The paper presents the results of a two-year research of properties and the way of use of briquettes and pellets made of separated and partially dehydrated digestate from agricultural BGSs （biogas stations）. Digesta...The paper presents the results of a two-year research of properties and the way of use of briquettes and pellets made of separated and partially dehydrated digestate from agricultural BGSs （biogas stations）. Digestate is a by-product of BGS. There are approximately 170 agricultural BGSs operating in the Czech Republic. Unprocessed digestate with the dry mass content around 6% is usually applied to soil as a lighter mineral fertilizer. If digestate is separated and the separated solid component of the digestate is further dehydrated to 14 % moisture, it can be processed by pressing to the form of very solid pellets and briquettes, also with various additives. It was also ascertained that mechanical strength and shape of briquettes does not change due to long-term storage. In this form, the compressed digestate can be used in various ways. One of the ways is its energetic use by direct burning. That is why we have observed its calorific value and combustion heat. Another alternative use of compressed digestate from BGS is its application in targeted treatment of in particular mechanical properties of soil and its water regime. The briquettes and pellets have great water sorption properties--the briquette retains water and as a consequence grows up to four times in size. This specific property was analysed and it was ascertained that the speed of water sorption depends on the composition of the compressed mixture （i.e., the type of material and the size of its particles）, but also on the total weight of the produced briquettes （i.e., their size）. Similar dependency was ascertained for other briquette materials that were analysed.展开更多
文摘The paper presents the results of a two-year research of properties and the way of use of briquettes and pellets made of separated and partially dehydrated digestate from agricultural BGSs （biogas stations）. Digestate is a by-product of BGS. There are approximately 170 agricultural BGSs operating in the Czech Republic. Unprocessed digestate with the dry mass content around 6% is usually applied to soil as a lighter mineral fertilizer. If digestate is separated and the separated solid component of the digestate is further dehydrated to 14 % moisture, it can be processed by pressing to the form of very solid pellets and briquettes, also with various additives. It was also ascertained that mechanical strength and shape of briquettes does not change due to long-term storage. In this form, the compressed digestate can be used in various ways. One of the ways is its energetic use by direct burning. That is why we have observed its calorific value and combustion heat. Another alternative use of compressed digestate from BGS is its application in targeted treatment of in particular mechanical properties of soil and its water regime. The briquettes and pellets have great water sorption properties--the briquette retains water and as a consequence grows up to four times in size. This specific property was analysed and it was ascertained that the speed of water sorption depends on the composition of the compressed mixture （i.e., the type of material and the size of its particles）, but also on the total weight of the produced briquettes （i.e., their size）. Similar dependency was ascertained for other briquette materials that were analysed.
