Pilot Plant Results Research Articles

Development of a rate-based model for CO2 absorption using aqueous NH3 in a packed column

A rigorous rate-based model for CO2 absorption using aqueous ammonia in a packed column has been developed and used to simulate results from a recent pilot plant trial of an aqueous ammonia-based post-combustion capture process at the Munmorah Power Station, New South Wales, Australia. The model is based on the RateSep module, a rate-based absorption and stripping unit operation model in Aspen Plus, and uses the available thermodynamic, kinetic and transport property models for the NH3–CO2–H2O system to predict the performance of CO2 capture. The thermodynamic and transport property models satisfactorily predict experimental results from the published literature. The modelling results from the rate-based model also agree reasonably well with pilot plant results, including CO2 absorption rate, NH3 loss rate, temperature profiles and mass transfer coefficients in the absorber. To gain insights into absorption performance, we used the rate-based model to analyse the species concentration profile, temperature profile, mass transfer rate and coefficient in the gas and liquid bulk phase along the packing height.

Simulation of solar chimney power plant with an external heat source

Solar chimney power plant is a sustainable source of power production. The key parameter to increase the system power output is to increase its size but the plant cannot operate during night hours. This study deals with simulation work to validate results of pilot plant at Manzanares and include the effects of waste heat from a gas turbine power plant in the system. The effects show continuous night operation, a 38.8 percent increase in power at 1000 W/m2 global solar irradiation at daytime and 1.14 percent increase in overall efficiency.

Experimental analysis of hydroquinone used as phase change material (PCM) to be applied in solar cooling refrigeration

This present paper is focused on the study of high temperature thermal energy storage (TES) using phase change materials (PCM) to be applied on cooling and refrigeration systems by solar cooling. Thus, a pilot plant with a working temperature range between 150 and 200 °C was designed and built at the University of Lleida (Spain). Hydroquinone was selected for the specific application from different PCM candidates as the most suitable material after a literature review and a differential scanning calorimetry (DSC) analysis. This PCM has a phase change temperature range between 166 °C and 173 °C and a melting enthalpy of 225 kJ kg−1. Two storage configurations were evaluated using the same PCM to have preliminary results before the final storage tank design. From the pilot plant results and experience, a 5 Tn PCM storage tank was designed and built to work in a real solar cooling installation in Seville (Spain).

Design and start-up experiences of 19,000 m3/d Camp de Tarragona-Vilaseca Water Reclamation Plant

Within the current and future world’s water scarcity, the reuse of treated waste water for specific applications offers an appealing alternative to conventional fresh water sources that cannot meet the expectations, mostly in terms of quantity. Spain is no exception to this global situation, with a constantly increasing population, in combination with growing water demand for applications such as production industry, exportation oriented agriculture, tourism development, and booming construction, access to sufficient quantities of fresh water is currently a rising concern. Camp de Tarragona (ACA) Water Reclamation Project is a prime example how water scarcity can be solved regionally by reclaiming water that would otherwise be discharged to the sea. The new reclamation plant treats municipal secondary effluent from Tarragona and Salou/Vilaseca Wastewater Treatment Plants to supply process water for the petrochemical industry of Tarragona. The plant capacity is currently 19,000 m3/d (Phase I), and further expansions are planned for increases up to 29,000 m3/d (Phase II) and even to 55,000 m3/d (Phase III) in the coming years. This additional supply would replace the water currently taken from the Ebro River, thus releasing this volume for drinking water supply to the population. Utilizing such a process, the industrial growth in water scarce regions can be supported and industry sustainability is increased further. A pipeline connects the two different Wastewater Treatment Plants (WWTPs), 10 km apart from each other, and feeds secondary treated effluent to the reverse osmosis (RO) pretreatment process. The pretreatment consists of ballasted flocculation, followed by disc filtration, sand filtration, and multimedia filtration prior feeding it to the two pass RO system. Final permeate treatment is done by UV light and chlorine disinfection, prior releasing water to the distribution system. This paper will review the detailed design of the plant, as a scale-up of pilot plant results, as well as the RO membranes performance data obtained during the start-up of the installation. RO performance is evaluated in detail taking into account the performance differences when different combinations of raw water sources were used. This paper will also explain in detail the preservation of the installation by means of 5-Chloro-2-Methyl-2H-Isothiazol-3-one/2-Methyl-2HIsothiazol-3-one (CMIT/MIT), during a medium term stop of the plant.

