Enrichment of carbon dioxide by humidity and temperature swing adsorption process for agricultural greenhouses

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K15012
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Agricultural environmental engineering/Agricultural information engineering
• Research Institution: Kanazawa University
• Principal Investigator: Kodama Akio 金沢大学, 機械工学系, 教授 (30274690)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 農業工学 / 二酸化炭素 / 園芸作物 / 光合成 / 吸着 / 炭酸塩 / 再生可能エネルギー

Outline of Final Research Achievements

In general, CO2 adsorption capacity of the thermally regenerative conventional desiccant wheels is normally small or disappeared by adsorbed water vapor. Then, CO2 absorption ability of KHCO3 and NaHCO3 is attractive. Prepared KHCO3 and NaHCO3 wheels indicated relatively high CO2 and H2O removal performance. However, as time went by, the performance was getting worse. It has been reported that chemical reaction of K2CO3 with aluminum produces a substance which has high thermal stability. But, this study concluded that destruction and re-bonding of K2CO3 particle during temperature swing was also a reason for the performance decrease, basing on thermogravimetric analysis and microscope observation. For the carbon dioxide supply system for agricultural greenhouses, this gives an important guideline towards establishment of the operating method for not causing performance decrease, and a rotor production method.

Free Research Field

プロセス工学、吸着応用工学

Academic Significance and Societal Importance of the Research Achievements

環境負荷の小さいオンサイト型の二酸化炭素施用法を確立し、作物収量の増加によって農業の生産性向上と競争力増強に貢献しようとするものである。燃焼系装置が導入し難い植物工場等への導入も容易である。水蒸気共存下でも二酸化炭素除去能を有し、また安全性の高い炭酸塩の利用が望ましい。本研究では、温度スイング操作における炭酸塩の反応機構と性能低下要因をおおよそ明らかにできた。これは、性能低下を引き起こさないための運転方法およびロータ担体への添着・含浸方法の確立に向けて重要な指針を与えるものである。希薄二酸化炭素の除去濃縮プロセスの実現は、農業だけでなく、空調の省エネルギー化にも貢献できる。