Coal Log Pipeline Research Articles

Development of life cycle water-demand coefficients for coal-based power generation technologies

This paper aims to develop benchmark coefficients for water consumption and water withdrawals over the full life cycle of coal-based power generation. This study considered not only all of the unit operations involved in the full electricity generation life cycle but also compared different coal-based power generating technologies. Overall this study develops the life cycle water footprint for 36 different coal-based electricity generation pathways. Power generation pathways involving new technologies of integrated gasification combined cycle (IGCC) or ultra supercritical technology with coal transportation by conventional means and using dry cooling systems have the least complete life cycle water-demand coefficients of about 1L/kWh. Sensitivity analysis is conducted to study the impact of power plant performance and coal transportation on the water demand coefficients. The consumption coefficient over life cycle of ultra supercritical or IGCC power plants are 0.12L/kWh higher when conventional transportation of coal is replaced by coal-log pipeline. Similarly, if the conventional transportation of coal is replaced by its transportation in the form of a slurry through a pipeline, the consumption coefficient of a subcritical power plant increases by 0.52L/kWh.

00/01209 Coal log pipeline for twenty-first century coal transportation

During the first years of the 21st century coal log pipeline (CLP) technology will be available for long-distance coal transportation. The purpose of this report is to present the state-of-the-art of coal log pipeline technology. Some recent developments are as follows: optimization of coal log compaction procedures, construction of a unique coal log prototype manufacturing machine, and its testing. Coal log abrasion while transported in water-filled pipelines is also discussed. A CLP pilot plant is currently under construction at the University of Missouri. For certain routes in the US a CLP system appears to be cost-competitive.

Economics of coal log pipeline for transporting coal

This economic study was conducted to compare the cost of transporting coal from mines to power plants by coal log pipeline with other modes of transportation including truck, rail and coal slurry pipeline. Unit cost is defined here as the cost of transporting a metric ton of coal for any prescribed distance in $/T (dollars per metric ton), and it includes not only capital and operational costs, but also a built-in profit for the investor. The unit cost of coal log pipeline can be compared with the current tariffs for coal transportation charged by railroads, trucks and other competing modes to determine whether it is economically competitive in a given situation. The study was conducted for different transportation distances and throughputs. Based on this comparison, the conditions are established under which coal log pipeline is more economical than slurry pipeline, truck and train.

98/02754 Status of coal log pipeline: coal log manufacturing methods: Marrero, T. R. Proc. Inst. Briquet. Agglom., Bienn. Conf., 1995 (Pub. 1996), 24, 39–52

98/02754 Status of coal log pipeline: coal log manufacturing methods: Marrero, T. R. Proc. Inst. Briquet. Agglom., Bienn. Conf., 1995 (Pub. 1996), 24, 39–52

Coal log pipeline technology: An overview

Coal log pipeline (CLP) technology, invented and patented in the United States in 1990, has undergone extensive research and development at the Capsule Pipeline Research Center, University of Missouri-Columbia. Areas explored thoroughly involve capsule flow hydrodynamics, compaction of coal logs, wear of coal logs in the pipeline, automatic control of the CLP, cost of coal log transportation through the pipeline, treatment of CLP effluents at power plants, and legal research concerning coal pipelines. This paper gives a brief review of some of these areas, and the state of development of this emerging technology. Implications for electric utilities, coal companies and the general public are also discussed.

97/03546 Fiber reinforcement of coal logs

The Coal Log Pipeline (CLP) is a novel technology based on the concept that coal ran be compacted into circular cylinders (coal logs), and transported by water or slurry flowing through an underground pipe. There are many advantages of the Coal Log Pipeline. Since 1992, the CLP technology has been the subject of intensive research and development at the Capsule Pipeline Research Center (CPRC), University of Missouri, Columbia. Many detailed studies have been accomplished in these years and the CLP technology is rapidly approaching commercialization. The commercial applications of the CLP depend, to a large extent, on the ability of coal logs to sustain limited wear and damage during pipeline transportation over a long distance. Therefore, a most important task for the development of the CLP is to develop economical processes that produce high strength, wear-resistant coal logs. The researchers at the CPRC have completed extensive research on the coal log manufacturing processes. Two main methods of coal agglomeration have been investigated: extrusion and compaction. Many promising processes of coal log fabrication have been developed and documented to facilitate the commercialization of the CLP technology. The purpose of this research is to determine whether adding a small amount of low-cost,more » combustible fiber can improve the wear resistance of coal logs. For this purpose, a review of literature concerning the fiber reinforcement of brittle materials was conducted first; Then the effect of fiber reinforcement of coal log on its wear resistance was studied. The results from this study showed that coal log wear resistant capability was increased to some extent under some compaction conditions.« less

