Recovery and upgrading of manool from Kraft black liquor

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University of New Brunswick


Manool is a compound found through the synthesis of wood that has high value applications as an essential oil in certain products. The demand for this product is predicted to be 28.9 tonnes/year in 2014, growing 2% per year. The reverse osmosis waste effluent from the JDI Pulp & Paper facility in Saint John, NB contains this valuable substance. The objective of this project to purify the manool present to 89 % wt. for resale at 23 tonnes/year. The JDI plant produces 38 kg/min of water effluent which contains extremely dilute amounts of manool, 150 ppm for hardwood and 1,750 ppm for softwood. The concentrate is passed to an adsorption step, where powdered talc is added at 17 kg/min as an adsorbent to bind manool to its surface. The bulk fluid, water, is separated through solid-liquid separation leaving the talc which is sent to a desorption step. The manool is removed from talc by using a 70% ethanol-water mixture of 38 kg/min. The talc is then separated from the bulk fluid mixture by solid-liquid separation. The ethanol-manool mixture is sent to a double effect evaporator operating at 78 °C that removes 37 kg/min of ethanol-water, leaving a weakly concentrated manool solution that is then stored. The vacuum distillation column is operated 16 hours per week, receiving a flow of 17 kg/min from storage. The vacuum distillation tower operates at 35 mmHg and 122 °C where the manool is concentrated to 89% purity, and 0.786 kg/min of product is sent for packaging and sale. The project has a total capital investment of $1.4 million, with an annual manufacturing cost of $2.5 million. The projected payback period is 3.8 months with a ROI of 181% an IRR of 118%. The discounted NPV after 15 years is $30 million. It's recommended this project proceed once purchasers for manool are found. Finally, further research should be done into the unknown organics present in the feed and the market price of manool should be confirmed.