Walt:The following is a discussion drawn from the Gasification email list, and reposted here with the kind permission of Robert Gersch and Tom Taylor. One of the marvels of the time in which we live is the ability of people from all sorts of backgrounds and locations to share information and insight via email lists. The body of shared knowledge that's available in real time is unprecedented.
In part, the Biomass to Methanol project evolved out of work done in Seattle, Washington, by Union Carbide in the late 60's and early 70's. The Pureox Project involved the conversion of municipal solid waste (MSW) into methanol. That undertaking did not succeed for a variety of reasons such as the huge size that the plant had to be given the technology available then, and the difficulty of obtaining the permits needed to haul and process that amount of waste in an urban area. Those where the days when city folk were shifting from "NIMBY" thinking‒meaning "Not In My Back Yard"‒to a mindset known as "BANANA" an acronym for "Build Absolutely Nothing Anywhere Near Anything."
Since those days, there have been a number of technological developments such as micro-computers and pressure-swing adsorption units which open up the potential for reducing the size of biomass to methanol plants from the traditional city scale plants to something relevant to a rural village.
In the world of gasification, there are a few well-seasoned people who's experience and understanding of the field of gasification stands out as exceptional. Tom Taylor is one of those people. His level of savvy knowledge regarding the realities of gasification is such that if he said something that appeared to me to be incorrect, I'm immediately go back and look to see where I'd gone wrong.
Tom's description of some of the hurdles that biomass projects currently have to clear in order to come online in the southwestern US touches on why the B2M project is located in south central Washington state instead of anywhere in California.
And if you're wondering what happened to all that municiple solid waste that would have gone into the Seattle plant, well six days a week it's loaded onto a freight train that hauls three-hundred plus 40' long shipping containers here to Klickitat county's landfill.
Inside the landfill, Seattle's MSW breaks down into methane which is collected and burned in an onsite electrical generation plant producing 10 megawatts of electricity and 20 megawatts of waste heat. The goal of B2M is to do that sort of conversion on a micro scale, and use the "waste" heat to meet community needs such as domestic and greenhouse heating, laundry and cooking.
Below is a link to a NPR story on Sweden's conversion of trash to energy. There is no mention of the method used. Does anyone know if this is gasification? If you read the article, other countries are paying Sweden to take their trash and Sweden produces energy from it. Is there a chance that this could actually be cost effective?
Sweden Wants Your Trash
To which Tom replied:
There are quite a few waste incinerators in Europe. Italy has sent it's trash by train to Germany to be incinerated. There are some gasifiers there also. One Norwegian firm has an incinerator design that doesn't produce dioxins above regulatory limits, but all are very expensive, one 300 tpd gasifier system is valued at $300mm. Some of the existing incinerators do not meet emissions levels, but the government has not shut them down as there is no option otherwise. EU capital and sale of electricity pricing is heavily subsidized by the government and does not compete in other parts of the world. One group had 4 dual stage "gasifier" but actually combustor systems in Europe, all have been shut down for emissions reasons, lack of continuing subsidies, expense of operation and the only remaining one operating that I know of is in Japan.
Leland T. "Tom" Taylor
To which Robert replied:
Thanks for the input. The NPR story makes us sound like idiots for not having similar programs in the US. Somehow, I had assumed that only with tax incentives, could such a program be viable. I am probably the most ignorant member of the group, but I have wondered why each city in the US doesn't install a gasifier plant to deal with the waste brush. For the ignorant, it would seem viable and reduce some of what we bury. Waste wood from homebuilding, old concrete forms, old fences, Christmas trees, old pallets and all the trees that are knocked down for new construction plus the trees that are trimmed equate to a lot of BTU's. I am in San Antonio and we at lease make mulch from so of the waste wood.I assume most other US cities do at least that.
To which Tom replied:
Los Angeles hauls it's green waste to east of Phoenix and dumps it. Getting a permit for an outhouse in the South Coast Air Quality Management District (Los Angeles area to San Bernadino and south) is virtually impossible. We had spent $300,000 on a waste to ethanol project (cellulosic ethanol) in the Cabezon Indian tribal land area only to find out there were no air credits available and the tribe adhered to the SCAQMD standards although they didn't have to.
Several groups have tried to do gasifiers in cities and have run into permitting, zoning, NIMBY issues and given up. In other instances, Occidental Chemical build a 200 tpd plant near San Diego, ran it for 8 hours and scrapped it after spending huge sums on it. With the failures of many attempts at gasification, in particular MSW, the investment world is very leery of getting involved.
One group I have been working with spent 5 years working on a PPA (not in this country) and it was issued in September.
In areas where there are mandated renewable energy portfolio mandates where the utility has to supplement with renewable energy purchases, you may not be able to get a Power Purchase Agreement as they don't need to issue one if they are mandated to buy one, or they will not give you renewable energy premium pricing as they can buy credits cheaply and the DoD has used this to keep their renewable energy pricing down, at least one branch of the DoD claims this.
It is a very complicated and in many cases, stupid process. As an example, if distributed systems were in the Los Angeles area, the truck traffic would be greatly reduced, reducing the emissions from truck traffic, but this doesn't matter in the emissions counting.
With natural gas pricing low, it is creeping into the power costs even in the East Coast and will shelve many renewable energy projects.
Leland T. "Tom" Taylor