Pilot Plant Results Research Articles

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 lab-scale methanogenic reactor was operated at a loading rate of 10 g COD/L 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 due to its easy conception and its high energy (methane) production.

Coupling solar photo-Fenton and biotreatment at industrial scale: Main results of a demonstration plant

This paper reports on the combined solar photo-Fenton/biological treatment of an industrial effluent (initial total organic carbon, TOC, around 500 mg L −1) containing a non-biodegradable organic substance (α-methylphenylglycine at 500 mg L −1), focusing on pilot plant tests performed for design of an industrial plant, the design itself and the plant layout. Pilot plant tests have demonstrated that biodegradability enhancement is closely related to disappearance of the parent compound, for which a certain illumination time and hydrogen peroxide consumption are required, working at pH 2.8 and adding Fe 2+ = 20 mg L −1. Based on pilot plant results, an industrial plant with 100 m 2 of CPC collectors for a 250 L/h treatment capacity has been designed. The solar system discharges the wastewater (WW) pre-treated by photo-Fenton into a biotreatment based on an immobilized biomass reactor. First, results of the industrial plant are also presented, demonstrating that it is able to treat up to 500 L h −1 at an average solar ultraviolet radiation of 22.9 W m −2, under the same conditions (pH, hydrogen peroxide consumption) tested in the pilot plant.

TREATMENT OF AN ETHYLENE PLANT WASTE WATER WITH A MEMBRANE BIOREACTOR: SUMMARY OF PILOT PLANT RESULTS IN THE FACE OF VARIABLE WASTE WATER CONDITIONS

TREATMENT OF AN ETHYLENE PLANT WASTE WATER WITH A MEMBRANE BIOREACTOR: SUMMARY OF PILOT PLANT RESULTS IN THE FACE OF VARIABLE WASTE WATER CONDITIONSA major chemical company has planned an expansion of their Singapore operations. A new waste water treatment plant (WWTP) is included in the planned project, and the company is evaluating options for improving the technology in terms of reliability, effluent quality, and reuse opportunities.The company was looking for a biological process that was robust in terms of effluent quality in the face of...Author(s)Robert WentaMichael HowdeshellSourceProceedings of the Water Environment FederationSubjectSession 65: Industrial Applications of Membrane BioreactorsDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2007ISSN1938-6478SICI1938-6478(20070101)2007:13L.5132;1-DOI10.2175/193864707787969342Volume / Issue2007 / 13Content sourceWEFTECFirst / last page(s)5132 - 5144Copyright2007Word count175

Solid State Nitriding of High and Medium Carbon Ferromanganese

The ferromanganese industry suffers from the accumulation of great amounts of high and medium carbon ferromanganese fines resulting during crushing of the alloy. These fines represent a problem due to the difficulty of their marketing with the consequence of a bad economic effect on the production process. In this study, bench and pilot plant experiments were carried out to investigate the process of nitriding of high carbon and medium carbon ferromanganese fines (−3 mm) in the solid state condition at a temperature range of 750-1050 °C using different pressures of nitrogen gas.A nitrogen content of 0.37 to 1.32% (by weight) was obtained when nitriding high carbon ferromanganese. Nitriding of medium carbon ferromanganese has successfully produced ferromanganese alloy with 2.2% carbon and 6.2% nitrogen at a pressure of 10 bar nitrogen mixed with 2 bar hydrogen pressure at 950 °C. It was also found that the duration of the nitriding process has a great effect on the nitrogen pickup by the ferroalloy. The maximum content of the nitrogen absorbed was found to depend on the temperature and pressure conditions. The pilot plant results were found to coincide with bench scale ones.

Solid State Nitriding of High and Medium Carbon Ferromanganese

The ferromanganese industry suffers from the accumulation of great amounts of high and medium carbon ferromanganese fines resulting during crushing of the alloy. These fines represent a problem due to the difficulty of their marketing with the consequence of a bad economic effect on the production process. In this study, bench and pilot plant experiments were carried out to investigate the process of nitriding of high carbon and medium carbon ferromanganese fines (−3 mm) in the solid state condition at a temperature range of 750-1050 °C using different pressures of nitrogen gas.A nitrogen content of 0.37 to 1.32% (by weight) was obtained when nitriding high carbon ferromanganese. Nitriding of medium carbon ferromanganese has successfully produced ferromanganese alloy with 2.2% carbon and 6.2% nitrogen at a pressure of 10 bar nitrogen mixed with 2 bar hydrogen pressure at 950 °C. It was also found that the duration of the nitriding process has a great effect on the nitrogen pickup by the ferroalloy. The maximum content of the nitrogen absorbed was found to depend on the temperature and pressure conditions. The pilot plant results were found to coincide with bench scale ones.

