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| Spent brewing grain. Source: blog.syracuse.com |
It's not St. Patrick’s Day yet but it's time to take a look at renewable energy, federal grants, and green beer.
A flurry of recent media attention was paid to the Alaskan Brewing Company (ABC), which has installed a new $1.8 million boiler that uses spent brewing grain as the fuel. The company is using the new boiler for its grain drying process, and for some of its process steam. ABC anticipates a 150,000 gallon annual savings in fuel oil by burning its spent grain.
Commentary on the project were uniformly lauding this as a new advance in combustion technology and brewing science. Like many green technologies being adopted under green technology agendas, the innovations aren't really new. Consider these inventions, some of which are over 20 years old.
Process and apparatus for incinerating wet refuse
US patent 5,010,830 issued to Masahiro Asuka (Ube, Japan) and co-inventors in April 1991. Assigned to Japan’s Ube Industries, Inc., the patent provides,
"An apparatus to be applicable as a boiler for incinerating wet refuse in a combustion chamber with a fluid and heat medium of solid particles fluidized by an air feed to form a fluidized bed, with the aid of combustion of auxiliary fuel effected below the fluidized bed, is provided with additional one or more adjacent upper fluidized fed chambers in series to have the wet refuse dried and partially incinerated in the lower primary fluidized bed chamber with the balance of the refuse in a form of unburnt carbon particles being forced to fly upward into the additional upper fluidized bed chambers and be incinerated therein. Heat recovery is carried out from a topmost fluidized bed chamber."
The Background of the Invention states that the “term ‘wet refuse’ as used herein refers mainly to manufacturing waste expelled from food production plants; for example, waste materials from barley and hops used by breweries, so called ‘beer dregs’, or coffee grounds, orange pulp or tea leaves expelled from a canning plant involved. These plants also emit sludge and other waste products which fall into the category of ‘wet matter’, and these products are treated in a similar manner. The generated heat energy is utilized in the same way as that of a boiler or the like.”
Waste incineration heat conversion system
Also from Japan, Toshiko Fukushima and co-inventors were granted US 5,678,420 in October 1997. The patent was assigned to Hitachi, Ltd. It provides for,
"A waste incineration heat conversion system has an incinerator for burning waste discharged from an installation, a heat recovering section for recovering the heat generated by combustion of the waste in the incinerator, a cold generating section for generating cold by utilizing the thus recovered heat, and a pipe line for conveying the thus generated cold to the installation so that the thus conveyed cold is utilized in the installation for a purpose."
The Summary of the Invention explains that the “combustible waste discharged from the installation is incinerated by the waste burning means of the system of the invention to generate heat which is directly or indirectly recovered by the heat recovering means as a thermal energy. … The installation may be a brewing plant and the combustible waste may comprise combustible brewer’s grains and sludge discharged from the brewing plant.”
Process for thermally utilizing spent grains
Not to be outdone, Austrian inventor Leopold Werner Kepplinger and his team were granted US 6,167,636 in January 2001. Brau-Union Osterreich Aktiengesselschaft was assigned this patent, which claims,
"a process for thermally utilizing wet spent grains (1), the wet spent grains (1) are mechanically predried in a first drying stage (2), thermally dried in a further drying stage (4) and finally thermally utilized by burning or gasification. In order to be able to realize a process of this kind economically, the mechanically dehydrated spent grains (15) in the further drying stage (4) are heated by the aid of a smoke gas occurring within the energy system of a brewery."
The patent specification teaches the following:
"When producing beer, the wet spent grains, or brewing draff, which occur in large quantities, constitute a problem of disposal and utilization. About 20 kg of wet spent grains occur per hectoliter beer such that large-scale breweries have to dispose of, or utilize, hundreds of tons of spent grains per week."
Due to their composition, spent grains constitute a valuable fodder; it is, however, difficult to use the spent grains as a fodder in a cost-effective manner. The proper time for selling same as a fodder without problems is in winter–on the other hand, spent grains occur in larger quantities in summer than in winter. Moreover, spent grains cannot be stored without predrying. Drying is expensive, since only indirect drying is possible due to the demands set on fodder; which means poor heat transmission. Appropriate driers are expensive, involving high energy expenditures.
