(EN)
ABSTRACT OF THE DISCLOSURE
Hereby a novel process is described which is
capable to take most any subdidvided, chipped, shredded,
hammermilled lignocellulosic forest and/or agricultural
residue, pure or in mixtures thereof, and with the aid of
a chemical agent,which is essentially a mixture of an
organic volatile solvent with water, such as ethanol or
acetone, acidified with either an inorganic strong acid
such as hydrochloric, sulphuric or phosphoric acid, or
an organic acid such as oxalic, formic, citric, maleic,
plicatic, tannic, tartaric, trichloroacetic or trifluoro-
acetic acid, convert it into pulp, crystalline cellulose,
dissolved chemicals such as sugars, lignins, furfurals and
organic acids in high yield. The process of conversion
is continuous but can be subdivided-into stages according
to the order of product formation. The conditions under
which these products are formed are very conducive to
rapid hydrolysis and usually involve liquor pH at 4 and
lower, a temperature of 160°C but not exceeding 210°C,
and a pressure appropriate with these temperatures and the
cooking liquor composition. Product composition is mainly
influenced by cooking time at maximum specified temperature
and liquor composition,i.e., more than one product mix
can be produced with a single set of temperature/pressure
and cooking liquor composition by merely increasing or
decreasing the exposure time at maximum temperature. The
equipment is so designed that it make possible the production
and recovery of the whole range of chemicals (products)
indicated above. It is a further characteristic of the pro-
cess that it treats most all lignocellulosics with nearly
equal efficiency and thus such plant materials may also be
processed in mixture without serious deterioration of
product quality and process efficiency. A high degree of
cooking chemical recovery is possible and continuous re-
covery is an integral and important part of the process.
Thus this invention does not limit itself to the
solvent system by which such rapid production of high to
low-yield pulps, bulk lignins and sugars and sugar dehyd-
ration products are possible from all types of lignocellu-
losics, neither is it limited to the conditions under which
such flexibility is possible but is also concerned with the
apparatus which would allow efficient, economic, orderly
and controlled high yield manufacture of such a product mix
as outlined in Figure 1.
