Geological Sequestration of C Carbon Sequestration in Sedimentary Basins Module VIII: Biosolids Injection – LA TIRE Project Maurice Dusseault Department of Earth Sciences University of Waterloo

Geological Sequestration of C Deep Injection of Biosolids…  Injection deep below GW level  Gets rid of sewage biosolids, animal biosolids without environmental risk  Permanent isolation of bioactive agents, heavy metals, etc.  CH 4 is generated, and quite rapidly at higher temperatures  Extra C is sequestered permanently, mostly as an anthropogenic coal!

Geological Sequestration of C Comparison of Methods Current Methods  Straightforward  Soil enhancement  Highly local (short transport distance)  Risks to water, soil  Odors  … DBI  “New” technology  True disposal  Central facility  No odors  No water risks  CH 4 generated for beneficial use  Carbon sequestered  Waste co-disposal

Geological Sequestration of C Based on Actual Experience Injection facility in Alberta, 1997

Geological Sequestration of C Risks and Costs  The “true” cost of waste disposal…  Includes primary costs  Must also include risk costs  Must also include beneficial side effects  The “true” risks of waste disposal  Neutralizing bacteria, prions, viruses  Water contamination potential  Related risks (heavy metals in soils…)  The chances (risks) of abuse

Geological Sequestration of C Conditions for Siting  Deep, well below potable water sources  In horizontal strata of great lateral extent  Stratum must be sufficiently thick & porous  Permeability must meet certain standards  Thick ductile overlying shales are desirable  At least one overlying permeable bed  Formation water briny, flowing horizontally  No exploitable resources to be impaired

Geological Sequestration of C Ideal Lithostratigraphy surficial deposits mudstone silty shale blanket sand in a thick shale channel sands in a silty shale continuous blanket sand limestone limestone stringer possible SFI™ well locations ,000’ 5-30 km flat or gently inclined strata not to scale

Geological Sequestration of C Steps in Implementation  Siting: geological and reservoir study  Interaction with regulatory agencies  Reservoir analysis: capacity, injection strategy, k, compressibility,, etc.  New wells or old well recompletion?  Design & install monitoring systems  Approach based on waste type, studies, siting…  Reporting, QC, regulatory interaction

Geological Sequestration of C Slurry and Injection Unit  Screening, mixing, controlling, injecting, monitoring are the functions of the system  Mixing assures a uniform slurry: mobile unit includes auger mixing, washing through a screen, and density control in an auger tank  All systems are operated by hydraulic motors  Pumping is by a triplex PDP, supercharged with a centrifugal pump (hydraulic)

Geological Sequestration of C Flow-Through System hopper ground wastes conveyor screen (5x8 mm) auger mix tank spray jets, auger-mixer centrifugal charger triplex pump high pressure line injection well make-up water

Geological Sequestration of C

View of SFI System

Geological Sequestration of C SFI in the Field Typical Processing and Injection Equipment Operations can be fully enclosed for severe weather or odor control

Geological Sequestration of C Typical Surface Uplift 10 cm uplift max slope ~1:5,000 no uplift at 1.5 km distance  V ~ 16,000 m m deep waste site, m radius maximum ~symmetric

Geological Sequestration of C Well Capacity  Proper formation choice is required  To date, the maximum injected in a single well is ~30,000 m 3 sand, 200,000 H 2 O  Water dissipates into the sediments rapidly  We believe 10 6 m 3 of slurry is quite feasible for a biosolids injection well  Monitoring and analysis allow continuous re- evaluation of capacity and well performance

Geological Sequestration of C Solids Injection Advantages  Wastes are permanently entombed  Proper stratum choice gives exceptionally high environmental security (minimal risk)  No chance of “repository” impairment  No chance of surface H 2 O contamination  Generated gases can be collected  Costs are reasonable, even for difficult wastes  Technology is “well-established”

Geological Sequestration of C Injection Cycles pressure time  v = 11.4MPa initial pore pressure = 4.6 MPa 24-hr cycle sand inj. repose period

