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Biomass derived alkaline carboxylate road deicers
Resources, Conservation and Recycling, 7 (1992) 155-160
155
Elsevier Science Publishers B.V.
Biomass derived alkaline carboxylate road deicers Klaus H. Oehr and Gordon Barrass British Columbia Research Corporation, Vancouver, B.C., Canada (Accepted 2 April 1992)
ABSTRACT Oehr, K.H. and Barrass, G., 1992. Biomass derived alkaline carboxylate road deicers. Resour., Conserv. Recycl., 7: 155-160. Alkaline carboxylate road deicers such as calcium magnesium acetate are beginning to replace conventional chloride-containing deicers since they are less damaging to concrete, metal surfaces and living systems. The purpose of this project was to develop economical methods for the recovery of these superior road deicers from aqueous biomass pyrolysis liquors. Calcium formate/acetate/propionate deicers were successfully prepared in high yield from aqueous pyrolysis liquors derived from wood. These deicers are expected to be superior to calcium magnesium acetate deicers due to their high formate content. Deicer recovery should become commercially viable if the recovery of highvalue industrial chemicals such as hydroxyacetaldehyde or glyoxal can be integrated with deicer recovery. Although technically straightforward, deicer production without by-product chemical recovely is uneconomical. Total pyrolysis liquor, derived from cellulose-rich biomass waste is a good source of deicer and other chemicals.
OBJECTIVE
The objective of this research program was to develop economical methods for the production of carboxylate deicers from aqueous biomass pyrolysis liquors. BACKGROUND
Conventional calcium and sodium chloride salt deicers corrode vehicles, bridges and other steel-reinforced concrete structures. They can also damage nearby vegetation and fresh water resources. An immediate market opportunity exists for inexpensive replacements for these deicers. Alkali metal carboxylate deicers such as calcium formate and calcium magnesium acetate have Correspondence to: K.H. Oehr, British Columbia Research Corporation, 3650 Westbrook Mall, Vancouver, B.C., V35 539, Canada.
0921-3449/92/$05.00 © 1992 Elsevier Science Publishers B.V. All rights reserved.
156
K.H. OEHR AND G. BARRASS
shown good deicing properties without the metal corrosion problem [ 1-4 ] (Table 1 ). Calcium formate has especially good deicing properties and has been found to be non-toxic to animals [ 5 ]. RESULTS AND DISCUSSION
Aqueous wood pyrolysis liquors were obtained from the University of Waterloo Flash Pyrolysis Process and the University of Laval Vacuum Pyrolysis Process. The % compositions (w/w) of these pyrolysis liquors are given in Table 2. Attempts were made to concentrate acetic acid in the pyrolysis liquors and their distillates by ion exchange and activated carbon adsorption. However, these methods were not satisfactory; acetic acid recovery was incomplete even at high adsorbent loadings. A novel, proprietary technique was developed for producing calcium carboxylate deicers from these liquors. The % compositions (w/w) of crude deicers prepared by this technique from both the Laval and Waterloo aqueous pyrolysis liquors are given in Table 3. Percent recovery of pyrolysis liquor carboxylic acids as crude deicer calcium carboxylates was high, in spite of the low acid content of the aqueous pyrolysis liquors as shown in Table 4. Refined deicers, prepared by cleaning the crude Laval and Waterloo deicers, had the % compositions (w/w) given in Table 5. TABLE1 Relative efficiency of deicers Deicer salt
kg Deicer needed to melt 100 kg ice at - 10 oC
Calcium formate Calcium acetate Calcium propionate Sodium chloride Magnesium acetate
12 25 25 16 25
TABLE 2 Percent composition (w~ w) of the Laval and Waterloo aqueous pyrolysis liquors Component
Laval
Waterloo
Acetate as acetic acid Formate as formic acid Propionate as propionic acid
1.6 0.8 0.1
2.7 0.9 0.1
BIOMASS DERIVED ALKALINE CARBOXYLATE ROAD DEICERS
157
TABLE 3 Percent compositions ( w / w ) of crude deicers from the Laval and Waterloo aqueous pyrolysis liquors Component
Laval
Waterloo
Calcium Acetate Formate Propionate Water Other (Water+other) Total
20.0 38.4 12.6 2.9 26.1 100.0
22.4 39.4 10.4 1.6 6.8 19.4 100.0
TABLE 4 Percent recovery of pyrolysis liquor carboxylic acids as crude deicer calcium carboxylates Component
Laval
Waterloo
Acetate Formate Propionate
90 61 78
98 80 97
TABLE 5 Percent compositions ( w / w ) of refined deicers prepared by cleaning the crude Laval and Waterloo deicers Component
Laval
Waterloo
Calcium Acetate Formate Propionate Water Other (Water+other) Total
25.7 45.0 19.0 2.9 7.4 100.0
23.8 52.7 13.9 2.0 5.7 1.9 100.0
Percent recovery of pyrolysis liquor carboxylic acids as refined deicer calcium carboxylates was as shown in Table 6. Hydroxyacetaldehydestripped biomass pyroltvsis liquor provided to B.C. Research by Ensyn Engineering Associates Inc., and their US Licensee Red Arrow Products Co. Inc., had the % composition (w/w) given in Table 7. Our novel, proprietary technique was used to produce crude deicer with the following % composition (w/w) (Table 8 ). Crude deicer yield was 306 g per kg hydroxyacetaldehyde stripped biomass pyrolysis liquor.
