Under the dual-carbon target, CO_(2) mineralization through solid wastes presents a mutually beneficial approach for permanent carbon emission reduction at a low material cost, while also enabling the resource utiliza...Under the dual-carbon target, CO_(2) mineralization through solid wastes presents a mutually beneficial approach for permanent carbon emission reduction at a low material cost, while also enabling the resource utilization of these wastes. However, despite its potential, a comprehensive understanding about the effect of industrial solid waste properties and operating parameters on the carbonation process, and the mechanism of direct aqueous carbonation is still lacking. A series of experiments were conducted to compare the carbonation performance of fly ash, steel slag, and carbide slag. Subsequently, CO_(2) mineralization by carbide slag was systematically studied under various operating parameters due to its high CO_(2) sequestration capacity. Results showed the reactivity of CaO and Ca(OH)2 was higher than that of CaO·SiO_(2) and 2CaO·SiO_(2). Carbide slag demonstrated a sequestration capacity of 610.8 g CO_(2)/kg and carbonation efficiency ζCa of 62.04% under the conditions of 65 ℃, 1.5 MPa initial CO_(2) pressure, 15 mL/g liquid-to-solid ratio, and 200 r/min stirring speed. Moreover, the formation of carbonates was confirmed through XRD, SEM-EDS, TG, and FTIR. A mechanism analysis revealed that initially, the rate of the carbonation process was primarily controlled by the mass transfer of CO_(2) in the gas–liquid interface. However, the rate-determining step gradually shifted to the mass transfer of Ca2+ in the solid–liquid interface as the reaction time increased. This study lays the foundation for the large-scale implementation of CO_(2) sequestration through carbide slag carbonation.展开更多
Kombucha is a beverage obtained by fermenting sweetened green or black tea with a symbiotic culture of bacteria and yeasts(SCOBY),which claims nutritional characteristics.As demand for kombucha increased,alternative e...Kombucha is a beverage obtained by fermenting sweetened green or black tea with a symbiotic culture of bacteria and yeasts(SCOBY),which claims nutritional characteristics.As demand for kombucha increased,alternative extracts to green or black tea such as herbs,fruits,milk,agro-industrial materials started to be used in fermentation,giving rise to kombucha-like beverages.The literature review shows that the procedure and conditions used to obtain kombucha-like beverages are similar to the traditional fermentation.However,some additional steps may be necessary to prepare the raw material for its use as an alternative to green or black tea,the main approaches being highlighted in this review.Bioactive compounds(mainly phenolics)are considered one of the main attractions of kombucha due to their antioxidant characteristics.It is observed that,regardless of the extract used,the bioactive compounds(mainly phenolics)and also the antioxidant activity tend to increase during the fermentation of these beverages.Thus,the use of alternative raw materials to tea for the preparation of kombucha is viable and tends to serve a wide range of products according to different regions of the world.These new beverages have similar characteristics to the traditional beverage and respect the diversity of consumer market trends.展开更多
This paper presents the feed marketing systems of Ethiopia in terms of feed demand and supply, feed quality issues, feed prices and price trends based on qualitative data generated through rapid market appraisal metho...This paper presents the feed marketing systems of Ethiopia in terms of feed demand and supply, feed quality issues, feed prices and price trends based on qualitative data generated through rapid market appraisal methodology. The results indicate that, the demand for roughages, agro-industrial by-products （AIBP） and compound feeds is showing increasing trend. The use of feed from commercial sources is, however, very limited due to shortage of feed supply and inefficient marketing system. The AIBP mainly from flour and grind mills, oil processing plants and breweries are in short supply and directly marketed to user or through traders. Consequently, most of the exiting feed mixers/processing enterprises are operating under capacity estimated at about 20%-30%. The main marketed roughages, which are mainly cereal straws and baled hay, are also in short supply. Feed prices are increasing from time to time and mainly exacerbated by the increasing trend in export market of AIBP and double taxation in mixed rations. There is no any feed quality control or assurance mechanism in Ethiopia. Precaution needs to be taken in the area of taxation in order to avoid double taxation. Implications to improve the feed marketing systems and opportunities for livestock development are drawn.展开更多
基金supported by China Petrochemical Corporation Scientific Research Projects(Nos.417002-4 and 418020-5).