Geological Sequestration of C Environmental Husbandry

Geological Sequestration of C Current Technology

Geological Sequestration of C Deep Biosolids Injection  Inject biosolids into old O&G reservoirs  Metals, bacteria, viruses, are isolated  CO 2 generation does not take place  Anaerobic decomposi- tion forms CH 4  CH 4 can be used  Small footprint  Solid C is sequestered Gas to EnergyBiosolids Injection Facility Methane Biosolids Injection Methane Production

Geological Sequestration of C A Brief History  Massive sand injection developed  Biosolids disposal plus CH 4 generation plus CO 2 sequestration concept in 1997  Vancouver assesses, declines (2000)  City of Los Angeles approached in 1999  Land spreading court case lost in 2001  DBI passes all permitting needs (late 2001)  EPA letter of acceptance (Sept 2003)  Etc., etc., etc., etc., hearings, etc.,  Project initiation date (Jan 2007)  First biosolids injection (Jan 2008?)

Geological Sequestration of C Why Los Angeles? LA Basin oilfields provide excellent geologic targets with known trapping mechanisms adjacent to all major sanitation plants LA recently lost a court case (2001), and will have to almost eliminate sludge spreading on fields (e.g. Kern County) by * With the predicted value of CH 4, plus the economics of DBI and eliminating secondary and tertiary treatment, DBI is 25% cheaper *California keeps on giving temporary extensions…

Geological Sequestration of C Los Angeles O&G Fields Hyperion Terminal Island OCSD Plant Carson JWPC Site under construction

Geological Sequestration of C View of SFI System

Geological Sequestration of C Flow-Through DBI System screened biosolids from a primary treatment plant screen (3x5 mm) sealed auger sealed mix tank spray jets, auger-mixer centrifugal charger triplex pumps high pressure line injection well make-up water

Geological Sequestration of C A DBI System

Geological Sequestration of C DBI Advantages landfarms Fresh water sand Brine filled sand Sealing shale Mud/shale CH 4, CO 2 Gas to Energy Facility 1. Improve groundwater protection 2. Reduce greenhouse gas emissions 3. Long-term carbon sequestration 4. Reduce transport costs 5. Clean energy

Geological Sequestration of C Uncertainties 1. How much gas will be produced, and how fast? 2. How much CO 2 will be absorbed by formation water, and for how long? 3. How best to control or eliminate H 2 S ? 4. What are optimum injection parameters? Estimated gas production for 5 yrs of biosolids injection at 200 wt tons/day Injection Period

Geological Sequestration of C Formation Response  Fluid bleed-off is rapid, allowing pressure decay and strain relaxation between injection episodes  Large target stratum provides necessary storage  Overlying shales provide hydrologic isolation from fresh water and stress barriers to minimize vertical migration  Solid wastes remain close to injection point due to high permeability induced fracture leak-off  Natural temperature, pressure, fluids, provide a good environment for anaerobic biodegradation water flow waste pod

Geological Sequestration of C Typical Injection Parameters  Slurry density  Injection rates1-2 m 3 /min  Injection period6-12 hours  Interval period12-40 hours  Daily volumes m 3 /d These rates are sufficient to handle a city of 300,000 – 450,000 at a single site!

Geological Sequestration of C Some DBI Details  CO 2, H 2 S stripped from gas by dissolving in the water (CH 4 has low solubility in H 2 O)  Carbohydrates have a 40% surplus of C; this is left behind: sequestered elemental carbon  No sludge ponds, no digesters …  Sealed DBI unit, no odor, no spray  May have to inoculate the biosolids with optimum bacteria for the T, pH conditions  Based on oilfield skills and technology

Geological Sequestration of C Applications  Los Angeles will be first (late 2008?)  Vancouver is watching, others will follow  Geology appears ideal in Oklahoma, Iowa, Kansas, Dakotas, Alberta, Saskatchewan, for animal wastes DBI  Implementation in India:  Little secondary/tertiary treatment  Massive contamination issues  DBI avoids expensive treatment plants  ……