US Dairy Farms: Untapped Biogas Potential

Countries like Holland and Norway have achieved success in widespread digester installation at dairy farms, but U.S. dairy states are slow to follow suit.
By Peter Brown | March 02, 2019

Dairy farms have been operating in the Pacific Northwest since 1836. Their owners, for the most part, were Dutch and Belgian immigrants. The land was plentiful and rich, with enough grass to feed the hundreds of small dairies holding 30 to 100 cows, resulting in a robust dairy industry from Canada down through Northern California, and as far east as Idaho and Alberta.

Then things started to change—the number of farms became fewer, but they became bigger with more cows, which became too many to handle in that free and easy way that cows like to be handled. For organizational purposes, they were housed in barns where they stayed most of the day, shuffling to and from milking stations.

In the old days, the first line of defense the first line of defense against that wall of manure in the barn was a lagoon. Periodically, accumulated manure was cleaned out of the barns and trucked out to a shallow cavity scooped out of the earth, and then allowed to decompose in the open air. The manure pile became an eye and nose sore, as it did not dry out and began leaching into the ground. In times of high rains, lagoons would overflow and dilute the contents. These were the holding ponds of a primitive system of fertilization for the silage needed to feed the animals in their stalls, and spread in the barns as bedding.  In present times, these some 9 million dairy cows can produce 209 million tons of milk a year, down from 22 million cows in 1950 and reducing the carbon hoof print by a third.

Around the world, natural gas was taking over the clean energy mantle. While it and tar sands were being harvested, a rolling opposition was building along the transportation routes, most vociferously along the Columbia River where a huge oil transfer terminal was to be built. The proposal was defeated, however, and later, a natural gas-to-methanol refinery was to be built, which came under fire for two reasons—the gas was not clean, and the builder and ultimate beneficiary would be China, switching from coal to our natural gas.

The immediate and visceral reaction ultimately made the project dead on arrival. But it did highlight the fact that methanol and dimethyl ether were two very highly marketable commodities, and attention turned to the dairies. In Washington, there are over 100 large dairies with greater than 500 cows and up to 15,000 cows—and this is just one dairy state that isn’t the largest. The math is simple—dairy cows produce an estimated a net daily biogas output of 40 cubic feet (1.2 m3) per cow, and Washington has 262,000 dairy cows. The state could be sitting on an estimated 104. million cubic feet of gas that is not being harvested, instead importing fracked gas for its needs.

The list of complaints against dairies always includes methane emissions and smell. And then, ground water, river and aquifer contamination, mostly from sulfur runoff.

Enter the digester, a self-contained environment where bacteria attack the manure stream in precisely controlled temperatures and rates of passage. Inside the digester is raw sewage—a toxic mix of the residue of the four cow stomachs cleaning or sluicing water, and often the grassy bedding of the cows. As the manure enters the container, it is exposed to an anaerobic environment that quickly generates bacteria that may have been injected from a menu of suitable bugs.  These break down the solids into methane and CO2, digestate, and some critically useful and recoverable components like dried fertilizers high in ammonia, water purified as highly as required for cleaning, and for irrigation on the fields. This is simple technology that dates back to the Greeks. The gas is piped off, and now the serious business of extracting revenue for the dairy from the second stream of cow production begins.

“We have many options, developed over the years, to convert waste to cash,” says Hans Camstra, a Dutch system engineer specializing in renewable energy, digesters and large recycling systems. “The easiest is to run a modern generator off the gas, remove the fertilizer and bag it, convert solids to bedding and spray the remaining digestate onto the fields.”

 That is all possible, Camstra says, with off-the-shelf equipment that, if bought in Holland or Norway, can benefit from those countries’ financing options. “One step further, and greater revenue, compress that gas and use it in trucking and other compressed natural gas systems. Finally, establishing small liquid natural gas facilities allows the farmer to sell his gas on the open market for maximum benefit.”

