Demonstration plant

The Aromax process was developed in the early 1970s by Toray Industries, Inc. in Japan (95—98). The adsorption column consists of a horizontal series of independent chambers containing fixed beds of adsorbent. Instead of a rotary valve, a sequence of specially designed on—off valves under computer control is used to move inlet and withdrawal ports around the bed. Adsorption is carried out in the Hquid phase at 140°C, 785—980 kPA, and 5—13 L/h. PX yields per pass is reported to exceed 90% with a typical purity of 99.5%. The first Aromax unit was installed at Toray s Kawasaki plant in March 1973. In 1994, IFP introduced the Eluxyl adsorption process (59,99). The proprietary adsorbent used is designated SPX 3000. Individual on-off valves controlled by a microprocessor are used. Raman spectroscopy to used to measure concentration profiles in the column. A 10,000 t/yr demonstration plant was started and successfully operated at Chevron s Pascagoula plant from 1995—96. IFP has Hcensed two hybrid units. 

Hybrid Crystallization/Adsorption Process. In 1994, IFP and Chevron announced the development of a hybrid process that reportedly combines the best features of adsorption and crystallization (59,99). In this option of the Eluxyl process, the adsorbent bed is used to initially produce PX of 90—95% purity. The PX product from the adsorption section is then further purified in a small single-stage crystallizer and the filtrate is recycled back to the adsorption section. It is reported that ultrahigh (99.9+%) purity PX can be produced easily and economically with this scheme for both retrofits of existing crystallization units as well as grass-roots units. A demonstration plant was built at Chevron s Pascagoula refinery in 1994. 

The alkalized zinc oxide—chromia process developed by SEHT was tested on a commercial scale between 1982 and 1987 in a renovated high pressure methanol synthesis plant in Italy. This plant produced 15,000 t/yr of methanol containing approximately 30% higher alcohols. A demonstration plant for the lEP copper—cobalt oxide process was built in China with a capacity of 670 t/yr, but other higher alcohol synthesis processes have been tested only at bench or pilot-plant scale (23). 

A similar process to SMDS using an improved catalyst is under development by Norway s state oil company, den norske state oHjeselskap AS (Statod) (46). High synthesis gas conversion per pass and high selectivity to wax are claimed. The process has been studied in bubble columns and a demonstration plant is planned. 

Fig. 8. Fluid-bed MTG demonstration plant schematic diagram. BPR = Back pressure regulator TC = temperature controller.

The MTO process employs a turbulent fluid-bed reactor system and typical conversions exceed 99.9%. The coked catalyst is continuously withdrawn from the reactor and burned in a regenerator. Coke yield and catalyst circulation are an order of magnitude lower than in fluid catalytic cracking (FCC). The MTO process was first scaled up in a 0.64 m /d (4 bbl/d) pilot plant and a successfiil 15.9 m /d (100 bbl/d) demonstration plant was operated in Germany with U.S. and German government support. 

Demonstration Plant, Clean BoilerFuels From Coal, OCR R D report no. 82, Interim report no. 1, Vols. 1—3, Ralph M. Parsons Co., Los Angeles, Calif., 1973-1975. 

Several manufacturers of ceramic powders are involved in commercializa tion of hydrothermaHy derived powders. In the United States, Cabot (Boyertown, Peimsylvania) has built a small manufacturing plant and is supplying materials to capacitor manufacturers. Other manufacturers include Sakai Chemical and Euji Titanium in Japan. Sakai Chemical is reportedly producing 1 t/d in its demonstration plant. A comparison of the characteristics of commercially available powders is given in Table 2. 

Figure 20 shows values of the channel enthalpy extraction ratio for a number of channels. Enthalpy extraction (111) equal to that required by a proposed demonstration plant (112) has been achieved. Channels have performed generally in accordance with predictions. 

Whereas considerable progress has been made towards achieving acceptable channel performance (power and enthalpy extraction) and durabiUty, as of this writing performance and durabiUty have not been demonstrated simultaneously. A larger scale demonstration plant has been proposed in the United States by the MHD Development Corp. (112). 

Conceptual Design of MHD Repowered Plant. The first step toward MHD plant commercialization is a pilot-scale demonstration plant. Repowering of existing plants, actively under study both in the United States and elsewhere (65), allows use of existing systems at considerable cost savings compared to building a new plant from the ground up. It also ensures that the pilot scale demonstration occurs in a reaHstic utiHty environment and... 

