Alkali-activated materials have become an active research topic as adsorbents for wastewater treatment. However, their regeneration is studied less frequently. In the present study, granular alkali-activated adsorbents were prepared from metakaolin or blast furnace slag with an inclusion of commercial MgCO3/MgO/Mg silicate-rich mineral adsorbent. The granules were used in a field experiment to treat effluent from a closed mine site containing 4.3 mg/L Ni, 1.3 mg/L Mn, 0.5 mg/L Fe, and 0.6 mg/L Zn. The granule regeneration was compared with 0.3 M NaOH, 0.3 M NaCl, 0.03–1.5 M HNO3, 0.3 M CH3COOH, and 0.05 M EDTA-2Na solutions. The best-performing granule type was based on blast furnace slag with the commercial Mg-rich adsorbent and it could be regenerated effectively with 0.3 M HNO3. The adsorption performance of the granules improved upon repeated regeneration (cumulative adsorption amounts in the field experiment reaching up to 1.0 mg/g Ni, 0.3 mg/g Mn, 0.1 mg/g Fe, and 0.2 mg/g Zn per cycle) which was likely due to enhanced specific surface area (reaching up 160–190 m2/g while the initial values were 0.5–20 m2/g). The granules had a mass loss of 27 % and 9.5 % during the first and second regeneration cycle, respectively, which is likely the limiting factor in their continued reuse.
作为废水处理的吸附剂，碱活性材料已成为一个活跃的研究课题。然而，对其再生的研究却较少。本研究利用偏高岭土或高炉渣制备了颗粒状碱活性吸附剂，并加入了富含 MgCO3/MgO/Mg 硅酸盐的商用矿物吸附剂。这些颗粒被用于现场实验，处理来自封闭矿区的废水，废水中含有 4.3 mg/L 镍、1.3 mg/L 锰、0.5 mg/L 铁和 0.6 mg/L 锌。将颗粒再生与 0.3 M NaOH、0.3 M NaCl、0.03-1.5 M HNO3、0.3 M CH3COOH 和 0.05 M EDTA-2Na 溶液进行了比较。性能最好的颗粒类型是基于高炉渣的商用富镁吸附剂，它可以在 0.3 M HNO3 溶液中有效再生。颗粒的吸附性能在反复再生后有所改善（现场实验中的累计吸附量在每个循环中可达 1.0 毫克/克镍、0.3 毫克/克锰、0.1 毫克/克铁和 0.2 毫克/克锌），这可能是由于比表面积增大所致（可达 160-190 平方米/克，而初始值为 0.5-20 平方米/克）。在第一和第二个再生周期中，颗粒的质量损失分别为 27% 和 9.5%，这可能是其继续再利用的限制因素。
{"title":"Regeneration of metal-containing alkali-activated adsorbent granules from a field experiment","authors":"Nusrat Kabir , Jenna Finnilä , Johanna Laukkanen , Tero Luukkonen","doi":"10.1016/j.cherd.2024.11.017","DOIUrl":"10.1016/j.cherd.2024.11.017","url":null,"abstract":"<div><div>Alkali-activated materials have become an active research topic as adsorbents for wastewater treatment. However, their regeneration is studied less frequently. In the present study, granular alkali-activated adsorbents were prepared from metakaolin or blast furnace slag with an inclusion of commercial MgCO<sub>3</sub>/MgO/Mg silicate-rich mineral adsorbent. The granules were used in a field experiment to treat effluent from a closed mine site containing 4.3 mg/L Ni, 1.3 mg/L Mn, 0.5 mg/L Fe, and 0.6 mg/L Zn. The granule regeneration was compared with 0.3 M NaOH, 0.3 M NaCl, 0.03–1.5 M HNO<sub>3</sub>, 0.3 M CH<sub>3</sub>COOH, and 0.05 M EDTA-2Na solutions. The best-performing granule type was based on blast furnace slag with the commercial Mg-rich adsorbent and it could be regenerated effectively with 0.3 M HNO<sub>3</sub>. The adsorption performance of the granules improved upon repeated regeneration (cumulative adsorption amounts in the field experiment reaching up to 1.0 mg/g Ni, 0.3 mg/g Mn, 0.1 mg/g Fe, and 0.2 mg/g Zn per cycle) which was likely due to enhanced specific surface area (reaching up 160–190 m<sup>2</sup>/g while the initial values were 0.5–20 m<sup>2</sup>/g). The granules had a mass loss of 27 % and 9.5 % during the first and second regeneration cycle, respectively, which is likely the limiting factor in their continued reuse.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 485-492"},"PeriodicalIF":3.7,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.cherd.2024.11.016
Liang Ding , Suilong Wang , Xiaohui Li , Ting Bai , Zegang Qiu , Zhiqin Li , Zhiqing Wang , Yitian Fang
