PROCESS ECONOMICS PROGRAM

Transcription

1 Abstract PROCESS ECONOMICS PROGRAM SRI INTERNATIONAL Mmlo Park, California Process Economics Program Report No. 154 COAL GASIFICATION (January 1983) This report reviews the current status of coal gasification tech- nology and presents cost estimates for the production of syugas (H2 + CO) by the following processes and feedstocks: Process Casifier Type Feedstock Texaco Entrained-flow Illinois No. 6 bitminous coal HT (high Fluidieed-bed Texas lignite temperature) Winkler Cost estimates are for syngas at five HZ-to-CO mol ratios, namely, as-gasified, 2, 5, 10, and industrial grade H2. Product values are correlated in graphs on the basis of plant capacity and H2-to-Co ratio. PEP '81 JJLW

2 Report No. 154 COAL GASIFICATION by JAMES J. L MA January 1983 A private report by the PROCESS ECONOMICS PROGRAM Menlo Park, California 94025

3 For detailed marketing data and information, the reader is referred to one of the SRI programs specializing in marketing research. The CHEMICAL ECONOMICS HANDBOOK Program covers most major chemicals and chemical products produced in the United States and the WORLD PETROCHEMICALS Program covers major hydrocarbons and their derivatives on a worldwide basis. In addition, the SRI DIRECTORY OF CHEMICAL PRODUCERS services provide detailed lists of chemical producers by company, product, and plant for the United States and Western Europe.

4 CONTENTS INTRODUCTION.... SUMMARY. General Aspects... Background... State of Technology... Development Trend in the United States... Development Trend Elsewhere... Economic Aspects... Technical Aspects... INDUSTRY STATUS... Historical Perspective... Available Technologies... Progress in the United States... Progress Abroad... Prospects... PROCESS TECHNOLOGIES... Stoichiometry... Reactions... Stoichiomet% ini Thl&l Constraints Coal Properties... Composition... Caloric Value... ;... Moisture... Ash.. Grindability Index... Reactivity... Free Swelling Index... Coal Gasification Processes... Gasifier Operating Characteristics. Acid Gases Removal Systems... Hz/CO Ratio and Water-Gas Shift.. Oxygen Production... Air Separation Process... Effect of Oxygen Purity on Power Consumption... Effect of Oxygen Delivery Pressure on Power Consumption.. Oxygen Economics iii

5 CONTENTS 5 COAL GASIFICATION BY THE TEXACO PROCESS... Review of Process Patents Solids Content of Slurry Sulfur Content of Coal... Gasification Temperature... Gasification Pressure... Heat Recovery Systems... Equipment Selection and Operating Experience... Process Description... Coal Receiving and Preparation. Air Separation... Coal Slurry Preparation and Gasification... Shift Conversion and COS Hydrolysis... Acid Gases Removal... Sulfur Plant and Tailgas Treating Process Discussion... Coal Gasification... Environmental Aspects... Cost Estimates... Capital Costs... Production Costs Effect of Coal Price and Syngas Delivery Pressure on Product Value Effect of H2/CO Ratio on Costs COAL GASIFICATION BY THE HT WINRLER Review of Process Patents Gasificatik'Pressure Gasification Temperature.... Moisture Content of Lignite... Gas Composition Demonstration Plant Flow Diagram Process Description Process Discussion Cost Estimates Capital Costs Production Costs Effect of HP/CO Ratio on Costs. 83 PROCESS iv

6 CONTENTS APPENDIX A DESIGN AND COST BASIS CITED REFERENCES PATENT REFERENCES V

7 ILLUSTRATIONS Coal Gasification Process Flow Block Diagram... Coal Conversion to Fuel and Chemical Feedstock Flow Scheme... Coal Gasification Processes... Stoichiometric and Energy Constraints on Coal Gasification Without Methane Formation... Effect of Coal Heating Value on Coal and Oxygen Consumptions... Gasifier Types... Solubility of Gases in Methanol. Schematic Flow Diagram of an Oxygen Plant Using Reverse Heat Exchanger... Reverse Heat Exchanger Operating Principle... Effect of Oxygen Purity on Power Consumption... Effect of Oxygen Delivery Pressure on Power Consumption.... Effect of Oxygen Train Size on Oxygen Cost... Effect of Slurry Solids Content on Coal and Oxygen Consumption8... Effect of Coal Sulfur Content on Coal and Oxygen Consumption8... Effect of Gasification Temperature on Coal, Oxygen, and Steam Consumptions....'... Flow Sheet... Steam Balance... Effect of Plant Capacity on Investment Cost... Effect of Operating Level and Plant Capacity on Product Value Vii

8 ILLUSTRATIONS 5.8 -Effect of Plant Capacity and HZ/CO Mol Ratio on Product Value Bldc Plow Diagram for Hheinbraun's HT Winkler Coal Gasifier Demonstration Project Coal Gasification by the HT Winkler Process Flow sheet Coal Gasification by the HT Winkler Process Steam Balance Coal Gasification by the HT Winkler Process Effect of Plant Capacity on Investment Cost Coal Gasification by the HT Winkler Process Effect of Operating Level and Plant Capacity on.product Value Coal Gasification by the HT Winkler Process Effect of Plant Capacity and H2/C0 Mol Ratio on Product Value Viii

9 TABLES Development Status of Major Coal Gasification Processes.. 5 Summary of Coal Gasification Economics Estimated World Coal Reserves and Resources Major Proposed Coal Conversion Projects in the United States Coal Conversion Pilot Plants in the United States... Existing and Proposed Coal Conversion Plants Outside the United States ASTM Coal Rankings Typical Compositions of Coal From Different Sources.. Ash Content and Ash Fusion Temperatures of some U.S. Coals and Lignite Summary of Gasifiers Advantages and Limitations of Gasifiers Operating Characteristics of Major Gasifiers..... Operating Characteristics of Acid Gas Removal Processes HZ/CO Ratio Requirements in Chemical Syntheses..... Summary of Texaco Patents on Coal Gasification.... Design Bases Stream Flows , Major Equipment (for each Parallel Train) Utilities Sununary Summary of Waste Streams Total Capital Investment IX

10 TABLES 5.8 Capital Investment by Section.., Production Costs Direct Operating Costs by Section Investment and Production Costs of Syngas at Different H2/C0 Ratios Summary of Bheinbraun Patents on Coal Gasification Feedstock Composition and Product Gas Composition Coal Gasification by the HT Winkler Process Design Bases Coal Gasification by the HT Winkler Process Stream Flows Coal Gasification by the HT Winkler Process Major Equipment (for one Parallel Train in each Plant Section) Coal Gasification by the HT Winkler Process Utilities Summary Coal Gasification by the HT Winkler Process Summary of Waste Streams Coal Gasification by the HT Winkler Process Total Capital Investment Coal Gasification by the HT Winkler Process Capital Investment by Section Coal Gasification by the HT Winkler Process Production Costs Coal Gasification by the HT Winkler Process Direct Operating Costs by Section , Investment and Production Costs of Syngas at Different HZ/CO Ratios X