinium lead triiodide

Formamidinium lead triiodide (FAPbI3) is the leading candidate for single-junction metal–halide perovskite photovoltaics, despite the metastability of this phase. To enhance its ambient-phase stability and produce world-record photovoltaic efficiencies, methylenediammonium dichloride (MDACl2) has been used as an additive in FAPbI3. MDA2+ has been reported as incorporated into the perovskite lattice alongside Cl–. However, the precise function and role of MDA2+ remain uncertain. Here, we grow FAPbI3 single crystals from a solution containing MDACl2 (FAPbI3-M). We demonstrate that FAPbI3-M crystals are stable against transformation to the photoinactive δ-phase for more than one year under ambient conditions. Critically, we reveal that MDA2+ is not the direct cause of the enhanced material stability. Instead, MDA2+ degrades rapidly to produce ammonium and methaniminium, which subsequently oligomerizes to yield hexamethylenetetramine (HMTA). FAPbI3 crystals grown from a solution containing HMTA (FAPbI3-H) replicate the enhanced α-phase stability of FAPbI3-M. However, we further determine that HMTA is unstable in the perovskite precursor solution, where reaction with FA+ is possible, leading instead to the formation of tetrahydrotriazinium (THTZ-H+). By a combination of liquid- and solid-state NMR techniques, we show that THTZ-H+ is selectively incorporated into the bulk of both FAPbI3-M and FAPbI3-H at ∼0.5 mol % and infer that this addition is responsible for the improved α-phase stability

The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions

During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequence