biomethane from biomass, bio waste, biofuels

commercial scale methods

50-97% conversion of substrates to methane depending on the feedstock, carbohydrates 50% methane, 50% carbon dioxide lipids = more methane. contamination low concern,

waste types

agricultural, municipal and industrial wastes can contribute to sustainable energy production especially when nutrients conserved in the process are returned to the agricultural production

biomethane

all food waste can be used to make this from landfills in New York, by 2022 all food waste will be banned in New York the waste generated from this can be used to make renewable energy

methanogens

all morphological forms are represented in this group including rods, cocci, spirals, sarcinae, and filamentous forms. they can metabolize a limited number of substrates including: acetate, formate, methanol, acetone, methyamines, carbon monoxide and hydrogen/carbon dioxide

design

anaerobic digesters are usually less expensive than industrial bioreactors and often insulated concrete or carbon steel tanks constructed with low cost materials either on or below the soil surface. no aeration needed, mixing needs are only so microbes come into contact with substrate, maintain uniform temperature and prevent solids accumulation not as important as aerobic. sterilization not an issue, posterize to help with foaming issues.

granular sludge

byproduct up UASB practical source of inoculum because it's stable to storage, good microbial density and good availability, has been used as inoculum to start up complex mix reactor, anaerobic filter and uasab,

feedstocks

can be composed of carbohydrates, lignocellulosics, proteins, fats, or a mixture of these. One is not enough you need multiple to make biomethane

cane juice

can be digested directly to produce methane, no alcohol fermentation, no centrifugation, no distillation, little consumption of high grade energy.

biogas

can be made from most biomass and waste materials regardless of composition and over a large range of moisture contents with limited feedstock preparation. flexible form of renewable energy that may be used directly for process heat and steam or converted to electricity

methane production is scalable

can do large commercial production or small scale production (individual farm). Uses a broad range of organic waste feedstocks, the most commonly used is animal manures

digestor timeframe

can run for 30-35 days mesophilic add new waste everyday. thermophilic turnover 15 days but higher temp, less diversity drives cost up could affect end product. can make too much methane the process works too well sometimes

methanogenic activity

cannot remove hydrogen and organic acids as fast as they are produced, accumulation of acids, depletion of buffer, decreasing pH if pH is not corrected then the levels can drop to where fermentation stops. very high concentrations of volatile acids will inhibit performance

nutrient limitation

cells also need sodium, potassium, calcium, magnesium and sulfur. combining waste can overcome nutrient limitations. codigestion with manure often enhances the conversion of other biomass and waste feedstocks

aceticlastic

cleave acetic acid

nutrients in organic matter

conserved and mineralized to more soluble and biologically available forms leading to a more predictable fertilizer N and P is retained and can be recycled to soil. can measure and recycle can be too high

codigestion

digestion of a given waste can often benefit from codigestion with other waste streams that are locally available. very dry feedstocks may be blended with wastewater to facilitate handling and digestion

methane production

effectively applied to improve energy yields from other biofuel production processes including bioethanol, biodiesel, and bio hydrogen production , makes those processes more economically feasible. traditionally has applied to wastes and wastewater but could also used anaerobic digestion of energy crops for sustainable bioenergy

methane

endproduct of anaerobic metabolism, carried out by communities of hydrolytic bacteria, acid producing bacteria, and finally methanogenic archaebacterteria, multiple groups is very complex

methane is sparingly soluble

endproduct recovery is efficient and economical, gas separates itself from the aqueous phase and is easily removed. very specific about temp. even up to 38C throws things off

non immobilized designed

generally used for feedstock with high levels of suspended solids (covered anaerobic lagoon, complete mixed reactor) they require relatively long hydraulic retention times 15-60 days and have a moderate organic loading rate used

washwater

generated after washing procedure to make biodiesel. can be a potential feedstock for methane production. can get a press cake byproduct

stillage

has high level of biodegradable COD as well as nutrients and has a high pollution potential,. up to 20 L of stillage may be generated for each liter of ethanol produced, convert to biogas and apply effluent to croplands makes more sustainable ethanol production

organic fraction of municipal solid waste

has high potential for biogas production, majority of it is disposed of in landfills, but they are implementing biogas recovery system. nutrients contained in MSW are sequestered in landfills and the land for these operations is unsuitable for economic development.

digestion technology

implementing this at agricultural, municipal, and industrial facilities allows efficient decentralized energy generation and distribution to local markets.

energy

little is consumed in the process, and net energy from biomass production is high

biofuel production

made from agricultural waste, industrial waste, and municipal waste efficiently accomplished through conversion to biogas, mixture of methane (mostly) and carbon dioxide via anaerobic digestion. use a whole new set of organism very complex process

synergy

makes 24 million gallons of methane a year, has reduced CO2 footprint by 10,000 lb a year,

anaerobic microbiology

methanogenic archaebacteria catabolize acetate to methane (aceticlastic methanogens) to reduce carbon dioxide to methane using hydrogen (hydrogenotrophic methanogens)

thermophilic digestors

microbial population operating in the thermophilic range are genetically unique do not survive at lower temperatures so they are quite sensitive to temperature fluctuations. ammonia is more toxic in the thermophilic digester due to a higher proportion of free ammonia. have higher energy requirements but heat losses can be minimized through effective insulation and using heat exchangers with outgoing effluents

biogas cycle

mixed organic waste goes into digester, it makes a very high quality renewable natural gas (RNG) and does not cause smog, clean burning natural gas. The sludge that comes out can be used as fertilizer

seasonal basis

much agricultural processing occurs on this and digester does not run year round so you will need to restart and recharge the digester. some wastes such as manures may already have the organisms present you just need to bring the levels of cells up to the correct density

nutrients

n and p are major nutrients required for anaerobic digestion if 10% of degradable solids are converted to cell biomass then the digester will need N at 1.2 % and 0.2% of the volatile solids. micronutrients can enhance methane production and volatile acid utilization iron, copper, manganese, zinc, molybdenum, nickel, and vanadium

digestor classifications

no equipment for product recovery, and must be gas tight and have the ability to remove effluent and biogas. digester can be one that rely on suspended growth of microbes and is easier or can be those that employ a mechanism of immobilization to retain active microbial biomass within the vessel. maybe better, more expensive but want solids to accumulate at end

mixed culture

no requirements for feedstock sterilization, no contamination occurs, mesophilic insulate it keep heat in, mixed culture and mixed waste. want bacterial groups in dynamic equilibrium the pH should be neutral or around 7.4 closer to optimal for methanogens.

