Method and apparatus for pasteurization, hydrolysis and carbonization

Abstract

This invention proposes the use of Thermal Hydrolysis (or Thermal Carbonization) at different temperatures and pressures in alternate waste streams to achieve an optimal mix of high digestion rates and pasteurization rates while still achieving large viscosity reduction. In the disclosed embodiments means of combining Thermal Hydrolysis (or Thermal Carbonization) and Pasteurization including but not limited to placing the waste streams in parallel, placing them in series, utilizing heat input in parallel and heat exchangers in series are explored to optimize hydrolysis rates, minimize the use of high pressure tanks, optimize energy used, and manage viscosity characteristics of the solids.

1 . An apparatus for Hydrolysis (or Thermal Carbonization) treatment wherein temperature of wastewater solids is increased between 60 and 220 degrees Celsius to decrease digester volume requirements, increase throughput rates of anaerobic treatment, increase cake solids, improve microbial hydrolysis rates, inactivate pathogens or indicators, or decrease head loss, mixing or pumping energy, and that reduces viscosity of the solids;
 a. wherein the mostly waste activated sludge, cellulosic waste, slowly digestible organic waste is hydrolyzed (using thermal, thermophilic aerobic, chemical, enzyme, or electron beam) at temperatures between 60 and 180 degrees Celsius (or up to 220 degrees Celsius for thermal carbonization) and;   b. wherein the mostly primary solids, food waste or any other organic waste or products is pasteurized at temperatures between 60 and 100 degrees Celsius, or   
     
     
         2 . The apparatus as described in  claim 1  further comprising a dewatering mechanism capable of dewatering the solids produced after treatment to increase cake solids of a content of 7-55% total dry solids prior to anaerobic digestion or composting of these solids. 
     
     
         3 . The apparatus described in  claim 1  further comprising piping connecting the removed liquid of the dewatering process to the biological nutrient removal, anaerobic digestion, capable of using it as a carbon source. 
     
     
         4 . The apparatus described in  claim 3  further comprising a mechanism for harvesting as a sterilized product for agriculture, fermentation feed stock, antimicrobial blends, or chelation the removed liquid of the dewatering process. 
     
     
         5 . The apparatus as described in  claim 3  wherein the dewatering mechanism is capable of retaining in the removed liquid of the dewatering process any humic and fulvic substances. 
     
     
         6 . The apparatus as described in  claim 1  further comprising a device to dewater the solids produced after additional anaerobic digestion enough to increase cake solids to a content of 7-55% total dry solids. 
     
     
         7 . The apparatus as described in  claim 1  further comprising a device to dewater the solids produced before treatment to increased cake solids of a content of 3-35% total dry solids. 
     
     
         8 . The apparatus as described in  claim 1  further comprising any number of components to regulate a minimum temperature of 75 degree Celsius for 20-40 minutes as required to address resuscitation and regrowth of indicator and pathogens. 
     
     
         9 . The apparatus as described in  claim 1  further comprising devices for decreasing the microbe to substrate proximity, microbe-microbe proximity, or increasing diffusivity through decreased viscosity such that the microbial hydrolysis rates are improved. 
     
     
         10 . The apparatus as described in  claim 1  further comprising components in pasteurization to regulate temperature directly or indirectly based on viscosity characteristics of the solids. 
     
     
         11 . The apparatus as described in  claim 7  further comprising system of devices calculates head loss in pumps, torque in a mixer to regulate indirect control and in-line or off-line or lab measured viscosity may be used to regulate direct control. 
     
     
         12 . The apparatus as described in  claim 1  further comprising solid dilution or thickening devices to control viscosity of solids. 
     
     
         13 . The apparatus as described in  claim 1  further comprising mixers in the solid streams or heat exchangers for recovering heat from the Thermal Hydrolysis (or Thermal Carbonization) process. 
     
     
         14 . The apparatus as described in  claim 1  further comprising a reactor for retaining sterilized solids are bioaugmented with specialized micro-organism to promote anaerobic digestion, dewatering and agricultural use of solids. 
     
     
         15 . The apparatus as described in  claim 13  further comprising any number of devices for retaining the sterilized solids long enough for the specialized micro-organisms are used to consume hydrogen, to increase Firmicutes over Bacteroidetes ratio or increase anaerobic nitrogen fixation. 
     
     
         16 . The apparatus of  claim 1  wherein the production of refractory substances during the thermal hydrolysis or carbonization processes are managed or controlled using a sensor that controls a pump, valve or other devices. 
     
     
         17 . The apparatus of  claim 1  wherein the production of refractory substances during thermal hydrolysis or carbonization is minimized through more rapid heat dissipation using better mixing, heat transfer or heat management approaches. 
     
     
         18 . The apparatus of  claim 1 , wherein the temperature can be increases using solar energy or solar cells that directly or indirectly heat sludge. 
     
     
         19 . An apparatus for Hydrolysis (or Thermal Carbonization) treatment comprising:
 a reactor, wherein temperature of wastewater solids is increased between 60 and 220 degrees Celsius to decrease digester volume requirements, increase throughput rates of anaerobic treatment, increase cake solids, improve microbial hydrolysis rates, inactivate pathogens or indicators, or decrease head loss, mixing or pumping energy, and that reduces viscosity of the solids,
 wherein more viscous waste streams are hydrolyzed (using thermal, thermophilic aerobic, chemical, enzyme, or electron beam) at temperatures between 60 and 180 degrees Celsius (or up to 220 degrees Celsius for thermal carbonization), 
 wherein the less viscous waste stream is hydrolyzed and/or pasteurized between 60 and 100 degrees Celsius, and 
 wherein the heat generator can regulate higher temperatures of 135 to 180 degrees Celsius as reserved for the higher viscosity solids or less digestible solids; and 
   a dewatering mechanism, wherein the stream for the high-temperature hydrolyses (or carbonization) process is dewatered to a solids concentration of approximately >8, while the stream for the pasteurization or low temperature hydrolysis process is thickened to a solids concentration of approximately <8% in order to manage the relative viscosities and the heat balances of the two streams.