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Torrefaction is a promising mild thermal treatment for biomass waste, typically between 473 and 573 K during a few tens of minutes in a default-oxygen atmosphere. The product is a solid, with properties close to coal. Some volatile species are released at the same time as by-products, with an interesting potential as source of “green” chemicals. In this context, the behaviour of the biomass during torrefaction is studied in a thermogravimetric analyzer (TGA). In order to build a robust kinetic model, chemical regime must be ensured. This can be assessed thanks to a characteristic time analysis of physical and chemical processes involved in torrefaction. The results show that chemical regime is generally achieved at particle-scale under classical conditions of torrefaction in TGA device. However, this is not always the case at bed-scale, limitations may appear when bed thickness becomes too high (> 4 mm). The proposed methodology can be applied to other torrefaction devices, in order to determine the regime as a function of the experimental conditions.

The article contains a brief retrospective assessment of the reasons given by various scholars and observers for the breakdown of the Soviet Union under Mikhail Gorbachev’s leadership and it situates that crisis in the larger context of history and the imperial legacy of the Russian state. It particularly looks at the issue of nationality as an ethnic, cultural and linguistic concept vis-a-vis the universalistic notion of empire as a community of destiny among diverse people. The author compares the Soviet Union’s structure as a ‘non classical’ empire to those of other European states and especially to Germany’s which has also evolved from being a loose Central and East European ‘Reich’ inspired by the Roman and Carolingian heritage – to becoming a federal nation surrounded by smaller countries that share with it ancient civilisational and political legacy. Whereas Germany is gradually asserting leadership among many of its former dependencies and in the post-Brexit European Union as a whole, Russia is led by geographical and strategic compulsions to rebuild a Eurasian confederal association with erstwhile Soviet Republics and possessions of the Tsarist Empire, in conformity with its location between the ‘West’, the Islamosphere and the Chinese world. Will Russia be able to create a synthesis between the Slav Orthodox Oikoumene envisioned by Nikolay Danilevsky and the Eurasian syncretistic model promoted by Lev Gumilyov?