Sacramento:  The  First  U.S.  City  to  Refuel  on  Food  Waste    California  has  long  been  a  pioneer  in  implementing  sustainable  transportation  strategies,  and  yet  again,  the  State  can  claim  another  first-­‐of-­‐its  kind  project  in  the  United  States  as  its  own.  By  collecting  and  diverting  food  waste  from  a  local  landfill,  two  Sacramento-­‐area  companies,  CleanWorld  and  Atlas  Disposal  Industries,  have  opened  the  Sacramento  Biodigester  —  the  first  closed-­‐loop  organic  waste  project  in  the  country,  in  which  a  portion  of  Atlas  Disposal’s  refuse  fleet  is  powered  by  the  very  waste  that  it  hauls.      Atlas  Disposal  hauls  food  and  organic  waste  from  local  restaurants,  supermarkets,  food  processing  companies  and  households  to  Sacramento’s  South  Area  Transfer  Station,  where  CleanWorld  has  built  a  commercial  scale  facility  to  convert  the  waste  into  electricity  and  vehicle  fuel  —  a  process  known  as  Anaerobic  Digestion.  This  process  involves  the  work  of  microorganisms  in  the  digester’s  airless  tanks  consuming  the  organic  waste  and  producing  biogas,  a  mixture  of  primarily  methane  and  carbon  dioxide.    This  biogas  is  “refined”  using  a  biogas  upgrading  system  –  designed  and  built  by  BioCNG,  LLC  –  at  which  point  it  is  referred  to  as  renewable  natural  gas  (RNG),  also  known  as  biomethane,  the  near  chemical  equivalent  of  pipeline  natural  gas.        The  RNG  is  stored  in  tanks  and  is  dispensed  into  vehicles  via  the  adjacent  compressed  natural  gas  refueling  station,  built  by  Clean  Energy  Fuels  (also  the  first  renewable  natural  gas  refueling  station  in  California).  A  small  portion  of  biogas  is  used  to  generate  the  electricity  that  powers  the  refueling  station.   One  of  the  major  advantages  of  RNG  is  that  it’s  what  is  known  as  a  “drop-­‐in”  fuel,  meaning  that  it  can  directly  replace  or  be  blended  with  fossil-­‐based  compressed  natural  gas  (CNG).  RNG  can  travel  through  the  same  pipelines  as  CNG,  can  be  delivered  through  the  same  refueling  infrastructure  and  power  the  same  engines  that  currently  run  on  CNG.  Since  Atlas  Disposal  had  already  replaced  10  (roughly  25%)  of  its  older  diesel  refuse  vehicles  with  Autocar  CNG  trucks  (and  has  since  added  10  more),  the  transition  to  waste-­‐based  renewable  natural  gas  was  a  logical  next  step.  Atlas  Disposal’s  Sustainability  Director  Andrea  Stephenson  said,  “As  our  fleet  ages  we’re  going  to  continue  to  replace  our  conventional  diesels  with  compressed  natural  gas  vehicles  that  can  run  on  either  pipeline  gas  or  waste-­‐derived  fuel.”    At  present,  the  Sacramento  Biodigester  is  open  and  operating,  converting  25  tons  of  food  waste  a  day  into  RNG,  but  is  scaling  up  the  digester  to  a  capacity  of  100  tons  per  day  by  the  fall  of  2014.  Once  fully  scaled,  the  facility  will  generate  more  than  700,000  diesel  gallon  equivalents  (DGEs)  of  RNG  annually,  which  will  be  distributed,  via  the  public  access  refueling  station,  to  CNG  vehicles  owned  by  Atlas  as  well  as  other  public  and  private  fleets,  including  some  of  Sacramento’s  municipal  vehicles.    

One  of  Atlas  Disposal’s  freshly  painted  CNG  refuse  trucks  

The  environmental  attributes  of  RNG  are  second  to  none  —  it  has  the  lowest-­‐carbon  intensity  of  any  commercially  available  fuel  that  exists  today.  Recent  lifecycle  analyses  conducted  by  the  California  Air  Resources  Board  (CARB)  conclude  that  the  production  and  use  of  renewable  natural  gas  as  a  transportation  fuel  via  high  solids  anaerobic  digestion  of  food  waste  is  a  net-­‐negative  greenhouse  gas  emissions  process.  This  means  that  unlike  any  other  commercially  available  fuel,  the  production  and  use  of  RNG  actually  removes  greenhouse  gases  from  the  atmosphere.    Combined  with  the  fact  that  once  the  biogases  are  extracted  from  the  decomposing  food  waste,  what’s  left  is  a  high-­‐grade  compost/soil  amendment,  the  project  illuminates  the  best  practice  for  sustainable  management  of  organic  wastes.  CleanWorld  CEO  Michelle  Wong  said,  “Anaerobic  Digestion  is  a  commercial  technology,  and  every  city  in  the  United  States  has  the  opportunity  to  capitalize  on  this  strategy  to  close  the  loop  on  organic  waste.”   The  project’s  environmental  and  economic  benefits  include  the  following:    

•   Diversion  of  nearly  40,000  tons  of  food  waste  from  landfills  annually    •   Greenhouse  gas  reductions  of  5,800  tons  per  year  •   Yearly  diesel  displacement  of  700,00  diesel  gallon  equivalents  •   The  creation  of  16  long-­‐term  green  jobs  •   Annual  combined  municipal  tax  revenue  of  more  than  $1.1  million    •   The  sale  of  high  value  organic  soil  amendment  co-­‐products    

 The  project  received  $6  million  in  grant  funding  from  the  California  Energy  Commission  to  help  offset  the  total  $12  million  price  tag  (digester,  biogas  upgrading,  refueling  station,  construction  costs,  etc.).    Synergex,  Five  Star  Bank,  Central  Valley  Community  Bank,  CalRecycle  and  the  California  Office  of  the  State  Treasurer  provided  the  additional  financing.        ______________________________________________________________________________________ Energy Vision is a national non-profit environmental organization that analyzes and promotes strategies for making a swift transition in the U.S. from petroleum-based vehicle fuels to the clean, renewable, and carbon-free fuels needed for a sustainable transportation future.  For  more  information,  visit  Energy  Vision’s  website  (www.energy-­‐vision.org),  or  contact:  Matt  Tomich  at  Tomich@energy-­‐vision.org.  Tel:  212  228-­‐0225.  Address:  EV,  138  E.  13th  St,  New  York,  NY  10003.  

CleanWorld’s  Sacramento  anaerobic  digester  system