Pressurized CO2 gasification of biomass represents an effective approach for the utilization of biomass and the reduction of CO2 emissions. The impact of CO2 partial pressure on the gasification kinetics of biomass chars was examined on a pressurized thermogravimetric analyzer at temperatures between 750 and 950 °C and elevated pressures (up to 1 MPa). The findings demonstrated that the gasification rates of corn stalk char (CSC), toonasinesis sawdust char (TSC), and rice husk char (RHC) exhibited an increase with rising CO2 partial pressure. The reaction order exhibited variability with respect to CO2 partial pressure, gasification temperature, and biomass type. The reaction order associated with biomass char exhibited a higher value at the elevated CO2 partial pressure range (0.25–1.0 MPa) relative to the low CO2 partial pressure range (0.025–0.1 MPa). The nth-order model was employed to elucidate the gasification behaviors of biomass chars. The results indicated that the modified random pore model was successfully applied to model the gasification of CSC and TSC. The grain model was effective in predicting the gasification behavior of RHC. The gasification rates of the three biomass chars were accurately predicted by the Langmuir-Hinshelwood model at both low and high CO2 partial pressures. This study presents information on the effect of CO2 partial pressure on biomass char gasification and methods for predicting biomass char gasification under pressurized conditions.
{"title":"Experimental and kinetic study of pressurized CO2 gasification of biomass chars","authors":"Liang Ding , Suilong Wang , Xiaohui Li , Ting Bai , Zegang Qiu , Zhiqin Li , Zhiqing Wang , Yitian Fang","doi":"10.1016/j.cherd.2024.11.016","DOIUrl":"10.1016/j.cherd.2024.11.016","url":null,"abstract":"<div><div>Pressurized CO<sub>2</sub> gasification of biomass represents an effective approach for the utilization of biomass and the reduction of CO<sub>2</sub> emissions. The impact of CO<sub>2</sub> partial pressure on the gasification kinetics of biomass chars was examined on a pressurized thermogravimetric analyzer at temperatures between 750 and 950 °C and elevated pressures (up to 1 MPa). The findings demonstrated that the gasification rates of corn stalk char (CSC), toonasinesis sawdust char (TSC), and rice husk char (RHC) exhibited an increase with rising CO<sub>2</sub> partial pressure. The reaction order exhibited variability with respect to CO<sub>2</sub> partial pressure, gasification temperature, and biomass type. The reaction order associated with biomass char exhibited a higher value at the elevated CO<sub>2</sub> partial pressure range (0.25–1.0 MPa) relative to the low CO<sub>2</sub> partial pressure range (0.025–0.1 MPa). The <em>n</em>th-order model was employed to elucidate the gasification behaviors of biomass chars. The results indicated that the modified random pore model was successfully applied to model the gasification of CSC and TSC. The grain model was effective in predicting the gasification behavior of RHC. The gasification rates of the three biomass chars were accurately predicted by the Langmuir-Hinshelwood model at both low and high CO<sub>2</sub> partial pressures. This study presents information on the effect of CO<sub>2</sub> partial pressure on biomass char gasification and methods for predicting biomass char gasification under pressurized conditions.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 349-361"},"PeriodicalIF":3.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.cherd.2024.11.013
Aynur Yardımcı, Ozlem Tepe
Remazol Brilliant Blue R (RBBR) is a dye frequently used in the textile industry. Discharging industrial effluents containing dye residues could pose a risk to biological systems. In the present study, the removal of RBBR from aqueous solutions was tested using MnOx in both batch and continuous systems. The effects of various parameters, including the solution’s initial pH, the amount of MnOx, the initial RBBR concentration, and temperature on RBBR removal by MnOx, were investigated. The optimum pH and MnOx amount at an initial RBBR concentration of 50 mg/L and 30°C were pH 7 and 0.3 g/L, respectively, resulting in an RBBR removal efficiency of 94.43 %. The adsorption capacity was found to be 227.06 mg/g at an initial RBBR concentration of 100 mg/L, pH 7, and 30°C. The adsorption process best fit the non-linear Langmuir isotherm and Elovich kinetic models, with the least error distributions and it was characterized as exothermic and spontaneous. The activation energy value was calculated to be 92.06 kJ/mol. In the fixed bed column reactor, the equilibrium uptake (qe) was 196.30 mg at an RBBR concentration of 200 mg/L and a flow rate of 3.70 mL/min. The results imply that MnOx shows great promise for wastewater treatment contaminated with dyes.