Improving FCC Product Distribution with Two-Stage Riser Technology

A novel two-stage riser (TSR) fluid catalytic cracking (FCC) technology was developed. This article summarizes the results of the TSR FCC pilot plant and commercial tests on vacuum gas oils (VGO) and blends of VGO and vacuum resid. Compared with the conventional single-stage riser FCC, the TSR FCC achieves a higher conversion and significantly improves product distribution and quality. The improved process performance of TSR FCC technology is attributed to catalyst relay and subsection reaction. The TSR FCC can also be a process option for debottlenecking the conventional FCC, which increases throughput capacity up to 30%. The theoretical basis and process implications of TSR FCC technology are also discussed.

SOLID STATE NITRIDING OF HIGH AND MEDIUM CARBON FERROMANGANESE

The ferromanganese industry suffers from the accumulation of great amounts of high and medium carbon ferromanganese fines resulting during crushing of the alloy. These fines represent a problem due to the difficulty of their marketing with the consequence of a bad economic effect on the production process. In this study, bench and pilot plant experiments were carried out to investigate the process of nitriding of high carbon and medium carbon ferromanganese fines (−3 mm) in the solid state condition at a temperature range of 750-1050 °C using different pressures of nitrogen gas.A nitrogen content of 0.37 to 1.32% (by weight) was obtained when nitriding high carbon ferromanganese. Nitriding of medium carbon ferromanganese has successfully produced ferromanganese alloy with 2.2% carbon and 6.2% nitrogen at a pressure of 10 bar nitrogen mixed with 2 bar hydrogen pressure at 950 °C. It was also found that the duration of the nitriding process has a great effect on the nitrogen pickup by the ferroalloy. The maximum content of the nitrogen absorbed was found to depend on the temperature and pressure conditions. The pilot plant results were found to coincide with bench scale ones.

Modelling of ladle glaze interactions

A potential source of inclusions in liquid steel is ladle glaze, the slag/inclusion coating on the refractory lining of the ladle which is always present after casting and before reuse of the ladle. The composition and quantity of this glaze can vary considerably, depending on the range of steel qualities being made and, in order to model the effect of glaze on inclusion/top slag formation, a combined fluid flow-thermodynamic model has been developed. The behaviour of ladle glaze for various different steels has been studied under pilot plant conditions and the results incorporated into the mathematical model. The implications of the pilot plant and model results are discussed in the context of the production of clean steel.

Improvements of Ebullated-Bed Technology for Upgrading Heavy Oils

Improvements of Ebullated-Bed Technology for Upgrading Heavy Oils — Residue from heavy crude oils can be upgraded through various existing processes. Among these processes, the catalytic hydroconversion ebullated-bed process (H-Oil) has the unique feature of deeply converting heavy feedstocks with high impurity contents while operating with a long cycle time. This is accomplished through daily on-line catalyst replacement of a small portion of the catalyst bed. The ebullated-bed reactor includes an internal recirculation of the reactor liquid to ebullate the catalyst bed. The paper will present background information on the H-Oil process and discuss some of the recent improvements that have been developed for this technology. A Residence-Time Distribution (RTD) study was conducted using a radiotracer on a new laboratory bench unit of this process. This experiment quantified the reactor hydrodynamics and the liquid holdup. These parameters are critical to insure a safe extrapolation of the pilot plant results. The technology of H-Oil process was improved for heavy feedstocks. A new hot high-pressure separator design, based on R&D studies, has been developed to improve the separation of gas/liquid avoiding excessive liquid carry-over and gas carry-under. The use of this new separator in a commercial H-Oil plant operation at higher feedstock throughput results in improved operation and minimization of operating costs.

