Coal Liquefaction Projects Research Articles

Erosion Wear Analysis on Valve Cage of Cage-Typed Sleeve Control Valve for Coal Liquefaction

Abstract Cage-typed sleeve control valve (CSCV) is the key basic equipment in direct coal liquefaction projects. The working condition of CSCV has the characteristics of high-pressure difference, high velocity, and high solid content. There is a general issue of liquid–solid two-phase erosion wear in CSCV, which can easily lead to the failure of the internal structure in the valve cage. Therefore, it is necessary to study erosion wear characteristics of internal structures in the valve cage. Considering the real conditions of erosion wear in the valve cage, a simplified T-shaped flow path is designed, and the precision of both the liquid–solid two-phase flow model and the erosion prediction model is validated. The flow characteristics and erosion wear characteristics in the T-shaped flow path under different working conditions are studied. Based on the simulation results of different structural parameters and boundary conditions, the erosion wear of the T-shaped flow path is predicted and calculated by the response surface method. Subsequently, the prediction formula for the maximum erosion rate is derived. The formula enables the swift determination of optimal structural parameters for the flow path, aiming to mitigate damage to the valve caused by erosion wear. This work can quickly predict the erosion wear rate of the key areas in the valve cage, which can provide a certain reference value for the life prediction and structural optimization of CSCV, and it can also benefit the safety and maintenance of the coal liquefaction system.

「石炭液化プロジェクト」から「ハイパーコールプロジェクト」まで ―国プロ推進の一翼を担えたのか？―

「石炭液化プロジェクト」から「ハイパーコールプロジェクト」まで ―国プロ推進の一翼を担えたのか？―

A System Dynamics Approach to the Impact of Carbon Policies on Indirect Coal Liquefaction Projects: A Case Study for China

A System Dynamics Approach to the Impact of Carbon Policies on Indirect Coal Liquefaction Projects: A Case Study for China

Investigation on Cavitation Flow in Pressure Relief Valve with High Pressure Differentials for Coal Liquefaction

Taking the cavitation and cavitation erosion of pressure relief valve with high pressure differentials in the coal liquefaction project as the object of the study, the mathematical model for the three dimensional cavitation flow of the pressure relief valve is established. Based on the mixture model, the Schnerr-Sauer cavitation model and RNG k-ɛ turbulent model are used to simulate the three dimensional cavitation flows. The characteristics of the cavitation flow with different valve opening, different inlet pressure and out pressure are analyzed. The present work shows that there is severe cavitation at the throttle area of the disc and downstream. As the increase of the valve opening, the area and the rate of back flow which is close to the head of disc are both decreased, and the degree of cavitation in the valve is reduced. It is also found that cavitation in flow field would be gradually reduced in different degree while increasing the outlet pressure or decreasing the inlet pressure.

Technoeconomic assessment of China’s indirect coal liquefaction projects with different CO 2 capture alternatives

ICL (Indirect coal liquefaction), an alternative fuel-supplying technology, has drawn much attention and caused considerable debate in China’s energy sector. The hurdles to its development include the high risk of investment into large-scale installations, the high CO 2 emissions and water resource consumption. A comprehensive assessment of ICL is urgently needed. This study provides an economic assessment and a technical analysis based on process simulations. To address the future challenge of curbing CO 2 emissions, three absorption methods are compared for capturing the CO 2 released from the ICL process: DMC (a novel absorbent), MEA and Rectisol. The comparative results suggest that physical absorbents, represented by Rectisol and DMC, have a remarkable advantage over chemical absorption processes, represented by MEA. The Rectisol process costs the least, while the DMC process is close to the same level. As a novel absorbent, DMC has the potential to be widely used in the future. The economic analysis of ICL predicted a high capital cost of over 35 billion yuan and an overall product cost of approximately 3800 yuan/ton for the baseline. In addition, via a sensitivity analysis, coal price, electricity price and capacity factor were identified as the three most influential factors affecting the overall product cost.

Potential for Coal-to-Liquids Conversion in the U.S.-Resource Base

By applying the multi-Hubbert curve analysis to coal production in the United States, we demonstrate that anthracite production can be modeled with a single Hubbert curve that extends to the practical end of commercial production of this highest-rank coal. The production of bituminous coal from existing mines is about 80% complete and can be carried out at the current rate for the next 20 years. The production of subbituminous coal from existing mines can be carried out at the current rate for 40–45 years. Significant new investment to extend the existing mines and build new ones would have to commence in 2009 to sustain the current rate of coal production, 1 billion tons per year, in 2029. In view of the existing data, we conclude that there is no spare coal production capacity of the size required for massive coal conversion to liquid transportation fuels. Our analysis is independent of other factors that will prevent large-scale coal liquefaction projects: the inefficiency of the process and either emissions of greenhouse gases or energy cost of sequestration.

8-1.日本における石炭液化プロジェクトのネットエネルギーと多段階リアルオプションによる意思決定評価((1)技術評価・シナリオ分析,Session 8 エネルギー評価・経済)

8-1.日本における石炭液化プロジェクトのネットエネルギーと多段階リアルオプションによる意思決定評価((1)技術評価・シナリオ分析,Session 8 エネルギー評価・経済)

Coal Liquefaction, Shenhua Group, and China’s Energy Security

Energy security requires the affordable, reliable and sustainable supply of energy, for commercial and household use. A low-cost and uninterrupted energy supply is fundamental for economic development and political stability. China’s emergence as a major world industrial producer means that its energy security is now of international concern. This paper presents the first in-depth case study of China’s pioneering coal liquefaction project carried out in the Shenhua Group. This project is of great potential significance for China’s energy security. It is likely to have important implications for China’s position within the structure of global energy supply, and have wide potential implications for international relations.