Pilot Plant Results with Piperazine

Concentrated (40wt %) piperazine (PZ) with two-stage flash regeneration is an advanced second generation amine-based process for CO2 capture. Two pilot campaigns with the two-stage flash process were completed in 2011 and successfully demonstrated high temperature stripping at 150°C with concentrated piperazine. Data reconciliation for the absorber with intercooling return spray was completed using Aspen Plus® Data-Fit. Data reconciliation for the two-stage flash with warm rich bypass was completed using Aspen Plus® Data-Fit and a dynamic model developed in MATLAB®. The results of data reconciliation analysis found that the CO2 loading in the lean and rich streams needed to be systematically shifted upward, 4.6–4.7% in the stripper analysis and 7.5% in the absorber analysis.An analysis of the October 2011 campaign pilot plant data identified the two configurations with the lowest equivalent work as the high temperature two-stage flash with warm rich bypass and low pressure simple stripper. The calculated equivalent work for the two-stage flash with warm rich bypass from raw pilot plant data and reconciled pilot plant data is approximately 35kJ/mol CO2 and 36.6kJ/mol CO2, respectively. Intercooling with a spray return improved absorber CO2 removal performance by 6–7% at the lower gas rates and was found to be equivalent to a 7– 20% increase in packing height based on reconciled data results. Warm rich bypass to the low pressure flash tank reduced piperazine volatility by factor of two in the condensate. In addition, analysis of the pilot plant piperazine inventory at the end of the campaign identified the following degradation products (mmol/kg): N-formyl PZ (1.3), ethylenediamine (13), aminoethylpiperazine (3.6), Hydroxyethylpiperazine (3.9), formate (1.0), and N-nitroso- piperazine (0.09). The solvent analysis also found that the CO2 capacity has decreased by 17%, with a slight decrease in CO2 absorption rate and heat of vaporization.

Pilot Plant Results with Three Different Types of UV Lamps for Advanced Oxidation

Three different types of ultraviolet lamps were tested for the advanced oxidation process application on pre-treated surface water in a pilot plant. The pilot setup consisted of three parallel reactors with either medium pressure, low pressure or dielectric barrier discharge UV lamps. Four model compounds (atrazine, bromacil, ibuprofen and N-nitroso-dimethylamine (NDMA)) and 0, 5 or 10 ppm hydrogen peroxide were dosed. Low pressure lamps were shown to have the lowest energy demand, calculated as electrical energy per order, followed by dielectric barrier discharge lamps and then medium pressure lamps. Medium pressure lamps gave the highest formation of genotoxic activity and nitrite formation, whereas no formation of genotoxic activity was observed for either of the other lamp types.

Modeling and Simulation of CO2 Capture Process for Coal- based Power Plant Using Amine Solvent in South Korea

The interest in carbon capture technology is continuously rising since worldwide climate-change problems have intensified the concern regarding efficient removal of carbon dioxide. Amine-based capture technology is a conventional technology to remove carbon dioxide in natural gas processing, and also can be used for carbon dioxide removal from flue gas in coal-based power plants. In particular, monoethanolamine is a conventional commercial absorbent to remove carbon dioxide and considered as a standard amine absorbent. Due to the high non-ideality of amine, rate-based models have been suggested to describe absorption and desorption of amine absorbent. However, most suggested models were validated against large-scale pilot plant results, and there were few models to consider both absorber and stripper with rate-based model. In this study, we applied two rate-based models introduced by previous literature to the actual pilot plant operation data in 0.1MW-scale Boryeong pilot plant, South Korea and developed a modified model with increased accuracy. The developed model showed good agreements with pilot plant results for both absorber and stripper. However, under low liquid-to-vapor ratio operation with high rich loading value, all model showed worse estimations.

Measurement of Grain Size of Hot-rolled Steel Sheets Using Laser-Based ultrasonics

The relationship between grain size of hot-rolled steel sheet and ultrasonic attenuation coefficient has been evaluated in laboarory and pilot plant using laser-based ultrasonic technology. For the measurement of ultrasonics in pilot plant, the Fabry-Perot interferometer was optimized to increase the signal to noise ratio. Also, the efficiency of ultrasonic generation using multiple laser pulses was evaluated experimentally for generation of ultrasonics in slightly ablative condition. The prototype measurement system was installed in pilot rolling plant and ultrasonic signals were measured during hot-rolling process. According to the results of laboratory and pilot plant, possibility of on-line measurement of grain size of hot-rolled steel sheet in production line has been confirmed.

