Alberta Innovates

Coal Characterisation and Benefication

AERI/AIEES has supported a number of projects with Sherritt technologies, including:

• Evaluation of beneficiation technologies to reduce moisture and ash content of western Canadian coal.
  This study evaluated a range of wet and dry technologies for reducing the ash and moisture content of low rank western Canadian coals by removing components in the ash which cause erosion and corrosion to boiler systems and reduce efficiency. Mechanical separation, pressure pyrolysis and solvent extraction were among the technologies considered. The study identified a number of potentially cost effective technology options for further development and piloting.

• Gasification characteristics of selected western Canadian coal and coal-coke blends.
  A range of western Canadian feedstocks, including lignite, sub-bituminous and bituminous coals and petcoke were tested at a gasification pilot plant. After reviewing available processes, the Siemens gasification test facility in Freiberg, Germany was selected, and all feedstocks were successfully gasified. The performance and major operating parameters were evaluated and showed that gasifier cold gas efficiencies and carbon conversions were high in each case, and that Western Canadian coals were suitable feedstocks for gasification.

• Design and construction of a small scale coal beneficiation pilot plant.
  A pilot plant was designed and constructed to evaluate the beneficiation performance of western Canadian coals using pressure pyrolysis and solvent extraction. The plant was successfully commissioned and is now in use preparing samples of beneficiated coals for further evaluation in combustion and gasification test facilities.

University Research

AIEES is supporting coal research at the University of Alberta by providing seed money to establish a coal research group.  Four tasks are included:

• Coal Upgrading for the reduction of minerals and ash content using wet and dry methods.
  Ash reduction by Air Dense Medium Fluidized Bed is being evaluated using sand and magnetite as the fluidization medium. Significant reduction in mercury content is also achieved.

• Coal Upgrading for the reduction of moisture content using non-evaporative techniques.
  Western Canadian coals generally cannot be slurried to give solids loadings above ~40%. Preliminary testing using steam pyrolysis has shown that by reducing the re-adsorption of moisture, higher slurry solids loading can be achieved. Slurry stability is also being investigated; this may provide a means of using treated Albertan and other low rank coals in slurry-fed gasification.

• Multi-Pollutant Reduction using sorbents to reduce trace elements as well as NOx & SOx.
  Initial work has focused on mercury removal. Novel sorbents using brominated biomass ash has shown significant promise. Investigation of the mechanism of bromination and mercury capture will be extended to multipollutant control of NOx and SOx.

• Computational Fluid Dynamic (CFD) and Flow Sheet Development for the above projects.
  CFD modeling is being developed to allow combustion and gasification processes to be simulated. Initial application in underground coal gasification has been used to model the ignition of the coal bed using 3-D simulation. This will later be extended to develop simulators for assessing the performance of the multi-pollutant sorbents in real boilers.

ADDENDUM

Substitute Natural Gas (SNG) Evaluations
Several studies were supported by the Alberta Energy Research Institute in the mid-1990s to evaluate the feasibility of producing SNG from Alberta coals. A joint project with TransAlta Utilities evaluated a gasification process developed by British Gas. This was followed by a comprehensive review of available gasification technologies by the Gas Technologies Institute (GTI) (now the Institute of Gas Technology) of Chicago, IL. A recent joint project with Great Point Energy tested coke and Alberta coal in a 1 ton/day pilot gasifier at the Institute of Gas Technology (IGT), Chicago, IL, with positive results.

Compact Gasifier
The Alberta Energy Research Institute and Alberta Innovates-Energy and Environment Solutions are supporting the development of the Pratt and Whitney Rocketdyne compact gasifier at an 18 ton/day pilot plant at the Institute of Gas Technology (IGT), Chicago, IL. ExxonMobile Research and Engineering is also supporting this project. In addition, a new high pressure solids feed pump is being tested with Alberta feedstocks at the Energy and Environmental Research Centre (EERC) at Grand Forks, ND.

Centralized Coke Gasification Study
Alberta Innovates-Energy and Environment Solutions and Alberta Finance and Enterprise are conducting a feasibility study for gasifying stockpiles oil sands coke to produce products such as power, hydrogen, methanol, and other syngas derived products. The study includes capture of the CO₂ produced. The aim is to determine the most profitable scale and product mix and to quantify the barriers and opportunities for commercial development.