Chemistry
 

Chemicals extracted from trees can be used to control insect infestations,
e.g. Rocky Mountain Pine Beetles. These natural products are made by trees to defend themselves against insects. Our product alters the feeding behaviour of insects and does not harm the environement.

Publications
 

Alfred Wong, J.M. Zhuang and Stanley Wu, Arbokem Inc., Vancouver, Canada

ABSTRACT. The use of H3PO4, instead of H2SO4, affords a novel approach to eliminate the input of sulphur into the pulp mill's chemical recovery system. Laboratory soap acidulation experiments have shown the H3PO4 soap acidulation approach to be practicable. The H3PO4 approach would provide the avoidance of adding about 27 kg sulphur (as S) per tonne of soap into the chemical recovery system of the kraft pulp mill. Under prevailing pricing of H3PO4 and NaOH, the phosphoric acid approach would have a higher chemical cost than the sulphuric acid approach, by a margin of about US$8 per tonne of soap processed. Small changes in the commodity pricing of H3PO4 and/or NaOH would render the H3PO4 soap acidulation method to be economically competitive. (AK21630W)

Cellulose Chemistry and Technology, 36: 381-388 (2002)

Al Wong, Arbokem Inc., Vancouver, Canada

ABSTRACT. The degradation of model components of crude tall oil (CTO) held under heated storage conditions was studied. Rate constants for the reactions of stearyl alcohol and mixed tall oil sterols separately and in combination with oleic acid were determined. These reactions were found to be "first-order", in the range of concentrations which are representative of commercial CTO. The rate of esterification between oleic acid and stearyl alcohol was found to be about three times faster than that of the reaction between oleic acid and tall oil sterols. (AK24523W)

Forest Chemicals Review, 113 (2): 12-16 (2003)

Al Wong, Arbokem Inc., Vancouver, Canada

ABSTRACT. Acid number decreases of ternary mixtures of CTO model compounds, viz., fatty alcohol, sterol and fatty acid, were studied. A practicable means to estimate the rate and magnitude of acid number losses of CTO during heated storage has been devised, in which esterification and decarboxylation reactions were included. (AK23445W)

Forest Chemicals Review, 113 (3): 11-14 (2003)

Al Wong and Yi Feng, Arbokem Inc., Vancouver, Canada

ABSTRACT. Chemical analysis of selected samples of crude sulphate turpentine (CST) from several kraft pulp mills in inland British Columbia and Alberta showed the pinene content to be less than 50% of those of CST of southern United States pulp mills. Both delta3-carene and para-menthadienes were found to be substantially higher than those present in CST of southern United States pulp mills. (AK21602W)

Forest Chemicals Review, 112 (1): 10-14 (2002)

Al Wong, Arbokem Inc., Vancouver, Canada

ABSTRACT. Representative samples of soap and CTO from 17 kraft pulp mills using coniferous pulpwood grown in the major forest regions of North America were evaluated over a period of 5 years. There were notable differences in the quality and quantity of sterols in the CTO and soap tested. CTO from the Northern, Rocky Mountain and Pacific Coast forest regions was found to be the best for the practical isolation of sterols containing a high fraction of C29 sterols and stanols, which are favourable for use in anti-hypercholesterolemic products for human consumption. The Southeastern CTO contained the lowest amount of sterols, among the CTO surveyed in North America. (AK21183W)

Forest Chemicals Review, 111 (5): 12-17 (2001)

Management of sulphur balance and tall oil production in unbleached kraft pulp mills

Al Wong, Arbokem Inc., Vancouver, Canada

ABSTRACT. Soap acidulation using sulphuric acid is a major source of involuntary input of sulphur into the cooking liquor system of a kraft pulp mill. The sulphur balance problem, under increasingly stringent rules for the discharge of pollutants, could be manageable if the mill produces a relatively lower amount of soap for acidulation with sulphuric acid. If new targets are mandated for COD in the effluent and hazardous air pollutants under the EPA Cluster Rules in the near future, pulp mills will have difficulties in the continuance of using any sulphuric acid for soap acidulation, without causing a sulphur imbalance in the mill liquor system. (AK19067W)

Forest Chemicals Review, 110 (4): 9-11 (2000)

J.M. Zhuang and A. Wong, Arbokem Inc., Vancouver, Canada

ABSTRACT. An improved method has been developed for the preparation of high-quality cellulose acetate. The novel technique involves the pressurized pretreatment of cellulose fibres with glacial acetic acid and acetic anhydride. The resulting fibres were found to be more uniformly activated and more reactive in subsequent acetylation. With the anhyrdous pretreatment stage, direct addition of acetylation reagents can be carried out at higher initial temperatures. The hydrolysis of cellulose triacetate to cellulose diacetate was also found to be improved significantly when the reaction was controlled under elevated temperature and pressure conditions.

Proc. 8th International Symposium on Wood and Pulping Chemistry, Helsinki, Finland, June, 1995. pp. 685-688.

Alfred Wong, Arbokem Canada, Vancouver, Canada

ABSTRACT. During the past 100 years, there have been substantial activities made in the research and development of chemical products from renewable forest resources. Yet, commercial successes have been few. One underlying problem is the large gap between scientific knowledge and commercial realization. In many cases, the successes such as extraction of taxol from Pacific yew tree, can be easily identified to be in the category of chemical products of unique silvichemical structures. The failures can be traced to poor economic premises of commodity chemical products. Some recent successful and unsuccessful examples of "research to commercial manufacture" of silvichemical products will be presented to illustrate the problems of scientific research and commercial implementation. (AK10085W)

Proc. 7th International Symposium on Wood and Pulping Chemistry, Beijing, China,
May 25-28, 1993.

Y. Xie and M.B. Isman, University of British Columbia, Vancouver, Canada
Y. Feng and A. Wong, Arbokem Inc., Vancouver, Canada

ABSTRACT. Tall oil, a by-product of the kraft process for pulping softwood, has been shown to have insecticidal properties. In the present study, the active principles in tall oil against the variegated cutworm, Peridroma saucia Hubner, were investigated. GC-MS analysis showed that abietic, dehydroabietic and isopimaric acids were major resin acid components of crude tall oil and depitched tall oil. When crude tall oil samples of differing resin acid composition were incorporated into artificial diet at a concentration of 2.0% fresh weight, they suppressed larval growth by 45-60% compared to controls. This suppression was significantly (P,0.05) correlated with the equivalent contents of abietic, dehydroabietic, isoprimaric, and total resin acids. These results were also evident from a diet choice test, showing that the second-instar larvae obviously selected diets with low levels of resin acids when different diets were randomly arranged in a Petri dish. Bioassays with pure resin acids (abietic, dehydroabietic, and isopimaric acids) demonstrated that all individual chemicals have similar bioactivity against this insect. Comparison of the bioactivities of depitched tall oil and an equivalent mixture of pure resin acids in the chronic Peridroma chronic growth bioassay indicated that pure resin resin acids and depitched tall oil share a common mode of action to this insect. This study confirms that resin acids are the major active principles in tall oil against the variegated cutworm, but other chemicals likely also contributed to the bioactivity of tall oil.

Journal of Chemical Ecology, 19:1075-1084 (1993).