158
K,H.OEHRANDG. BARRASS
TABLE 6 Percent recovery of pyrolysis liquor carboxylic acids as refined deicer calcium carboxylates Component
Laval
Waterloo
Acetate Formate Propionate
55 48 42
82 67 77
TABLE 7 Percent composition (w/w) of hydroxyacetaldehyde stripped biomass pyrolysis liquor provided by Ensyn EngineeringAssociates Inc. and their US Licensee Red Arrow Products Co. Inc. Component
%
(w/w) Acetate as acetic acid Formate as formic acid Water Other
13.3 3.3 68.8 14.6
TABLE 8 Percent composition (w/w) of crude deicer produced from present novel, proprietary technique Component
%
(w/w) Calcium Acetate Formate Water Other
21.8 32.8 10. I 5.3 30.0
TABLE 9 Percent composition (w/w) of refined deicer prepared by cleaning crude Ensyn-Red Arrow deicer Component
%
(w/w) Calcium Acetate Formate Water Other
25.1 47.4 13.3 6.4 7.8
BIOMASS DERIVED ALKALINE CARBOXYLATE ROAD DEICERS
159
Refined deicer, prepared by cleaning the crude Ensyn-Red Arrow deicer, had the following % composition (w/w) (Table 9). Refined deicer yield was 202 g per kg hydroxyacetaldehyde stripped biomass pyrolysis liquor. CONCLUSIONS
(1) Economic modelling revealed that deicer production from aqueous pyrolysis liquors derived from wood would only be feasible with by-product chemical production, since the carboxylic acid content of the aqueous pyrolysis liquor was too low. (2) The deicer recovery technology should be given serious consideration as one component of a biomass "refinery" which would optimise production of a wide range of high-value chemicals, such as hydroxyacetaldehyde or glyoxal, derivable from the full selection of pyrolysis liquor components. (3) Commercial viability of deicer production will depend on the availability of cellulosic material in high volume near a given location, such as lowgrade waste paper, the economics of by-product chemicals recovery, the water content of the pyrolysis liquor, and the degree to which the deicer must be purified for sale. RECOMMENDATIONS
( 1 ) Integrate the recovery of high-value industrial chemicals, such as hydroxyacetaldehyde or glyoxal, with deicer salt recovery from total pyrolysis liquor, of low water content and high acid content, derived from celluloserich waste biomass. (2) Once economic modelling shows that such refining of biomass pyrolysis liquors is economical, e.g. > 20% return on investment for capital cost below $50 000 000, the calcium carboxylate deicers should be tested to determine their value and characteristics as compared to CMA and other deicers. ACKNOWLEDGEMENTS
We thank Energy, Mines and Resources, Renewable Energy Division, for providing funding for this project and Mr. Ed Hogan for guidance as the Scientific Authority and in the administration area. The cooperation of Dr. Don Scott, Dr. Desmond Radlein and Mr. Jan Piskorz of the University of Waterloo, Dr. Christian Roy of the University of Laval, and Mr. R. Graham of Ensyn Engineering Associates Inc., in providing pyrolysis liquor feedstocks is appreciated.
160
K.H.OEHRANDG. BARRASS
REFERENCES 1 Dunn, S.A. and Schenk, R.U., 1979. Alternate Highway Deicing Chemicals. Final Report prepared for Federal Highway Administration, Offices of Research and Development, Department of Transportation, Washington, DC NTIS Report PB82-242629:157 pp. 2 Wyatt, J. and Fritzsche, C., 1989. The snow battle: salt vs. chemicals. American City and County, April, 4 pp. 3 Wyatt, J. (Chevron Chemical Company), 1988. Status Report on the New Highway Deicer, Calcium Magnesium Acetate (CMA), July, 6 pp. 4 Coghlan, A., 1990. A Salt Free Diet for Ailing Roads. New Sci., 17: 34. 5 Von Malorny, G., 1969. Acute and chronic toxicity of formic acid and formates. Z. Ernaehrungswiss., 9(4): 332-339.
