Waste from Rice Industry
Biomass accounts for approximately 15% of global primary energy use and 38% of the primary energy use in developing countries. More than 80% of biomass energy is used by more than two billion consumers, many of whom have no access to modern energy services. However, in some agricultural industries, large concentrations of biomass waste can be utilised for power and heat production, thereby providing access to modern energy services. In some places rice production is industrialised to such an extent that rice husks are available in amounts sufficient for incineration in a boiler, thus, securing a basis for power and heat production.
Description of technology
Biomass primarily refers to agricultural residues that are converted into electricity and steam through direct combustion – usually of solids. Such generation involves the construction of a boiler, a steam turbine a generator and auxiliary facilities such as a water demineralisation plant, a cooling tower, air pollution control devices and a storage yard. In some cases the cooling tower may be replaced by a heat exchanger, allowing the utilisation of waste heat when there is a demand for low-temperature process heating (e.g. for drying) or cooling in the area where the power plant is located. Very often such power production replaces captive diesel power generation at the plant thereby reducing greenhouse gas emissions.
Incineration of Rice Husk
The production of rice leaves rice husks as a waste material, which may be utilised as fuel in a boiler if quantities are sufficient. It takes five tons of rice paddy to produce one ton of rice husk waste, and it takes approximately 100,000 tons of rice husk per year to fuel a 10 MW power plant. The normal yield for rice is 3-4 tons per hectare (although the yield in China is almost double that), thus, requiring approximately 150,000 hectares (1500 square kilometres) to fuel a power plant.
Biomass energy projects can be built in a wide range of sizes and for a wide range of applications. Projects can be as large as 100 MW power stations generating both electricity and heat but are typically 15-30 MW in size. Biomass energy projects are also technically feasible in much smaller sizes, but are rarely commercially viable below 8-10 MW, depending on availability and pricing of biomass residues.
Clinker Replacement in Cement
Ash from incineration of rice husk may further be used as pozzolana for cement production, where it reduces the need for clinker. This creates more options for greenhouse gas emissions reduction that may be explored if cement production facilities exist within a reasonable distance from a rice husk incineration plant. For more on the cement industry, see ‘other industrial processes’.
Sub-type
- Agricultural Residues: Rice Husk
Methodologies
- Agricultural Residues: Rice Husk
- Large Scale
- ACM0002
- ACM0003
- ACM0006
- ACM0018
- AM0004
- AM0036
- Small Scale
- AMS-I.A.
- AMS-I.C.
- AMS-I.D.
- AMS-III.E.
- AMS-III.G.
- Large Scale