How to convert a coal-fired boiler into a rice husk-fired boiler?

The boiler was modified to burn rice husks instead of coal. The cost of burning coal is over 300 yuan per ton, while burning rice husks costs only around 150 yuan per ton. This alone results in savings of over 400,000 yuan per year in fuel costs. The boiler can be used for burning rice husks, eliminating the secondary pollution caused by water mist removal and reducing wastewater discharge. You can send me messages via the site’s messaging system if there’s anything you need to let me know. This post was last edited by qiming888 on 2008-3-17 at 20:23

For reciprocating grate boilers, it is only necessary to add a feeder and an in-furnace dust collector; modifying circulating fluidized bed boilers is more complicated.

Renovation of small-scale thermal power plants: I would like to ask how to convert small-scale thermal power plants into biomass power plants? :) This post was last edited by I Have a Question on 2007-11-13 09:19 ] lin 2007-10-24 09:41 Stop using coal and switch to biomass fuel. The boiler may also need to be modified. mxsir 2007-11-3 12:52 Modifying the combustion system of boilers: Henan Longtai Technology Development Co., Ltd. has developed cyclic fluidized bed boilers that can be used with existing small-scale thermal power plants, employing particle fuel power generation technology; the company is seeking cooperation with partners from various fields. http://blog.sina.com.cn/longtaikj Tian Tian 2007-11-12 15:55 Reply: Someone on the third floor, please talk about something technical! ! ! Cucumber 2007-11-12 17:22 I can’t figure it out! ! I can’t figure it out! “Transform small-scale fires into biomass power generation? ”What does that even mean? :Q I have a question. 2007-11-13 09:21 Reply to 5#: I made a typo, but I’ve already corrected it. Is there any need to get upset about it? Fifth floor! ! :L Piaoyun Mengying 2007-11-13 09:39 Reply to post #3: Don’t just promote the equipment; also introduce the technology. Only by understanding the technology can one decide whether it is feasible. mxsir 2007-11-14 10:43 replied: Converting small thermal power plants into biomass power plants is the only way for them to survive. This can be achieved by using the existing circulating fluidized bed boilers or chain grate boilers in small thermal power plants, and modifying the boiler’s combustion system by employing biomass solid fuel (i.e., pellet fuel) together with the biomass burners developed by Henan Longtai Technology Development Co., Ltd. Using this technology for the retrofitting of small thermal power plants features low investment, a short cycle, and rapid results. Its investment is equivalent only to the cost of building a fuel storage facility for a new biomass power plant. The renovation cycle is only 2-3 months, which is much shorter than the 12-18 months required for building new power plants. magicpeng 2007-11-29 22:09 Modifying boilers – these are trivial matters. Focus: How to ensure the supply of fuel. If you use pellet fuel, you can either process it yourself or purchase it, and its price is not as low as that of coal. Conclusion: It’s better to shut down the small thermal power plants. mxsir 2007-12-1 15:36 Reply to 9# Reply to 9# Biomass power generation is only suitable for small generator sets, and this is due to the properties of biomass. Due to its widespread distribution and low yield per unit area, biomass is also not suitable for long-distance transportation (mainly because the shipping costs are too high). Once it is used in large thermal power plants, it is difficult to ensure a sufficient supply. For two 12MW generator sets, the annual biomass consumption is at least 200,000 tons, which essentially requires a supply of straw within a radius of 30 km around the power plant. If transported in its raw form, the shipping cost can reach 40–50 yuan per ton; additional factors may make the cost even higher. magicpeng 2007-12-3 12:38 I would like to ask Mxsir: regarding the small-scale thermal power plants mentioned in the question, what does \"small\" refer to in terms of scale? kW class or MW class. Thank you for the reply. mxsir 2007-12-6 20:21 replied to #11 KW and MW are just different units; they do not indicate the size of thermal power generators. For example, 6000 KW is also expressed as 6 MW. Generally, the capacity of small power plants used for converting straw into electricity should be less than 25MW. I’m not sure if this is correct; please advise. magicpeng 2007-12-6 21:53 mxsir: Thank you for the reply. If the 25MW you mentioned refers to coal-fired power, then it is indeed very small – it was phased out years ago, with only a few self-owned power plants remaining. If 25MW is for biomass power generation, that is a very large scale. At present, most newly built biomass direct-fired power plants in China are of the 12, 25, or 50 MW class. Returning to the transformation of small thermal power plants mentioned earlier: if a 25MW coal-fired power plant is to be converted into a biomass power plant, I estimate there are two possible approaches. 1. The boiler is replaced to convert the plant into a direct-burning biomass power plant; other additional equipment includes a fuel processing system, etc. There are also limited auxiliary facilities that can be retained – the investment required for this approach is roughly the same as that for building a new 25MW biomass power plant. 2. Biomass pellet fuel can be used in combination with coal (the blending ratio can range from 10% to 50% or even higher). Its advantage is that there is little need for modification; biomass pellet fuel can be ground into powder using existing coal grinding systems and then injected into the boiler for combustion. – This method doesn’t seem to be very encouraged at the moment (due to concerns about distortion), but there are many studies in the West, especially in Europe, and the results are fairly good. Combining the above two approaches, if the second option doesn’t work, it’s still better to shut down the existing small-scale thermal power plants. magicpeng 2007-12-6 21:59 Additional note: In my opinion, the technology you mentioned for generating electricity using biomass pellet fuel does have some value; it can be used as a distributed power generation system (with costs likely lower than those of photovoltaic systems). It has promotional value in some remote areas. Of course, if **appropriate policies are in place, large-scale construction for grid connection is not impossible, just as is the case with wind power today. biochi 2007-12-14 10:48 We were the first in China to propose conducting industrial-scale experiments using co-gasification of biomass and coal, and we achieved very significant results. 1. The tar problem has been completely resolved. 2. No biomass slagging issue occurred even when the furnace temperature was raised above 1000°C. 3. The calorific value of the gas has increased significantly. 4. The goal of using steam-air as a vaporization agent to produce gas with medium calorific value has been achieved. Researcher Lin Weigang from the Institute of Process Engineering, Chinese Academy of Sciences, attended the project appraisal meeting. biochi 2007-12-14 10:51 The co-combustion of substances and coal is already commercialized abroad. Under normal circumstances, it is feasible to mix biomass into coal; when the mixing ratio is below 20% of the total heat input, it has little impact on the combustion properties of the coal. The blending method can involve grinding it together with coal in the same coal grinder; however, this is more difficult to do and requires more electricity from the grinder. For every 1 wt% of biomass added, the electricity consumption increases by 100–200/kW/h ； It can be ground separately and then burned using a separate burner, but the cost is higher. There is extensive research on biomass reburning abroad; in China, one can refer to Li Ge’s doctoral thesis from Zhejiang University, which contains a chapter dedicated to the study of biomass reburning. chen*ang7718 2007-12-21 11:16 We are currently working on upgrading a small thermal power plant with a capacity of 24 MW; it’s very complex! First, you need to conduct an investigation into the local resources, and second, you must get approval from the provincial development and reform commission before proceeding with the preliminary work (in principle, the existing generating units must be removed). These are the prerequisites. After that, the investor needs to be identified