155
Elsevier Science Publishers B.V.
Biomass derived alkaline carboxylate road deicers Klaus H. Oehr and Gordon Barrass British Columbia Research Corporation, Vancouver, B.C., Canada (Accepted 2 April 1992)
ABSTRACT Oehr, K.H. and Barrass, G., 1992. Biomass derived alkaline carboxylate road deicers. Resour., Conserv. Recycl., 7: 155-160. Alkaline carboxylate road deicers such as calcium magnesium acetate are beginning to replace conventional chloride-containing deicers since they are less damaging to concrete, metal surfaces and living systems. The purpose of this project was to develop economical methods for the recovery of these superior road deicers from aqueous biomass pyrolysis liquors. Calcium formate/acetate/propionate deicers were successfully prepared in high yield from aqueous pyrolysis liquors derived from wood. These deicers are expected to be superior to calcium magnesium acetate deicers due to their high formate content. Deicer recovery should become commercially viable if the recovery of highvalue industrial chemicals such as hydroxyacetaldehyde or glyoxal can be integrated with deicer recovery. Although technically straightforward, deicer production without by-product chemical recovely is uneconomical. Total pyrolysis liquor, derived from cellulose-rich biomass waste is a good source of deicer and other chemicals.
OBJECTIVE
The objective of this research program was to develop economical methods for the production of carboxylate deicers from aqueous biomass pyrolysis liquors. BACKGROUND
Conventional calcium and sodium chloride salt deicers corrode vehicles, bridges and other steel-reinforced concrete structures. They can also damage nearby vegetation and fresh water resources. An immediate market opportunity exists for inexpensive replacements for these deicers. Alkali metal carboxylate deicers such as calcium formate and calcium magnesium acetate have Correspondence to: K.H. Oehr, British Columbia Research Corporation, 3650 Westbrook Mall, Vancouver, B.C., V35 539, Canada.
0921-3449/92/$05.00 © 1992 Elsevier Science Publishers B.V. All rights reserved.
156
K.H. OEHR AND G. BARRASS
shown good deicing properties without the metal corrosion problem [ 1-4 ] (Table 1 ). Calcium formate has especially good deicing properties and has been found to be non-toxic to animals [ 5 ]. RESULTS AND DISCUSSION
Aqueous wood pyrolysis liquors were obtained from the University of Waterloo Flash Pyrolysis Process and the University of Laval Vacuum Pyrolysis Process. The % compositions (w/w) of these pyrolysis liquors are given in Table 2. Attempts were made to concentrate acetic acid in the pyrolysis liquors and their distillates by ion exchange and activated carbon adsorption. However, these methods were not satisfactory; acetic acid recovery was incomplete even at high adsorbent loadings. A novel, proprietary technique was developed for producing calcium carboxylate deicers from these liquors. The % compositions (w/w) of crude deicers prepared by this technique from both the Laval and Waterloo aqueous pyrolysis liquors are given in Table 3. Percent recovery of pyrolysis liquor carboxylic acids as crude deicer calcium carboxylates was high, in spite of the low acid content of the aqueous pyrolysis liquors as shown in Table 4. Refined deicers, prepared by cleaning the crude Laval and Waterloo deicers, had the % compositions (w/w) given in Table 5. TABLE1 Relative efficiency of deicers Deicer salt
kg Deicer needed to melt 100 kg ice at - 10 oC
Calcium formate Calcium acetate Calcium propionate Sodium chloride Magnesium acetate
12 25 25 16 25
TABLE 2 Percent composition (w~ w) of the Laval and Waterloo aqueous pyrolysis liquors Component
Laval
Waterloo
Acetate as acetic acid Formate as formic acid Propionate as propionic acid
1.6 0.8 0.1
2.7 0.9 0.1
BIOMASS DERIVED ALKALINE CARBOXYLATE ROAD DEICERS
157
TABLE 3 Percent compositions ( w / w ) of crude deicers from the Laval and Waterloo aqueous pyrolysis liquors Component
Laval
Waterloo
Calcium Acetate Formate Propionate Water Other (Water+other) Total
20.0 38.4 12.6 2.9 26.1 100.0
22.4 39.4 10.4 1.6 6.8 19.4 100.0
TABLE 4 Percent recovery of pyrolysis liquor carboxylic acids as crude deicer calcium carboxylates Component
Laval
Waterloo
Acetate Formate Propionate
90 61 78
98 80 97
TABLE 5 Percent compositions ( w / w ) of refined deicers prepared by cleaning the crude Laval and Waterloo deicers Component
Laval
Waterloo
Calcium Acetate Formate Propionate Water Other (Water+other) Total
25.7 45.0 19.0 2.9 7.4 100.0
23.8 52.7 13.9 2.0 5.7 1.9 100.0
Percent recovery of pyrolysis liquor carboxylic acids as refined deicer calcium carboxylates was as shown in Table 6. Hydroxyacetaldehydestripped biomass pyroltvsis liquor provided to B.C. Research by Ensyn Engineering Associates Inc., and their US Licensee Red Arrow Products Co. Inc., had the % composition (w/w) given in Table 7. Our novel, proprietary technique was used to produce crude deicer with the following % composition (w/w) (Table 8 ). Crude deicer yield was 306 g per kg hydroxyacetaldehyde stripped biomass pyrolysis liquor.
