John Groppo - Academia.edu (original) (raw)

Papers by John Groppo

Materials

The leaching of Cu in ammoniacal solutions has proven an efficient method to recover Cu from wast... more The leaching of Cu in ammoniacal solutions has proven an efficient method to recover Cu from waste printed circuit boards (WPCBs) that has used by many researchers over the last two decades. This study investigates the feasibility of a counter-current leaching circuit that would be coupled with an electrowinning (EW) cell. To accomplish this objective, the paper is divided into three parts. In Part 1, a leaching kinetic framework is developed from a set of experiments that were designed and conducted using end-of-life waste RAM chips as feed sources and Cu(II)-ammoniacal solution as the lixiviant. Various processing parameters, such as particle size, stirring rates, initial Cu(II) concentrations, and temperatures, were evaluated for their effects on the Cu recovery and the leaching rate. It was found that the particle size and initial Cu(II) concentration were the two most important factors in Cu leaching. Using a 1.2 mm particle size diameter and 40 g/L of initial Cu(II) concentrat...

Carbon, 1995

Mass spectrometric studies have shown that contact-arc vaporization of polytetrafluoroethylene-co... more Mass spectrometric studies have shown that contact-arc vaporization of polytetrafluoroethylene-containing graphite rods leads to the formation of mainly trifluoromethylated [60]-fullerenes of the general formula C,(CF,),H,, where n = l-8 and m = O-9. Similar results were achieved by using sodium trifluoroacetate/graphite composite rods.

$Research paper thumbnail of Beneficial Reuse of Industrial CO\u3csub\u3e2\u3c/sub\u3e Emissions Using a Microalgae Photobioreactor: Waste Heat Utilization Assessment$

Microalgae are a potential means of recycling CO2 from industrial point sources. With this in min... more Microalgae are a potential means of recycling CO2 from industrial point sources. With this in mind, a novel photobioreactor (PBR) was designed and deployed at a coal-fired power plant. To ascertain the feasibility of using waste heat from the power plant to heat algae cultures during cold periods, two heat transfer models were constructed to quantify PBR cooling times. The first, which was based on tabulated data, material properties and the physical orientation of the PBR tubes, yielded a range of heat transfer coefficients of 19–64 W m−2 K−1 for the PBR at wind speeds of 1–10 m s−1. The second model was based on data collected from the PBR and gave an overall heat transfer coefficient of 24.8 W m−2 K−1. Energy penalties associated with waste heat utilization were found to incur an 18%–103% increase in energy consumption, resulting in a 22%–70% reduction in CO2 capture for the scenarios considered. A techno-economic analysis showed that the cost of heat integration equipment increa...

Minerals

Four suites of fly ash, all generated at the same power plant, were selected for the study of the... more Four suites of fly ash, all generated at the same power plant, were selected for the study of the distribution of rare earth elements (REE). The fly ashes represented two runs of single‐seam/single‐mine coals and two runs of run‐of‐mine coals representing several coal seams from several mines. Plots of the upper continental crust‐normalized REE, other parameters derived from the normalization, and the principal components analysis of the derived REE parameters (including the sum of the lanthanides plus yttrium and the ratio of the light to heavy REE) all demonstrated that the relatively rare earth‐rich Fire Clay coal‐derived fly ashes have a different REE distribution, with a greater concentration of REE with a relative dominance of the heavy REE, than the other fly ashes. Particularly with the Fire Clay coal‐derived fly ashes, there is a systematic partitioning of the overall amount and distribution of the REE in the passage from the mechanical fly ash collection through to the las...

$Research paper thumbnail of Gadolinium enrichment in association with the magnetic fraction of fly ash: Real or an illusion?$

Coal Combustion and Gasification Products

Gadolinium, and possibly praseodymium, are relatively enriched in the magnetic fractions of Class... more Gadolinium, and possibly praseodymium, are relatively enriched in the magnetic fractions of Class F fly ashes from Central Appalachian coal sources. Although the enrichment is evident in the inductively coupled plasma–atomic emission spectroscopy (ICP-AES) determinations of the rare earth content, transmission electron microscopy–energy dispersive x-ray spectroscopy (TEM-EDS) examination of the fly ash fails to show the sites of the Gd or Pr. This apparent lack of correlation could be due to the inability of the EDS to detect low concentrations of the rare earth elements definitively; interferences in the analytics, leading to false positives in the chemical analysis; or the overlap of the energies of Gd and/or Pr with more abundant elements, leading to inaccurate negative results.

$Research paper thumbnail of Capture and Recycle of Industrial CO\\u3csub\\u3e2\\u3c/sub\\u3e Emissions Using Mircoalgae$

A novel cyclic flow photobioreactor (PBR) for the capture and recycle of CO2 using microalgae was... more A novel cyclic flow photobioreactor (PBR) for the capture and recycle of CO2 using microalgae was designed and deployed at a coal-fired power plant (Duke Energy’s East Bend Station). The PBR was operated continuously during the period May–September 2015, during which algae productivity of typically 0.1–0.2 g/(L day) was obtained. Maximum CO2 capture efficiency was achieved during peak sunlight hours, the largest recorded CO2 emission reduction corresponding to a value of 81 % (using a sparge time of 5 s/min). On average, CO2 capture efficiency during daylight hours was 44 %. The PBR at East Bend Station also served as a secondary scrubber for NOx and SOx, removing on average 41.5 % of the NOx and 100 % of the SOx from the flue gas. The effect of solar availability and self-shading on a rudimentary digital model of the cyclic flow PBR was examined using Autodesk Ecotect Analysis software. Initial results suggest that this is a promising tool for the optimization of PBR layout with re...