文摘Under the dual-carbon target, CO_(2) mineralization through solid wastes presents a mutually beneficial approach for permanent carbon emission reduction at a low material cost, while also enabling the resource utilization of these wastes. However, despite its potential, a comprehensive understanding about the effect of industrial solid waste properties and operating parameters on the carbonation process, and the mechanism of direct aqueous carbonation is still lacking. A series of experiments were conducted to compare the carbonation performance of fly ash, steel slag, and carbide slag. Subsequently, CO_(2) mineralization by carbide slag was systematically studied under various operating parameters due to its high CO_(2) sequestration capacity. Results showed the reactivity of CaO and Ca(OH)2 was higher than that of CaO·SiO_(2) and 2CaO·SiO_(2). Carbide slag demonstrated a sequestration capacity of 610.8 g CO_(2)/kg and carbonation efficiency ζCa of 62.04% under the conditions of 65 ℃, 1.5 MPa initial CO_(2) pressure, 15 mL/g liquid-to-solid ratio, and 200 r/min stirring speed. Moreover, the formation of carbonates was confirmed through XRD, SEM-EDS, TG, and FTIR. A mechanism analysis revealed that initially, the rate of the carbonation process was primarily controlled by the mass transfer of CO_(2) in the gas–liquid interface. However, the rate-determining step gradually shifted to the mass transfer of Ca2+ in the solid–liquid interface as the reaction time increased. This study lays the foundation for the large-scale implementation of CO_(2) sequestration through carbide slag carbonation.
基金The authors are grateful to CAPES-PRINT,project number 88887.310560/2018-00.
文摘Kombucha is a beverage obtained by fermenting sweetened green or black tea with a symbiotic culture of bacteria and yeasts(SCOBY),which claims nutritional characteristics.As demand for kombucha increased,alternative extracts to green or black tea such as herbs,fruits,milk,agro-industrial materials started to be used in fermentation,giving rise to kombucha-like beverages.The literature review shows that the procedure and conditions used to obtain kombucha-like beverages are similar to the traditional fermentation.However,some additional steps may be necessary to prepare the raw material for its use as an alternative to green or black tea,the main approaches being highlighted in this review.Bioactive compounds(mainly phenolics)are considered one of the main attractions of kombucha due to their antioxidant characteristics.It is observed that,regardless of the extract used,the bioactive compounds(mainly phenolics)and also the antioxidant activity tend to increase during the fermentation of these beverages.Thus,the use of alternative raw materials to tea for the preparation of kombucha is viable and tends to serve a wide range of products according to different regions of the world.These new beverages have similar characteristics to the traditional beverage and respect the diversity of consumer market trends.
文摘This paper presents the feed marketing systems of Ethiopia in terms of feed demand and supply, feed quality issues, feed prices and price trends based on qualitative data generated through rapid market appraisal methodology. The results indicate that, the demand for roughages, agro-industrial by-products （AIBP） and compound feeds is showing increasing trend. The use of feed from commercial sources is, however, very limited due to shortage of feed supply and inefficient marketing system. The AIBP mainly from flour and grind mills, oil processing plants and breweries are in short supply and directly marketed to user or through traders. Consequently, most of the exiting feed mixers/processing enterprises are operating under capacity estimated at about 20%-30%. The main marketed roughages, which are mainly cereal straws and baled hay, are also in short supply. Feed prices are increasing from time to time and mainly exacerbated by the increasing trend in export market of AIBP and double taxation in mixed rations. There is no any feed quality control or assurance mechanism in Ethiopia. Precaution needs to be taken in the area of taxation in order to avoid double taxation. Implications to improve the feed marketing systems and opportunities for livestock development are drawn.
