China has abundance of biomass energy resources, from agricultural (such as straw and forestry), residential and industrial wastes, energy crops and plantations, etc. Annually, there are nearly 300 million tons of crop straw wastes, 300 million tons of forestry waste are available for fuel production. Besides biogas and municipal solid waste (MSW), the total biomass resource with equivalent of around 500 million tons of coal can be potentially converted into fuel.
Targets, Laws and Policies
With increasing demand for energy and rising environmental concerns, the Chinese government issued series of laws and policies to ensure the realization of its target that by 2010 the percentage of renewable energy share will take 10 percent of the country’s total energy consumption and by 2020 it will be 15 percent. While the percentage of the biomass energy will be largely increased (shown in the diagram above).
In order to realize the energy target, the Chinese government issued Renewable Energy Law in 2005 to support the development of the renewable energy, including biomass energy. In 2006, the law came into force and functioned as a framework for renewable energy development strategy and meant to increase the energy supply domestically, optimizing energy structure and realizing the continuous development of economy and society. Following Renewable Energy Law of the People’s Republic of China, series of regulations and policy measures are issued to support the realization of the renewable targets, such as fiscal subsidies, tax policies, pricing schemes and green production rewarding scheme.
Four schemes are identified legislatively:
- Cost–sharing scheme is meant to low energy production cost, which will be shared by the end-users, with the price as low as RMB 0.002 or US cent 0.03 per kWh averagely.
- Feed-in tariff scheme is also provided which means a certain amount will be added to the price for renewable energy production especially for the biomass energy production connected to the grid. For biomass power, the subsided in 2008 is RMB 0.25 or US cent 3.7 per kWh which is creased to RMB 0.35 or US cent 5.1 per kWh in 15 years.
- Production subsidies are provided to drive the up the conversion of various biomass wastes into biomass energy, i.e. a subsidy of RMB 130-150 or USD 19-22 is given for the production of each ton of biomass pellets.
- Preferential pricing schemes are introduced for renewable power generation.
Biomass Market Status in China
Biomass energy development in China focuses on the biomass power generation, biogas, biomass pellets and liquid biofuels. By 2020, the capacity of installed biomass power will be abound 30 GW, with the annual use of 50 million tons of biomass pellets , 44 billion cubic meters of biogas, 10 million tons of bio-ethanol, and 2 millions of bio-diesel.
In the above diagram, the biomass energy target and actual utilization of various fuels are clearly shown. Even though any type of biomass fuel is important and contributes the realization of 2020 renewable goals, solid biomass fuel will be the focus of the article because of its significant importance in China and the time and space limitation of the article.
Solid Biomass Fuel
Solid biomass fuel refers to the solid fuel made from the biomass materials, which usually refers to biomass pellets, briquettes and pucks. In 2010, around 100 biomass pellet plants in the agricultural areas have been established to produce pellets and briquettes with the unit capacity of 10,000 tons per year and with the total annual capacity of 3 million tons.
In 2010, there were around 500 pilot biomass pellets use areas, established to meet the basic energy needs in the rural areas. In 2010, 1 million tons of biomass pellet fuels were consumed nation widely in China and by 2020, the total biomass pellet consumption will be around 50 million tons. As for briquettes, 3 million tons of briquettes were consumed as bio-charcoal in heating boilers in 2010. This number will be 10 million tons in 2015, with a compound growth rate of 27 percent.
Solid Biomass Fuel Production Technologies
Most natural biomass materials cannot be utilized large scale due to low density and high moisture. The solid biomass fuel production technology makes it possible to convert the natural plant residues into solid fuels which is generally known as pelletizing and briquetting.
Biomass pellet production technology in China began in 1990s, when the unit capacity was 100- 200 kg/h. While now, with the development of technology, the unit capacity of main pellet production equipment is high up to 1-3 t/h. As for briquetting technology, the briquette production equipment widely used in China is with the capacity of 1 t/h. The small-scale briquette manufacturers produce about 280,000 tons of briquettes annually, taking more than 90 percent of the total production. As for industrial use, China has introduced over 20 large-scale briquetting production lines from other counties. By 2008, China had constructed 102 biomass production plants all over the country with the total annual production capacity of 200, 000 tons, being 7% of Chinese total production.
When it comes to industrial scales production, the total process involves a series of equipment, from the raw material preparation to the packaging of the solid biomass fuels, i.e. pellets and briquettes. Generally, the production line is consisted of the following main machines, hammer mill, dryer, conveyer, pelletizing or briquetting machine, cooler, and bagger, etc. However, the construction of the biomass pellet or briquette production line can be different according to the conditions of the raw materials and the individual situations. No matter how different they are, biomass pellet machines and briquette machines are necessary for a pellet line or a briquette line.
A typical diagram of Pellet production site
Biomass pellet machines
Ring die biomass pellet machines and flat die pellet machines are most well known two types of pellets making machines, especially the Chinese flat die pellet machines are well-known in the international market. The biomass pellet machines take advantage of the pressure and the heat caused by the mechanical integration of the pellet die and pellet rollers to reform the biomass materials into pellets. Ring die pellet machines are usually applied for large scale biomass pellet production while the flat die pellet machines are used for medium and small scale pellet production. The output capability of the flat die pellet mill ranges from around 80 to 1000 kg /h at most while the ring die pellet mill can produce around 0.8 to 2 t/h at most. For the small scale pellet production, you can read this pdf file to learn more.
Solid biomass fuel application in China
Solid biomass fuel in China are mainly use for hotel heating, industry boilers and power plants. With introducing of the Renewable Energy Law, small scale biomass stove and boilers technology developed rapidly which stimulated the installation of biomass stove and boilers. By 2009, about 400,000 biomass stoves had been installed. And the tendency of biomass stove installation in households is growing nation widely, especially in provinces like Jiangxi, Yunnan, Qinghai, etc.
With abundant biomass recourse and mature biomass power generation technologies, the utilization of solid biomass fuel in power plant is expanded, which also drives the construction of larger biomass power. The installed capacity of biomass power by the end of 2005 in China was 2 GW. With the construction of large biomass power plants, the number is expected to grow steadily and continuously. In 2011, the largest biomass power plant in the world was put into operation in Guangdong, by Yuedian Group, with two 50 MW capacity units. While in 2012, Wuhan Kaidi Electric had three biomass power plants came into operation.
Even though solid biomass fuel is developing and have gained certain achievement so far, there are still problems and obstacles.
1. proper production standard and pricing system is in want.
2. related statistic system also needs to be improved.
3. the geography obstacles. The geographically scattered agricultural production cause troubles to feedstock supply chain, which may increasing biomass fuel production cost.