Abstract
Algae are considered as a promising alternative fuel to produce energy due to its advantages such as high production yield, short growth cycle and flexible growing environment. Unfortunately, ash-related issues restrict its thermochemical utilization due to the high ash content and especially the high alkali metal concentration. In this paper, the gasification performance and ash behavior were experimentally analysed for three macro- and micro-algal species. Clear differences in the proximate and ultimate compositions were found between the cultivated algae used in this study and macroalgae (seaweed) harvested from the marine environments. Algal biomass generally contained higher Na and P contents than lignocellulosic biomass. Microalgae also had a relatively high mineral content due to the impurities in the harvesting process which included centrifugal pumping followed by sedimentation. Co-gasification of 20 wt% algae with softwood was investigated using an entrained flow reactor. The addition of both macroalgal species Derbersia tenuissima and Oedogonium to softwood had a limited influence on the gas yields and carbon conversion. On the other hand, the addition of the microalgal species Scenedesmus significantly decreased the main gas yields and carbon conversion. Moreover, the addition of algae clearly changed the residual ash composition of the base fuel. Finally, a preliminary understanding of the ash behavior of the tested algae blends was obtained through the analysis of the fuel ashes and the collected residual ashes. Fouling and corrosion were presumably occurred during the co-gasification of wood/macroalgae blends in view of the high alkali metal content. Microalga Scenedesmus had a high mineral content which could potentially capture the alkali metal in the ash and mitigate fouling when gasified with softwood. The growing environment and harvesting method were found to be significantly affecting the ash behavior implying the need for careful consideration regarding co-gasification process.
| Original language | English |
|---|---|
| Pages (from-to) | 26-34 |
| Number of pages | 9 |
| Journal | Fuel Processing Technology |
| Volume | 175 |
| DOIs | |
| Publication status | Published - 15 Jun 2018 |
| MoE publication type | A1 Journal article-refereed |
Funding
This research was supported by the Gasification of Algae: Swedish−Australian Research Platform (GASAR) Project funded through the Swedish Foundation for International Cooperation in Research and Higher Education (STINT), Natural Science Foundation of China (51706210), Provincial Key Research Project of Higher Education Institutions in Henan (Project 15600097), Doctoral Research Foundation of Zhengzhou University of Light Industry (13100368), the Swedish Strategic Research Program Bio4Energy, Australian Research Council's Linkage Projects Funding Scheme (Project LP100200616) with our industry partner SQC Pty Ltd., the Australian Government through the Australian Renewable Energy Agency (ARENA), and the Advanced Manufacturing Cooperative Research Centre (AMCRC), funded through Australian Government's Cooperative Research Centre Scheme. The financial support of J. Gust. Richert stiftelse is also appreciated. Francesco G. Gentili greatly appreciates the financial support of the Swedish Energy Agency and SP Processum. The authors also acknowledge the support of Muradel Pty Ltd. and MBD Energy. Dr. Britt Andersson at Umeå University is acknowledged for help during SEM/EDX analyses. Dr. Marie Magnusson at James Cook University is acknowledged for the culture and supply of algal pellets. This research was supported by the Gasification of Algae: Swedish−Australian Research Platform (GASAR) Project funded through the Swedish Foundation for International Cooperation in Research and Higher Education (STINT), Natural Science Foundation of China ( 51706210 ), Provincial Key Research Project of Higher Education Institutions in Henan (Project 15600097 ), Doctoral Research Foundation of Zhengzhou University of Light Industry ( 13100368 ), the Swedish Strategic Research Program Bio4Energy, Australian Research Council 's Linkage Projects Funding Scheme (Project LP100200616 ) with our industry partner SQC Pty Ltd., the Australian Government through the Australian Renewable Energy Agency (ARENA), and the Advanced Manufacturing Cooperative Research Centre (AMCRC), funded through Australian Government's Cooperative Research Centre Scheme. The financial support of J. Gust. Richert stiftelse is also appreciated. Francesco G. Gentili greatly appreciates the financial support of the Swedish Energy Agency and SP Processum. The authors also acknowledge the support of Muradel Pty Ltd. and MBD Energy. Dr. Britt Andersson at Umeå University is acknowledged for help during SEM/EDX analyses. Dr. Marie Magnusson at James Cook University is acknowledged for the culture and supply of algal pellets.
Keywords
- Algae
- Ash behavior
- Ash transformation
- Co-gasification
- Fouling
