Abstract PEP Review ACETIC ACID, UPDATE OF OXIDATION ROUTES By P. D. Pavlechko, PhD (April 2012)

Transcription

1 Abstract PEP Review ACETIC ACID, UPDATE OF OXIDATION ROUTES By P. D. Pavlechko, PhD (April 2012) ABSTRACT While methanol carbonylation dominates the current era of acetic acid production, two routes employing the oxidation of hydrocarbons (ethylene and ethane) vie for recognition. These routes have previously been evaluated in PEP Report 37C [PEP037C] at reduced scale, and the analysis concluded that the routes might serve isolated local demands but could not compete on the commercial scale. Since methanol carbonylation supplanted the two-step oxidation route via isolated acetaldehyde, the prospect of a single-step feedstock to acetic acid route might recapture economic efficiency from carbonylation. However, the findings from the previous analyses suggested otherwise, which raises several questions. Is the reduced scale the sole aspect that rendered the previous analyses suboptimal? Or is the oxidation technology inherently inferior? This review addresses those questions by updating the previous evaluations to the present and extrapolating the plant size to the current maximum world scale set by Celanese, namely 600 thousand metric tons per year (kta). The Showa Denko (SD) route oxidizes ethylene to acetic acid in a single-step conversion, which should generally be more cost effective than the conventional two-step ethylene oxidation process (via acetaldehyde). Therefore, the initial expectation is that the SD route should be closer to economic equivalence with carbonylation at the same economy of scale. SABIC s ethane-based oxidation route to acetic acid functions as a single-step oxidation using surplus ethane, but also generates by-product ethylene and CO 2. The single reaction step with no intermediate isolation suggests a similar impact as the SD route, and the use of surplus feedstock that might otherwise be flared hints at a potential economic advantage. However, significant by-product production requires more of a trade-off assessment depending on the marketability of the by-products. The CO 2 by-product presents a particular concern since it becomes an environmental problem and an economic liability for this process if no end use is available. Unsatisfactory economics shown in the previous analysis [PEP037C] at reduced scale again suggests that a world-scale configuration might provide economic feasibility IHS PEP Review

2 A private report by the Process Economics Program Review No ACETIC ACID, UPDATE OF OXIDATION ROUTES by P. D. Pavlechko, PhD April 2012 Menlo Park, California 94025

3 IHS Chemical agrees to assign professionally qualified personnel to the preparation of the Process Economics Program s reports and will perform the work in conformance with generally accepted professional standards. No other warranties expressed or implied are made. Because the reports are of an advisory nature, neither IHS Chemical nor its employees will assume any liability for the special or consequential damages arising from the Client s use of the results contained in the reports. The Client agrees to indemnify, defend, and hold IHS Chemical, its officers, and employees harmless from any liability to any third party resulting directly or indirectly from the Client s use of the reports or other deliverables produced by IHS Chemical pursuant to this agreement. For detailed marketing data and information, the reader is referred to one of the IHS Chemical programs specializing in marketing research. THE IHS CHEMICAL ECONOMICS HANDBOOK Program covers most major chemicals and chemical products produced throughout the world. In addition the IHS Chemical DIRECTORY OF CHEMICAL PRODUCERS services provide detailed lists of chemical producers by company, product, and plant for the United States, Europe, Asia, South and Central America, the Middle East, Canada and Mexico.

4 CONTENTS INTRODUCTION... 1 ACETIC ACID VIA SHOWA DENKO ONE-STEP ETHYLENE OXIDATION PROCESS... 1 Technology Review... 1 Chemistry... 2 Process Description... 2 Section 100: Ethylene Oxidation... 2 Section 200: Acid Purification... 3 Process Discussion Feed Conditions Catalyst Reactor Byproduct Steam Product Purification Materials of Construction Process Waste Effluents Cost Estimates Capital Costs Production Costs Conclusions ACETIC ACID VIA SABIC ETHANE OXIDATION PROCESS Technology Review Chemistry Process Description Section 100: Ethane Oxidation Section 200: Acid Purification Process Discussion Feed Conditions Catalyst Reactor Byproduct Steam Product Purification Materials of Construction Process Waste Effluents IHS iii PEP Review

5 CONTENTS (Concluded) Cost Estimates Capital Costs Production Costs Conclusions REFERENCES IHS iv PEP Review

6 FIGURES 1 Acetic Acid via Showa Denko Ethylene Oxidation Process Process Flow Diagram Acetic Acid via SABIC Ethane Oxidation Process Process Flow Diagram IHS v PEP Review

7 TABLES 1 Acetic Acid via Showa Denko One-Step Ethylene Oxidation Process Design Bases and Assumptions Acetic Acid via Showa Denko One-Step Ethylene Oxidation Process Stream Flows Acetic Acid via Showa Denko One-Step Ethylene Oxidation Process Major Equipment Acetic Acid via Showa Denko One-Step Ethylene Oxidation Process Utilities Summary Acetic Acid via Showa Denko One-Step Ethylene Oxidation Process Total Capital Investment Acetic Acid via Showa Denko One-Step Ethylene Oxidation Process Capital Investment by Section Acetic Acid via Showa Denko One-Step Ethylene Oxidation Process Production Costs Acetic Acid via SABIC Ethane Oxidation Process Design Bases and Assumptions Acetic Acid via SABIC Ethane Oxidation Process Stream Flows Acetic Acid via SABIC Ethane Oxidation Process Major Equipment Acetic Acid via SABIC Ethane Oxidation Process Utilities Summary Acetic Acid via SABIC Ethane Oxidation Process Total Capital Investment Acetic Acid via SABIC Ethane Oxidation Process Capital Investment by Section Acetic Acid via SABIC Ethane Oxidation Process Production Costs IHS vi PEP Review