Heat Pump Drying of Kelp (Laminaria japonica): Drying Kinetics and Thermodynamic Properties

Zhang, Qian; Li, Shiyu; Zhang, Minqi; Mu, Gang; Li, Xiuchen; Zhang, Guochen; Xiong, Shanbai

doi:10.3390/pr10030514

Cited by 11 publications

(7 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This may be due to the rapid evaporation on the surface of kelp, which makes it difficult to form a stable water concentration difference between the surface and the interior of kelp [ 26 ]. The results were consistent with the pattern observed by Zhang et al [ 9 ] in the HP for small-sized kelp slices, though the drying time of the proposed SHPD was shortened by 2–7 h. In addition, when the temperature was 40−50 °C, the drying time of HP was 33% longer than that of S−HP, and the average drying rate was 7.3% lower, indicating that solar irradiation could significantly improve the drying rate of kelp.…”

Section: Resultssupporting

confidence: 93%

“…This indicated that the Page model could describe the drying kinetics of kelp more accurately. In a previous study on the HP for small-sized kelp slices, the Page model also demonstrated effective fitting to the variations in MRs [ 9 ], but Samimi et al [ 27 ] and Roa et al [ 28 ] found that the Aghbashlo model and the Midilli−Kucuk model were better in describing solar hot air drying of tomato slices and in solar drying of cherries.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, the introduction of solar irradiation facilitated energy penetration through the surface to realize direct heating for the interior. Since the thickness of kelp slices could significantly change the activation energy and enthalpy of the kelp [ 9 ], the thermal radiation in S−HP mode made up for the defect that the heat convection energy provided by the simple HP mode cannot quickly penetrate into the interior of kelp, and the efficient heat transfer contributed to the rapid moisture migration.…”

Section: Resultsmentioning

confidence: 99%

“…This method transfers heat from low-temperature media to high-temperature media, which can reduce energy consumption and improve the quality of its products. Zhang et al [ 9 ] studied the kinetic and thermodynamic characteristics of HP for kelp and discovered that temperature, wind speed, humidity, and kelp thickness all affected the kinetic characteristics of HP. In the study, the ideal condition for kelp drying was a temperature of 40 °C, a wind speed of 1.3 m/s, and a humidity of 40%, without considering the heat pump system’s performance.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Design of a Greenhouse Solar-Assisted Heat Pump Dryer for Kelp (Laminaria japonica): System Performance and Drying Kinetics

Kang

Zhang

et al. 2022

Foods

Self Cite

View full text Add to dashboard Cite

In order to solve a series of problems with kelp drying including long drying time, high energy consumption, low drying efficiency, and poor quality of dried kelp, this work proposes the design of a novel greenhouse double-evaporator solar-assisted heat pump drying system. Experiments on kelp solar-assisted heat pump drying (S−HP) and heat pump drying (HP) under the condition of irradiance of 100−700 W/m2 and a temperature of 30, 40, or 50 °C were conducted and their results were compared in terms of system performance, drying kinetics, and quality impact. The drying time was reduced with increasing irradiance or temperature. The coefficient of performance (COP) and specific moisture extraction rate (SMER) of S−HP were 3.590−6.810, and 1.660−3.725 kg/kW·h, respectively, roughly double those of HP when the temperatures are identical. The Deff of S-HP and HP were 5.431 × 10−11~11.316 × 10−11 m2/s, and 1.037 × 10−11~1.432 × 10−11 m2/s, respectively; additionally, solar radiation greatly improves Deff. The Page model almost perfectly described the changes in the moisture ratio of kelp by S−HP and HP with an inaccuracy of less than 5%. When the temperature was 40 °C and the irradiance was above 400 W/m2, the drying time of S−HP was only 3 h, and the dried kelp maintained the green color with a strong flavor and richness in mannitol. Meanwhile, the coefficient of performance was 6.810, the specific moisture extraction rate was 3.725 kg/kWh, and the energy consumption was 45.2%, lower than that of HP. It can be concluded that S−HP is highly efficient and energy-saving for macroalgae drying and can serve as an alternate technique for the drying of other aquatic products.

show abstract

Section: Resultssupporting

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Design of a Greenhouse Solar-Assisted Heat Pump Dryer for Kelp (Laminaria japonica): System Performance and Drying Kinetics

