240 likes | 474 Views
ONION DEHYDRATION WITH GEOTHERMAL ENERGY IN THE USA. John W. Lund Andrew Chiasson, Toni Boyd Geo-Heat Center Oregon Institute of Technology Klamath Falls, OR, USA. PROCESSING. Creoloe, Southport Globe and Hybrid Southport types used
E N D
ONION DEHYDRATION WITH GEOTHERMAL ENERGY IN THE USA John W. Lund Andrew Chiasson, Toni Boyd Geo-Heat Center Oregon Institute of Technology Klamath Falls, OR, USA
PROCESSING • Creoloe, Southport Globe and Hybrid Southport types used • White in color and process a higher solid content which yields a more flavorful and pungent onion • Continuous belt conveyor used • Proctor & Schwartz dehydrator single line • Special silica gel – Bryair desiccation often used for the final drying • $1,500,000/yr in fuel used (180 days) • Geothermal saves 116 million cubic feet of NG
PROCESSING 2 • Dehydration – basic steps • Harvesting • Transporting • Curing - 100oF heated air used – ease of peeling and processing – 48 to 72 hours • Washing and chlorinated to reduce bacteria • Slicing • Dehydration – in 3 to 4 stages – high air volumes • Milling (powdered, granulated, ground, minced, chopped or sliced) • Packaging
AGRICULTURAL DRYING 1 • Two large geothermal onion and garlic dehydrators are located in NW Nevada • These units can each process 5 - 7 tons of wet onions/hr – drying them from 83% to 4% moisture (output = 0.9 – 1.2 tons/hr dried product) • 0.15 therms/lb used = 500 million Btu/day or 76 billion Btu/yr (22 GWh) (150 days period) • Product used in soups, baked goods, salt, & seasoning as powders to slices
AGRICULTURAL DRYING 2 • Single-line, continuous-belt dryer use • 12.5 ft wide • 190 to 212 ft. long • 3 to 4 sections (A to D) –210 to 120oF • Processing 5 to 7 tons/hr of wet onions • Using 86,500 ft3/hr of air • 26 million Btu/hr • Onions 2 inches to 6 feet deep • Bryair desiccation unit required in final stage
AGRICULTURAL DRYING 3 • Brady’s Hot Spring plant – first in U.S. - 1978 • 270oF geothermal fluid • Only has 3 stages (A thru C) • 6-months operation season - 65 employees • 25,000 tons of wet onions are processed during season – producing 5,000 tons of dry product • 190-ft. long dryer by 12.5 ft. wide • Uses 190 to 120oF air in various stages • Has also processed celery and carrots to extend season • Product trucked from S. California to S. Oregon (300 to 600 miles)
AGRICULTURAL DRYING 4 • Empire Foods plant – constructed 1994 • Capacity • 37 tons/day onions; 42.5 tons/day garlic • 7 tons/yr (60% onions and 40% garlic) • 900 gpm of geothermal fluid @ 266oF • 45 million Btu/hr – discharge at 160oF • Cold storage warehouse allows year-round operation – 2nd line being considered • Geothermal energy also used for four ORMAT 1.5-MWe binary units – net output 3.6 MWe • Now shut down due to garlic imports from China
CONCLUSIONS 1 • A survey in the U.S. found that of 108 industrial processes surveyed (representing 80% of U.S. industrial energy usage), 97% of all processes required heat input in the form of steam at 250oF or higher. • An examination of geothermal wells in 8 western U.S. states reveals that 99% are 250oF or less. • High load factor important (0.44 to 0.68 in 2000) • Wells above 250oF would normally be used for electric power generation, however ---- * source: K. Rafferty, GHC Bulletin Vol. 24, No. 3 (Sept., 2003)
CONCLUSION 2 • Consider: Power plant vs dehydration plant • Assumptions • 300oF resource • 20 MW net binary power plant • US$0.07 per kWh power sales price • 10-month dehydration operation • 15,000 tons annual production (2 lines) • US$1.00/lb dried product wholesale price
CONCLUSIONS 3 • Power plant vs dehydration plant Power Dehydration plantplant Capital Expenditure $50 mill. $15 mill. Gross Revenue $11 mill. $30 mill. Resource require. 12,000 gpm 1,200 gpm Employees 15 75 *source: D. Mendive,Geothermal Development Assoc., Reno, NV
RESOURCE EVALUATION • Initial search of data base • Ontario, Lancaster, Vale, Nyssa , Harper and Adrain • 42 by 36 mile area • 9 springs • 270 wells identified • 68 to 239oF – high temp. at Vale • Most below 200oF • One “dry well” – 10,052 ft at 334oF - Ontario
PROPOSED SCOPE OF WORK • Determine source and market of product • Estimate size of development • Determine temperature and flow rate needed • Review literature and determine resource available to meet requirements • Recommend site(s) for resource (well) • Perform economic analysis • Make recommendation(s) • Write final report