US 5,728,271 AGranted

Energy efficient liquefaction of biomaterials by thermolysis

AssigneeRTI Resource Transforms International Ltd.

InventorsJan Piskorz, Piotr Majerski, Desmond Radlein

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Abstract

A thermolysis process for liquefaction of biomass solids in which specific and previously unrecognized conditions are employed. The thermolysis is carried out in a single fluidized bed of inert material operating at near atmospheric pressure, relatively low temperature, long solids and gas residence times and moderate heating rates. The distribution of the thermolysis products among liquid (bio-oil), solid (char) and gases under these conditions is unique. In particular, contrary to the prior art, both high liquid and low char yields are obtained. Furthermore the liquid is of similar composition to those obtained by so called fast pyrolysis processes of the prior art. The specified conditions are such as to allow production of liquids in high yields in an energy efficient manner. The low severity of the conditions in comparison with previous approaches allows simplified process design and scaleup leading to lower capital and operating costs as well as easier control.

Claims24

Dependent claims

A process for the thermolysis of shredded biomass to produce liquid similar in composition to liquid produced from fast pyrolysis, comprising:

(a) introducing the biomass, shredded to a sufficiently small size so that its size does not limit significantly the production of liquid, into a thermolysis reactor having a bed of inert material with a height to width ratio greater than one;
(b) introducing substantially non-oxidizing gas upwardly through the bed at a linear velocity so as to cause automatic elutriation of product char and fluidizing of the bed of inert material to form a fluidized bed;
(c) heating indirectly the fluidized bed so that the substantially non-oxidizing gas and fluidized bed have a temperature in the range of 360.degree. to 490.degree. C. and the substantially non-oxidizing gas and fluidized bed cause the thermolysis of the biomass producing an effluent reactor stream comprising hot char particles and volatiles, namely, gas, aerosols, and vapours;
(d) removing the elutriated char particles from the effluent reactor stream;
and
(e) quenching the gas, aerosols and vapours to partly liquify the vapours and aerosols so that the vapours and aerosols do not contact dry surfaces of the quencher whose temperatures are in the range of 100.degree. C. to 360.degree. C.
wherein the fluidized bed is sufficiently deep so that the residence time of the substantially non-oxidizing gas in the reactor is greater than 2 seconds.

4 more elements

A process for the thermolysis of shredded biomass to produce liquid similar in composition to liquid produced from fast pyrolysis, comprising:

(a) introducing the biomass particles having a smallest dimension less than 3 millimeters into a thermolysis reactor having a bed of inert material with a height to width ratio greater than one;
(b) introducing substantially non-oxidizing gas upwardly through the bed at a linear velocity in the range of 10 to 80 centimeters per second so as to cause automatic elutriation of product char and fluidizing of the bed of inert material to form a fluidized bed;
(c) heating indirectly the fluidized bed to a temperature in the range of 395.degree. to 465.degree. C. and said substantially non-oxidizing gas and said fluidized bed cause the thermolysis of the biomass particles producing an effluent reactor stream comprising hot char particles and volatiles, namely, gas, aerosols, and vapours;
(d) removing the elutriated char particles from the effluent reactor stream;
(e) quenching the gas, aerosols and vapours to partly liquify the vapours and aerosols so that the vapours and aerosols do not contact dry surfaces of the quencher whose temperatures are in the range of 100.degree. C. to 360.degree. C.;
and
wherein the residence time of the substantially non-oxidizing gas in the fluidized bed is greater than 2 seconds;
and wherein the ratio of the mass of the substantially non-oxidizing gas to that of the biomass particles is less than 2 to 1.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/650,947Filed 20 May 1996
Granted: 17 Mar 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

C10B 47/24
In dispersed form: according to the "fluidised bed" technique
B01J 8/1836
With fluidised particles: heating and cooling the reactor
C10B 53/02
Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form: of cellulose-containing…
C10G 1/10
Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal: from…