Making Biogas at Slave Lake Pulp
July 31, 2013 1:20 pm Leave your thoughts
Biomethanation with Power Generation Project
My work at Slave Lake Pulp has been exclusive to the current biomethanation project at Slave Lake Pulp, and up to this point I have not talked much about the ins and outs of the project. So here is a small project breakdown:
The scope of the $40 million biomethanation project currently underway at Slave Lake Pulp is quite substantial; encompassing anaerobic wastewater treatment, biogas scrubbing and handling, the Power Island and the balance of plant (BOP.) The project integrates an energy efficient anaerobic digestion system with the mill’s existing wastewater treatment system.
Pulp mills generate effluent that has a high chemical oxygen demand (COD) and it currently requires a digester system with a high biochemical oxygen demand (BOD) in order to decompose the influent organic material. The addition of the anaerobic system will reduce the amount of COD being processed by the aerobic digester. This will reduce the amount of activated sludge produced by the aerobic digester; ultimately lowering the carbon dioxide emissions of the mill. With the integration of the new system, the treatment facility will be able to generate a methane rich biogas to generate electricity and heat for use in the pulping process.
Overview of the Process:
In any process there are multiple opportunities to extract useable energy, and the pulping process is no exception. The intent of the project is to convert lost energy in the system into useful energy. The system effectively works by utilizing the effluent from the mill as the primary feedstock, and converting it into a useful fuel for combustion. That fuel is then fed to a series of Gensets (engine generators) to produce electricity.
The benefits of the project:
- Production of up to 9 MW of electricity
- Reduced reliance on coal-generated electricity and grid
- Decreased sludge generation
- Decreased nutrient utilization
- Additional effluent treatment stage
- Lower carbon footprint
This project is considered a green initiative as the carbon footprint for the mill will be reduced and it utilizes a renewable energy source for energy production. The efforts made by Slave Lake Pulp to reduce their green house gas emissions to bend their respective carbon emission curve align with the core values of Alberta’s Climate Change Strategy. Specifically, the project focuses on conserving and using energy efficiently, greening energy production and implementing carbon capture and storage. Because of this, both Ecotrust and the Climate Change Emissions Management Corporation (CCEMC) are funding members of the project.
Personally, as a 2nd year green process engineer I find this project extremely interesting. Not only does it deal directly with some of the core concepts of my program it has given me a lot of insight into the legislation and programs encompassing green energy. I’m just excited for what I will learn/be exposed to for the next month of my internship.
Check out my blog next for more interesting aspects of life at West Fraser.
Mark Pipher
Glossary and Additional Information:
Balance of Plant: means the rest of the stuff. In this case, all the plant that is not part of a turbine/tower.
Activated Sludge: is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoa.
Genset – Engine Generator: is a machine used to generate electricity.
Aerobic Digestion: is a collection of processes by which microorganisms break down biodegradable material when the microorganisms access free, gaseous oxygen directly from the surrounding atmosphere. The byproduct is carbon dioxide and trace amounts of other greenhouse gases.
Anaerobic Digestion: is a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen. The process is used for industrial or domestic purposes to manage waste and/or to produce fuels.
Activated Sludge: Activated sludge is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoa.
Biochemical Oxygen Demand or (BOD): is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample
Chemical Oxygen Demand (COD): the amount of organic compounds in water.
Ecotrust:
“Ecotrust Canada is an enterprising nonprofit whose purpose is to build the conservation economy. We work at the intersection of conservation and community economic development promoting innovation and providing services for communities, First Nations and enterprises to green and grow their local economies.”
See Link for more: http://ecotrust.ca/
CCEMC:
“The CCEMC is an independent organization that supports and builds on the strategic direction established in Alberta’s 2008 Climate Change Strategy. It also recognizes the direction set by Alberta’s Carbon Capture and Storage Development Council and seeks to complement decisions made on large carbon capture and storage (CCS) projects. The mandate of the CCEMC is to establish or participate in funding initiatives that reduce GHG emissions or improve our ability to adapt to climate change. The mission of the CCEMC is to achieve actual and sustainable reductions in greenhouse gas emissions and facilitate climate change adaptation by stimulating transformative change through investments in climate change knowledge, clean technology development and operational deployment.”
See link for more: http://ccemc.ca/