$Research paper thumbnail of CO\u3csub\u3e2\u3c/sub\u3e Recycling Using Microalgae for the Production of Fuels$

CO2 capture and recycle using microalgae was demonstrated at a coal-fired power plant (Duke Energ... more CO2 capture and recycle using microalgae was demonstrated at a coal-fired power plant (Duke Energy’s East Bend Station, Kentucky). Using an in-house designed closed loop, vertical tube photobioreactor, Scenedesmus acutus was cultured using flue gas as the CO2 source. Algae productivity of 39 g/(m2 day) in June–July was achieved at significant scale (18,000 L), while average daily productivity slightly in excess of 10 g/(m2 day) was demonstrated in the month of December. A protocol for low-cost algae harvesting and dewatering was developed, and the conversion of algal lipids—extracted from the harvested biomass—to diesel-range hydrocarbons via catalytic deoxygenation was demonstrated. Assuming an amortization period of 10 years, calculations suggest that the current cost of capturing and recycling CO2 using this approach will fall close to $1,600/ton CO2, the main expense corresponding to the capital cost of the photobioreactor system and the associated installation cost. From this i...

2012 ASEE Annual Conference & Exposition Proceedings

Transactions of the ASABE, 2017

International Journal of Coal Preparation and Utilization, 2015

Previous research indicates that coal and coal by-products are a potential source of critical ele... more Previous research indicates that coal and coal by-products are a potential source of critical elements including rare earth elements (REE) with estimated amounts in the range of 50 million metric tons. Despite the proven presence of elevated REE concentrations, commercial extraction and recovery have not been realized. This article provides a review of the abundance, mode of occurrence, and recovery methods of rare earth elements in coal and coal by-products. The feasibility of using established REE extraction and recovery technologies is discussed along with issues associated with their use with coal resources.

Fuel and Energy Abstracts, 1996

Composition, Geochemistry and Conversion of Oil Shales, 1995

Physical beneficiation has frequently been proposed as a method for upgrading oil shale feedstock... more Physical beneficiation has frequently been proposed as a method for upgrading oil shale feedstocks in order to improve the economic feasibility of exploiting these resources to produce synthetic fuels. Oil shales typically contain four to six times as much ash-forming minerals as oil-forming kerogen; hence large amounts of inorganic material need to be processed along with the kerogen during retorting which increases the subsequent problems of waste disposal and management. The reduction of inorganic material prior to retorting offers the attractive alternative of reducing the capital and operating costs.

Minerals Engineering, 1993

Coal Min. Process.;(United States), 1986

... Subject, 01 COAL, LIGNITE, AND PEAT; COAL FINES; FLOTATION; ASH CONTENT; ASHES; BUBBLES; CLAY... more ... Subject, 01 COAL, LIGNITE, AND PEAT; COAL FINES; FLOTATION; ASH CONTENT; ASHES; BUBBLES; CLAYS; COAL; COAL PREPARATION; COPPER; COUNTER CURRENT; GRAPHITE;MOLYBDENUM; PARTICLE SIZE; STORAGE FACILITIES; WATER; CARBON ...

Minerals, 2015

Certain Central Appalachian coals, most notably the Fire Clay coal with a REY-enriched volcanic a... more Certain Central Appalachian coals, most notably the Fire Clay coal with a REY-enriched volcanic ash fall tonstein, are known to be enriched in rare earth elements. The Fire Clay tonstein has a greater contribution to the total coal + parting REY than would be inferred from its thickness, accounting for about 20%-35% of the REY in the coal + parting sequence. Underground mining, in particular, might include roof and floor rock and the within-seam partings in the mined product. Beneficiation, necessary to meet utility specifications, will remove some of the REY from the delivered product. In at least one previously published example, even though the tonstein was not present in the Fire Clay coal, the coal was enriched in REY. In this case, as well as mines that ship run-of-mine products to the utility, the shipped REY content should be virtually the same as for the mined coal. At the power plant, however, the delivered coal will be pulverized, generally accompanied by the elimination of some of the harder rock, before it is fired into the boiler. Overall, there are a wide range of variables between the geologic sample at the mine and the power plant, any or all of which could impact the concentration of REY or other critical materials in the coal combustion products.

209/164' 166' 459; 106/405' DIG' 1' 705 A method for improving the poZZolanic character of ?y ash... more 209/164' 166' 459; 106/405' DIG' 1' 705 A method for improving the poZZolanic character of ?y ash [56] References Cited includes the steps of ?rst hydrauhcally classifying and then ?otation separating the ?y ash in order to reduce particle size [)3 PATENT DOCUMENTS distribution and remove carbon. The method also includes the steps of spiral concentrating separated coarse particles to recover iron, pyrite and marcasite and screening the ?y ash to remove ultra-light carbon and plant debris.