Thermal Catalytic Syngas Cleanup for High-Efficiency Waste-to-Energy Converters
WP-2210
Objective
Waste disposal and fuel consumption are issues that challenge the operating logistics of deployed base camps. In response to these challenges, the military has established an objective to develop an efficient and compact waste-to-energy converter (WEC) that can be used at base camps to consume the waste and reduce it to nonhazardous ash while recovering energy that can be used to offset generator fuel consumption. Several gasification- or pyrolysis-based WECs have been pursued in past development projects, but these advanced designs have still not met the military's efficiency or size targets.
Based on these shortcomings, the objective for this project is to develop a robust, efficient, and compact syngas-cleaning system that will complement distributed-scale updraft gasifier technology. Updraft, or countercurrent, gasification is an inherently more thermally efficient conversion process that is also less sensitive to fuel pretreatment compared to other distributed gasification technologies. These characteristics can be used to design a more efficient WEC that is efficient and smaller in overall size because of the reduced number of fuel pretreatment steps. The key disadvantage of updraft gasifiers and the reason they are not commonly recommended for small-scale power production is that the resulting syngas contains significant fractions of condensable organic compounds (tars) that typically make the gas unsuitable for any purpose other than close-coupled combustion. Effective gas cleanup systems have been designed for larger updraft gasifiers that use thermal cracking, wet scrubbing, or a combination of both. However, a reliable, compact, and effective syngas-cleaning train for high-tar syngas has not been demonstrated that can meet the military's needs for a deployable WEC.
Technical Approach
The operating principle of the cleanup system is based on thermal catalytic tar cracking, which is the most feasible cleanup strategy that is also compatible with the needs of the military. In comparison to other cleanup systems, catalytic tar cracking requires smaller reactor volumes compared to pure thermal decomposition, and it does not require water as with wet scrubbing. Furthermore, catalytic cracking converts the tars into lighter, gaseous fuel components so that their energy content is not lost.
This project consists of a parametric evaluation of the catalytic cracking process followed by performance testing of a complete syngas-cleaning circuit. Results from this testing will support an engineering analysis of the solution to determine if it can meet the military's goals for minimum conversion efficiency and maximum physical size.
Benefits
The expected benefits from this project include the original goals set by the military for WEC technology: to reduce a troublesome waste disposal problem while offsetting generator fuel consumption. A key benefit of this specific approach, beyond meeting the military's conversion efficiency and size goals, is the fact that it is a dry system and no water is required for operation. This greatly simplifies operating logistics and by-product disposal issues. Furthermore, the reduced fuel-processing demands of updraft gasifiers may enable the use of a wider array of feedstocks to supplement energy production at base camps, e.g., from locally sourced biomass. (Anticipated Project Completion - 2015)
Points of Contact
Principal Investigator
Dr. Christopher Martin
University of North Dakota
Phone: 701-777-5083
Fax: 701-777-5181
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.