{"title":"Investigation of Remazol Brilliant Blue R removal in batch and fixed bed column reactor systems by MnOx: Non-linear isotherm and kinetic modelling","authors":"Aynur Yardımcı, Ozlem Tepe","doi":"10.1016/j.cherd.2024.11.013","DOIUrl":"10.1016/j.cherd.2024.11.013","url":null,"abstract":"<div><div>Remazol Brilliant Blue R (RBBR) is a dye frequently used in the textile industry. Discharging industrial effluents containing dye residues could pose a risk to biological systems. In the present study, the removal of RBBR from aqueous solutions was tested using MnO<sub>x</sub> in both batch and continuous systems. The effects of various parameters, including the solution’s initial pH, the amount of MnO<sub>x</sub>, the initial RBBR concentration, and temperature on RBBR removal by MnO<sub>x</sub>, were investigated. The optimum pH and MnO<sub>x</sub> amount at an initial RBBR concentration of 50 mg/L and 30°C were pH 7 and 0.3 g/L, respectively, resulting in an RBBR removal efficiency of 94.43 %. The adsorption capacity was found to be 227.06 mg/g at an initial RBBR concentration of 100 mg/L, pH 7, and 30°C. The adsorption process best fit the non-linear Langmuir isotherm and Elovich kinetic models, with the least error distributions and it was characterized as exothermic and spontaneous. The activation energy value was calculated to be 92.06 kJ/mol. In the fixed bed column reactor, the equilibrium uptake (q<sub>e</sub>) was 196.30 mg at an RBBR concentration of 200 mg/L and a flow rate of 3.70 mL/min. The results imply that MnO<sub>x</sub> shows great promise for wastewater treatment contaminated with dyes.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 520-535"},"PeriodicalIF":3.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.cherd.2024.11.014
Rahim Boylu, Mustafa Erguvan, Shahriar Amini
This study investigates a microwave-assisted Direct Air Capture (DAC) application using Zeolite 13X to capture CO2 from the atmospheric air in Tuscaloosa, Alabama. For the regeneration process, a mono-mode solid state microwave generator with E orientation cavity was applied to desorb CO2 from the sorbent. The main purpose of this study is to explore microwave-based DAC system since there is no detailed parametric study which evaluates all desorption characteristics including temperature and microwave initial power effects on CO2 productivity, regeneration efficiency, desorption kinetics, energy consumption, temperature homogeneity, adsorption, and desorption capacities. In order to investigate all these desorption characteristics, sixteen non-cycling and ten cycling experiments were performed. In non-cycling experiments, regeneration temperature and microwave initial power changed from 45 ℃ to 100 ℃ and from 5 W to 60 W, respectively. The results illustrate that energy consumption to desorb a kg of CO2 can be as low as 60.37 MJ and 23.97 MJ for 100 % and 70 % regeneration, respectively. In cycling experiments, adsorption capacity of each experiment and the effects of 70 % desorption on the adsorption capacity of following experiments were analyzed at the lowest temperature and power conditions (45 ℃ and 5 W). It was found that 70 % desorption does not have significant effects on the adsorption capacity for the following cycles. This study also proves that complete CO2 regeneration can be achieved even at low temperature and initial power values in 3100 seconds.