A model of post‐combustion and heat transfer at smelting reduction with a foamy slag

A smelting reduction reactor with post‐combustion in a foamy stag has two slag layers. In the lower, iron oxide from the slag is reduced to iron by carbon. In the upper, the gas from the reduction is post‐combusted to CO2+H2O. The post‐combustion heat is transferred from the rising post‐combustion gas to the upper slag, and, therefrom, by slag circulation to the lower slag layer where the endothermic reduction reaction takes place. Unavoidably, slag circulation also transfers part of the char into the upper slag where it is oxidised. A kinetic post‐combustion and heat transfer model describes these phenomena. The main process parameters, namely real post‐combustion degree, carbon oxidation, heat transfer efficiency, distribution of temperatures of gas and slag in the single regions of the reactor, coal consumption, and iron production rate are given as functions of the ratio of post‐combustion oxygen to gas evolution rate of the system. The main influences on which heat efficiency and off‐gas temperature as the most important output parameter depend are discussed. Controlled stirring and a regular gas through‐put are of primary importance. The required values are given. A comparison with pilot plant results of the CSM process shows good agreement with the model results.

The removal of sulfate and metals from mine waters using bacterial sulfate reduction: Pilot plant results

A treatment process that bacterially converts sulfate into elemental sulfur via a hydrogen sulfide intermediate was demonstrated at pilot scale for the treatment of three mine waters that contained metals and sulfate. Ethanol served as the bacterial carbon and energy source. The mine waters were treated at rates that ranged from 50–150 L day−1. Contaminant concentrations up to 13 mg L−1 copper, 0.1 mg L−1 mercury, 0.04 mg L−1 cadmium, 3.5 mg L−1 zinc, 0.68 mg L−1 cobalt, 1.3 mg L−1 nickel, 49 mg L−1 iron, and 63 mg L−1 aluminum were removed to meet water quality effluent limits. Manganese removal was about 80% under normal operating conditions but increased to 96% when the process was optimized for manganese removal. The process was shown to be capable of decreasing sulfate concentrations from 1800 mg L−1 to less than 250 mg L−1, nitrate from 100 mg L−1 to less than 1 mg L−1, arsenic from 8 mg L−1 to less than 0.03 mg L−1, and calcium from 310 mg L−1 to less than 100 mg L−1. Acid mine waters were neutralized using bacterially-generated alkalinity; no external alkalinity source was needed.

97/02001 Ethanol steam reforming in a molten carbonate fuel cell: a thermodynamic approach

Ahlstrom Pyropower, Inc. (API) pioneered the development of atmospheric circulating fluidized bed (ACFB) technology. The sustained success with ACFB and continued research in ACFB systems has led Ahlstrom towards the development of pressurized circulating fluidized bed (PCFB) technology. Since the mid-1980s many components of the PCFB combined cycle power plant were developed. Based on the component development experience, a 10 MWth PCFB pilot plant was built to support the design of commercial size PCFB units.The PCFB pilot plant has operated over 4500 hours since its commissioning in mid 1989. Five types of coals and five types of sorbents have been tested. Emissions and load following performance of the pilot plant have demonstrated that the PCFB performs significantly better than required under the current stringent environmental standards. The sulfur capture has been 95 to 98%; the NOx level with SNCR is less than 25 mg/MJ; the ash generated from the PCFB is less basic than the ash from conventional system.API, under the U.S. Department of Energy's Clean Coal Technology III program, was awarded a contract to build a nominal 80 MWe PCFB combined cycle repowering unit. The unit is scheduled for commissioning in early 1997. API has also performed design studies for larger capacity units in the range of 100 – 400 MWe. These designs include a second generation PCFB technology combined cycle system for the use of high ash coals. The second generation PCFB technology involves partial gasification of coal and the use of the syngas to heat up the PCFB exhaust flue gas to 1300°C at the gas turbine inlet. This paper, in addition to presenting the pilot plant results, summarizes the salient features of PCFB combined cycle plants for various fuels including high ash Indian coals.

