Pilot plant liquefaction

Coal Liquefaction at Wilsonville. Starting ia 1974 the Advanced Coal Liquefaction R D Facihty at WilsonviUe, Alabama operated a 6 t/d pilot plant and studied various coal Hquefaction processiag schemes. The facihty, cosponsored by the DOE, the Electric Power Research Institute (EPRI) and Amoco Oil Co, was shut down ia early 1992. 

Work has also continued on the solvent-refined coal + hydrocracking concept (the NT.SL, or non-integrat-ed, two-stage liquefaction process), and a pilot plant was operated by Amoco, DOE and the Electric Power Research Institute (EPRI) from 1974 to 1992. 

It is well known that during liquefaction there is always some amount of material which appears as insoluble, residual solids (65,71). These materials are composed of mixtures of coal-related minerals, unreacted (or partially reacted) macerals and a diverse range of solids that are formed during processing. Practical experience obtained in liquefaction pilot plant operations has frequently shown that these materials are not completely eluted out of reaction vessels. Thus, there is a net accumulation of solids within vessels and fluid transfer lines in the form of agglomerated masses and wall deposits. These materials are often referred to as reactor solids. It is important to understand the phenomena involved in reactor solids retention for several reasons. Firstly, they can be detrimental to the successful operation of a plant because extensive accumulation can lead to reduced conversion, enhanced abrasion rates, poor heat transfer and, in severe cases, reactor plugging. Secondly, some retention of minerals, especially pyrrhotites, may be desirable because of their potential catalytic activity. 

In absolute terms, the quantities of reactor solids found in various processes do vary considerably. The rate of accumulation is related to several factors, such as coal characteristics, recycle solvent quality and reactor design. However, it can be stated in general terms that liquefaction of low rank coals (sub-bituminous C and lignites) does result in higher rates of accumulation of solids than do similar operations with bituminous coals. For example, during normal operations of the SRC-I pilot plant at Wilsonville, Ala., it has been found that the amount of solids retained varies from about 0.2-0.5 wt.% (moisture-free) for bituminous coals to 1.0-1.9 wt.% (moisture free) for a subbituminous C coal (Wyodak) (72). Exxon also reports much larger accumulations for lignites and subbituminous coals than those found for bituminous coals (73). 

In addition to continuous bench-scale work, CCDC carried out a rather extensive laboratory program involving the use of the microautoclave reactor. The program developed tests to compare the activities of different solvents. These tests quickly evaluated a solvent so that the performance under coal liquefaction conditions could be predicted. The tests are now used at the Wilsonville SRC Pilot Plant as a means of determining when stable operation has been achieved. 

The best-known processes are the IGOR (Germany), HTI (America), and NEDOL (Japan). The New Energy and Industrial Technology Development Organization (NEDO) finished a 1501 coal per day coal liquefaction pilot plant in 1998. Shenhua Group Corporation is building a 40001 coal per day (1 Mt oil/year) commercial plant in China. 

Liquefaction - Pilot Plant-Scale. 35% DS com starch slurries (30 lbs.) were liquefied widi the CGTase at a dose of 4.46 or 8.92 Phadebas units/gram DS starch at pH 4.5 for 5 minutes at IO5OC (primary) followed by 2 hours at 95 C or 4 hours at 90 C (secondary). 

An enormous amount of work both at bench scale and at pilot plant scale have been conducted to study the production of liquid and gaseous hydrocarbons from coal. Since most of the analytical methods are either very time consuming or very specialized, almost all the data available on the coal liquefaction process are based on distillation data or on the assumption that all products which are not insoluble solids are converted. It is known that products of liquefaction vary based on coal, reaction conditions, and media of reaction hence, conversion and yield may be based on very different products. 

The Illinois H-Coal and SRC-II syncrudes contain large amounts of chloride, 32 parts per million (ppm) and 50 ppm, respectively. The Wyodak H-Coal syncrude contains only 3 ppm. Because the exit line from the pilot plants which processed the SRC-II syncrude occasionally plugged with ammonium chloride, we water washed the Illinois H-Coal syncrude prior to hydrotreating. It is our understanding that chloride will be removed by water washing at a commercial coal liquefaction facility. 

This paper describes the status of the development of the Exxon Donor Solvent (or EDS) coal liquefaction process. It includes an overview of the jointly funded project and a brief description of the EDS process. It also includes a discussion of the project status, including a description of coal feed flexibility, hydrogen and fuel gas production alternatives and the progress in the construction of the 250 T/D pilot plant. Other communications have covered the R D program, the outlook for commercialization, and the organization of the EDS Project (1,2, 3,, 5, 6, J) ... 

The operations of the 250 T/D pilot plant are designed to demonstrate the operability of the EDS liquefaction section and obtain the scaleup data required for design of a commercial facility. Key objectives are demonstration of unit operability,... 