{"title":"Investigation of microwave-based CO2 regeneration in a packed bed reactor for Direct Air Capture","authors":"Rahim Boylu, Mustafa Erguvan, Shahriar Amini","doi":"10.1016/j.cherd.2024.11.014","DOIUrl":"10.1016/j.cherd.2024.11.014","url":null,"abstract":"<div><div>This study investigates a microwave-assisted Direct Air Capture (DAC) application using Zeolite 13X to capture CO<sub>2</sub> from the atmospheric air in Tuscaloosa, Alabama. For the regeneration process, a mono-mode solid state microwave generator with E orientation cavity was applied to desorb CO<sub>2</sub> from the sorbent. The main purpose of this study is to explore microwave-based DAC system since there is no detailed parametric study which evaluates all desorption characteristics including temperature and microwave initial power effects on CO<sub>2</sub> productivity, regeneration efficiency, desorption kinetics, energy consumption, temperature homogeneity, adsorption, and desorption capacities. In order to investigate all these desorption characteristics, sixteen non-cycling and ten cycling experiments were performed. In non-cycling experiments, regeneration temperature and microwave initial power changed from 45 ℃ to 100 ℃ and from 5 W to 60 W, respectively. The results illustrate that energy consumption to desorb a kg of CO<sub>2</sub> can be as low as 60.37 MJ and 23.97 MJ for 100 % and 70 % regeneration, respectively. In cycling experiments, adsorption capacity of each experiment and the effects of 70 % desorption on the adsorption capacity of following experiments were analyzed at the lowest temperature and power conditions (45 ℃ and 5 W). It was found that 70 % desorption does not have significant effects on the adsorption capacity for the following cycles. This study also proves that complete CO<sub>2</sub> regeneration can be achieved even at low temperature and initial power values in 3100 seconds.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 391-404"},"PeriodicalIF":3.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.cherd.2024.11.020
Michael Schultes
Raschig Super-Ring® PLUS is a new 4th+ generation packing with optimized geometry. It offers lower pressure drop and higher capacity compared to other high-capacity random packings. This comes without sacrificing efficiency and makes this new development ideal for grass root column designs with reduced vessel diameters or for revamp cases to maximize tower capacities. The key improvement of Raschig Super-Ring® PLUS comes from the design, i.e. by arranging a more open column cross-sectional area for gas and liquid flow. The principles for new random packing designs are disclosed in the text. Details of developments for modern random packings are described in the text for the first time. Rigorous testing at various institutes supports these claims detailed further in the text along with industrial applications.