genetic engineering

not happening with this process. too complex of process best adapted for this system just let them be

hydrogenotrophic methanogens

obligate anaerobes that can pick up electrons and shuttle them through a unique form of respiration that results in the reduction of carbon dioxide to methane (regarded as earliest life forms)

anaerobic filter reactor

packed bed, developed because this microbial consortium adheres to surface and grows as a biofilm. need to pick the right packing material it can affect performance and cost, use stones, clay, wood, PVC, polyethylene or polypropylene

high levels of acetate

predominance of clusters of aceticlastic methanogens who have a lower surface to volume ratio to help protect from high acid concentrations and its inhibitory effects

methane in bioethanol

production of bio methane at bioethanol production facilities can contribute to the energy requirements of ethanol production or to increasing the energy yields from substrates for sale to local markets as fuel or electricity

anaerobic digestion

purely microbial process, process by which a complex mixture of symbiotic microbes transform organic materials under oxygen free conditions into biogas, nutrients and additional cell matter, doesn't matter amount digested more than cell matter provided. this leaves salts and refractory organic matter. process is based on what happens in soils naturally and is. a totally renewable process

inoculation

quality and quantity is important, has to be added to industrial waste, add glycerol in winter, up methane production too much blow top off from gas production

biological methanogenesis

reported at temp ranging from 2 C to over 100 C, most applications fall into 3 temperature changes ambient 15-25 C, mesophilic 30-40 C and thermophilic 50-60 C

biogas uses

similar to natural gas, can be readily used in all applications designed for natural gas like direct consumption for absorption heating and cooling, space and water heating, and drying. can be upgraded to natural gas specifications. can also be compressed for use as an alternative transportation fuel in light and heavy duty vehicles. viewed as an attractive alternative for diesel and gasoline in other countries

activated sludge process

sludge yield can be as high as 0.5 kg of dry solids per COD utilized. anaerobic process 0.03 to 0.15 kg dry solids per kg COD utilized. anaerobic process produces very little sludge as a byproduct and this sludge is more stable and less capable of causing odors or pollution problems compared to the sludge generated from an aerobic process. anaerobic sludge can be used in sustainable crop production as a fertilizer

aceticlastic methanogens

some can metabolize both 1-carbon compounds and acetic acid, can handle contaminated waste sources. low levels of acetate (less than 50mg/L) favor growth of more filamentous forms (methanorsaeta) who need a larger surface to volume ratio in order to improve substrate diffusion rates.

alkalis

the alkalis contributing to alkalinity are ammonia and bicarbonate. most common chemicals for pH control include NaOH, lime, magnesium hydroxide, and sodium bicarbonate

byproduct

the sludge that comes out can be used as fertilizer

microbial anaerobic conversion

to make methane the process is effective and waste treatment and sustainable source of energy production, can reduce pollution and orders, can overload soil with nutrients from manure.

waste resources

traditionally treatment of manures and municipal sludge may have been the most prominent applications of anaerobic digestion. seen a promotion of on-farm biogas production from animal manure. anaerobic digestion of municipal sludge is applied at many municipal wastewater treatment plants. pretreatment of municipal wastewater by high rate anaerobic treatment offers a new application of biogas production in municipal wastewater treatment works

process anaerobic digestion

unheated at 25C takes way longer and can run thermophilic at 35C. this is the process of engineered methanogenic decomposition of organic matter either mixed, unmixed, heated or unheated. play with ratios to get optimal production mixed culture and mixed waste.

high rate immobilized reactor

used for feeds with low concentration of solids (less than 2%) such as an upflow anaerobic sludge bed, or anaerobic filter. they have a high concentration of immobilized anaerobes, low HRT without microbe washout, and are suited for soluble wastewater.

closed carbon cycle

using renewable methane represents this and does not contribute to increase in carbon dioxide concentration

hydrogenotrophic

utilize hydrogen and 1-carbon compounds

methane producing communities

very stable and resilient but also very complex, mesophilic at 35C. thermophilic temp is fast but ruins the diversity of organisms wanted. fermentative/ hydrolytic bacteria hydrolyze complex organic polymers to organic acid, hydrogen and carbon dioxide. homoacetogenic bacteria synthesize acetic acid from hydrogen/ carbon dioxide

carbohydrate rich substrate

yields more methane than feedstocks with high lignocellulose. need to understand what organisms there, major players and boost production, no requirement for genetically modified organisms to extend catabolic activity. too much protein make ammonia mess everything up. high turnover of substrates with low microbial growth rate. must convert lots of substrates for little cell growth because there is not much free energy available for growth

anaerobic process for waste degradation

you want no oxygen in here. 70% of methane comes from acetate and hydrogen, don't make too much it will screw up pH. run on neutral pH for methanogens other bacteria have broader pH range. can use cheese and yogurt whey to make lactose amino acids etc. methanogens quit at pH6 if stop large back up in system, 45 days to get started from scratch.