Principles of an enhanced MBR-process with mechanical cleaning

Up to date, different physical and chemical cleaning protocols are necessary to limit membrane fouling in membrane bioreactors. This paper deals with a mechanical cleaning process, which aims at the avoidance of hypochlorite and other critical chemicals in MBR with submerged flat sheet modules. The process basically consists of the addition of plastic particles into the loop circulation within submerged membrane modules. Investigations of two pilot plants are presented: Pilot plant 1 is equipped with a 10 m(2) membrane module and operated with a translucent model suspension; pilot plant 2 is equipped with four 50 m(2) membrane modules and operated with pretreated sewage. Results of pilot plant 1 show that the establishment of a fluidised bed with regular particle distribution is possible for a variety of particles. Particles with maximum densities of 1.05 g/cm(3) and between 3 and 5 mm diameter form a stable fluidised bed almost regardless of activated sludge concentration, viscosity and reactor geometry. Particles with densities between 1.05 g/cm(3) and 1.2 g/cm(3) form a stable fluidised bed, if the velocity at the reactor bottom is sufficiently high. Activities within pilot plant 2 focused on plant optimisation and the development of an adequate particle retention system.

Post-combustion Capture of CO2: Results from the Solvent Absorption Capture Plant at Hazelwood Power Station Using Potassium Carbonate Solvent

Post-combustion capture of CO2 from flue gas generated in a 1600 MW brown-coal-fired power station has been demonstrated using a solvent absorption process. The plant, located at International Power’s Hazelwood power station in Victoria’s Latrobe Valley, was designed to capture up to 25 tons/day of CO2 (expandable to 50 tons/day of CO2). The design of the capture plant was based on a proprietary solvent (BASF PuraTreat F). The main focus of this work, however, is to describe the performance of the plant using an unpromoted 30 wt % potassium carbonate (K2CO3) solution. The CO2-capture plant was successfully operated using both BASF PuratTreat F and K2CO3, during which performance data were collected and analyzed. Although the plant only absorbed 20–25% of CO2 from the flue gas when using the potassium carbonate solvent, valuable operating data were collected, which enabled process simulations to be compared to real plant data. Aspen Plus software was used to predict the performance of the plant while operating with potassium carbonate. In general, the model shows a slight difference (within ±5%) compared to the pilot-plant results. This benchmarked model is an important part of the ongoing development of novel precipitating potassium carbonate processes for large-scale post-combustion CO2 capture.

Kinetics of Carbon Dioxide Absorption into Aqueous Amino Acid Salt: Potassium Salt of Sarcosine Solution

The kinetics of CO2 absorption into an unloaded aqueous solution of the potassium salt of sarcosine (KSAR) was studied using a string-of-disks contactor for the concentration range of 1.0–4.0 kmol m–3 and temperatures of 25–62 °C. The zwitterion and termolecular mechanisms were reinterpreted to account for nonidealities in salt systems due to the effect of ionic strength through the introduction of an ionic factor, kion. Both models adequately represent the experimental data with no practical difference. The reaction rate constant for KSAR is high but comparable to values for amines. It increases considerably with temperature and concentration. The reaction order varies with KSAR concentration from 1.25 to 1.81, with an overall average value of 1.58. The experimentally derived kinetic model was combined with a thermodynamic model of aqueous KSAR from Aronu et al. (Chem. Eng. Sci. 2011, 66, 2191−2198) to predict the loading dependency of the overall mass-transfer coefficient, KG, determined in pilot-plant experiment. The predicted results show that the experimental data agree well with the pilot-plant results.

Pilot plant study of post-combustion carbon dioxide capture by reactive absorption: Methodology, comparison of different structured packings, and comprehensive results for monoethanolamine

Post-combustion carbon capture (PCC) from fossil fuel power plants by reactive absorption can substantially contribute to reduce emissions of the greenhouse gas CO 2. To test new solvents for this purpose small pilot plants are used. The present paper describes results of comprehensive studies of the standard PCC solvent MEA (0.3 g/g monoethanolamine in water) in a pilot plant in which the closed cycle of absorption/desorption process is continuously operated (column diameters: 0.125 m, absorber/desorber packing height: 4.25/2.55 m, packing type: Sulzer BX 500, flue gas flow: 30–110 kg/h, CO 2 partial pressure: 35–135 mbar). The data establish a base line for comparisons with new solvents tested in the pilot plant and can be used for a validation of models of the PCC process with MEA. The ratio of the solvent to the flue gas mass flow is systematically varied at constant CO 2 removal rate, and CO 2 partial pressure in the flue gas. Optimal operating points are determined. In the present study the structured packing Sulzer BX 500 is used. The experiments with the removal rate variation are carried out so that the results can directly be compared to those from a previous study in the same plant that was carried out using Sulzer Mellapak 250.Y. A strategy for identifying the influence of absorption kinetics on the results is proposed, which is based on a variation of the gas load at a constant L/ G ratio and provides valuable insight on the transferability of pilot plant results.