Kang

Zhang

et al. 2022

Foods

Self Cite

View full text Add to dashboard Cite

show abstract

“…HPD recycles the sensible and latent heat in the exhaust gas during drying, reducing energy consumption. It is the most suitable new environmental-friendly and energy-saving drying method to replace traditional drying at this stage and has been employed in the drying of kelp (Zhang et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

Impact of Various Drying Technologies on the Drying Characteristics, Physico-chemical Properties, and Antioxidant Capacity of Walnut Green Husk

Ao,

Wang,

Shen

et al. 2024

Food Bioprocess Technol

View full text Add to dashboard Cite

Walnut green husk (WGH) is common agricultural by-product with high yield and serious pollution. The present study aimed to evaluate the impacts of solar drying (SD), pulsed vacuum drying (PVD), short and medium infrared radiation drying (SMIR), hot air drying based on temperature and humidity control (TH-HAD), and heat pump drying (HPD) on the drying characteristics, energy consumption, physicochemical properties, bioactive compounds content and antioxidant capacity of WGH. Drying characteristics and drying kinetics showed that artificial drying can significantly improve drying efficiency. Compared with SD, the drying time of PVD, SMIR, TH-HAD, and HPD were reduced by 63.57%, 78.68%, 66.28%, and 53.97%, respectively. Specific energy consumption analysis demonstrated that HPD showed the lowest specific energy consumption, 2.15 kW•h/kg. Hydration properties analysis revealed PVD had the best water holding capacity and HPD sample had the best water solubility index (43.44%). Structural analysis showed the cell wall structure of WGH was damaged by different drying methods. Overall, Among the five drying methods, HPD has lower energy consumption, less time, and maintains good antioxidant activity. HPD has good potential in the commercial-scale production of WGH.

show abstract

Drying kinetics and mathematical modeling of seeds of two mango varieties at different temperatures and with different pretreatments

Gebre,

Keneni,

Gebremariam

et al. 2024

Biofuels Bioprod Bioref

View full text Add to dashboard Cite

Increasing global waste generation is not only a threat but also an opportunity to address energy insecurity and pollution using green valorization techniques. However, this requires pretreatment of waste and byproducts and optimization of drying to obtain high‐quality biofuels. Hence, this study aims to analyze the performance of currently used drying models, the influence of different drying temperatures, drying time, and seed pretreatment on the drying kinetics of two varieties of mango seed. Accordingly, whole seeds and crushed seeds were exposed to five drying temperatures (313–353 K) in a heating furnace. Weight loss was recorded systematically, converted into moisture ratio, and then fitted to four semitheoretical mathematical models, namely: (i) Lewis, (ii) Henderson and Pabis, (iii) Page, and (iv) Avhad and Marchetti models. The fitness of these models was compared using statistical parameters, such as R2, X2, root mean square error (RMSE), mean bias error (MBE), and mean absolute error (MAE). The results showed that seed pretreatment and increasing the drying temperature led to an increase in the rate of moisture evaporation and reduced the time required for drying. Among all models, the Avhad and Marchetti model provided higher R2 values of 0.9994 and 0.9991 for local and hybrid mango at 313 K, and 0.9977, and 0.9970 for local and hybrid crushed mango seeds at 353 K and 313 K, respectively; hence, it showed the best performance. The activation energy (Ea) showed a slight differences for both varieties of mango seed and among pretreatments in all mathematical models. The mean Ea values for local and hybrid mango seeds were 41.18 kJ mol−1 and 46.21 kJ mol−1, respectively. For whole and crushed local and hybrid mango varieties, the mean Ea values were 31.37 kJ mol−1, 40.80 kJ mol−1, 50.99 kJ mol−1, and 51.61 kJ mol−1. The likely reason for this variation might be differences in variety, chemical composition, growing conditions, and cellular structure of the seed varieties.

show abstract

Heat Pump Drying of Kelp (Laminaria japonica): Drying Kinetics and Thermodynamic Properties

Cited by 11 publications

References 33 publications

Design of a Greenhouse Solar-Assisted Heat Pump Dryer for Kelp (Laminaria japonica): System Performance and Drying Kinetics

Design of a Greenhouse Solar-Assisted Heat Pump Dryer for Kelp (Laminaria japonica): System Performance and Drying Kinetics

Impact of Various Drying Technologies on the Drying Characteristics, Physico-chemical Properties, and Antioxidant Capacity of Walnut Green Husk

Drying kinetics and mathematical modeling of seeds of two mango varieties at different temperatures and with different pretreatments

Contact Info

Product

Resources

About