Raschig Super-Ring® PLUS 是第四代以上的新型填料，具有优化的几何形状。与其他高容量随机填料相比，它具有更低的压降和更高的容量。在不牺牲效率的情况下，这种新开发的填料非常适合于缩小容器直径的基层塔设计，或用于改造以最大限度地提高塔容量。Raschig Super-Ring® PLUS 的主要改进来自于设计，即为气体和液体流动设计了更开阔的塔横截面积。文中介绍了新型随机填料设计的原理。文中首次介绍了现代无规填料的发展细节。文中还进一步详细介绍了各种研究所进行的严格测试以及工业应用。
{"title":"Raschig Super-Ring PLUS a new 4th+ generation random packing","authors":"Michael Schultes","doi":"10.1016/j.cherd.2024.11.020","DOIUrl":"10.1016/j.cherd.2024.11.020","url":null,"abstract":"<div><div>Raschig Super-Ring® PLUS is a new 4th+ generation packing with optimized geometry. It offers lower pressure drop and higher capacity compared to other high-capacity random packings. This comes without sacrificing efficiency and makes this new development ideal for grass root column designs with reduced vessel diameters or for revamp cases to maximize tower capacities. The key improvement of Raschig Super-Ring® PLUS comes from the design, i.e. by arranging a more open column cross-sectional area for gas and liquid flow. The principles for new random packing designs are disclosed in the text. Details of developments for modern random packings are described in the text for the first time. Rigorous testing at various institutes supports these claims detailed further in the text along with industrial applications.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 332-340"},"PeriodicalIF":3.7,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Waste printed circuit boards (WPCBs) have become the major source of e-waste and offer the prospect of being a secondary resource. In this work, copper (Cu) and silver (Ag) from WPCBs leached solution were treated using the integrated emulsion liquid membrane (IELM) process. Almost complete Cu (39660 mg/L) and Ag (300 mg/L) were treated using the precipitation and ELM process, respectively. The Cu was removed and recovered as CuO nanoparticles using hydroxide precipitation at pH=8.34. Subsequently, the Cu-free WPCBs leached solution loaded with Ag was treated using the ELM process. The best optimum formulation for the stable ELM process was accomplished at 7.74 mM of Cyanex 302, 70.0 mM thiourea/2.5 mM HNO3 and 1 % w/v of Span 80 as a carrier, synergistic stripping agent, and surfactant, respectively. For high recovery of Ag, the optimum condition was obtained at a treat ratio of 1:3.243 with 200 rpm agitation speed at 4.36 minutes of extraction time. Under these conditions, more than 95 % and 80 % of Ag were successfully extracted and recovered, respectively with an enrichment ratio of 5.2. Hence, it is of great significance that this IELM process is proposed for the treatment of WPCBs leached solution.
废印刷电路板（WPCB）已成为电子垃圾的主要来源，并有望成为一种二次资源。在这项工作中，利用集成乳液膜（IELM）工艺处理了废印刷电路板浸出液中的铜（Cu）和银（Ag）。沉淀法和综合乳化液膜法分别处理了几乎完全的铜（39660 毫克/升）和银（300 毫克/升）。在 pH=8.34 的条件下，使用氢氧化物沉淀法去除铜，并以 CuO 纳米颗粒的形式回收。随后，使用 ELM 工艺处理负载有银的无铜 WPCBs 浸出液。稳定的 ELM 工艺的最佳配方为 7.74 mM 的 Cyanex 302、70.0 mM 的硫脲/2.5 mM 的 HNO3 和 1 % w/v 的 Span 80，它们分别用作载体、协同剥离剂和表面活性剂。为了获得较高的银回收率，最佳条件是处理比为 1:3.243，搅拌速度为 200 rpm，萃取时间为 4.36 分钟。在这些条件下，分别成功提取和回收了 95% 和 80% 以上的银，富集比为 5.2。因此，将这种 IELM 工艺用于处理多氯联苯浸出液具有重要意义。
{"title":"Integrated emulsion liquid membrane process for enhanced silver recovery from copper-silver leached solution","authors":"Izzat Naim Shamsul Kahar , Norasikin Othman , Shuhada A. Idrus-Saidi , Norul Fatiha Mohamed Noah , Nurul Danisyah Nozaizeli , Sazmin Sufi Suliman","doi":"10.1016/j.cherd.2024.11.018","DOIUrl":"10.1016/j.cherd.2024.11.018","url":null,"abstract":"<div><div>Waste printed circuit boards (WPCBs) have become the major source of e-waste and offer the prospect of being a secondary resource. In this work, copper (Cu) and silver (Ag) from WPCBs leached solution were treated using the integrated emulsion liquid membrane (IELM) process. Almost complete Cu (39660 mg/L) and Ag (300 mg/L) were treated using the precipitation and ELM process, respectively. The Cu was removed and recovered as CuO nanoparticles using hydroxide precipitation at pH=8.34. Subsequently, the Cu-free WPCBs leached solution loaded with Ag was treated using the ELM process. The best optimum formulation for the stable ELM process was accomplished at 7.74 mM of Cyanex 302, 70.0 mM thiourea/2.5 mM HNO<sub>3</sub> and 1 % w/v of Span 80 as a carrier, synergistic stripping agent, and surfactant, respectively. For high recovery of Ag, the optimum condition was obtained at a treat ratio of 1:3.243 with 200 rpm agitation speed at 4.36 minutes of extraction time. Under these conditions, more than 95 % and 80 % of Ag were successfully extracted and recovered, respectively with an enrichment ratio of 5.2. Hence, it is of great significance that this IELM process is proposed for the treatment of WPCBs leached solution.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 434-444"},"PeriodicalIF":3.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.cherd.2024.11.012
