JULY 2010
                                        

ON TOPIC


More and more technologies are being developed to convert trash into energy – gases and electricity – and these systems are slowly being installed in communities to help to reduce the costs of dealing with trash.

Existing models to deal with waste are being challenged, but like many new products or processes, it takes time to establish working models that meet the criteria of municipalities that will eventually replace traditional models.

American Recycler spoke with Conrad Oakey, marketing specialist for Owing Mills, Maryland-based NovaTech, LLC, a company that specializes in electric utility and industrial process automation.

With landfilling garbage becoming more expensive, especially along the east and west coasts, how important is it for cities and counties to develop alternative means of dealing with their recyclable materials and the residual materials?

Oakey: On the policy side, it is important for the people who live in cities to understand and decide on the policies they’re going to insist on from their governments. Economically, the price per-ton of tipping fees going into landfills is really like the price of oil, only more so going down the line. It’s going to drive investment in conversion technologies and other solutions.

The first few pilot scale systems that can demonstrate cash positive operation after running for a few years will show which technologies and approaches make real world sense.

Are technologies to maximize recyclables processing for reuse and power generation available today?

Oakey: Pyrolysis and anaerobic digestion are pretty mature in certain applications. There is a lot of research going on in algae. The technology is available and a lot of them are at the point that we just need the first project phase and towns that select good innovative projects that will breakout and will be successful stories. It should be good for the towns if they become the places that learn how to convert their waste into revenue, learn what policies go with those technologies and can create local employment with them. Then they will have opportunities to educate other towns around them and be leaders in sustainability.

Three or four towns could pool their resources to install a system. If you take pyrolysis as an example, you might need 100 tons of combustible waste per day to have enough incoming fuel stock to meet a utility contract. Power generating operations require a certain volume, so whatever that number is, if these towns could consolidate their capital together into a shared facility that works too. A shared set up of upstream sorting policies (i.e., organics, glass, metal and all else) and a central collection and conversion point for all the partners could be selected. The vehicles that collect the garbage for that site can even be converted to run on the syn gas (or extracted hydrogen) that is produced at that facility. Depending on the state and how the waste conversion technology is classified, there may be renewable energy credits to help pay for the investment.

What types of technologies and systems should municipalities invest in? Can future improvements be incorporated?

Oakey: An example that comes to mind would be a town that has an existing incinerator with their collection practices in place and they want to turn that incinerator into an energy source. That would mean updating some equipment and re-engineering the facility. The policy points vary, but pyrolysis has been classified as recycling technology, so it would enable those that already have incinerators to look at alternatives and additional incentives.

Are technologies like pyrolysis expensive to purchase or is it a question of a large initial outlay that pays for itself in a few years and then generates a revenue for the municipal operator? What steps would municipalities need to take to set up the infrastructure needed?

Oakey: It is an investment and there is supposed to be a payoff down the line. It’s very individual to local municipalities as to what combinations of technologies and incentives are going to work to help pay for it, but there are a lot of people trying to figure out how to do these projects and project developers will look at individual situations and tell you what could work in your situation.

In terms of the actual processes, there are probably some separation issues. In Seattle I understand that that if you put anything that is vegetable in your regular garbage, they can give you a sizeable fine. A lot of conversion technologies that are available do better when the waste stream is of high BTU content and not wet, so a municipality would probably want to take food waste to an anaerobic digester and take combustible garbage to a pyrolysis unit, with hard metals and glass sent to a recycling operation, so upstream separation and separation at the facilities themselves is an important and somewhat hard to quantify ongoing cost. What are the insurance risks involved in having people hand-sift waste streams? That will be an additional cost.

Eco Soul Ventures LLC is working with its local partners in French Polynesia to establish waste to energy systems in Tahiti that will extract energy from the local solid waste streams. What type of system will be installed?

Oakey: It is a phased project that is in the engineering stage at this time. Phase I is a solar PV installation on a purpose built structure that will house the pyrolysis unit in Phase II. The revenue from the solar system will help support the waste to energy system in Phase II that may be expanded over time to meet local material flows.

You can also utilize carbon dioxide from the pyrolysis unit and feed it to algae in closed bio-reactors to produce fuel. It’s a complimentary system that is part of an integrated approach. Tahiti is a natural to become a leader in local power production. The reason that Tahiti and other islands are early candidates for this type of system integration is due to their isolation, they have high fossil fuel energy cost – the majority of electrical power comes from diesel via tanker. Compared to the mainland coal-fired grid, they have a higher cost which is a clear incentive to innovate.

When do you foresee major American cities abandoning the traditional system of landfilling trash and utilizing alternative methods?

Oakey: When the technology has been proven somewhere and enough people could see that it is environmentally sound, cash positive and does not harm local employment – that an existing infrastructure is being repurposed. When that sinks in, the opportunities will present themselves.