CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Yunqi Wu,Tinggui Yan,Weixue Xiang,Peixu Zhu,Nanxi Luo,Banglian Tang,Miao Luo
Co-combusting biomass with sewage sludge can effectively inhibit the release of alkali metals. In addition to calcium phosphates, AlPO 4 and FePO 4 are typical phosphates in fresh sludge, resulting from phosphorus removal process compliant discharge. However, the inhibitory effect of AlPO 4 and FePO 4 on potassium release have rarely been studied. This oversight may stem from the absence of AlPO 4 and FePO 4 in high-temperature ash, which instead indicates their preferred reactivity. Thus, we proposed the hypothesis regarding whether the fixation effect of AlPO 4 and FePO 4 on potassium occurs earlier than that of calcium phosphate. This research investigated the interactions and inhibitory effects of these phosphates on potassium release during the co-combustion. In this simplified system using model compounds, the conversion of volatile potassium salts was quantitively assessed by measuring the content of produced water-soluble K-phosphates. The interaction mechanism has been discussed with multiple characterization methods. The results demonstrate a significant inhibitory effect of phosphates on KOH, KNO 3 and K 2 CO 3 , with the effectiveness ranking as follows: AlPO 4 > FePO 4 > Ca 3 (PO 4 ) 2 . Over 80 % of potassium remained as soluble K-phosphates in samples treated with AlPO 4 or FePO 4 at 1000 ℃. In contrast, none of the three additives exhibited a significant inhibitory effect on KCl and K 2 SO 4 . However, the priority of the reactions converting KOH, KNO 3 and K 2 CO 3 into K-phosphates by using AlPO 4 and FePO 4 , along with the stability of the produced phosphates, suggests a promising approach to enhance the formation of more potassium phosphate while reducing KCl—the most problematic volatile component—thereby effectively mitigating potassium release.
CAS / MDL:
研究领域:
环境科学
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能源与燃料
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2024
·
IF 3.5
Yao Pin,Yan Tinggui,Dai Xin,Xiao Ya,Xiang Weixue,Wu Yunqi
Deposition and corrosion in boilers caused by the release of alkali compounds in agricultural residua pose significant challenges to the widespread utilization of biomass energy. Phosphate tailings (PT), which is rich in Ca, Mg, and P, have the potential to mitigate the potassium (K) release of biomass straw. However, the impact of PT on K immigration has not been investigated. To elucidate the influence of PT on K immigration, thermal analysis, K concentration determination, and mineral evolution during heating of ash were conducted. These results were compared with those obtained from biomass mixed with kaolin, an effective additive known to alleviate K release in biomass. The findings revealed that PT resulted in lower K release at temperatures below 600 ℃ compared to kaolin. Because the reaction between PT and K-compounds to form K-phosphate occurs more readily than the formation of K-silicate at lower temperatures. However, the effectiveness of PT diminished as the temperature increased. One reason is the decomposition of K-phosphate, resulting in the volatilization of K at higher temperatures. Another reason is the competition among Ca, Mg, and K for the opportunity to react with Si and Al, leading to the formation of more stable Ca and Mg aluminosilicate and facilitating the release of K. It is noteworthy that the addition of kaolin to rice straw causes a violent release of K in 1000–1200 ℃. This can be attributed to the surplus of Si in the system, promoting the release after the eutectic melting between K-silicate and SiO 2 .
研究领域:
能源与环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2020
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IF 6.551
Huiying Zhang,Qingyang Li,Xia Zhang,Weifeng Chen,Jinzhi Ni,Liuming Yang,Ran Wei
A crucial mechanism for the application of biochar in soil improvement is the direct release of nutrients from biochar. Low molecular weight organic acids (LMWOAs) ubiquitously exist in soil. However, the mechanism of LMWOAs-mediated release of nutrients from biochars remains little known. Ten biochars with different mineral element stoichiometric ratio were produced, and four LMWOAs [acetic (HAc), glycolic (GA), tartaric (TA), and citric acids (CA)] were employed, to enunciate the influence mechanism of LMWOAs on the release of phosphorus and potassium from biochar. The results showed that HAc suppressed the release of P from biochars, while TA and CA facilitated the release of P from biochars with high ratios of polyvalent metals to P. A new mechanism was proposed that the deprotonated HAc combined with the dissolved HPO 4 2− or H 2 PO 4 − to form a complex through hydrogen bond and cation bridging. The hydrophobic methyl group of HAc was exposed outside of the complex, which decreased the water-solubility of phosphate. Meanwhile, a high ratio of polyvalent metals to P benefited more P to combine with polyvalent metals, which decreased the water-solubility of P, but the deprotonated TA and CA are polyvalent anions that could substitute this part of P by anion exchange. Also, LMWOAs promoted the release of K from biochars with low K/(P + S) ratios, possibly due to unionized carboxyl of LMWOAs served as a hydrogen bond donor to displace K out of biochars. This study gives a deep understanding of the fate of biochar originated nutrients response to LMWOAs.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2023
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IF 11.2
Chenxi Niu,Zhibo Lin,Qian Fu,Yutao Xu,Youhui Chen,Lingbin Lu
In this paper, an eco-friendly versatile superabsorbent material was designed for soil improvement, and a synchronous chemical loading strategy was proposed. In this strategy, urea not only acted as fertilizer but also acted as a crosslinker to construct an alginate network. The microstructure, chemical structure, thermal stability and composition of the obtained SA/urea hydrogel were characterized in detail. Adsorption behavior and application performance in agriculture were evaluated. The results demonstrated that urea had two different conformations in the network. The SA/urea hydrogel had abundant pore structures with excellent water absorption performance. It could not only improve the water retention capacity of soil but also release nitrogen, phosphorus and potassium elements with degradation for as long as 9 weeks. Moreover, the hydrogel could promote plant growth, increase the nutritional composition of plants and inhibit the accumulation of harmful nitrate in plants. With advantages, including biodegradability , high water absorption, controllable degradation, excellent water retention, sustained NPK release and improved plant nutrition value, the SA/urea hydrogel has great potential for soil improvement in agriculture as an eco-friendly versatile water retention agent and can be expected to extend to more fields as a novel superabsorbent material.
研究领域:
农业科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）