Viet Hung Nguyen, Arto Laari, Tuomas Koiranen
Methanol is a promising fuel and important intermediate chemical in the transformation of renewable power to chemical products since it can be directly synthesized from captured CO2 and electrolytic H2. However, the intermittency of renewable power generation poses challenges to green methanol production process design and operation, necessitating high operational flexibility to facilitate coupling with intermittent renewable power. In this study, a green crude methanol (a mixture of methanol and water from methanol synthesis) production process was dynamically modeled. The results show that the minimum load of the model is 20 %, with maximum allowable ramping rates of 3.25 %/minute for ramp-down and 2.10 %/minute for ramp-up between full and minimum load. The introduction of a standby mode, in which a make-up H2 stream is supplied when electrolytic H2 is unavailable, allows continuous operation of the process at the minimum load. With the constructed control structure, the model demonstrates that the process can effectively handle continuous variations of electrolytic H2 input.
{"title":"The effect of green hydrogen feed rate variations on e-methanol synthesis by dynamic simulation","authors":"Viet Hung Nguyen, Arto Laari, Tuomas Koiranen","doi":"10.1016/j.cherd.2024.11.012","DOIUrl":"10.1016/j.cherd.2024.11.012","url":null,"abstract":"<div><div>Methanol is a promising fuel and important intermediate chemical in the transformation of renewable power to chemical products since it can be directly synthesized from captured CO<sub>2</sub> and electrolytic H<sub>2</sub>. However, the intermittency of renewable power generation poses challenges to green methanol production process design and operation, necessitating high operational flexibility to facilitate coupling with intermittent renewable power. In this study, a green crude methanol (a mixture of methanol and water from methanol synthesis) production process was dynamically modeled. The results show that the minimum load of the model is 20 %, with maximum allowable ramping rates of 3.25 %/minute for ramp-down and 2.10 %/minute for ramp-up between full and minimum load. The introduction of a standby mode, in which a make-up H<sub>2</sub> stream is supplied when electrolytic H<sub>2</sub> is unavailable, allows continuous operation of the process at the minimum load. With the constructed control structure, the model demonstrates that the process can effectively handle continuous variations of electrolytic H<sub>2</sub> input.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 293-306"},"PeriodicalIF":3.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.cherd.2024.11.007
Honglei Yu , Lihua Fan , Dexi Wang , Hanshuo Yang , Ze Gong , Yunlong Li
Efficient dispersion of MgCl2 solution is crucial in saline lake industries. Understanding how structural variables influence atomization can improve nozzle design. This study uses Computational Fluid Dynamics (CFD) modeling to examine the effects of key structural parameters on MgCl2 solution mixing in atomization nozzles. It focuses on the impact of liquid injection hole size, number of air injection holes, and mixing chamber length on the nozzle's fluid dynamics. The analysis covers variations in internal velocity and MgCl2 volume fraction. Simulations show that increasing the liquid injection hole diameter reduces liquid flow resistance, while adding more air injection holes leads to a more uniform air distribution, though with a slight increase in atomization efficiency. A longer mixing chamber reduces gas phase velocity. Optimal mixing efficiency is achieved with 4 air injection holes, a 1.5 mm liquid injection hole, a 7 mm mixing chamber, a 2 mm nozzle outlet, 0.3 MPa inlet gas pressure, and an 80 L/h solution flow rate. This study provides insights into key parameters for improving performance and refining industrial applications.