Illinois 6 bituminous coal and Wyoming subbituminous coal were specified initially as project coals and DOE, Carter Oil, EPRI and JCLD chose additional coals for evaluation. Operations of the 250 T/D liquefaction pilot plant are to include processing three coals Illinois 6, a subbituminous coal, and a third coal to be selected by the project sponsors. 

Analyses of coals which have been processed in the continuously operated pilot plants are listed in Table 1. Process liquid yields from the liquefaction step for these coals are shown in Figure 4 for different residence times in the liquefaction reactor. Longer residence time increases conversion of coal to liquids, but also increases hydrocracking of liquids to gas. 

Both FLEXICOKING and partial oxidation are commercial processes for petroleum residue (12,13). In addition, partial oxidation has been utilized to generate Synthesis gas with coal as a feed (14,15). Coal liquefaction bottoms have been processed in small pilot units in recent studies including Exxon s 2 B/D FLEXICOKING pilot plant (3) and Texaco s 12 T/D partial oxidation unit (16). Studies in Exxon s unit have included EDS bottoms from Illinois and Wyoming coals while SRC-I, SRC-II, H-Coal and... 

ER E discussions with Texaco and with Shell on bottoms processing are summarized herein. Texaco has indicated that its partial oxidation process could be applied to coal liquefaction bottoms on a commercial scale and that operation of their 12 T/D pilot plant with coal liquefaction bottoms representative of a projected commercial feedstock would be adequate to set the design basis for a commercial facility. Texaco indicated that three to four years after successful operation of the 12 T/D unit a commercial facility could be ready for startup. In initial discussions, Shell has indicated that development of the Shell/ Koppers partial oxidation process for coal liquefaction bottoms would involve operations of both their 6 T/D pilot plant and their 150 T/D demonstration unit. It was estimated that the 150 T/D facility might become available in the late 1980/early 1981 time frame for possible operation on vacuum bottoms. 

In conclusion, increased understanding of the requirements for successful development of coal liquefaction for a wide variety of coals has been achieved. Operations of the large liquefaction and FLEXICOKING pilot plants, scheduled to begin in 1980 and 1981, should provide the data base needed for scale up to commercial size. 

A sizeable amount of work expended in Fischer-Tropsch in both catalyst research as well as pilot plant studies and design. Much of the design work in the SASOL I indirect liquefaction plant in South Africa and the pilot plant in Louisiana, Missouri, was obtained from the bank of information that was generated at PETC. 

The SRC-I coal liquefaction process is designed to produce a clean, coal-derived solid fuel in a single, noncatalytic reaction step. (1) Design of a demonstration plant for the SRC-I process is new under way. (2) A two-step, hydrogen efficient modification of the noncatalytic SRC I technology has been proposed and studied extensively on a laboratory scale. (3-6) Two-step SRC I technology is also being tested in pilot plant scale facilities. 07, S)... 

Product oils from direct liquefaction of Blacksville Number 2 coal in the 1000 pound per day pilot plant at Pittsburgh Energy Technology Center (PETC) were examined by cyclicvoltammetry. 

The work reported here was carried out in two phases. The first phase was conducted in a laboratory test boiler to determine the relative PNA emissions from a variety of EDS and petroleum fuels. The second phase of testing was conducted in a commercial boiler to determine the effect of unit size on PNA emissions. This testing was made possible by the start-up and operation of the Exxon Coal Liquefaction Pilot Plant (ECLP) which has a throughput of 250 tons per day and can produce approximately... 

Several processes have been developed for coal liquefaction. Large-scale pilot plants have been in operation for the solvent-refining coal (SRC) process, and a pilot plant is being constructed for the H-Coal process, which is a direct catalytic process. Construction of demonstration plants is under consideration. The coal liquids produced from the current processes contain large amounts of residual fuels. They probably will be used initially as boiler fuels for stationary power plants. However, the nitrogen content of coal liquids is much higher than the petroleum residual fuels. The sulfur contents of coal liquids can vary considerably they depend on the type of coal and the liquefaction process used. Current coal liquefaction processes are capable of produc-... 

IG-NUE A coal liquefaction process developed by Bergbau-Forschung in Germany during World War II. Catalytic metal salts were impregnated in, or precipitated on, the coal. A pilot plant was to have been built in Westphalia in 1977. 

PILOT PLANT SCALE STUDIES FOR THE LIQUEFACTION OF PVC MIXED PLASTICS... 

Pilot plant test for containers and packaging plastics at Kawasaki city. (PWMI) Liquefaction (6,000t/y) at Niigata city supported by MITI.(Rekisei) Liquefaction (3,000t/y) at Tachikawa city supported by MHW.fJWRF) ... 

---