My research interest is in the area of organic waste-to-resource recovery and recycling. At present, the research projects may be divided into two major sub-areas: biomass feedstock engineering, and bioconversion processes and systems.
Biomass feedstock engineering
Research activities include the characterization, preprocessing, storage and quality control of biomass as the main components of the supply chain logistics, which bridges the gap between biomass harvesting and bioenergy production in a variety of biorefineries. The biomass feedstock may be in non-densified form such as the high-moisture forest and agricultural residues, or densified form such as wood pellets. The goal is to better manage the biomass and products with potential economic benefits and improve their long-term sustainability. Our research work is in line with the biomass supply and utilization industries’ overall strategy to maintain both the quantity and quality of biomass feedstock during handling, transportation and storage.
Bioconversion processes and systems
Research activities on bioconversion processes and systems are primarily focused on aerobic composting and anaerobic fermentation of non-woody biomass/organic wastes. Odor emission can still be a significant problem in today’s composting practice. The feasibility of using an integrated approach for odor management is being investigated. It involves monitoring of odor emissions and implementing odor control techniques such as biofiltration, which can be applied to other odor-generating industries. Anaerobic digestion of organic wastes for biogas production has environmental benefits in terms of reduced odour and greenhouse gas emissions. By incorporating genome sequencing analysis in our study, we found that diverse microbial communities are taking part in the biohydrogen production process and certain microbes could still be dominant in producing hydrogen without the need to pretreat the seed sludge as most other researchers did. The metabolic pathway for biohydrogen production was affirmed via relationship analysis of the soluble metabolite products. Besides, we have identified the optimal operational conditions that could lead to enhanced biohydrogen productivity. These techniques can be extended to analyze biomethane production.
· He, X., A.K. Lau, S. Sokhansanj, C.J. Lim and X.T. Bi. 2014. Application of a model to simulate the wetting and drying processes of woody biomass in the field. Drying Technology. In press.
· Yazdanpanah, F., S. Sokhansanj, C.J. Lim, A.K. Lau, X.T. Bi, P.Y. Lam and S. Melin. 2014. Effectiveness of purging on preventing gas emission buildup in wood pellet storage. In press.
· Yazdanpanah, F., S. Sokhansanj, C.J. Lim, A.K. Lau, X. Bi and S. Melin. 2014. Stratification of off-gases in stored wood pellets. Special Issue, Biomass and Bioenergy. DOI: 10.1016/j.biombioe.2014.04.019.
· He, X., A.K. Lau, S. Sokhansanj, C.J. Lim, X.T. Bi and S. Melin. 2014. Quantification of gas emissions from stored softwood chips as solid biofuels. International Journal of Environmental Science and Technology. DOI: 10.1007/s13762-014-0541-z.
· He, X., A. K. Lau, S. Sokhansanj, C.J. Lim, X.T. Bi and S. Melin. 2014. Investigating gas emissions and dry matter loss from stored biomass residues. Fuel 134: 159-165.
· Yazdanpanah, F., S. Sokhansanj, C.J. Lim, A.K. Lau, X.T. Bi, P.Y. Lam and S. Melin. 2013. Potential for flammability of gases emitted from stored wood pellets. Canadian Journal of Chemical Engineering 92(4): 603-609.
· He, X., A.K. Lau, S. Sokhansanj, C.J. Lim, X.T. Bi, S. Melin and T. Keddy. 2013. Moisture sorption isotherms and drying characteristics of aspen. Biomass and Bioenergy 57: 161-167.
· Won, S.G., S.B. Baldwin, A.K. Lau and M. Rezadehbashi. 2013. Optimal operational conditions for biohydrogen production from sugar refinery wastewater in an ASBR. International Journal of Hydrogen Energy 38:13895-13906.
· Oveisi, E., A. K. Lau, S. Sokhansanj, C.J. Lim, X. Bi, S. Larsson and S. Melin. 2013. Wood pellet breakage due to free fall. Powder Technology 235: 493-499.
· Naimi, L.J., S. S. Sokhansanj, A.R. Womac, X. Bi, C.J. Lim, A.K. Lau, T. Sowlati and S. Melin. 2013. Development of size reduction equations for calculating energy input for grinding lignocellulosic particles. Applied Engineering in Agriculture 29(1): 93-100.
· Tooyserkani, Z., S. Sokhansanj, X.T. Bi, C.J. Lim, A.K. Lau, J. Saddler, L. Kumar, P.S. Lam, S. Melin. 2013. Steam treatment of softwood particles to produce torrefied material. Applied Energy 103: 514-521.