Apparatus and method for resource recovery from organic substance
Back to the Japanese. Hiromu Shishido and Norio Omoda obtained US 6,474,067 in November 2002; it is assigned to Chugoku Maintenance Co., Ltd. of Hiroshima, Japan. A more advanced invention:
"In a gasification furnace, a combustible gas is generated from an organic substance for gasification containing biomass of organic wastes or the like. An engine of a cogeneration is operated using this combustible gas to generate electricity by an electric generator driven by the engine, and hot water is generated by heating water in a radiator. The hot water is heated by a superheated steam generator of a heat storage type utilizing the electric power from the electric generator to generate superheated steam. Furthermore, a dry-distilled gas and a carbide are generated by dry-distilling and carbonizing an organic substance for carbonization containing biomass of organic wastes or the like with this superheated steam in the carbonization furnace. Thus, the resources are recovered from the organic substances containing biomass of organic wastes or the like by gasifying or carbonizing the organic substances with the superheated steam."
It can be applied to a wide range of organic fuels as described in claim 20:
"the organic substance for carbonization heated in the carbonization step is at least one selected from the group consisting of agricultural wastes including chaff and straw, livestock wastes including fowl droppings and droppings of pigs and cattle, forestry wastes including lumber from thinning, waste wood and bamboo, industrial wastes discharged in a food production process, a brew process or a lumber production process, domestic wastes including food refuse, domestic garbage and waste edible oil, organic resources, waste rubber materials and resins including fiber reinforced resins."
Method for thermal processing of a slurry and biomass
Not to be left out is German inventor Jurgen Buchert, whose patent US 7,799,960 was issued in September 2010; Buchert retained ownership. He envisions an electricity-producing system:
"In a method and apparatus for thermal processing of slurry, the slurry is combined with a bio-mass to produce a mixture which is then subjected to a cracking temperature in a receiving tank, thereby liquefying and allowing the mixture to catalytically undergo a cracking reaction. The cracking reaction which the liquefied mixture undergoes is continued in a mixer pump to thereby produce a reaction mixture. The reaction mixture is outgased in an intermediate tank to separate an outgased fraction from a non-outgased fraction. Subsequently, the outgased fraction is allowed to cool down, thereby producing fuel, while the non-outgased fraction is returned to the receiving tank and subjected again to the cracking temperature. Residual matter of the non-outgased fraction settles in the intermediate tank and is periodically removed."
Further, “the bio-mass may be biological waste material, e.g. rape residues or wood residues, e.g. sawdust, sugar beet residues, husks obtained during beer brewing or liquor production, animal meal, cellulose from paper production, press cake from feedstock production for animals, straw and the like, as well as other substances, such as various grains, corn, etc.”
Process for a disposal of waste solutions
Not only can breweries use their spent grain for boiler fuel, steam generation, or electricity generation, they can also build their facility with it according to Hugh Bogle and Charles Buchanan of Sarasota, FL and Nazareth, PA, respectively. Their patent, US 4,571,175, issued in February 1986 and was assigned to Roan Industries, Inc. They use spent grain in cement:
"A method of disposing of aqueous waste in which the aqueous waste is mixed with cement raw materials to form a slurry for the preparation of Portland cement or the like, for example in a rotary kiln. Prior to forming the slurry, the aqueous waste is treated to remove volatiles and other pollutants which vaporize when heated to a temperature below the boiling point of water. Such volatile materials are removed by contacting the aqueous waste with the effluent exhaust gases from the kiln itself and with the effluent air from the clinker cooler with suitable controls to avoid loss of the water component of the aqueous waste through boiling. The treated aqueous waste is then embodied in the slurry fed to the kiln and the pollutants in the water which can be combusted by the high temperature in the kiln are destroyed. The gaseous effluent which is cooled by contact with the aqueous waste may be discharged or further treated to recover the volatiles and other components which may be salvaged."
The aqueous waste? “One example of a waste solution is brewery waste which not only includes ethyl alcohol, but also is extremely odoriferous because of the yeast, malt and alcohol contained in it.”
Why Are US Tax Dollars Paying For This?
An Alaskan Brewing Company executive was quoted as saying that “Reducing our energy use makes good business sense” If it makes good business sense, why do you need a federal grant to the tune of $450,000?
It's unclear why, given current economic conditions and the fact that the Alaskan Brewing Company is achieving a significant cost savings why USDA is funding this type of a project.
The web page for USDA’s Rural Energy for America Program explains,
"REAP creates opportunities for economic development for rural businesses by supporting renewable energy and energy efficiency projects, via loan guarantees and grants. The program provides assistance to qualified applicants to finance renewable energy (renewable biomass, anaerobic digesters, geothermal for electric generation, geothermal for direct use, hydroelectric (30 megawatts or less), hydrogen, small and large wind, small and large solar and ocean (including tidal, wave, current, and thermal) and energy efficiency projects. It expands the existing private credit structure by providing a credit enhancement via a loan guarantee."
It's surprising that this technology hasn't been more widely adopted and that it takes federal funding to get inventions like these into production. The question is what will the taxpayers return in investment be.
These technologies can be found in Way Better Patents’ Energy Index.