Technology and pilot plant results of the advanced amine process

The development of CO2 capture technologies is being pursued by US, European, Japanese and other suppliers in collaboration with utility companies, universities and Governments in the USA, Europe, Canada and Australia. Among the more promising post-combustion solutions is the Advanced Amine Process (AAP), jointly developed by Alstom and The Dow Chemical Company (Dow). This paper describes the AAP pilot plant located at a Dow-owned site in South Charleston, West Virginia, USA. It provides an update on how the experience from the pilot plant is used to improve the design and predicted performance of large-scale demonstration plants. It will summarize pilot plant results and show the progress of the technology development. The pilot plant is processing flue gas from a bituminous coal-fired boiler with UCARSOLTM FGC 3000 series of solvents, advanced amine solvents specifically developed by Dow for flue gas applications. The pilot plant has a CO2 removal capacity of ∼5 tonne CO2/day and can capture in excess of 90% of inlet CO2. A test program with a wide range of operating conditions provides information on capture performance, including solvent and operational stability. A state-of-the-art laboratory measures solvent composition, CO2 loading, solvent contamination and degradation species. Long term solvent composition is controlled by a combination of flue gas pre-treatment and solvent reclamation. These results are being used to develop a large-scale demonstration plant (above 250 MWe) under the EU Flagship program in Europe.

Modeling pilot plant results for CO2 capture by aqueous piperazine

Abstract Concentrated aqueous piperazine has been proposed as a possible evolutionary step from monoethanolamine (MEA) as a solvent for post-combustion capture. High concentration piperazine (>5 m) has volatility similar to MEA but provides CO 2 absorption rate and capacity that is almost double that of 7 m MEA. It is also more resistant to oxidative and thermal degradation and can be used up to 150 °C. In order demonstrate these benefits a one month pilot plant campaign was conducted in November 2008 at The University of Texas at Austin with 5 m, 8 m and 9 m PZ. An absorber model for concentrated PZ was developed in Aspen Plus ® RateSep™. The model was validated with the pilot plant results and served to assess the quality of the pilot plant data using the reconciliation tool in Aspen Plus ® . The model simulates the temperature profile of the absorber. Loadings are matched within 0.03 and the deviation of the removal fraction is no more than 0.03. The absorber model was used to study intercooling and determine optimum conditions for its implementation. Based on pilot plant data and model results 90% CO 2 removal can be achieved with 8 m piperazine, 9 meters of packing, and intercooling with a loading shift from 0.32 (lean) to 0.39 (rich) mol CO 2 /mol alkalinity and steam heat rate in the stripper of 148 kJ/mol CO 2 and an equivalent work of 33.6 kJ/mol CO 2

Extra colour removal in a refinery

The main factor affecting the raw sugar refining process is certainly “colour”. The higher colour removal, the higher is the obtained sugar yield. Therefore, colour removal is the main goal throughout the process. In a conventional sugar refinery colour is removed in the purification and decolorisation steps – the second one is normally done using ion-exchange resins – but there are some other ways of colour removal such as adding some colour removing agents (powdered carbon, sodium bisulphite, PCC [precipitated calcium carbonate]). In this article the pilot plant results of experiments of increasing colour removal in the refining process are described, such as PCC addition, 3rd carbonatation (re-purification), hydrogen peroxide addition, powdered carbon addition, sodium bisulphite addition and crystallization improvements. The good results achieved in some of these trials led to perform some industrial trials, the results of wich are summarized in this article as well.

Evaluation of Various Mechanical Pulping Processes for Mature and Juvenile Loblolly Pine in Lightweight Coated Paper

Although loblolly pine (Pinus taeda) is less costly than northern softwoods, loblolly pine mechanical pulps tend to be of poor quality and are mainly used in low-value grades such as newsprint. We evaluated various mechanical pulping processes for mature and juvenile loblolly pine and their potential for use in value-added grades, especially in lightweight coated (LWC) paper. Results for black spruce were also included for comparison purposes. Pilot plant results have shown that loblolly pine is inferior to spruce in terms of sheet density, brightness ceiling, and long fiber coarseness. To some extent, the quality disadvantages of pine pulps could be offset by proper chemi-cal pre-treatment, high specific-energy application, or both, in the pulping process. With proper chemical pretreat-ment or refining, all the loblolly pine mechanical pulps should have adequate strength and light-scattering ability for LWC and supercalendered grades, compared with the general requirements reported in the literature. However, paper containing pine mechanical pulp is rougher on the surface, less dense, and has higher air permeability than the paper with spruce mechanical pulp. Therefore, proper papermaking strategies, such as precalendering, are essential to reduce sheet surface roughness and pore size before coating. This was confirmed by a LWC dynamic sheet former (DSF) sheet study that used three selected loblolly pine mechanical pulps.