· Tooyserkani, Z., L. Kumar, S. Sokhansanj, J. Saddler, X.T. Bi, C.J. Lim, A. Lau, S. Melin. 2013. SO2-catalyzed steam pretreatment enhances the strength and stability of softwood pellets. Bioresource Technology130: 59-68.
· Tooyserkani, Z., S. Sokhansanj, X. Bi, C.J. Lim, J. Saddler, A. Lau, S. Melin, P.S. Lam and L. Kumar. 2012. Effect of steam treatment on pellet strength and the energy input in pelleting of softwood particles. Transactions of the American Society of Agricultural and Biological Engineers (ASABE) 55 (6): 2265-2272.
· He, X., A.K. Lau, S. Sokhansanj, C.J. Lim, X.T. Bi and S. Melin. 2012. Dry matter losses in combination with gaseous emissions during the storage of forest residues. Fuel 95: 662-664.
· Yazdanpanah, F., A.K. Lau, S. Sokhansanj, C.J. Lim, X. Bi and S. Melin. 2012. Resistance of wood pellets to low airflow. Canadian Journal of Chemical Engineering 90(6): 1479-1483.
· Zhang, S., X.T. Bi, A.K. Lau and R. Clift. 2012. Life cycle costing of an integrated animal farm-greenhouse eco-industrial system in British Columbia. Proceedings LCA XI Conference, October 4-6, 2011, Chicago, IL.
· Yazdanpanah, F., S. Sokhansanj, A.K. Lau, C.J. Lim, X. Bi and S. Melin. 2011. Airflow versus pressure drop for bulk wood pellets. Biomass & Bioenergy 35(5): 1960-1966.
· Zhang, W. and A.K. Lau. 2011. Effects of bioadditives on the thermal performance, odor emissions and compost quality for poultry manure composting. International Journal of Environmental Engineering 3(1): 1-17.
· Naimi, L.J., S. Sokhansanj, A.R. Womac, X. Bi, C.J. Lim, A.K. Lau, T. Sowlati and S. Melin. 2011. Development of a population balance model to simulate fractionation of ground switchgrass. Transactions of ASABE 54 (1): 219-227.
· Won, S.G. and A.K. Lau. 2011. Effects of key operating parameters on biohydrogen production via fermentation of sucrose-rich wastewater in an anaerobic sequencing batch reactor. Bioresource Technology 102: 6876-6883.
· Yazdanpanah, F., S. Sokhansanj, A.K. Lau, C.J. Lim, X. Bi and S. Melin. 2010. Permeability of wood pellets in the presence of fines. Bioresource Technology 101: 5565–5570.
· Tumuluru, J. S., S. Sokhansanj, C.J. Lim, X.T. Bi, A.K. Lau, S. Melin, T. Sowlati and E. Oveisi. 2010. Quality of wood pellets produced in BC for export. Applied Engineering in Agriculture 26(6): 1013-1020.
· Ra, C.S. and A.K. Lau. 2010. Swine wastewater treatment using submerged biofilm SBR process: Enhancement of performance by internal circulation through sand filter. Journal of Environmental Engineering – ASCE 136(6): 585-590.
· Lau, A.K., S. Baldwin and M. Wang. 2010. Techno-economic assessment of anaerobic digestion systems for agri-food wastes. Paper No. CSBE 10163, XVIIth World Congress of the International Commission of Agricultural and Biosystems Engineering. June 13-17, Quebec City, QC.
· Lau, A.K., W.L. Cheuk and K.V. Lo. 2009. Degradation of greenhouse twines derived from natural fibers and biodegradable polymer during composting. Journal of Environmental Management 90: 668-671.
· Zhang, W., A.K. Lau and Z.P. Wen. 2009. Preventive control of odor emissions through manipulation of operational parameters during the active phase of composting. Journal of Environmental Science & Health Part B – Pesticides, Food Contaminants and Agricultural Wastes. 44(5): 496-505.
· Lau, A.K., S. Bittman and D. Hunt. 2008. Development of ammoniaemission factors for the land application of poultry manure in the Lower Fraser Valley of British Columbia. Canadian Biosystems Engineering 50: 6.47-6.55.
· Zhang, W. and A.K. Lau. 2007. Reducing ammonia emission from poultry manure composting via struvite formation. Journal of Chemical Technology and Biotechnology 82(6): 598-602.
· Lau, A.K. and K. Cheng. 2007. Removal of odor using biofilter from duck confinement buildings. Journal of Environmental Science and Health, Part A – Environmental Science and Engineering A42 (7): 955-960.