During its 40-year development, three different si2es of PETROSIX retorts have been operated on a continuous basis a 1.83-m (6-ft) diameter demonstration plant a 5.49-m (18-ft) diameter Prototype Unit (UPI) and a 10.97-m (36-ft) diameter Industrial Module (MI). Within the SIX facihty are numerous pilot plants available for retorting coarse-si2ed oil shale, fines utih2ation, and oil shale upgrading (3,67). 

The monohalide vapors are conveyed to a slightly cooler zone (700—800°C) where the reaction reverses, resulting in the condensation of pure aluminum. The monochloride process was carried to the demonstration plant stage but was abandoned because of corrosion problems (24). 

The wodd s total capacity of grid-coimected electric power derived from wave energy is less than half a megawatt, distributed among several demonstration plants. The largest unit, the 350-kWe Tapered Channel plant in Norway, uses the hydropower approach. The plant was developed by Norwave AS and has operated continuously since 1986. Based on this durabiUty, two commercial orders were placed from other parts of the wodd. 

Sulfur-Coated Fertilizers. Sulfur-coated urea technology (SCU) was developed in the 1960s and 1970s by the Tennessee Valley Authority, now called the National Fertilizer and Environmental Research Center. A commercial-scale demonstration plant (9.1 t/h) was put in operation by TVA in late 1978. Sulfur was chosen as the principle coating material because of its low cost and its value as a secondary nutrient. 

Bubbling AFBCs A simplified schematic of a bubbling AFBC is presented in Fig. 27-47. A demonstration plant generating 160 MWe, with a power production intensity of 1.49 MWe/m (1 MWe/16 ft ), began operation in 1988. Also operating is a 350-MWe unit that employs many of the same design features. 

A PFBC boiler is visually similar to an AFBC boiler. The combustor is made of water-wall tubing, which contains the high-temperature environment, but the whole assembly is placed within a pressure vessel. Unlike an AFBC unit, there is no convection pass, as the flue-gas temperature must be maintained at boiler temperature to maximize energy recovery by the expansion turbine. There is an economizer after the turbine for final heat recoveiy. A simplified schematic is presented in Fig. 27-49. An 80-MWe demonstration plant, operating at 1.2 MPa (180 psia), began operation in 1989 with a power producdion intensity of 3 MWe/m (1 MWe/3.5 fU). By 1996, five units of this size had been construcded, and a 320-MWe unit is planned to commence operation in 1998. 

In this study detailed fault trees with probability and failure rate calculations were generated for the events (1) Fatality due to Explosion, Fire, Toxic Release or Asphyxiation at the Process Development Unit (PDU) Coal Gasification Process and (2) Loss of Availability of the PDU. The fault trees for the PDU were synthesized by Design Sciences, Inc., and then subjected to multiple reviews by Combustion Engineering. The steps involved in hazard identification and evaluation, fault tree generation, probability assessment, and design alteration are presented in the main body of this report. The fault trees, cut sets, failure rate data and unavailability calculations are included as attachments to this report. Although both safety and reliability trees have been constructed for the PDU, the verification and analysis of these trees were not completed as a result of the curtailment of the demonstration plant project. Certain items not completed for the PDU risk and reliability assessment are listed. 

The activity loss measured here is caused by recrystallizations. This was demonstrated by using scanning electron microscopy to determine nickel crystallite size in the same catalyst samples. These tests revealed that the catalyst used in demonstration plants has only a slight tendency to recrystallize or sinter after steam formation and loss of starting activity. 

These tests were performed to establish the limits in flexibility and operability of a methanation scheme. The two demonstration plants have been operated in order to determine the optimum design parameters as well as the possible variation range which can be tolerated without an effect on catalyst life and SNG specification. Using a recycle methanation system, the requirements for the synthesis gas concerning H2/CO ratio, C02 content, and higher hydrocarbon content are not fixed to a small range only the content of poisons should be kept to a minimum. The catalyst has proved thermostability and resistance to high steam content with a resultant expected life of more than 16,000 hrs. 

In recent months, three nylon producers (DMS, DuPont, and Honeywell) have developed closed-loop recycling processes for nylon carpet,15 thereby joining companies like BASF, Allied, and Rhodia, which have been recycling nylon on a modest level for years. DuPont is building a demonstration plant in Maitland, Ontario, which will be dedicated to the chemical recycling of nylon-6,6 and nylon-6. The newly developed ammonolysis process invented by DuPont can be used to depolymerize both nylon-6 and nylon-6,6. However, the cost of recycled nylon is estimated to exceed that of virgin nylon by ca. 25%. 

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