{"title":"Enhancing mixing characteristics of MgCl2 solution within atomization nozzles: A computational fluid dynamics investigation of structural parameter","authors":"Honglei Yu , Lihua Fan , Dexi Wang , Hanshuo Yang , Ze Gong , Yunlong Li","doi":"10.1016/j.cherd.2024.11.007","DOIUrl":"10.1016/j.cherd.2024.11.007","url":null,"abstract":"<div><div>Efficient dispersion of MgCl<sub>2</sub> solution is crucial in saline lake industries. Understanding how structural variables influence atomization can improve nozzle design. This study uses Computational Fluid Dynamics (CFD) modeling to examine the effects of key structural parameters on MgCl<sub>2</sub> solution mixing in atomization nozzles. It focuses on the impact of liquid injection hole size, number of air injection holes, and mixing chamber length on the nozzle's fluid dynamics. The analysis covers variations in internal velocity and MgCl<sub>2</sub> volume fraction. Simulations show that increasing the liquid injection hole diameter reduces liquid flow resistance, while adding more air injection holes leads to a more uniform air distribution, though with a slight increase in atomization efficiency. A longer mixing chamber reduces gas phase velocity. Optimal mixing efficiency is achieved with 4 air injection holes, a 1.5 mm liquid injection hole, a 7 mm mixing chamber, a 2 mm nozzle outlet, 0.3 MPa inlet gas pressure, and an 80 L/h solution flow rate. This study provides insights into key parameters for improving performance and refining industrial applications.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 378-390"},"PeriodicalIF":3.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.cherd.2024.11.010
Sampath Suranjan Salins , Shiva Kumar , Kota Reddy , Sawan Shetty , Ana Tejero-González
Cooling towers are used in industries to remove the excess heat produced by industrial processes and machineries. This cooling phenomenon and its rate can be improved by mixing it with the nanoparticles. The present work focuses on the design and construction of a counter flow forced draft cooling tower with the addition of aluminum oxide (Al2O3) nanoparticles with water to enhance heat & mass transfer. Experiments are performed with the variation of the flow rate of water, water temperature, and the volume fraction of nanoparticles from 0 % to 2 % by volume fraction. The output parameters like coefficient of performance (COP), cooling characteristics coefficient (CCC), Rate of evaporation (ER), cooling tower efficiency & range have been analyzed. Nanofluid properties like viscosity, density & thermal conductivity for different volume fractions have been examined. It is observed that viscosity and thermal conductivity increased with an increase in volume fractions. Viscosity decreased whereas conductivity increased with temperature rise. Results obtained from cooling tower experiments indicated a maximum COP, CCC, ER, efficiency, and range equal to 7.12, 3.54, 3.95 g/s, 75.55 %, and 29.8ᵒC, respectively. For the various volume fractions studied, nanofluid with 2 % outperformed others with higher heat transfer rates and range values. For the 2 % volume fraction of the nanoparticles, make-up water requirements reduced by 76.19 % when it is compared to the normal water without the nanoparticles. Also, it is found that the cooling tower range, heat transfer rate, and efficiency increased by 10 %, 10.2 %, and 4.16 % when nanofluid concentration is varied from 0 % to 2 % by volume for the air velocity and water flow rate of 13 m/s and 3.5 Liters per minute (LPM) respectively.
