DELHI CHARTER TOWNSHIP

Transcription

1 Sustainability Efforts at the Publicly Owned Treatment Plant Sandra Diorka, Director of Public Services Delhi Charter Township DELHI CHARTER TOWNSHIP

2

3 Project Background 1962 first primary treatment facility was built and it included two anaerobic digesters 1978 secondary treatment was added to the plant and two new larger digesters were added ~1984 boilers failed due to sulfuric acid damage from digester gas From 1984 on, all digester gas was wasted to a flare 2004 Master Plan indicated an increase in solids handling capacity was needed ASAP

4 Project Background 2007 Project involved installing two phase anaerobic digestion (Thermophilic/Acid Phase Mesophilic/Gas Phase) producing class A biosolids instead of class B Two micro turbine generators to produce electricity from methane (30 KW each) Generator exhaust heat would be used to heat the process Michigan s first Integrated Biomass to Energy System was finished in 2009

5

6

7

8

9

10

11

12 Project Finances Option Project Cost* Present Worth Cost* Annual Equivalent Cost* Conventional Mesophilic Digestion $6,307,000 $11,242,000 $912,000 2PAD with CHP $7,113,000 $11,263,000 $913,000 *Does not include $500,000 SRF S2 Grant for Project Planning, Design and Revenue System Development received by the Twp.

13 Metrics Facility natural gas use reduced by 63% while producing class A sludge (~$40,000 now less due to price) KWH produced (not sure of time frame): 336,177 equates to roughly $30,256. Maximum generation around 10% of total facility usage KWH produced on peak: 192,586 Used primarily during peak hours Heat exchanger NOT in service during cold months

14 Lessons Learned Internal combustion engines produce more heat Do not locate units outside in a cold climate Do not mix thermo/acid phase gas with mesophilic gas Do not get a flare with a continuous burn pilot light ALWAYS treat boiler gas Monitor boiler exhaust temperature and clean boiler often Incorporate gas storage

15

16 Poo to Power 2 - Poo Pooed by Public 2012 SRF funded project with >50% green project grant Dewater sludge and dry utilizing a solar sludge dryer Sell dried product to MSU as a fuel Subjected to a referendum vote Voted down

17

18

19 Scrappy Food Waste Program March 2011 began with Horizon Elementary School Principle very supportive School district working toward Green designation Video for student training

20 Scrappy Logistic Issues What containers? How to transport containers (van, pickup)? Who will pickup the food? Who will train the students? How to measure the food? How to get food into a digester (sealed system)? What if the food floats? What if the food clogs up the heat exchanger?

21 Scrappy - 1

22 Scrappy - 1 Added underground valve to allow raw sludge to be diverted into Scrappy Fill with sludge, add food waste, and mix with chopper pump until well chopped Open valve and pump to sludge feed tank Take sample and analyze for total and volatile solids Problem chopper pump seal water/winter

23 Scrappy 2 Need to be able to feed year round Too hard to haul giant tank up and down the hill Too stinky to keep in the heated barn area Some heat exchanger clogging caused by plastics Made a visit to the local commercial kitchen supply house Choices: industrial disposal, pulper, meat grinder

24

25 Scrappy - 2 Staff picks out contaminates Plastics Drink boxes Serving utensils Citrus Bones Process through Grinder Sample for solids Measure weight and volume dump into feed tank

26 Scrappy Metrics Currently collect three schools, main kitchen, and care facility Accept cooking oil (oil is not included in calculations) Thus far in 2015, 45,600 pounds of food have been collected producing 155,689 ft3 biogas Average biogas production = 921 ft3 per collection (total digester production ~20,000 ft3/day) Average power generation per day (given all gas generates power) is 58 kwh 2.6 average Michigan homes powered per day by one day of lunch waste collected (schools are just lunch care facility unknown)

27

28 Energy Usage Practices Power use monitored 24/7 Power demand trended on main screen Operators record peak use during peak and off peak daily Lag blower disabled during peak Turbines run only during peak usage hours and during heat cycle for Thermophlic Digester Power factor monitored 24/7 Gravity transfer sludge during peak

29 Electricity Peak Demand Turbines Water KW Generated North Digester Meter #1 Meter #2 Total Peak 24hr Turbine #1 Turbine #2 Total Meter #1 Boiler Boiler kwh kwh kwh Demand Peak CF Gal Gal Gal

30 Other Sustainable Stuff

31

32

33

34

35 - Delhi POTW Timber Sale - Forester - Bill Botti was contracted to survey and set up the timber sale. Highest bidder Post Hardwoods Inc. of Hamilton, MI. Initial contract was signed July 28 th, The contract was extended for one more year due to wet weather conditions. An extra $ was added to the contracted price for accrued timber growth during the one year that the contract was extended. Generally at first cutting most trees taken are of lower quality, this allows for a healthier forest with a greater value at second and third cuttings. Timber marked for sale was estimated at 20,645 board feet from 116 trees. This is determined by diameter, height, and quantity of saw logs in each tree. The value of the stand is determined greatly by species and quality of trees. Contract bid value = $ $ (for accrued growth) = Total Value of Timber $ Forester Fees included - timber survey report and plan = $5.00/acre X 39 wooded acres = $ timber scaling, marking, and prospectus for bidders = minimum of $ or 10% of payment = $ Total Value of Timber = $ Forester survey report - $ Forester prospectus - $ = $ total revenue generated for Delhi Township The buyer was required to submit 10% o total at signing and full payment before cutting began. A bond payment of 10% of bid total to be held by Bill Botti (forester), to be returned to contracted logging company upon satisfactory completion of tree removal. The logging event took place Fall of Actual tree felling took only approximately five days with skidding of the logs to staging area within that time range. Logs were marked and hauled away at a much later date; this was not a problem as the logs were in a harvested soybean field and were not in the way. Note: stipulations as to the manner in which the Parks Department would like the contracted logging company to operate would be spelled out in the contract language; - Duration of project - Condition in which the forest is to be maintained Time of year cutting is to take place Staging area location

36

37

38

39

40