Extraction and synthesis

The pyrolysis liquids can be used for production of higher value commodities as chemicals rather than fuels. Most are based on physical extraction processes, of which some are commercial and proprietary (32) and some are under development and subject to patent applications and again data is not available (17, 18, 19, 20, 21,22, 30,31).

Table 6.3 Organisations Involved in Chemicals

Recovery from

Pyrolysis Oils since 1980

Oraanisation

Chemicals

References

BC Research

Levoglucosan,

17,18,19

Calcium acetate

20,21

Hydroxyacetaldehyde, glyoxal

22

China Lake

Olefins, gasoline

23

CPERI (a)

Phenols, ethers, anisole

24,25,26,27, 28

DuPont

Phenols and cresols

29

NREL (b)

Phenols, polyphenols, adhesives

30,31

Gasoline, olefins, aromatics, ethers

See Table 5

Red Arrow

Food flavourings

32

Texas A&M University

Oxychemicals

33

University of Alicante

2-furaldehyde

34

University of Hamburg

Oxychemicals

35

University of Laval

Specific phenols and specialities

36, 37, 38, 39

University of Montana

Levoglucosan, furaldehyde

40,41

University of Toronto

Alkanes and alkenes

42

University of Tubingen

Fatty acids

16

University of Waterloo

Levoglucosan, sugars,

43,44,45,46

Hydroxyacetaldehyde, acetol, acetic acid 47, 48, 49

Notes a) Centre for

Process Engineering Research Institute, University of

Thessalonika, Greece

b) National Renewable Energy Laboratory, Golden, CO, USA

Phenols are one of the largest group of chemicals in flash pyrolysis liquids and chemical recovery has focused on these compounds. Polyphenols, for example, are potentially valuable chemicals for substitution in phenol-formaldehyde resins for wood processing such as in plywood manufacture (30, 31, 48). Anisole has been derived from phenol extracted from pyrolysis oil (25), in which both proprietary and in-house manufactured catalysts modified with Mn and Cd were used with up to 72% conversion of phenol.

Levoglucosan is a major intermediate in the thermal degradation process. Yields of up to 20% on a dry feed basis have been reported when the feed is pre-treated by acid washing to reduce the alkali metals which catalyse sugar decomposition (47, 48, 49). The extraction and recovery of the levoglucosan at high purity has recently been patented by BC Research (19). High yields of hydroxyacetaldehyde have similarly been reported by the University of Waterloo, some through additions of simple (unspecified) catalysts to the biomass prior to pyrolysis (47, 48, 49).

Table 6.4 Chemicals Recovered from Biomass Pyrolysis Liquids

Chemical

Oraanisations

References

Acetol

University of Waterloo

47, 48, 49

Adhesives

NREL

30, 31

Alkanes and alkenes

University of Toronto

42

Anhydrosugars

University of Montana

40

University of Waterloo

43-46

Anisole

CPERI

25

Aromatics

NREL

See Table 5

Aryl ethers

CPERI

24, 25, 27, 28

Calcium acetate

BC Research

20, 21

Carboxylic acids

University of Laval

37-39

Cresols

DuPont

29

Fatty acids

University of Tubingen

16

Food flavourings

Red Arrow

32

Glyoxal

BC Research

22

Hydroxyacetaldehyde

BC Research,

22

University of Waterloo

39, 40

Levoglucosan

BC Research,

16 — 18

University of Waterloo

47, 48

University of Montana

40

Olefins and gasoline

China Lake

23

NREL

See Table 5

Oxychemicals

Texas A&M, University of Hamburg

33, 35

Phenols

CPERI

24, 28

Du DuPont

29

NREL

30, 31

University of Laval

36, — 39

Polyphenols

NREL

30, 31

Reformulated gasoline

NREL

See Table 5