97/03563 Theoretical and experimental considerations for coal log pipeline control systems—preliminary studies

97/03563 Theoretical and experimental considerations for coal log pipeline control systems—preliminary studies

97/03562 A technical and economic assessment of coal log pipeline technology at electric power generating plants

97/03562 A technical and economic assessment of coal log pipeline technology at electric power generating plants

97/02617 Coal log pipeline design and economics

97/02617 Coal log pipeline design and economics

Polymer drag reduction in hydraulic capsule pipeline

A hydraulic capsule pipeline (HCP) transports solids as large cylindrical objects, or in cargo-carrying containers, by pipeline over long distances using water or another liquid as the carrier fluid. Based on the HCP concept, Liu and Marrero (1990) invented the coal log pipeline (CLP), a technology for transporting compressed coal cylinders. Application of HCP and CLP for solids transport over long distances requires the minimization of energy consumption. The research reported in this note explores the possibility of using high molecular weight polymers for drag reduction in HCP and CLP in order to reduce energy consumption.

Analysis of coal log ram extrusion

Abstract Ram extrusion of coal logs was studied for thr purpose of coal log pipeline transportation of coal. Due to the existence of wall friction and contraction of the die (mold) cross-sectional area, high pressure may be needed to cause the flow of coal through the die. One common problem of ram extrusion is the predetermination of the extrusion load. In this study, equations are derived to predict the pressure drop inside a conical die under static conditions. It was found that the extrusion area ratio, the Janssen constant (i.e. the radial-to-axial stress ratio), the contact friction coefficient, and the cone angle all contribute to the extrusion load. Experiments were carried out on a conical die using a bituminous coal. There was less than 10% difference between the experimental results and the theory. It was also found that the Janssen constant approaches a constant when the compaction pressure is high. Water content, binder, and lubricant all effect the force transmitted to the wall and the contact friction coefficient.

Capsule Transport in Coal Slurry Medium

The use of coal slurry instead of water in a coal log pipeline (CLP) is investigated for the first time. This investigation reveals significant differences and possible benefits by using coal slurry instead of water in CLPs. The lift-off velocity, and capsule and total pressure gradients are presented for a 51 mm pipeline using two capsule geometries. The fluid velocity was tested from 1 to 3 m/s, which includes the lift-off velocity of the capsule train. The diameter ratio (k) and specific gravity (S) are held constant at 0.75 and 1.3, respectively. Two capsule lengths were studied corresponding to aspect ratios (a) of 2 and 4. Aluminum-Plexiglas capsules are used to simulate the coal logs. The coal slurry significantly lowered the lift-off velocity, and transported more coal per total pressure gradient than coal logs in water. The capsule pressure gradient was nearly constant over the velocity range investigated. This indicates that the optimal operation velocity range may be much larger for coal slurry compared to water. Further tests and abrasion studies are required to fully assess the potential benefits of using coal slurry.

Binderless compaction of hot water formed coal logs for pipeline transport

Coal log pipelines will transport compacted coal through a water filled pipeline. To fully develop this technology and make it ready for commercial use it is necessary to make high strength, water resistant coal compacts. Means for making coal compacts without binders that are strong and water resistant enough for pipeline transport are not currently available. It is possible to make high strength coal compacts by several means. However, these compacts suffer from an excessive loss of strength when exposed to water. If logs are formed at a moisture content equal to the equilibrium moisture content for the coal, water absorption is minimal, and there is little loss of strength. However, for many coals, that equilibrium moisture content is high and logs formed at that moisture content have low mechanical strength. The moisture content of the coal compact can be lowered when the compact is formed under appropriate conditions. If the appropriate moisture, temperature and pressure conditions are created during the formation of a coal compact, the resultant coal compact's moisture content is also lowered. These compacts adsorb little water and retain their mechanical strength when exposed to high-pressure water. We refer to compacts formed in this manner as hot water formed coal compacts or HWF compacts. HWF compacts have performed very well in durability and strength tests and are belived to be suitable for coal log pipeline transport.