Method for the hydrothermal carbonization of renewable raw materials and organic residues

摘要

The present invention relates to a continuous method for the hydrothermal carbonization of renewable raw materials and organic residues, in which, in a first processing stage, a pressure increase essentially to the pressure level of the carbonization occurs, in the second processing stage, the carbonization, which is performed at a pressure of at least 5 bar and at most boiling temperature, the obtained carbonized product is at least partially settled as sediment, and the filling height of the water in the second processing stage is set by removing water, and the temperature of the sediment delivered from the second processing stage is reduced by the vaporization of water and it is supplied to the third processing stage, drying which is heated using steam, in which the drying is performed in steam atmosphere, and subsequently discharged from the process.

主权项

1. A method for continuous hydrothermal carbonization of feedstock comprising biomass to produce marketable coal having a water content of less than 30 mass percent, the method comprising:
a first step, comprising pressurizing the feedstock to at least 5 bar; a second step, comprising converting the feedstock into a carbonized product inside a reactor, wherein the feedstock undergoes dehydration and decarboxylation at a pressure of at least 5 bar and a temperature at or below the boiling point of water, resulting in reaction products comprising water, carbon dioxide, and carbon-containing product, wherein the second step further comprises:
(a) circulating water in an upper portion of the reactor to circulate the feedstock in the upper portion, wherein removal and at least partial resupply of water from the upper portion of the reactor results produces at least a portion of the circulation,(b) settling the carbon-containing product in a lower portion of the reactor as water-containing sediment, wherein the lower portion of the reactor is not subject to mixing,(c) selecting a minimum height of water-containing sediment so that the solid content of the water-containing sediment is increased by sedimentation to at least 15% and selecting a maximum height of sediment layer so that a solid bottom fraction does not form due to static pressure,(d) regulating the water level in the reactor by removing or supplying water, and(e) discharging at least some gaseous products arising in the reactor in counterflow to the feedstock entering the reactor so that at least some faction of gaseous water condenses on the feedstock; and a third step, comprising delivering the water-containing sediment to a dryer, wherein the dryer dries the water-containing sediment in a steam atmosphere.