Rice production, processing, and distribution
Rice production, processing, and distribution are some of the major sources of income and labor in the Indonesian economy. Rice is consumed by more than 40% of Indonesia’s population. Per capita, rice consumption increased sharply from 110 kg in 1968 to 146 kg in 1983 and the increase appeared sluggish after achieving rice self-sufficiency.
Several things have spurred an increase in demand for rice, namely an increase in per capita consumption, an increase in population, and an economic improvement that has prompted a shift in the diet from non-rice to rice. In 1992-1996 rice consumption was around 150 kg/capita/year and there has been a slight decrease since the multidimensional crisis occurred in 1998.
Facts on the ground show that the rate of increase in rice production tended to be low after the achievement of rice self-sufficiency in 1984, even starting in 1994 our country became a rice importer again. Currently, the rate of increase in rice production is only 50% of the rate of population growth.
In the process of milling rice into milled rice
- Husk (15-20%), which is part of the covering / outer shell of the seeds.
- Bran/bran (8-12%) which is the epidermis, is produced from the rubbing process.
- Menir (± 5%) is part of crushed rice. If the national dry milled unhulled rice production is 49.8 million t / year, it will obtain 7.5-10 million tonnes of the husk, 4-6 million tonnes of bran/bran and 2.5 million tonnes of groats.
Utilization of these by-products is still limited, sometimes it even becomes waste and pollutes the environment, especially in rice production centers during the rainy season harvest.
These by-products actually have good economic and use-value if handled properly so that they can increase added value in the paddy agro-industrial system in rural areas.
Several alternatives to the utilization of these results will be described in this article, both from the results of research, experiences, and community habits that need to be disseminated.
Rice Husk as an Alternative Energy
Waste is often defined as waste material / residual material from the processing of agricultural products. The process of natural waste destruction is slow so that the waste not only disturbs the surrounding environment but also disturbs human health.
At every rice mill, we will always see piles and even mountains of husks that are getting higher and higher. Currently, the use of rice husks is still very little, so the husks remain a waste material that disturbs the environment.
The husk is categorized as biomass
Rice husk is a hard layer that includes caryopsis which consists of two parts called lemma and palea which are interlocked. In the process of milling rice, the husks will separate from the rice grains and become residual materials or milling waste. The husk is categorized as biomass which can be used for various needs such as industrial raw materials, animal feed, and energy or fuel.
From the rice milling process, usually, about 20-30% of the grain weight is obtained. The use of rice husk energy aims to reduce the cost of fuel for farmer households. The use of fuel oil whose price continues to increase will affect the household costs that must be spent every day.
From the rice milling process, usually, about 20-30% of the husk, 8-12% of the bran, and 50-63.5% of milled rice are obtained. Husk with a high percentage can cause environmental problems. In terms of chemical composition data, husks contain several important chemical elements as can be seen below.
Chemical composition of rice husks
- Water content: 9.02%
- Crude protein: 3.03%
- Fat: 1.18%
- Crude fiber: 35.68%
- Ash: 17.17%
- Basic carbohydrates: 33.71
- Carbon (charcoal): 1.33%
- Hydrogen: 1.54%
- Oxygen: 33.64%
- Silica: 16.98%
Benefits of Rice Husk
With the composition of chemical content as above, husks can be used for various purposes including:
- As a raw material for the chemical industry, especially furfural chemical substances which can be used as a raw material in various chemical industries.
- As a raw material for the building materials industry, especially the silica (sio2) content which can be used for mixtures in the manufacture of Portland cement, insulation materials, husk-board, and mixtures in the red brick industry.
- As a source of heat energy for various human needs, high levels of cellulose can provide even and stable combustion.
Husk has a bulk density of 1.125 kg / m3, with a calorific value of 1 kg of the husk of 3300-kilo calories.