158
K,H.OEHRANDG. BARRASS
TABLE 6 Percent recovery of pyrolysis liquor carboxylic acids as refined deicer calcium carboxylates Component
Laval
Waterloo
Acetate Formate Propionate
55 48 42
82 67 77
TABLE 7 Percent composition (w/w) of hydroxyacetaldehyde stripped biomass pyrolysis liquor provided by Ensyn EngineeringAssociates Inc. and their US Licensee Red Arrow Products Co. Inc. Component
%
(w/w) Acetate as acetic acid Formate as formic acid Water Other
13.3 3.3 68.8 14.6
TABLE 8 Percent composition (w/w) of crude deicer produced from present novel, proprietary technique Component
%
(w/w) Calcium Acetate Formate Water Other
21.8 32.8 10. I 5.3 30.0
TABLE 9 Percent composition (w/w) of refined deicer prepared by cleaning crude Ensyn-Red Arrow deicer Component
%
(w/w) Calcium Acetate Formate Water Other
25.1 47.4 13.3 6.4 7.8
BIOMASS DERIVED ALKALINE CARBOXYLATE ROAD DEICERS
159
Refined deicer, prepared by cleaning the crude Ensyn-Red Arrow deicer, had the following % composition (w/w) (Table 9). Refined deicer yield was 202 g per kg hydroxyacetaldehyde stripped biomass pyrolysis liquor. CONCLUSIONS
(1) Economic modelling revealed that deicer production from aqueous pyrolysis liquors derived from wood would only be feasible with by-product chemical production, since the carboxylic acid content of the aqueous pyrolysis liquor was too low. (2) The deicer recovery technology should be given serious consideration as one component of a biomass "refinery" which would optimise production of a wide range of high-value chemicals, such as hydroxyacetaldehyde or glyoxal, derivable from the full selection of pyrolysis liquor components. (3) Commercial viability of deicer production will depend on the availability of cellulosic material in high volume near a given location, such as lowgrade waste paper, the economics of by-product chemicals recovery, the water content of the pyrolysis liquor, and the degree to which the deicer must be purified for sale. RECOMMENDATIONS
( 1 ) Integrate the recovery of high-value industrial chemicals, such as hydroxyacetaldehyde or glyoxal, with deicer salt recovery from total pyrolysis liquor, of low water content and high acid content, derived from celluloserich waste biomass. (2) Once economic modelling shows that such refining of biomass pyrolysis liquors is economical, e.g. > 20% return on investment for capital cost below $50 000 000, the calcium carboxylate deicers should be tested to determine their value and characteristics as compared to CMA and other deicers. ACKNOWLEDGEMENTS
We thank Energy, Mines and Resources, Renewable Energy Division, for providing funding for this project and Mr. Ed Hogan for guidance as the Scientific Authority and in the administration area. The cooperation of Dr. Don Scott, Dr. Desmond Radlein and Mr. Jan Piskorz of the University of Waterloo, Dr. Christian Roy of the University of Laval, and Mr. R. Graham of Ensyn Engineering Associates Inc., in providing pyrolysis liquor feedstocks is appreciated.
160
K.H.OEHRANDG. BARRASS
REFERENCES 1 Dunn, S.A. and Schenk, R.U., 1979. Alternate Highway Deicing Chemicals. Final Report prepared for Federal Highway Administration, Offices of Research and Development, Department of Transportation, Washington, DC NTIS Report PB82-242629:157 pp. 2 Wyatt, J. and Fritzsche, C., 1989. The snow battle: salt vs. chemicals. American City and County, April, 4 pp. 3 Wyatt, J. (Chevron Chemical Company), 1988. Status Report on the New Highway Deicer, Calcium Magnesium Acetate (CMA), July, 6 pp. 4 Coghlan, A., 1990. A Salt Free Diet for Ailing Roads. New Sci., 17: 34. 5 Von Malorny, G., 1969. Acute and chronic toxicity of formic acid and formates. Z. Ernaehrungswiss., 9(4): 332-339.