Application of pressurized circulating fluidized bed technology for combined cycle power generation

Ahlstrom Pyropower, Inc. (API) pioneered the development of atmospheric circulating fluidized bed (ACFB) technology. The sustained success with ACFB and continued research in ACFB systems has led Ahlstrom towards the development of pressurized circulating fluidized bed (PCFB) technology. Since the mid-1980s many components of the PCFB combined cycle power plant were developed. Based on the component development experience, a 10 MW th PCFB pilot plant was built to support the design of commercial size PCFB units. The PCFB pilot plant has operated over 4500 hours since its commissioning in mid 1989. Five types of coals and five types of sorbents have been tested. Emissions and load following performance of the pilot plant have demonstrated that the PCFB performs significantly better than required under the current stringent environmental standards. The sulfur capture has been 95 to 98%; the NO x level with SNCR is less than 25 mg/MJ; the ash generated from the PCFB is less basic than the ash from conventional system. API, under the U.S. Department of Energy's Clean Coal Technology III program, was awarded a contract to build a nominal 80 MW e PCFB combined cycle repowering unit. The unit is scheduled for commissioning in early 1997. API has also performed design studies for larger capacity units in the range of 100 – 400 MW e. These designs include a second generation PCFB technology combined cycle system for the use of high ash coals. The second generation PCFB technology involves partial gasification of coal and the use of the syngas to heat up the PCFB exhaust flue gas to 1300°C at the gas turbine inlet. This paper, in addition to presenting the pilot plant results, summarizes the salient features of PCFB combined cycle plants for various fuels including high ash Indian coals.

Treatment of landfill gas by gas permeation — pilot plant results and comparison to alternatives

Landfill gas is an interesting source of prime energy since it contains about 50–55 vol.% methane. Utilization, however, must take into account the traces of halogenated hydrocarbons and H 2S, which are present in the gas. The paper reports of 2 years experience with a pilot plant for the production of a gas with natural gas quality. Essentially the process consists of two stages, an adsorption stage for the separation of the trace components and a membrane unit for the separation of CO 2. The process is discussed in detail and compared with alternatives for the utilization of landfill gas such as power generation by gas engines/generator, if desired in combination with a waste heat boiler.

Process for recycling spent potliner and electric arc furnace dust into commercial products using oxygen enrichment

This paper discusses the Enviroscience, Inc (ESI) process for recycling hazardous wastes by extractive metallurgy followed by vitrification of non-reducible metal oxides. In this process, volatile and reducible metals are reclaimed as their respective oxides and elements. Non-reducible metal oxides are converted into a man-made vitreous fiber identical in chemical content to mineral wool fiber known as rock or slag wool. The project discussed here involved aluminum plant and steel plant recycling of potliner and EAF dust into commercial products. Potliner (K088) is produced by primary aluminum plants. The annual waste generation rate is 130,000 tons/year. Electric Arc furnace dust (K061) is produced by 76 steel companies and the annual generation rate is estimated to be 600,000 tons/year. An 18-inch I.D. (pilot plant scale) countercurrent mineral wool type shaft furnace was used in the project. The feed was spent potliner and electric arc furnace dust. The pilot plant results were 1) cyanide consumption as a reductant: 96.89% to 99.55%, 2) fluoride utilization: 69.2% to 89.50%, 3) zinc recovery: 96.54% to 97.76%, 4) cadmium recovery: 99.47% to 99.99%, 5) lead recovery: 97.98% to 99.41%, 6) slag (fiber) recovery: 49.33% to 64.31%, 7) iron recovery: 95.12% to 96.93% in the iron and slag (fiber) products. Oxygen enrichment tests conducted by Airco increased the furnace melt rate by 44.8% and reduced coke consumption (energy use) by 41.4%. No detectable levels of NO 2, N 2O 3, H 2S, SO, or SO 2 were found in limited emissions test. Oxygen enrichment resulted in 66.3% fiber production. Analytical results on the enriched zinc oxide iron and fiber products are comparable to prior tests conducted by Enviroscience. As a result of these tests, extractive metallurgy combined with fiber production (vitrification) has now been proven to be a cost-effective recycle process when compared to thermal treatment, secure landfill disposal or standard HTMR processes. The process provides for the production of commercial products from select inorganic liquid, semi-solid, and solid hazardous wastes.

Treatment of landfill gas by gas permeation — pilot plant results and comparison to alternatives

Landfill gas is an interesting source of prime energy since it contains about 50–55% volume methane. Utilization, however, must take into account the traces of halogenated hydrocarbons and H 2S, which are present in the gas. The paper reports of two years experience with a pilot plant for the production of a gas with natural gas quality. Essentially the process consists of two stages, an adsorption for the separation of the trace components and a membrane unit for the separation of CO 2. The process is discussed in detail and compared with alternatives for the utilization of landfill gas such as power generation by gas engines/generator, eventually in combination with a waste heat boiler.

