The production costs of a lignocellulosic ethanol process, both currently and projected for 2020, were compared to a corn ethanol process, to determine its economic competitiveness. A techno‐economic model was used to estimate the current production costs for a base‐case, 50 ML yr‐1 softwood facility, as well as providing a basis for cost‐reduction test cases assessing different feedstock, scaling, enzyme, and coproduct options. The progress ratio indicated that lignocellulosic ethanol could be competitive with corn ethanol by 2020, based on volumes mandated by 2007 EISA. However, cost reductions must occur across all components of the production process. The ambitious cellulase enzyme cost reductions that have been projected were shown to be challenging as cellulase costs still need to be significantly lower than those of amylase enzymes on a unit‐of‐protein basis. Opportunities for capital cost reduction relative to first‐generation plants were primarily restricted to the pre‐treatment/hydrolysis unit operations, with operational conditions such as the severity of pre‐treatment and hydrolysis residence times, significantly influencing operating costs. Alternative operating strategies, such as maximizing hydrolysis rate with shorter residence times rather than maximizing ethanol yield and using the unhydrolyzed residue for heat and power production, showed some promise. Increasing the size of the facility to 1 BL yr‐1 output substantially reduced the per unit capital costs, but not to a level competitive with an average (150 ML yr‐1) corn ethanol facility. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd

The effect of steam explosion pretreatment on the physical and mechanical properties of the pellets made from empty fruit bunch (EFB) and palm kernel shell (PKS) was investigated and compared to that of softwood Douglas fir (DF). It was found that the high heating value of the empty fruit bunch was increased by 21% after steam explosion

Feedstock logistics, as dictated by biomass physical properties, location, and distribution, as well as transportation infrastructure, were shown to be a primary determinant of the scale, location, and technology selection of any future biorefi neries. The maximum capacity of both biochemical-and thermochemical-based second-generation biofuel facilities was established based on feedstock logistics including delivery mode (road, rail, or ship), maximum number of deliveries by mode, feedstock type (whole logs, chips, pellets, or bio-oil), and biofuel yield from those feedstocks. The world's largest ethanol plant, pulp mill, coal-based power plant, and oil refi nery were used to approximate maximum plant size for different technologies, and to set an upper limit on the number of deliveries logistically possible for each transport mode. It was apparent that thermochemical conversion to transportation biofuels was favored for large, multimodal coastal facilities that are able to receive imported biomass in the form of feedstock intermediates, such as pellets and bio-oil (maximum capacities of 2844 and 6001 million liters gasoline equivalent (MLGE) respectively). Biochemically-based conversion processes, primarily due to smaller economies of scale and the typical use of higher moisture content and undensifi ed feedstocks, such as whole logs and chips, are better suited for smaller facilities (maximum 1405 and 1542 MLGE, respectively) that rely on local feedstocks delivered by truck and/or rail. It was also apparent that optimization of the feedstock-intermediate-product chain, including biomass densifi cation for transportation and high conversion yield, is essential if the scale of the any second-generation biofuels facility is to be maximized.

a b s t r a c tMost residents of Canada's 300 remote communities do not have access to natural gas and must rely upon higher cost and/or less convenient heat sources such as electric heat, heating (furnace) oil, propane, and/or cord wood. This research sought to determine the techno-economic feasibility of increasing biomass utilization for space and hot water heating in remote, off-grid communities in Canada and abroad using a two-option case study approach: 1) a district energy system (DES) connected to a centralized heat generation energy centre fuelled by wood chips; and 2) a decentralized heating option with wood pellet boilers in each individual residence and commercial building. The Nuxalk First Nation Bella Coola community was selected as a case study, with GIS, ground surveys, and climate data used to design DES routes and determine heat demand. It was determined that biomass has the potential to reduce heat costs, reduce the cost of electricity subsidization for electrical utilities, reduce greenhouse gas emissions, and increase energy independence of remote communities. Although results of the analysis are site-specific, the research methodology and general findings on heat-source economic competitiveness could be utilized to support increased bioheat production in remote, off-grid communities for improved socio-economic and environmental outcomes.

Oil palm residues are not currently suitable as feedstock for thermal energy generation because their high ash content can cause slagging, corrosion, and fouling. A water leaching treatment is a potential strategy to reduce the ash content in these residues. This study evaluates the effects of the duration and temperature of water leaching on two types of oil palm residues, namely, empty fruit bunches (EFBs) and palm kernel shells (PKSs). The optimum process duration for ash removal from EFBs was found to be 5 min, as the effect of convection on scrubbing was observed to remove substantial ash from the substrate during this period. A cross-flow model with estimated kinetic parameters of water leaching for EFB and PKS was developed and showed that three leaching stages of EFB achieved the greatest ash reduction from 5.47% to 2.63%. A low ash content of PKS showed no value for ash removal in any leaching process. Although there was no significance in the total ash reduction due to temperature effects, the leaching treatment was found to be most effective in reducing potassium, from 2.42% to 0.69% and 0.36% at 25 and 55 °C, respectively.