Energy Utilization and Environmental Aspects of Rice Processing Industries in Bangladesh

Abstract

Abstract:In this study, the energy utilization and environmental aspects of the rice processing industries in Bangladesh was analyzed. Rice husk, a milling by-product of rice, is used as a source of thermal energy to produce steam for parboiling of raw rice. The rice is mostly dried on a concrete floor under the sunshine. In mechanical drying, rice husks are used as a source of primary energy. In Bangladesh, the annual estimated energy used in 2000 for the drying of rice by sunshine was 10.7 million GJ and for drying and parboiling by rice husks it was 48.2 million GJ. These amounts will increase to 20.5 and 92.5 million GJ in 2030, respectively. Electrical energy consumption for mechanical drying and milling of rice was calculated as 1.83 million GJ e and 3.51 million GJ e in 2000 and in 2030, respectively. Biogenic carbon dioxide emission from burning of rice husk is renewed every year by the rice plant. Both the biogenic and non-biogenic carbon dioxide emissions in 2000 were calculated as 5.7 and 0.4 million tonnes, respectively, which will increase to 10.9 and 0.7 million tonnes in 2030. The demand of energy for rice processing increases every year, therefore, energy conservation in rice processing industries would be a viable option to reduce the intensity of energy by increasing the efficiency of rice processing systems which leads to a reduction in emissions and an increased supply of rice husk energy to other sectors as well.

Arsenic Bioaccessibility in Cooked Rice as Affected by Arsenic in Cooking Water

“…The average concentration in the discarded gruel was 38, 37, 66, 282, and 499 μg As L −1 when cooking water with 0, 10, 47, 222, and 450 μg As L −1 was used, respectively. This could worsen the scenario of As exposure in As‐endemic areas since discarded gruel is widely used to feed livestock and it is also often consumed by humans, especially from poverty stricken families (Roy and others 2007; Ahiduzzaman and Sadrul‐Islam 2009; Rahman and Hasegawa 2011). Livestock are fed rice straw, rice bran, rice gruel, and they also drink As contaminated water.…”

Harvesting electrical power from waste heat using stirling engine

“…The thermal efficiency of the rise mills is very low (15-30%) [10].The amount of heat wasted in brick fields is about 50-60% [11].…”

Energy use pattern in rice milling industries—a critical appraisal

“…(2) Cyclone type husk fired furnace According to Ahiduzzaman and Islam (2009) the principle of operation of cyclone furnace is similar to that of vortex burner. The centrifugal force keeps the fuel particles rotating in fixed circles according to their size in equilibrium against the drag of inwardly spiraling air so that relative motion between air and the fuel accelerate combustion.…”

“…An energy analysis was conducted by Ahiduzzaman and Islam (2009) on the steam power plant of a large white mill. The boiler fired by paddy husk raised steam for a steam engine coupled to a generator.…”