July 26, 2024
Report

High-Surface-Area Inorganic Membrane for Process Water Removal: Application to Ethanol Fuel Production

Abstract

This report summarizes process research results about concept development of thin flat sheet water-selective molecular sieve membrane – a breakthrough membrane product technology for separation of water from ethanol-enriched process streams. The studies include 1) membrane separation performance testing with real-world feeds sampled from Pacific Ethanol Inc’s ethanol plant at Boardman, Oregon and 2) process design and simulation of membrane separation implementation into a corn ethanol plant. The separation tests were conducted on a laboratory-bench testing apparatus in a batch operation mode with small membrane samples (about 1-inch diameter) but under practical conditions, while the process simulation was performed using ASPEN and USDA models. A two-stage membrane separation system is proposed to conduct ethanol enrichment and purification by replacing respective distillation and adsorption process. More than 90% energy saving can be obtained using the membrane separation. It is estimated that the membrane unit for a 40 million gal/year of ethanol plant can be fairly compact - about the sizes of a plate heat exchanger due to high flux of the new membrane. The cost and lifetime of this new membrane product are critical factors to lower the capital cost. This membrane technology is promising for upgrading of existing corn ethanol plants and for building of new cellulosic ethanol plants in the future as well. The results obtained in this work warrant further development of membrane module prototypes and demonstration of their long-term operation stability with slip streams at ethanol plants, which is necessary to move the technology toward commercialization.

Published: July 26, 2024

Citation

Liu W., S.B. Jones, and R. Xing. 2012. High-Surface-Area Inorganic Membrane for Process Water Removal: Application to Ethanol Fuel Production Richland, WA: Pacific Northwest National Laboratory.