Comprehensive environmental and economic analysis of active‐mode greenhouse solar dryers for green peas processing

Abstract In the natural drying, as the agro products are directly bare to the sun, nutrition's have been lost and the quality is spoiled by dust particles, insects etc. In this work to perform drying experiments on red chili and green peas, four greenhouse solar dryers are designed with two dissimilar roof shapes and cover materials. The roof shapes investigated are even span and parabolic and covering materials such as polyethylene and poly vinyl chloride sheets. All the four dryers consist of three layers as black painted plywood at the bottom, black PVC sheet of 3 mm thickness in the middle and the upper layer is prepared with Stainless Steel mesh tray which is used to place the product to be dried. To study the results with two different roofs shape and cover materials by using green peas. The outcomes show that humidity is reduced from 76% to 8%(wet basis) in the dryer of parabolic shape with polyethylene cover material within 20 solar hours whereas open sun drying requires 36 solar hours, hence it is efficient in saving the drying time of 44.4%. Thermal and environmental analyses are carried out to ensure the efficiency of the dryer and environmental impact. The net CO 2 mitigation was calculated to be 22.07 tons, and the generated carbon credit was calculated to be Rs. 21,006. The total quantity of dried green peas from each greenhouse solar dryer is estimated as 52 kg and reimbursement period for the parabolic polyethylene greenhouse solar dryer is 2 years.