Towards the Industrial Solar Carbothermal Production of Zinc

Based on the experimental results of a 300kW solar chemical pilot plant for the production of zinc by carbothermal reduction of ZnO, we performed a conceptual design of a 5MW demonstration plant and of a 30MW commercial plant. Zinc can be used as a fuel for zinc-air batteries and fuel cells, or it can be reacted with water to form high-purity hydrogen. In either case, the chemical product is ZnO, which in turn is solar recycled to zinc. The proposed thermochemical process provides an energy efficient route for the conversion, storage, and transportation of solar energy in the form of solar fuels.

Protective coatings for the graphite facing in calcium–aluminothermal processes

Results of pilot plant and full scale studies on the elaboration of high temperature protective coatings for graphite in the process of the reductive melting of niobium pentoxide and NbAl alloys production are presented. Graphite has found extensive application in high temperature processes due to its unique thermophysical properties. However, in these conditions it r eacts very easily with air oxygen, liquid metals, oxides, and fluorides. As a result, porous graphite gets impregnated with liquid metal; besides, carbonization of melt and formation of a layer of metal carbides on graphite surf ace takes place. The layer of metal carbides has a low adhesion with graphite and a major part of them is transferred to the melt. The graphite facing of a furnace is quickly destructed. To avoid these harmful processes, special plasma sprayed protective coatings are used. In this work various coatings ( l2 3, l2 3·CaO, ZrO2, NbC, l2 3 + Nb, ZrO2 + Nb, NbC + Nb, Nb) were tested in pilot plant and industrial conditions. It was established that the best durability of the pr otective coating on graphite can be achieved in the case of it s three- layer composition: Nb (0.07 mm) + NbC (0.4 mm) + Nb (0.3 mm). After industrial melting of 500-2000 kg ingots about 80% of this coating on the belt of the shaft furnace had preserved. Plasma sprayed protective coatings on the graphite facing extended its operation time, reduced the carbon content in the metal ingots to 0.02% (mass), and slag carbon content to 0.05-0.15% (mass).

Supercritical carbon dioxide fractionation of Lavandin essential oil: Experiments and modeling

The two main components of Lavandin essential oil are linalool and linalyl acetate. These components have different applications in the food and fragrance industry, and also for producing natural herbicides and insecticides in the case of linalool. Thus there is a commercial interest in the separation of the essential oil into linalool- and linalyl acetate-rich fractions. This work presents a study of this fractionation using supercritical CO 2 in a continuous operating high-pressure counter-current packed column. The influence of process parameters like flowrate, pressure and temperature has been determined. The separation is limited by the low gas load achieved, and it has been observed that in order to increase the load, high temperatures and CO 2/oil phase ratios were necessary with operating pressures close to the mixture critical point. Additionally, a detailed mathematical model of the fractionation column has been developed and validated with the pilot plant results. This model has been used to study the operation with conditions that exceed the capabilities of the pilot plant such as a higher CO 2/oil phase ratio or a longer fractionation column, and to propose the optimum conditions for this fractionation.

Pilot-plant results of the electro-Fenton treatment of olive mill wastewaters followed by anaerobic digestion

In this work, we investigated an integrated technology for the treatment of the recalcitrant contaminants of olive mill wastewaters (OMW), allowing water recovery and reuse for agricultural purposes. The method involves an electrochemical pre-treatment step of the wastewater using the electro-Fenton reaction followed by an anaerobic bio-treatment. The electro-Fenton pre-treatment process removed 66% of the total polyphenolic compounds and subsequently decreased the OMW toxicity from 100 to 66.9%, which resulted in improving the performance of the anaerobic digestion. A continuous laboratory-scale methanogenic reactor was operated at a loading rate of 10g COD/L per day without any apparent toxicity. Furthermore, in the combined process, a high overall reduction in COD, suspended solids, polyphenols and lipids content was achieved by the two successive stages. Moreover, this combined process which was experimented at a real scale (25 m3 digester) demonstrated its technical feasibility and opens promising perspectives for industrial application in the Mediterranean countries because of its easy conception and high energy (methane) production.