Treatment of landfill gas by gas permeation: Pilot plant results and comparison with alternative uses

Landfill gas is an interesting source of prime energy since it contains about 50–55 vol% methane. Utilization, however, must take into account the traces of halogenated hydrocarbons and H 2S that are present in the gas. This paper reports two years of experience with a pilot plant for the production of a gas with natural-gas quality. Essentially the process consists of two stages: an adsorption for the separation of the trace components and a membrane unit for the separation of CO 2. The process is discussed in detail and compared with alternatives for the utilization of landfill gas such as power generation by gas-engines with generators, eventually in combination with a waste-heat boiler

Bench–scale evaluation of calcium sorbents for acid gas emission control

AbstractCalcium sorbents for acid gas emission control were evaluated for effectiveness in removing SO2/HCl and SO2/NO from simulated incinerator and boiler flue gases. All tests were conducted in a bench‐scale reactor (fixed‐bed) simulating fabric filter conditions in an acid gas removal process. Reagent grade Ca(OH)2 was used to establish baseline sorbent performance. The reactivity of reagent grade Ca(OH)2 with HCl from SO2/HCl mixtures gradually increased with decreasing approach to saturation temperature. SO2 reactivity toward Ca(OH)2 was very sensitive to approach to saturation. Novel calcium silicate sorbents were tested for reactivity with both SO2 and HCl. A “thermal window” for optimum NO removal was found at 90°C (194°F) when Ca(OH)2 was used at SO2/NO ratios of 1:1. Reactivity of Ca(OH)2 toward SO2 from SO2/NO mixtures was very sensitive to approach to saturation, while reactivity with NO was insensitive. Several additives were subsequently tested to determine optimum sorbent combinations for SO2/NO control. To date the most promising additives are Mg(OH)2 and Na2HPO4 at 10 mol percent concentrations. As with SO2/HCl, calcium silicate has been shown to be superior for SO2/NO capture. Some implications for larger‐scale process configurations and sorbent selection for HCl/SO2/NO control are discussed. Future activities and limited larger–scale pilot plant results are also discussed.

Fluidized Bed Biological Wastewater Treatment: Effects of Scale-Up on System Performance

The operation of a number of small and large scale biological fluidized bed pilot plants over the past ten years has resulted in the derivation of process and component information for design of commercial facilities. The General Motors (GM) Corporation represents the single, largest industrial user of the technology in the United States. Ten fluidized bed reactors are located at GM automotive manufacturing facilities. Nine of the reactors are designed to treat wastewaters originating from metalworking operations pretreated for removal of petroleum oils. The other reactor is designed for treatment of sanitary waste-water. In 1984 and 1985, GM completed extensive pilot plant studies and on the basis of the results selected the aerobic fluidized bed (AFB) process configuration for full scale implementation at various plant sites. The fluidized bed reactors located at the sites range in reactor volume from approximately 60 to 730 m3. The pilot plant results which formed the basis for process design of the full scale reactors involved operation of 77 l fluidized bed reactors. Operating information and performance results were derived from evaluation of full scale GM fluidized bed reactors located at the New Departure Hyatt (NDH) plant in Sandusky, Ohio and the Oldsmobile engine plant in Lansing, Michigan. The full scale results were compared to the pilot plant results with the objective of understanding the effects of scale-up on system operation and performance. A comparable level of reactor attached volatile solids (VS) was measured in the pilot and full scale reactors. Biomass net yield coefficients were higher in the full scale reactors, likely due to differences in the composition of the wastewater fed to the full scale versus the pilot scale units. Oxygen utilization coefficients were comparable. The full scale performance results compared favorably with results from the pilot plant studies on the basis of the relationship between effluent quality and reactor solids retention time (SRT).

In‐situ extraction of industrial sludges

AbstractIn‐situ extraction for the removal of organic contaminants from impounded industrial sludges has been carried out at pilot‐scale at a Superfund site. Laboratory studies were carried out on split‐spoon core samples obtained at the end of the operational year and on untreated sludges. Pilot plant results and sludge characteristics before and after treatment are presented, focusing on the effectiveness of the forced extraction process.