As an organic material, biomass can also decompose either by physics, biology or chemistry. All biomass is no exception include PKS will decompose over time emmit some toxic gas and reduce oxygen concentration, such as carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4). As a product or commodity to be sold then the decline in quality and quantity due to the decomposition process as much as possible to be avoided. Good handling from PKS collection, cleaning and storage will minimize the decomposition.
Biological decomposition that mainly occurs in the pile of the PKS. A number of organic materials as PKS impurities such as fibers, oils and so on will be easy to decompose biologically. Microbial activity in the PKS bed encourages the fermentation of organic matter. The softer and higher water content of the organic material will be decomposed biologically quickly, namely the fermentation. PKS itself is a hard material with high lignin content so it is not easily fermented in a short time. So how about a pile of PKS that is left for months and even years? What microbial activity happens? And how much the decline in quality and quantity?
In compost production, the production of CH4 or methane is usually related to biomass anaerobic decomposition, whereas CO2 is more in aerobic decomposition. The higher the temperature the CO / CO2 ratio is also greater. As the temperature increases, both CO2 and CH4 are also increasing, and CH4 becomes larger than CO2 at higher temperatures.
In comparison, namely with the storage of wood pellets. The similarity of PKS with wood pellets is the same biomass fuel that has nearly equal calorific value and can be pourable so it is possible for automatic feeding with very accurate calibration. Wood pellets are made or produced by densification of wood powder in general the size of sawdust with a moisture content of 10%, being 10-30 mm in length and 6-12 mm in diameter. Wood pellets should be stored in a dry space and protected from water / rain. Storage of wood pellets in large quantities ie at a capacity level of 30,000 tons and above, can cause its own problems.
Aeration with inserting the adequate air (ambient water) in the pile of wood pellets into a solution for storage of wood pellets. The purpose of wood pellets aeration is to cool the pellets, regulate the temperature on the pile of pellets, prevent biological heating on wet pellets, circulate gas emissions, and eliminate odors generated from gas emissions. The speed of chemical reactions deterioration or decline in quality becomes very slow and sometimes insignificant at low temperatures. The increase in chemical reaction is noticeable every 10 ° C temperature increase, so keeping it at a low temperature is essential in wood pellets storage.