{"title":"Experimental investigation in a forced draft wet cooling tower using aluminum oxide nano particles","authors":"Sampath Suranjan Salins , Shiva Kumar , Kota Reddy , Sawan Shetty , Ana Tejero-González","doi":"10.1016/j.cherd.2024.11.010","DOIUrl":"10.1016/j.cherd.2024.11.010","url":null,"abstract":"<div><div>Cooling towers are used in industries to remove the excess heat produced by industrial processes and machineries. This cooling phenomenon and its rate can be improved by mixing it with the nanoparticles. The present work focuses on the design and construction of a counter flow forced draft cooling tower with the addition of aluminum oxide (Al2O3) nanoparticles with water to enhance heat & mass transfer. Experiments are performed with the variation of the flow rate of water, water temperature, and the volume fraction of nanoparticles from 0 % to 2 % by volume fraction. The output parameters like coefficient of performance (COP), cooling characteristics coefficient (CCC), Rate of evaporation (ER), cooling tower efficiency & range have been analyzed. Nanofluid properties like viscosity, density & thermal conductivity for different volume fractions have been examined. It is observed that viscosity and thermal conductivity increased with an increase in volume fractions. Viscosity decreased whereas conductivity increased with temperature rise. Results obtained from cooling tower experiments indicated a maximum COP, CCC, ER, efficiency, and range equal to 7.12, 3.54, 3.95 g/s, 75.55 %, and 29.8ᵒC, respectively. For the various volume fractions studied, nanofluid with 2 % outperformed others with higher heat transfer rates and range values. For the 2 % volume fraction of the nanoparticles, make-up water requirements reduced by 76.19 % when it is compared to the normal water without the nanoparticles. Also, it is found that the cooling tower range, heat transfer rate, and efficiency increased by 10 %, 10.2 %, and 4.16 % when nanofluid concentration is varied from 0 % to 2 % by volume for the air velocity and water flow rate of 13 m/s and 3.5 Liters per minute (LPM) respectively.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 281-292"},"PeriodicalIF":3.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.cherd.2024.11.004
Bin Wang , Weitong Pan , Zichao Hu , Guoyu Zhang , Longfei Tang , Xueli Chen , Fuchen Wang
The flow distribution in the Flow Field Plate (FFP) has a significant impact on the performance and durability of large-scale Proton Exchange Membrane (PEM) fuel cells. Most of the existing studies focused only on gas-phase flow, while the actual cell operation is gas-liquid two-phase flow. In this study, numerical simulations of single- and two-phase flow distributions are performed for three-dimensional FFPs. The Coefficient of Variation (CV), defined as the ratio between the standard deviation and the mean of the velocities in channels, serves as the indicator of flow uniformity. Firstly, the differences between gas- and two-phase flow distribution characteristics of the FFP with the combined-mesh-type transition zone we previously constructed are elucidated. Secondly, a re-optimized layout with horizontal mesh apertures in the distribution zone and the addition of horizontal mesh in the collection zone is proposed. The design philosophy and methodology based on the coupled flow and resistance regulation mechanism are elucidated. The single- and two-phase CV values are further reduced by 41.25 % and 6.05 %, respectively. Thirdly, the re-optimized structure is applied to different FFP geometries, including smaller development spaces and larger cell areas, where the superior effects on flow distribution are validated.
{"title":"A re-optimized design of mesh-type transition zone for large-scale PEM fuel cells considering two-phase flow distribution","authors":"Bin Wang , Weitong Pan , Zichao Hu , Guoyu Zhang , Longfei Tang , Xueli Chen , Fuchen Wang","doi":"10.1016/j.cherd.2024.11.004","DOIUrl":"10.1016/j.cherd.2024.11.004","url":null,"abstract":"<div><div>The flow distribution in the Flow Field Plate (FFP) has a significant impact on the performance and durability of large-scale Proton Exchange Membrane (PEM) fuel cells. Most of the existing studies focused only on gas-phase flow, while the actual cell operation is gas-liquid two-phase flow. In this study, numerical simulations of single- and two-phase flow distributions are performed for three-dimensional FFPs. The Coefficient of Variation (<em>CV</em>), defined as the ratio between the standard deviation and the mean of the velocities in channels, serves as the indicator of flow uniformity. Firstly, the differences between gas- and two-phase flow distribution characteristics of the FFP with the combined-mesh-type transition zone we previously constructed are elucidated. Secondly, a re-optimized layout with horizontal mesh apertures in the distribution zone and the addition of horizontal mesh in the collection zone is proposed. The design philosophy and methodology based on the coupled flow and resistance regulation mechanism are elucidated. The single- and two-phase <em>CV</em> values are further reduced by 41.25 % and 6.05 %, respectively. Thirdly, the re-optimized structure is applied to different FFP geometries, including smaller development spaces and larger cell areas, where the superior effects on flow distribution are validated.</div></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":"212 ","pages":"Pages 217-229"},"PeriodicalIF":3.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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