石炭液化油のアップグレーディング反応におけるＮｉ‐Ｗ／Ａｌ２Ｏ３触媒の活性低下

Coal-derived liquid contains a large amount of nitrogen compounds which should be removed for a clean motor fuel. In the coal liquefaction project in Japan, Ni-W/Al2O3 has been developped for the hydrodenitrogenation of coal liquid. The purpose of this paper is to show the high performance of the developped catalyst and to estimate the catalyst life.A continuos trickeled-bed microreactor was used in this work. The preliminary experiments showed that 1) the catalyst shoud be presulfided at the high temperature such as 400°C under a H2S-H2 stream, 2) the raw coal liquid should be distilled before hydrotreating because of the existence of sludge material, 3) the higher puressure of H2 is preferable for deeper denitrogenation and longer catalyst life.Based on the above information, the hydrotreatmnet of coal liquid (N; 5600wtppm) was carried out under 12MPa H2 and H2/oil ratio 1000 (L/L) for five months. It was supposed that the Ni-W/Al2O3 catalyst could reduce the nitrogen content from 5600ppm to 10ppm for about one year in the case of LHSV 1h-1.

Status of direct coal liquefaction research in China

Coal liquefaction projects are now among the key coal conversion efforts in China. At present, research on direct coal liquefaction is being carried out in the following areas: 1. (1) evaluation of coal liquefaction characteristics; 2. (2) suitability of coal for small-scale continuous liquefaction units; 3. (3) selection and evaluation of catalysts for coal liquefaction; and 4. (4) upgrading of coal liquefaction products. Tests have shown that some Chinese lignites and high-sulfur coals are ideal feedstock for liquefaction. The process route will be selected through tests with the aim of producing medium to light oils to meet the energy demand both at home and abroad.

石炭のガス化，液化技術の開発計画

Four pilot plant projects regarding coal conversion process are being carried out by NEDO under the Sunshine project which was established as a governmental alternative energy program to promote comprehensive R & D for the new energy technology.1. Integrated Coal Gasification Combined Cycle project is planned to commercialize a power generation system consists of a highly efficient (air blown, pressurized, 2-rooms, 2-stage, entrained bed) gasifier, a dry gas clean-up system and a high temperature (1, 300°C class) gas turbine system in the beginning of 21st century. A 200t/d pilot plant is now being designed to begin the initial operation in 1989.2. The project of Hydrogen Manufacturing Technology from Coal aims for the economical hydrogen production from various types of coal with a high performance (oxygen blown two-swirling-stream type) gasifier. A 20t/d pilot plant is being designed to be operational by 1991.3. Brown Coal Liquefaction project is demonstrating an advanced two stage hydrogen-ation process to convert Victorian brown coal containing 60‰ of moisture to liquid fuel economically. Construction of a 50t of dry coal/d pilot plant is nearing completion scheduled for the end of the next March in Morwell of Victoria, Australia. The 1st hydrogenation stage was tested by coal-in operation from Nov.1980 to Jan. 1981.4. Bituminous Coal Liquefaction project is to promote a new single stage hydrogenation (NEDOL) process to utilize various types of coal from subbituminous to low rank bitumi-nous coal. A detailed design of 250t/d pilot plant is now in progress and its construction is scheduled for 1987.

Analysis and prevention of metallurgical failures at a major direct coal liquefaction pilot plant

The H-Coal Pilot Plant in Catlettsburg, KY was the largest-capacity direct coal liquefaction project operating in the United States. Since the start of operations, performance of its components was carefully monitored and occasional failures were examined and documented. The results of the examinations were used to develop remedial steps and improve the design of scale-up units. In this paper, the metallurgical aspects of the following incidents will be described: 1) stress corrosion cracking of martensitic stainless steel bolting on the waterside of a heat exchanger; 2) stress corrosion cracking of a superalloy seal ring; 3) brittle failure of a low alloy nut in a block valve body; 4) corrosion damage in the fractionator and side stripper; 5) erosion/corrosion of a coal liquid transfer line in the atmospheric fractionation area; 6) pitting corrosion in a deaerator carbon steel inlet pipe; 7) brittle failure of a martensitic stainless steel ball in a block valve handling coal liquids; and 8) cracking of cobalt-base alloy seat rings in block valve applications. In addition, remedial steps and preventive measures leading to successful performance after repair will be briefly described.

Wasserstoff-Erzeugung und Kreislaufgas-Zerlegung für die Kohleverflüssigung

Hydrogen generation and recycle gas separation for coal liquefaction. Just as 40 years ago, low-temperature processes are now again being considered for recycle gas separation in today's large scale coal liquefaction projects. Hydrogen can be generated by gasification of heavy residues and by steam reforming of ethane. Alternatives for recycle gas separation into hydrogen and gas products are butane and methane absorption or low-temperature condensation processes at high or medium pressure. These processes employ several additional absorption and adsorption steps for gas purification. They are proven on a large technical scale, and fulfill the requirements of environmental legislation.

Development of Overseas Coal Liquefaction Projects

Although three kinds of large-scale pilot plants, that is, Exxon Donor Solvent, H-Coal and Improved German Process are operating, it seems to take more several years for the construction of demonstration plant, because the development of new technologies and the supply of huge amount of capital are necessary. In order to establish new and more effective liquefaction process, various types of bench scale plants and elementary technologies are under development.Present state and direction of main coal liquefaction projects in United States, West Germany, United Kingdom, Canada, Australia and South Africa are briefly reviewed.