Prof.Xiao Bo’s Team “TURNED” Scrap Firewood into Clean Coal

December 13, 2015

A lot of biomasses, including straw and weeds, withered branches and fallen leaves, crap materials from trees, are often deserted or combusted following with various pollutants. However, the research team of Professor Xiao Bo, School of Environmental Science & Engineering, HUST, has made these biomasses turned into treasures. On June 3rd, this research team reported that these biomasses could be crushed into the micro-materials through the PIPR technology. Then the micro-materials could achieve the controlled combustion using the principle of dust explosion and the temperature could reach to a high temperature of more than 1450℃. So, the micro-materials had the same combustion value with the coals and natural gases. And, it will be possible that the renewable low-pollution biomass energy can replace the increasing shortage of fossil energy.

The core of industry is the process of high temperature production. The important industrial materials and power equipments couldn’t operate without the high temperature. However, the direct combustion of biomasses can only produce a temperature of 600℃-700℃. What’s more, it also produces a lot of black smoke mainly composed of tar and light powder carbon, which can lead to haze. In recent years, biomasses have been used in power generation and steam production of industrial boilers. However, these biomasses are processed into lumps and granules, and the combustion could only reach to an average temperature of 900℃. The tars and light powdered carbons were also generated. So, the utilization of biomasses is faced with the long-term problem following with its low producing temperature, low thermal energy efficiency and high environmental pollution.

Since 2002, Xiao Bo’s team has developed their researches on micron fuels of biomass and combustion technology with high temperature. They have owned some breakthrough recently. The team used their self-invented equipment to crush the biomasses into granules with a diameter below 250 microns, called “micron fuel”, a powder fuel just like flour. The micron fuel can make biomasses easier to be stored, transmitted and provided in a large scale. The team further developed the dust cloud combustion technology, which can instantly burn the solid fuels into gas and produce a high temperature. In January, the team produced a high temperature of 1452 ℃ in a boiler, located at a low-carbon industrial pilot of the Jiangcheng Boiler Co., Ltd situated in the Caidian District of Wuhan, using the micron fuel.

In April, the technology was applied in Wuhan MeiTaikang Medical Material Co., Ltd situated in Xinzhou District of Wuhan. A micron fuel boiler weighing 4 ton continuously provided steam for the production of medical gauzes. And the energy utilization efficiency of the micron fuel boiler is the same with the natural gas boiler. During the test of exhausts, the tars and powdered carbons were not contained. The white powders separated from the smoke were similar with the lime. The powders were the residual of the incombustible metallic oxide which produced after the complete combustion of the hydrocarbons over the high temperature of 1400℃.  Through the collection of the Bag-filtering, the powders could be put into the farmland or reused as the raw industrial materials.

Professor Yao Kefu, Tsinghua Univeristy, considers that it's a historic breakthrough in the biomass energy technology. The history of using coals, oil and gases in high temperature industry will be ended. And the industrial production can be got rid of the passive situation of totally depending on fossil fuels.
It’s introduced that the boilers burning coals are prohibited in some regions. Meantime, the cost of natural gas boilers is very high, and the long-term supply of natural gases can’t be guaranteed. If all of the industrial boilers adopt the micron fuels in China, the consumption of coals will be reduced to nearly 600 billion tons, and the utilization of the farm and forest crap materials will be reached to more than 1 billion tons, and the income of farmers will be increased 300 billion yuan every year. Finally, we can develop an industrial boiler equipment system and a biomass energy equipment system with IPR.

Xiao Bo said that although the high temperature technology of micron fuels  could solve the core problem of low carbon industry and provide ecological energy guarantee for the translation of many industries including metal smelting, industrial boilers, construction materials, heating, thermal power, the transformation of gas and oil and biomass chemical into low carbon industry. And turning “crap firewood” into “gold”. However, because the infrastructures of biomass collecting and transportation are not established, these biomasses can’t be produced, stored, transmitted and supplied as general energy in a large scale and high efficiency. So the present technology can only allow us to collect biomasses in a traditional way. In most cases, the utilized biomasses are often the craps of agroforestry with the few sources and the high price.
In June of 2014, in the demonstration meeting of this technology, after comprehensive investigation, the expert panel suggested that the infrastructures including the collection, preparation, storage and transmission of biomass materials should be established by the government. Then, the biomasses could be gradually made cheaper and easier to obtain. And finally an ecological energy industrial chain should be formed with micron fuels as its core technology.

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