 The latest and possibly the most lucrative option, according to Camstra, would be extraction of pure biogas for transformation into one of the new, small-scale methanol plants. “Once you have biomethanol, you have serious buyers willing to ship it all the way to China,” he says. “But you need a lot of cows, a lot of manure, and probably a co-op or joint collection organization to assemble the large amounts needed to make the operation a huge commercial success for all the investors.”

Odor is eliminated by extracting the ammonium, and a number of off-the-shelf items like scrubbers, biofilters and water purification to grey water industrial and cleaning use on the farm, all the way to irrigation on the fields.

Running the numbers, for a hypothetical 15,000-cow operation in the Pacific Northwest, about 420,000 tons of manure annually at dry solids content of 8.6 percent and organic dry solids at 74 percent, net gas equates to 5 million cubic meters a year (97 percent methane).

As for gas that could be generated from the 387,000 cows in Oregon and Washington, plus the roughly 1.7 million cows in California, it adds up to 66 million-plus cubic meters of gas—serious production for serious biochemical production.

So how many cows are there in America? One census claims that there 87 million— good reason to bring all that methane to market, and if funding is provided, replacing oil terminals, tar sands, fracked gas and the whole fossil fuel infrastructure with the same gas, diesel, methanol, oil and other products from the modern alchemy of our biochemist.

Matt Plowman, a dairy farmer between Yelm and Olympia, Washington, points out a number of issues with why the digester concept has had slow traction here and across America. “We have always been able to operate safe and sane dairies here because we have had the land to mitigate damage caused by excessive manure spreads,” he says. “The Cow Palace decision did hit us where it hurt, but this dairy has a manure handling system that includes underground cisterns, pumping stations, settling tanks and a centrifuge to separate out the more exuberant wastes. It never occurred to us to try and eliminate the actually toxic substances since they are so closely affiliated with fertilizer, and the sulfur in the treatment we spread over our fields has always been considered as an organic plus.”

Plowman runs the Black River Ranch, a 700-cow dairy with a nearby 1,000-cow sister dairy. It is typical Pacific Northwest operation, as it has been around for a long time and built up both a reputation and a solid business model. Now, he is being forced to reconsider for a very simple and economic reason—the land has reached saturation point, and a digester will allow him some breathing room to expand with more cows. “I am also very interested in how far a digester and gas handling system can go to add to the bottom line,” he says. “I have heard some rare horror stories from California dairies where contracts last two years and suddenly income drops, or new transformers have to be added making the upgrades a total liability.”

Something that is often overlooked is that if the intention is to sell biogas-generated electricity, Washington has the highest renewable electricity ratio in the nation, and is amongst the lowest for the cost of electricity, which is why PV panels are an interesting choice in Seattle and Vancouver. Location, as well as the rainy climate, make them a very poor investment over the long haul.

When informed that in Holland, co-ops have become the norm, Plowman says he would discuss the possibility of creating a group with 10,000 cows to have the economy of scale that would vault his dairy into real, industrial production of methanol or coordinated food production.

 As for how to pay for a system and get it built, the real play will be in how to generate long-term financing from the same place the equipment is purchased. Norway, for example, has EXIM financing that, after qualifying, can bring 85 percent of a project for around 2.5 percent for 18 years, using Norwegian technology and equipment. Rabo Bank in Holland has a massive agricultural investment in the U.S., and covered the Lost Valley Farm. The money is there; the rates and the service are based on working with dairy and other farms around the world. Each system should be built as a springboard for additional services, more offtakes and more revenue, designer bugs for direct diesel production, additional additives grown on the farm and a small biodiesel esterification unit.

Tailor-made, naturally produced chemicals will have to be produced as the fossil fuel industry goes into terminal decline due to pollution issues, greenhouse gases and unavailable new deposits.

Author: Peter Brown
Euro Marketing Tools, FFA Fuels Inc.
[email protected]

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