According to researchers at the Chinese Academy of Sciences’ (CAS) Institute of Process Engineering, it has been found that using small boilers that operate horizontally instead of vertically can help decrease air pollution.
Professor Liu Xinhua, lead scientist of the project said: “Coal can be as clean as natural gas. It depends on how you burn it”.
After two decades, the technology for this research has been put into practice and tests have been carried out. During tests in Hebei province, which surrounds Beijing, scientists laid the boiler on the ground instead of standing upright. The coal was burnt side to side: coal was added into a low-heat chamber on the right and was converted to gas under controlled temperatures of under 400°C and then passed to the left side chamber where it was burned at up to 1000°C – a process researchers called ‘decoupling combustion’. This resulted in removed nitrogen oxide, fine particulate matter and many major air pollutants that are created when burning coal.
Liu commented on the research: “It was simple in theory, but extremely difficult in practice”.
Nevertheless, there are challenges that accompany this process, such as maintaining the delicate chain reaction of combustion between the two chambers. There may be several obstructions to enabling widespread application of the technology such as boilers are more expensive and it requires large investment and a new heating plant and pipelines in order to implement it, which is considered unrealistic as it is difficult to obtain government subsidies.
Liu gave an example of the boilers use in practice: one 700 kW ‘decoupling boiler’ was installed at a village in the Gu-an county. It provides central heating to approximately one third of the local population at a low cost with minimum pollution.
Read the article online at: https://www.worldcoal.com/coal/08062015/one-small-change-for-boilers-one-big-change-for-coal-2386/